JPH04209931A - Torque fluctuation reducer for internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce vibratory excitation force generated based on a difference between target torque and generated torque by detecting the target torque and a present value of the generated torque of an internal combustion engine, and further generating compensation torque, for reducing the torque difference based on the difference, in the detected present value. CONSTITUTION:A present value of load torque necessary in accordance with an operative condition of an internal combustion engine is calculated in a target torque calculating means A. A present value of generated torque of the internal combustion engine is calculated in a generated torque detecting means B. Further, a difference between a present value of target torque and the present value of the generated torque is calculated in a torque difference calculating means C. On the other hand, a torque transfer means E is connected to the internal combustion engine so that torque can be given and received. The torque transfer means E is driven to generate compensation torque for reducing the torque difference in a torque transfer means control means D. In this way, vibration due to torque fluctuation in various modes of operation of the internal combustion engine is reduced.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to reducing torque fluctuations in internal combustion engines.

[Conventional technology]

The torque fluctuation control device disclosed in Japanese Patent Application Laid-Open No. 61-61922 includes an electric drive device and a power generation device that are connected to the crankshaft of an engine to generate positive and negative torques, and a known periodic fluctuation of crankshaft torque (e.g. In synchronization with FIG. 3(a)), the electric drive device and the power generator are alternately driven to reduce torque fluctuations.

On the other hand, Japanese Patent Application Laid-Open No. 53-115408 discloses an example of an internal combustion engine using a cylinder reduction operation system in which operation of some cylinders is stopped during light load operation. By performing such cylinder reduction operation, it is possible to reduce fuel consumption.

[Problem to be solved by the invention]

However, in the above-mentioned cylinder reduction operation, there is a problem in that the torque fluctuation (that is, the difference between the generated torque and the target torque) increases and vibration increases. Also, Figure 3 (C)
As shown in Figure 8 (B), the torque fluctuation does not become a slam when transitioning from full cylinder operation to reduced cylinder operation, and furthermore, as shown in Figure 8 (B), the torque fluctuation remains constant even during acceleration. .

Therefore, it is possible to use the above-mentioned torque fluctuation control device for the above-mentioned conventional vibration suppression, but this device reduces a predetermined torque periodic fluctuation slam (based on the crank angle). Therefore, when the torque fluctuates rapidly or is not constant, such as during acceleration operation or cylinder reduction operation,
The effect was not sufficient.

In other words, torque fluctuations during the transition period when switching between full-cylinder operation and reduced-cylinder operation, torque fluctuations during sudden acceleration/deceleration, torque fluctuations due to sudden changes in road surface conditions, etc. are irregular and steep. -It was difficult to reduce torque fluctuations.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a device that reduces vibrations caused by torque fluctuations in various operating modes of an internal combustion engine.

[Means to solve the problem]

゛The torque fluctuation reduction device for an internal combustion engine of the present invention includes a target torque calculation means for calculating the current value of the load torque required according to the operating state of the internal combustion engine, and a current value of the torque generated by the internal combustion engine. a torque difference calculating means for calculating a difference between the current value of the target torque and the current value of the generated torque; a torque transfer means connected to the internal combustion engine so as to be able to transfer torque; The present invention is characterized by comprising a torque transfer means control means for driving the absorption means to generate a compensation torque that reduces the torque difference.

[Action and effect of the invention]

In the internal combustion engine torque fluctuation reduction device of the present invention, the current values of the target torque and the generated torque of the internal combustion engine are detected directly or based on parameters related to these torques, and based on the difference between the detected current values of both torques. and drives the torque transfer means to generate a compensation torque that reduces this torque difference.

As a result, it is possible to reduce the excitation force generated based on the difference between the target torque of the internal combustion engine and the generated torque.

In particular, in this invention, compensation torque is generated in real time based on the difference between the current value of the target torque and the generated torque to cancel out this torque difference. At the time of transition between cylinder operation and reduced cylinder operation, the excitation force can be reduced or offset to realize quiet operation. Additionally, energy can be regenerated during deceleration.

Further, the flywheel can be omitted or the flywheel can be made smaller and lighter, thereby improving fuel efficiency.

〔Example〕

below. An embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, this internal combustion engine torque fluctuation reduction device comprises an auxiliary machine (part of the torque transfer means in the present invention) 2 connected to a crankshaft of a reciprocating internal combustion engine 1 for a vehicle.
, a battery 3 (remaining part of the torque transfer means in the present invention) that transfers power to and receives power from the auxiliary machine 2, and a controller (target torque calculation means, generation unit in the present invention) that controls the amount of power received by the auxiliary machine 2. A three-phase AC voltage having a magnitude and frequency according to the output signals of the torque detection means, torque difference calculation means, and torque transfer means control means) 4 and the controller 4 is applied to the stator winding of the auxiliary machine 2 to excite it. It is equipped with an auxiliary drive circuit 5 for controlling current and supplying armature current or regenerating generated current.

In this embodiment, the auxiliary machine 2 is composed of a three-phase squirrel-cage induction machine that also serves as a starter and power generator, and is connected to the crankshaft of the internal combustion engine 1 via a timing belt, speed-up gear, etc. in order to increase the speed of the auxiliary machine and make it smaller. are connected.

Of course, the auxiliary machine 2 may be configured with a separate generator and electric motor.

In this embodiment, the battery 3 also serves as a battery for driving the vehicle load, but it may also be a dedicated battery.

The controller 4 is a digital signal processor (DS
A/D converter 41 (
The primary voltage (three-phase AC voltage), current, and frequency are read from the auxiliary equipment 2 through the auxiliary equipment 2 (consisting of multiple A/D converters).

