JP3387511B2 - Rotation 0.5th order vibration reduction device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reduces the engine rotational 0.5th order vibration caused by combustion variation of each cylinder during idling operation or low load operation of an engine having a plurality of cylinders. The present invention relates to a vibration reducing device for rotating a vehicle body at 0.5 rotation, which is suitable for improving riding comfort when the vehicle is idling.

[0002]

2. Description of the Related Art An engine mounted on a vehicle and having a plurality of cylinders, such as a diesel engine, is affected by so-called rotational 0.5th order vibration caused by combustion variations in each cylinder, especially during idling operation. Becomes noticeable. Heretofore, such 0.5th order vibration has not been paid attention to and positively reduced. 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).
issue). This torque control device suppresses torque fluctuations caused by fluctuations in combustion pressure during operation, thereby reducing vibrations of the cylinder block.

[0003]

As described above, conventionally, there is no device for reducing the 0.5th order vibration that appears remarkably during idling operation of a diesel engine or the like. Generally, the waveform characteristic of the rotation speed of an engine having a plurality of cylinders has a waveform having a fluctuation peak of a number equal to the number of cylinders during a crank angle of 720 degrees when there is a variation in the combustion state among the cylinders. When there is no variation in the state, the fluctuation peak disappears in the same load state, and the waveforms have almost the same height. By the way, the fuel supply amount, which is one of the factors that determine the combustion state, is not always the same in all cylinders. For example, in a gasoline engine, the amount of fuel in a specific cylinder may decrease due to the shape of the intake manifold in a carburetor, etc., and even when fuel is distributed by injection, the flow rate characteristics of the fuel may change depending on the initial characteristics of the injector and changes over time. May vary, and the fuel in a specific cylinder may run low. Further, even in a diesel engine, the flow characteristics of the injection pump and the injector vary, so that the fuel in the specific cylinder may be reduced.

As described above, in the engine having a plurality of cylinders, when the fuel supply amount of the cylinders varies, the combustion state varies among the cylinders, which causes 0.5th order vibration. Specifically, the combustion of a specific cylinder is always strong or weak so that the engine torque varies and the engine is vibrated in the roll direction around the axle. For example, in a four-cylinder engine, if the rotation speed is 750 rpm, the vibration cycle is 160 ms and the 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, the 0.5th order vibration is generated. Such a 0.5th order vibration is particularly noticeable to the occupant when the engine is idling, and gives a very uncomfortable feeling to the occupant, which makes the ride comfort of the vehicle worst.

To solve the above-mentioned problem of riding comfort, if the variation in the fuel supply amount for each cylinder is eliminated, the 0.5th order vibration can be eliminated and the riding comfort is improved. For example, in a gasoline engine, it is possible to eliminate the 0.5th order vibration to some extent by adjusting the fuel injection amount for each cylinder using electronic control. However, since it is difficult to control electronically in a diesel engine, conventionally, the adjustment of the variation in the fuel supply amount for each cylinder is performed by combining the injection pump and the injector to check the flow rate characteristics, and changing the combination to readjust. Was repeated.

As described above, efforts have conventionally been made to reduce the uncomfortable riding comfort by reducing the 0.5th order vibration, but conventionally, the adjustment is troublesome and inefficient,
It cannot be said that the 0.5th order vibration was effectively reduced. Further, the control for reducing the 0.5th-order vibration is required in the idle state, but conventionally, the configuration is such that the idle switch or the mission switch detects whether or not it is in the idle state, so that the number of parts is increased. There is a problem.

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

A second object of the present invention is to provide a rotational 0.5th order vibration reducing device capable of directly suppressing the 0.5th order vibration itself.

[0009]

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

The second object is to use an auxiliary machine as a torque generating means, and control the auxiliary machine so as to balance the charge and discharge so that the battery voltage becomes a predetermined voltage and suppress the 0.5th order vibration. It will be achieved.

[0011]

By using the average value of the rotational speed and the average value of the speed fluctuation amount, it can be determined whether or not the engine is in the idle state, and the 0.5th order vibration suppression control is required without using the idle switch or the like. It is possible to determine a proper driving range.

In addition, since the control is performed by using a structure for reducing the 0.5th order vibration by using an auxiliary machine, that is, an auxiliary machine which is connected to the engine output shaft and can apply a torque to the output shaft, is controlled. Moreover, it is possible to suppress the 0.5th order vibration.

