JPH01182538A - Torque fluctuation control device for engine - Google Patents

Abstract

PURPOSE:To shorten an overlap period by making an electric drive means work so that the engine speed in a suction and exhaust valve opening period may increase in a device in which positive torque is acted on the output shaft of an engine by the electric drive means. CONSTITUTION:The output shaft 2 of an engine 1 is provided with a torque addition device 3, and electricity is conducted to the device 3 to give positive torque to the output shaft 2. An overlap period detecting means 5 to detect overlap period in which the suction and exhaust valves of the engine 1 open simultaneously is provided, and in a torque control device 6 in which the output signal of the detecting means 5 is input, the electric drive means 4 is operated at the time corresponding to the overlap period so as to give the output shaft 2 positive torque. This leads to the increase in engine speed and shortening of the overlap period and prevents such phenomenon that a part of the combustion gas of a former cycle is brought into the combustion room of the next cycle.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine torque fluctuation control device.

(Prior art) Traditionally, as an engine operates, torque fluctuations occur periodically on its output shaft in response to the repetition of the combustion cycle. For example, the technology of a starter charging device, so-called selternator, as seen in Japanese Patent Publication No. 61-54949 is well known.

The above-mentioned selternator has a rotating field pole on the output shaft of the engine, an excitation coil inside the rotating field pole, and a stator coil outside the rotating field pole, and has an electric drive function as a motor by controlling the energization of the stator coil and the excitation coil. It is designed to provide a positive torque to the engine output shaft by obtaining a power generation function, and to provide a reverse torque to the output shaft by obtaining a power generation function.

Then, in order to suppress engine torque fluctuations, torque is controlled by controlling the energization of the excitation coil and stator coil in response to engine torque fluctuations, so that positive torque is applied when torque decreases, and reverse torque is applied when torque increases. can be done.

(Problem to be Solved by the Invention) Furthermore, during combustion in an engine, a part of the combustion gas from the previous cycle is brought into the combustion chamber of the next cycle, resulting in so-called dilution gas, which causes a reduction in combustibility. The amount of dilution gas brought in tends to increase as the valve overlap period in which both the intake valve and the exhaust valve are open is longer.

Therefore, in view of the above circumstances, the present invention provides an engine that utilizes the above-mentioned function of applying positive torque to the output shaft of the engine to reduce the amount of dilution gas carried in and ensure torque stability. The object of the present invention is to provide a torque fluctuation control device.

(Means for Solving the Problems) In order to achieve the above object, the torque fluctuation control device of the present invention includes an electric drive means that applies positive torque to the output shaft of the engine, and an opening operation of both the intake valve and the exhaust valve. an overlap period detection means for detecting an overlap period during which the overlap period occurs, and a torque control means for receiving an output of the overlap period detection means and operating the electric drive means at a timing set so that the engine rotational speed during the overlap period increases. It is designed so that it can be prepared.

FIG. 1 is an overall configuration diagram for clearly showing the configuration of the present invention.

The output shaft 2 of the engine 1 is provided with a torque adding device 3 that includes, for example, a rotating field pole, an excitation coil inside the rotating field pole, and a stator coil outside the rotating field pole and operates as an electric motor. An electric drive means 4 for applying positive torque to the engine output shaft 2 is provided.

On the other hand, an overlap period detection means 5 is provided for detecting an overlap period in which both the intake valve and the exhaust valve of the engine 1 are open at the same time, and the signal from the overlap period detection means 5 is outputted to the torque control means 6. , the torque control means 6 outputs a control signal to the electric drive means 4. The torque control means 6 operates the electric drive means 4 at a timing corresponding to the overlap period to control the torque applying device 3 to apply a positive torque to the engine output shaft 2, thereby increasing the engine rotation speed during the overlap period. It is something that makes you

(Function) In the engine torque fluctuation control device as described above, a positive torque is applied to the engine output shaft by controlling the electric drive means by the torque control means at a timing corresponding to the overlap period between the intake valve and the exhaust valve. The engine speed during the overlap period is increased to shorten the time during the overlap period, reduce the amount of dilution gas brought in, improve combustion stability, and obtain good torque performance. ing.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 2 is an overall configuration diagram of a specific example. In this example,
An example will be shown in which the engine output shaft is equipped with a non-commutated motor that provides forward torque or reverse torque through current control.