Furthermore, the necessary signals relating to the status of the internal combustion engine 1 and the battery 3 are received from the ECU (engine control unit). Then, the controller 4 calculates the torque (compensation torque) that the auxiliary machine 2 should generate (absorb or release) from the received signal, and further calculates the torque (compensation torque) that the auxiliary machine 2 should generate (absorbs or releases). The primary voltage signal is output as a digital value to the auxiliary drive circuit 5.

The auxiliary equipment drive circuit 5 includes three D/A converters that respectively D/A convert the input three-phase primary voltage signals, and individually power-amplifies the analog outputs of the above-mentioned D/A converters to drive the auxiliary equipment. It is equipped with a power amplifier that applies to each phase of the primary winding of 2, and a three-phase AC voltage (U, V, W) of the required frequency.
is applied to the second winding of auxiliary machine 2 to excite the stator of auxiliary machine 2.

Note that the magnitude and frequency of the three-phase AC voltage are determined so that the necessary compensation torque can be generated as efficiently as possible within the allowable current range whether the auxiliary machine 2 is in the motor mode or the generator mode.

Next, the operation of the controller 4 will be explained with reference to the flowchart shown in FIG. This routine takes approximately 1ms e C
executed every time. Of course, the routine shown in the flowchart of FIG. 2 conceptually shows the control operation, and it goes without saying that parallel processing is possible to improve the calculation speed.

First, in step 100, the accelerator opening, engine speed, crank angle, and battery voltage are read from the ECU, and the three-phase AC voltage, frequency, and secondary current applied to the primary winding from the auxiliary equipment 2 are read.

Next, in step 200, the torque (generated torque) TG actually generated by the internal combustion engine 1 and the target torque (target torque) TL of the internal combustion engine l are calculated.

Here, the generated torque TG is calculated based on a value obtained by differentiating the crank angle signal to obtain the crank angular acceleration and multiplying it by a predetermined constant. Alternatively, a strain sensor may be provided on the crankshaft to directly detect the generated torque. On the other hand, the target torque is determined from a running load torque consisting of a thrust for moving at a constant speed and a thrust for acceleration/deceleration, and a battery charging torque for charging the discharged portion of the battery. The running load torque is calculated from a map (with built-in memory) based on the accelerator opening, engine speed, and vehicle body inclination received from the ECU.
table).

Next, in step 300, compensation torque TR=TL-TG
is calculated, and when the calculated compensation torque TR is positive, auxiliary equipment 2
is used as an electric motor, and when it is negative, it is used as a generator to absorb the torque difference and suppress torque fluctuations.

Specifically, the magnitude and frequency (phase) of the three-phase AC voltage of the auxiliary machine 2 are determined based on the compensation torque and the rotation speed. Torque is controlled using instantaneous values. Therefore, a well-known dq conversion is first performed to control the output torque by keeping the excitation current constant and changing the torque current. At this time, information for calculating the magnitude and direction of the magnetic flux due to the excitation current can be obtained by the AD converter 41.

Next, in step 300, the obtained primary voltage, that is, the current value of the three-phase AC voltage is output to the motor controller 5, and
Return to step 100 again.

Note that the control of the magnitude and frequency of the three-phase AC voltage in step 400 may be calculated based on conventional induction machine theory.

Furthermore, a prediction circuit can be incorporated into the controller 4 in order to compensate for the time delay between inputting data and controlling the current. This predicts the torque command value after one calculation cycle based on past torque fluctuation data using known methods such as learning and fuzzy.

Furthermore, when the torque fluctuation is periodic with respect to the rotation angle, such as during idling, it is also possible to refer to data obtained before one rotation of the crankshaft.

In addition, if torque fluctuations are irregular, such as during muscle reduction or acceleration,
It is also possible to form a film or memorize this button and control it with this registered button under these conditions.

Naturally, the auxiliary machine 2 and the internal combustion engine 1 can also be directly connected.

Furthermore, an electromagnetic drive type flywheel can also be employed as the torque transfer means of the present invention.

For example, an armature body (or field coil and core) is provided on the rotating shaft connected to the crankshaft via a speed increasing gear, and a field coil and core (or armature body) are provided on the flywheel side. The armature body and the field element body may be electromagnetically coupled to exchange electromagnetic energy between them. It is also possible to exchange electric power between a rotating machine that is connected to the crankshaft and also serves as a starter and generator, and an electromagnetically driven flywheel that is housed in a vacuum case. In this case, the number of rotations of the flywheel can be significantly increased, and the frictional wear and tear is also small, so that the flywheel can be made smaller despite the large amount of stored energy.

Furthermore, it is of course possible to use other types of rotating machines, such as a DC machine or a synchronous machine, as an auxiliary machine.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing one embodiment of the present invention, and FIG.
The figure is a flowchart showing the operation of the controller, Figure 3 is a torque fluctuation diagram showing torque fluctuations during constant speed running, acceleration, and transition from full cylinder operation to reduced cylinder operation, and Figure 4 is a complaint response diagram. . 1 is an internal combustion engine, 2 is an auxiliary machine (torque transfer means), 3 is a battery (torque transfer means), 4 is a controller (target torque calculation means, generated torque detection means, torque difference detection means,
(torque transfer means control means), 5 is an auxiliary drive circuit.

Claims (1)

[Scope of Claims] Target torque calculation means for calculating the current value of the load torque required according to the operating state of the internal combustion engine; Generated torque detection means for detecting the current value of the generated torque of the internal combustion engine; a torque difference calculation means for calculating the difference between the current value of the target torque and the current value of the generated torque; a torque transfer means connected to the internal combustion engine so as to be able to transfer torque; and a torque transfer means that drives the torque transfer means to calculate the torque difference. A torque fluctuation reduction device for an internal combustion engine, comprising: a torque transfer means control means for generating a compensation torque that reduces the torque.