[0013]

DETAILED 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 rotation 0.5th order vibration reduction device according to an embodiment of the present invention. As shown in FIG. 1, a rotation 0.5th order vibration reduction device includes an engine 1 having a plurality of cylinders, a crank angle signal generator 2 for generating a signal synchronized with a crank angle, and a crank angle signal (POS signal) for the crank angle signal generator 2. ，
The rotation speed detection device 3 that detects the rotation speed N of the engine 1 based on the REF signal) and the crank angle for each of the plurality of cylinders based on the change in the rotation speed detection value N output by the rotation speed detection device 3. The speed of two sections within an angle of ± 720 degrees / 4M (M is the number of cylinders) sandwiching the angle at which the combustion torque to be synchronized is sandwiched is calculated, the speed difference α is calculated, and the determination signal s5 of the idle state of the engine 1 is obtained. And a processing unit 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.
And a load torque generating device 5 that receives the control signal and generates a load on the crankshaft of the engine 1. The engine 1 is an engine of any type such as a gasoline engine or a diesel engine, and the number of cylinders thereof is also arbitrary. For example, in the case of four cylinders, the above two sections occur within ± 45 degrees of the angle at which the maximum combustion torque is generated. The arithmetic processing unit 4 includes a backup memory 6, and various kinds of data prepared in advance and predetermined data calculated by the arithmetic processing unit 4 are stored in the memory 6.

As the load torque generator 5, any one of various auxiliary machines connected to the crankshaft of the engine 1 by a power transmission mechanism is used. In this embodiment, an alternator having good controllability is used as the load torque generator.
When the load is controlled by the alternator, the field current control method and the generated current control method can be used, but in the present embodiment, the field current control method that requires only low current control is adopted.

FIG. 2 is a block diagram of a rotation 0.5th order vibration reducing device in which the load torque generating device 5 is used as the alternator.
In FIG. 2, 10 is a crank pulley fixed to the crank shaft, 11 is a pulley connected to the crank pulley 10 by a belt 12, and the rotation center of the pulley 11 is the rotation center of the rotor coil 13 of the alternator 5A and the shaft 14. It is connected. The rotation of the crankshaft is detected by the crank angle sensor 2a, which is a crank angle signal generator, and the detection signal is input to the arithmetic processing unit 4.

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

The detection device 7 shown in FIG. 1 receives a signal from the crank angle signal generation device 2 and outputs a rotation speed fluctuation amount α corresponding to the engine rotation speed N and the combustion torque of each cylinder of the engine. In addition to the above, the idle determination signal s5 for determining whether to control the 0.5th order vibration reduction based on the average value of the rotational speed N and the average value of the rotational speed fluctuation amount α is also output. More specifically, in the current engine control, the rotation speed is controlled to be constant at the time of idling, and therefore, if the rotation speed N is observed, it can be determined whether or not the engine is substantially idle. However, when a load such as a mission is connected, this idle rotation speed may occur. Therefore, in this embodiment, at a low rotation speed near the idle, the rotation speed fluctuation amount α substantially proportional to the combustion torque of the engine is also seen. It is determined whether or not it is in the idle state.

Next, the alternator field current control in this embodiment will be described with reference to the timing chart of FIG. As shown in FIG. 3, the control signal is an ON / OFF signal having one cycle of the engine 1 in a cycle. When ON, the field current rises, and when OFF, the field current If falls with a certain time constant. However, since the field current has a response delay, in order to form a waveform such as a sine wave, switching is performed at the falling edge (in the present embodiment, this switching is used as a PWM signal and the pulse width is controlled to control the field current. Control the falling slope of the. By doing so, the waveform of the generated current IL generated due to the field current If also becomes a sine wave, and the waveform of the generated load torque also becomes a sine wave. It should be noted that small fluctuations in the generated current waveform occur due to fluctuations in the rotational speed of each cylinder.

Next, how to balance the charge and discharge of the battery when the 0.5th order vibration reduction control is performed will be described with reference to the flowchart of FIG. The charge / discharge balance is basically the same as the operation of an IC regulator of a normal alternator, and the battery voltage VB is kept constant while observing it. Here, when the electric load is extremely large, it is possible to reduce the O
Facilitates N, OFF control. The battery voltage VB
However, as shown in FIG. 3, the control signal O
The voltage VB measured at the rising and falling positions of N is used, and the average voltage is used as the regulated voltage. The regulation method will be described with reference to the flowchart shown in FIG.