A flywheel 15 is attached to one end of the output shaft 2 of the in-line four-cylinder engine 1, and the outer peripheral portion of the flywheel 15 is provided at a rotating field pole 16. The rotating field poles 16 are made of a ferromagnetic material and are integrally coupled via a non-magnetic material by a pair of comb-shaped magnetic poles or the like such that the magnetic pole portions are alternately located in the circumferential direction. An excitation coil 17 is provided inside the rotating field pole 16, and this excitation coil 17 is for exciting the rotating field pole 16, and is attached to the stationary side via a magnetic member 18. This excitation coil 17
is opposed to the rotating field pole 16 with a slight gap in between.

On the other hand, a stator coil 19 is provided outside the rotating field pole 16 with a predetermined gap therebetween.
Numeral 9 is for applying magnetic force to the rotating field pole 16 when energized, and is wound around the core material 20 and attached to the stationary side. With these, the engine output shaft 2
Commutatorless motor 2 that provides positive or reverse torque to
1 is configured.

A clutch device 23 is disposed outside the flywheel 15 to connect and disconnect power transmission between the engine output shaft 2 and the transmission drive shaft 22. The above commutatorless motor 21
The clutch device 23 and the like are covered by a housing 24 attached to the engine 1.

The control system of the non-commutator motor 21 includes its excitation coil 1
7 and an inverter 26 that applies a three-phase AC stator current to the stator coil 19. The field controller 25 and the inverter 26 are controlled by an engine control unit 27. A signal is output and a forward torque or reverse torque is applied to the engine output shaft 2 to perform engine starting, charging control, torque control, and dilution gas control.

This engine control unit 27 includes an ignition signal IG and a starter signal ST from a key switch 30 and an angle sensor 28 that detects the rotational crank angle of the engine output shaft 2 in order to detect the operating state of the engine.
a crank angle signal from the engine 1 via the amplifier 29, a signal from the idle switch 33 that detects the idle state from the fully closed state of the throttle valve 32 installed in the intake passage 31 of the engine 1, and a negative pressure sensor that detects the intake negative pressure. Boost signals from 34 are respectively input.

In the power generation state, the field controller 25 controls the excitation coil 17 based on a control signal output from the engine control unit 27 so as to maintain the voltage value at a predetermined value corresponding to the terminal voltage of the battery 35. Charging control is performed by adjusting the field current. In the above power generation state, the stator coil 19
The output voltage generated by the inverter 26 is converted into direct current by a rectifier circuit in the inverter 26, and the battery 35 is charged. On the other hand, in the starting state, a large current flows, so the terminal voltage of the battery 35 becomes low, and the field current becomes constant at maximum.

Current control to the stator coil 19 is performed by stator coil 1
The output lines of the inverter 26 are connected to the U, V, and W phase terminals of the inverter 26, and the engine control unit 27 sends switching signals for the U, V, and W phases to the inverter 26, and outputs them to the stator coil 19. A current command signal that commands the magnitude of the stator current is output, and startup control, idling dilution gas control, and torque control are performed.

At the time of starting, the engine control unit 27 receives a signal from the starter contact ST of the key switch 30, and the maximum stator current for starting is outputted via the inno-cooter 26. Further, crank angle signals from the angle sensors 2 and 8 are transmitted to the engine control unit 2 via an amplifier 29.
7, it outputs a signal that switches the direction of current for each phase of U, V, and W in accordance with the phase of the engine output shaft 2.

Then, U of the stator coil 19 from the inverter 26,
The stator current output to the V and W phase terminals is based on the signal from the engine control unit 27 that corresponds to the phase of the engine output shaft 2. In the next period, the current flows from the U-phase and V-phase terminals to the W-phase terminal, and in the next period, the current flows from the V-phase terminal to the U-phase and W-phase terminals. As in a normal commutatorless motor, the direction of the current is switched so that the magnetic field created by the stator coil 19 becomes a rotating magnetic field that always has a constant phase difference with respect to the magnetic field generated by the rotating field magnetic poles 16.

In addition, in the idling state, the timing of applying positive torque to the engine output shaft 2 is set so that the engine rotation speed reaches its peak during the overlap period between the intake valve and exhaust valve, which is the transition from the latter half of the exhaust stroke to the intake stroke in each cylinder. Perform illusion gas control. In other words, as shown in Fig. 3, the rotation of the output shaft 2 of a four-cylinder engine is such that the pistons of two cylinders are at top dead center and the other cylinders are at bottom dead center for every 180 degrees of crank angle. , when one of the cylinders transitions from the exhaust stroke to the intake stroke near the top dead center and bottom dead center, an overlap occurs in which the intake valve immediately after opening and the exhaust valve immediately before closing open at the same time. Period A is occurring, and this overlap period A
Correspondingly, for a predetermined period B before the top dead center and bottom dead center of each cylinder, the stator current control signal is set to positive phase (the phase in which torque is generated in the rotational direction of the engine), and positive torque is applied. A three-phase alternating current is sent to the stator coil 19 in a negative phase (a phase in which torque is generated in the counterrotational direction).

This causes the engine to speed up in the positive phase and decelerate in the negative phase so that the engine rotational speed repeats fluctuations having a peak C during the overlap period.

In addition, the ratio of dilution gas to the engine speed is as shown in FIG. 4 during the overlap period A.
increases rapidly when the engine speed decreases.

Furthermore, in the region where the engine speed is low and the stability is reduced, the increase in dilution gas reduces combustibility, further disadvantageous in terms of stability, and this is especially noticeable in the idling state. The rotational speed during the overlap period during operation is increased to shorten the time, thereby reducing the amount of dilution gas brought in and ensuring combustion stability. On the other hand, in other areas, the engine speed increases and the proportion of dilution gas brought in decreases.
In order to reduce the effects of this, in the torque control zone where the engine speed is below a predetermined value in a non-idling state,
In order to suppress torque fluctuations that occur in response to engine rotation, torque control is performed to provide a positive torque when the rotational speed decreases and a reverse torque when the rotational speed increases. Further, in a region where the engine speed has increased, problems such as engine vibration due to the torque fluctuation are eliminated, so the torque control is stopped and only the charging control is performed.

FIG. 5 is a flowchart showing the processing of the engine control unit 27. After the start, step S
Initialize in Step 1, and start signal, boost signal, and crank angle signal (engine speed) in Step S2.
, read battery voltage, etc. Then, in step S3, it is determined whether or not it is the time of starting (during cranking) based on whether the starter signal is on.

If the determination in step S3 is YES and the engine is started, the process proceeds to step S4, where a signal is output to the inverter 26, the stator current is passed from the inverter 26 to the stator coil 19, and a positive torque is applied to the engine output shaft 2 to start the engine. Performs only electric control to rotate the ranking.

Further, when the determination in step S3 is No and the engine 1 is started, it is determined in step S5 whether the battery voltage vb is higher than the reference value C1, and if it is high (YES).
In step S6, since the battery 35 is in a sufficiently charged state, the field current to the excitation coil 17 is reduced to reduce the amount of charge.However, when the battery voltage vb is low and the battery 35 is insufficiently charged, In S7, the field current to the excitation coil is increased to increase the amount of charge.

Next, in step S8, it is determined whether the engine rotation speed N (average value) is lower than a predetermined value C2 (torque control cut rotation speed). This predetermined value C2 is set as a region where, at a rotation speed lower than this, torque fluctuation during one rotation is detected as engine vibration or the like, and torque control is required.