First, the average value of the battery voltage VB and the rotational speed fluctuation amount α is taken in. When the average value of the rotation speed fluctuation amount α is larger than the specified value, the maximum value Vmax and the 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
To use. Changing the regulated voltage range in this way is a countermeasure against flicker. Next, it is determined whether or not the taken-in 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. To do. When the taken-in battery voltage VB is smaller than the above-mentioned minimum value Vmin, the average generated current is increased so that the voltage VB is within the specified value range. As a method of increasing or decreasing the generated current, there are a method of changing the pulse width when the control signal is ON and a method of changing the pulse width of the switching unit. In this embodiment, the effect of vibration control is taken into consideration.
First, the pulse width of the switching unit is adjusted. But,
With this adjusting method, the generated current cannot exceed a certain specified value, so in that case, the pulse width when the control signal is turned on is changed next.

Next, how to obtain the control phase for the 0.5th order rotation vibration will be described with reference to the flowchart of FIG. First, it is determined whether or not the control flag (ON during this control) is ON. When the control flag is OFF, the rotation 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 the memory. Since the rotational speed fluctuation amount α also shows the torque fluctuation amount generated by this control when the 0.5th order vibration control is executed, that is, it appears as an error, the control obtained when the control is not performed. The phase, that is, the accurate 0.5th-order component is stored in the memory, and the stored control phase is read and used during control.

When the control flag is ON, the IC regulator of the alternator is stopped and the field current control of the alternator by the 0.5th order vibration reduction control is started. next,
Similarly to the above, the rotation speed fluctuation amount α is averaged for each cylinder, and the control phase is calculated from the average value. This is to check whether or not the control phase is largely deviated due to other factors. When the control phase is largely deviated, the 0.5th 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 the field current is controlled to reduce the 0.5th order vibration in the control phase.

FIG. 6 shows the cylinder-specific α for obtaining the control phase.
It is explanatory drawing of a detection method. The cylinder-specific α detection method includes a method of obtaining the rotational speed fluctuation amount α from two section pulse signals for each cylinder (FIG. 6A), and a mission ring gear signal is captured as an angle signal for each cylinder There are a method of obtaining α from the signal coming from one pulse (FIG. 6B) and a method of obtaining α from only the ring gear signal (FIG. 6C).

In the method of FIG. 6 (a), as shown in FIG.
First, the cylinder number i is fetched , and the rotation 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 rotational speed and the lower rotational speed is taken as the rotational speed fluctuation amount α of the cylinder, stored in the memory for each cylinder, and the cylinder number i is incremented to obtain α for the next cylinder.

In the method of FIG. 6B, as shown in FIG.
Each 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 calculated and stored as α for each cylinder. Store at. However, in this case, it is assumed that the rotation speed is fetched for each ring gear signal and stored in the memory, and there is rotation speed data for one cylinder between cylinder signals.

In the method of FIG. 6C, as shown in FIG.
Each time a ring gear signal comes in, not only is the rotation speed taken in, but it also detects where the reference position for measuring α is, and the position where the rotation speed is the lowest is used as the reference for the specified low rotation measurement position and high Calculate the rotation speed at the rotation measurement position,
The difference is taken and stored in the memory as α for each cylinder.

[0027]

The present invention has the following effects.
The variation of the combustion intensity of each cylinder is detected based on the variation of the engine speed, etc., the cycle information of the 0.5th order vibration generated in the engine is extracted based on the variation of the combustion state, and based on this cycle information A control periodic wave signal for canceling the vibration is generated, and its phase and amplitude are adjusted so as to reduce variations in the combustion state, and the load torque is generated in the auxiliary machine by the periodic wave signal. Therefore, the 0.5th order vibration can be effectively suppressed, whereby rolling of the vehicle can be eliminated, and ride comfort can be improved particularly when the engine is idling.

[Brief description of drawings]

FIG. 1 is a principle diagram of a rotation 0.5th order vibration reduction device according to an embodiment of the present invention.

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

FIG. 3 is a timing chart for explaining alternator field current control.

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

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

6 (a), 6 (b), and 6 (c) are explanatory diagrams of how to determine the cylinder-by-cylinder rotational speed fluctuation amount α, respectively.