If the determination in step S8 is YES, it is determined in step S9 whether the vehicle is in an idle state based on whether the idle switch 33 is on or not.

If the engine is in the idle state, the process proceeds to step SIO where it is determined whether the engine rotational position is within the first or third angle range. This angle range is, as shown in Figure 6,
The rotational position of a specific cylinder is divided into four zones every 90'' with respect to top dead center TDC and bottom dead center BDC, and the rotational range is 90'' from top dead center and bottom dead center.

If the determination in step SIO is YES, the current command is set to a negative phase in step Sll, and a reverse torque is applied as a power generation state. S12
To prevent dilution gas during idling, the current command is set to positive phase and positive torque is applied by electric drive.

On the other hand, if the determination in step S9 is No, the predetermined rotation speed is 0.
2 or less, that is, in the torque control zone, the process proceeds to step S13, where it is determined whether the engine rotation range is within the first or third angle range. If this determination is YES, in step S14 the current command is set to positive phase and positive torque is applied by electric drive, while
If the determination in step S13 is NO, step S1
In step 5, the current command is set to a negative phase, a power generation state is established, and a reverse torque is applied to suppress torque fluctuations in engine rotation.

Further, if the determination in step S8 is No, the engine rotation speed N (average value) is set to a predetermined value C2 (torque control cut rotation speed).
If the voltage has increased above that level, the process proceeds to step SlB, where the control signal to the inverter 26 is cut off and only charging control is performed.

According to the above embodiment, since the engine speed is low during idling operation, the overlap period is long and the combustibility is reduced due to the influence of dilution gas, but the timing is set corresponding to the overlap period to generate positive torque. By adding this, it is possible to increase the engine rotational speed during this overlap period and shorten the time, thereby reducing the amount of dilution gas brought in and ensuring combustion stability.

In addition, in the above embodiment, the control for carrying in the dilution gas is performed only during idling operation, but it may be set to be performed in a wider low load range than this. Further, the positive torque addition period corresponding to the overlap period during idling is set to be added at least in the initial region of the overlap period,
It may be extended to the entire overlap period or to a period before or after it.

Further, in the above embodiment, the excitation coil 17 is installed on the fixed side, but it may be installed on the rotating side and energized via a slip ring.

(Effects of the Invention) According to the present invention as described above, by controlling the electric drive means to apply positive torque to the engine output shaft at a timing corresponding to the overlap period, the rotation of the engine during the overlap period is controlled. It is possible to increase the speed and shorten the overlap period, reduce the amount of illusion gas brought in, improve combustion stability, and obtain good torque performance.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram to clearly show the configuration of the present invention; Fig. 2 is an overall configuration diagram of an engine torque fluctuation control device showing a specific example of the invention; An explanatory diagram showing the characteristics of the control signal, Fig. 4 is a graph showing the ratio of dilution gas to the engine speed, Fig. 5 is a flowchart to explain the basic processing of the control unit, and Fig. 6 is the engine output. It is an explanatory view showing the rotation angle range of a shaft. 1...Engine, 2...Output shaft, 3.
. . . Torque applying device, 4 . . . Electric drive means, 5 . . . Overlap period detection means, 6.
... Torque control means, 16 ... Rotating field pole, 17 ... Excitation coil, 19 ... Stator coil, 21 ... Non-commutator electric motor, 25
......Field controller, 26...Inverter, 27...Engine control unit. Figure 3 Figure 4 Engine 1

Claims (1)

[Claims] (1) An electric drive means that applies positive torque to the output shaft of the engine, an overlap period detection means that detects an overlap period in which both the intake valve and the exhaust valve are open, and the overlap period detection means 1. A torque fluctuation control device for an engine, comprising: torque control means for receiving an output from the means and operating the electric drive means at a timing set so that the engine rotational speed during the overlap period increases.