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

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 generator, 3 ... Rotational speed detector, 4 ... Arithmetic control device, 5 ... Load torque generator, 6 ... Backup memory, 7 ... (alpha), N detector.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identifier FI F16F 15/18 F16F 15/18 Z (72) Inventor Kenichi Nakamura 2520 Takaba, Katsuta-shi, Ibaraki Hitachi Ltd. Automotive Equipment (72) Inventor Makoto Yamamon, 502 Kintatemachi, Tsuchiura-shi, Ibaraki 502 Hitachi Mechanical Laboratory Co., Ltd. (72) Inventor Jun Teruma, 2 Takaramachi, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Kei Murakami 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (56) References JP-A-63-212723 (JP, A) JP-A-61-135936 (JP, A) (58) Survey Fields (Int.Cl. ⁷ , DB name) F16F 15/18 F02B 75/06 F02D 29/06 F02D 45/00 314 F02D 45/00 330 F02D 45/00 362

Claims (13)

(57) [Claims] 1. A torque generating means, which is applied to an engine having a plurality of cylinders, detects a parameter caused by a variation in a combustion state of each cylinder, and applies a load torque to an output shaft of the engine according to a 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 of the combustion state, the above-mentioned 0 is obtained by the average value of the engine rotational speed and the average value of the fluctuation amount of the rotational speed. . Rotational 0.5th-order vibration reduction device characterized by determining whether or not control for suppressing the 5th-order vibration is performed. 2. A torque generating means, which is applied to an engine having a plurality of cylinders, detects a parameter caused by a variation in a combustion state of each cylinder, and applies a load torque to an output shaft of the engine according to a value of the parameter. in the control rotated 0.5 order vibration reduction apparatus for suppressing a rotational 0.5 order vibration due to variation in the combustion state, the auxiliary used as the torque generating means, a charge-discharge balance as the battery voltage becomes a predetermined voltage The auxiliary equipment is controlled so as to take 0.
A rotational 0.5th order vibration reduction device characterized by suppressing the 5th order vibration. 3. A field current or a generated current of an alternator, which is applied to an engine having a plurality of cylinders, detects a parameter caused by variations in combustion states of the cylinders, and applies a load torque to an output shaft of the engine. controlled according to the value rotation due to variations in the combustion state
In rotary 0.5 order vibration reduction apparatus for suppressing a 0.5-order vibration, rotation 0.5 order vibration suppression control, characterized in that the control to take charge and discharge balance as the battery voltage becomes a predetermined voltage Vibration reduction device. 4. The rotational 0.5th order vibration reduction device according to claim 2 or 3, wherein the predetermined voltage is changed according to an average value of engine speed fluctuations during idling. 5. The rotational 0.5th order vibration reducing device according to claim 3 or 4, wherein the IC regulator of the alternator is stopped during the vibration suppressing control. 6. The rotation 0.5th order vibration according to claim 3, wherein the battery voltage is detected at the rising and falling timings of a signal for turning on the vibration suppression control. Reduction device. 7. The rotational speed control method according to claim 3, wherein when the vibration suppression control is turned off, switching is performed by a PWM signal to change the falling slope of the field current. 5th order vibration reduction device. 8. The rotation 0.5 order according to any one of claims 3 to 7, characterized in that a control phase is matched with a falling timing of an on / off signal for controlling a field current as a load torque peak value. Vibration reduction device. 9. The engine according to any one of claims 1 to 8, wherein the combustion state is detected by only two rotation speed measurement section pulses sandwiching a combustion torque peak for each cylinder. Secondary vibration reduction device. 10. The method according to claim 1, wherein the combustion state is detected by a signal generated at every constant rotation angle and a signal generated by one pulse in synchronization with the combustion stroke of each cylinder. A rotation 0.5th order vibration reduction device characterized by: 11. The method according to any one of claims 1 to 8, wherein the combustion state is detected by using only an angle signal pulse continuously generated at a predetermined rotation angle within one combustion cycle. Rotation 0.5 order vibration reduction device. 12. The control phase according to claim 1, wherein a control phase is obtained in advance from a rotation speed fluctuation amount obtained without applying a load torque by the vibration suppression control, and the vibration suppression is performed using this control phase. A rotational 0.5th order vibration reduction device characterized by performing control. 13. The method according to any one of claims 1 to 12, wherein it is determined whether or not the torque fluctuation cycle has changed from the rotation speed fluctuation amount obtained in a state where the load torque is applied by the vibration suppression control. Rotation 0.5 order vibration reduction device.