JPH0326825A - Intake controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent the variation of the engine torque, vibration, intake sound, etc., by independently correction-controlling the opening/closing timing of a plurality of intake control valves for opening/closing intake passages which communicate to the respective cylinders on the basis of the proscribed conditions for an internal Combustion engine. CONSTITUTION:At the intake ports which communicate to the cylinders 5-8 of an engine 1, intake control valves 21-24 are arranged, and the intake ports are opened and closed independently by actuators 25-28. In a throttle valve 40, the intake pressure which is supplied into each cylinder 5-8 through the intake control valve 21-24 is adjusted by the opening degree of a valve body. In this case, an ECU 4 independently correction-controls the opening/closing timing of the intake control valves 21-24 on the basis of the prescribed conditions of the engine 1. Therefore, the optimum control can be carried out for each cylinder 5-8. Therefore, when correction control is carried out so that the intake air quantity which is inhaled to each cylinder 5-8 is made equal, the variation of the engine torque, vibration, intake sound, etc., due to the dispersion of the intake air quantity can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a plurality of intake control valves that are separate from the intake valves of an internal combustion engine and are arranged for each intake passage that communicates with each cylinder.

[Conventional technology]

Conventionally, it has been considered to prevent backflow in an internal combustion engine by providing such an intake control valve for each intake passage. In other words, at the start of the intake stroke of an internal combustion engine, valve overlap occurs. This prevents burnt gas in the cylinders and exhaust passages from flowing back into the intake passage, reducing intake air filling efficiency, and by using an intake control valve to prevent intake air from flowing backwards, intake air filling efficiency is improved. This aims to improve the internal combustion engine's torque amplifier and fuel efficiency.

In order to switch the opening and closing of such intake control valves, there is a system in which an intake control valve is provided for each intake passage communicating with each cylinder, and each of the plurality of intake control valves is controlled to open and close by an independent actuator.

In this system, each intake control valve controls the opening/closing timing according to the operating condition (rotational speed, load, etc.), but when comparing each cylinder, the opening/closing timing is the same for all cylinders. If the amount of intake air varies due to the layout of the intake system, there is a problem in that engine torque, vibration, intake noise, etc. will vary. In particular, regarding the intake sound, as shown in Figure 6, when the intake sound during an explosion is analyzed by order, it is divided into the explosion first-order component, second-order component, third-order component, and their adjacent ±1/4 component. If the difference is small, and this difference is within 5 dB, it will result in a whining sound that will cause discomfort to the driver and passengers.

Therefore, an object of the present invention is to control each intake control valve at optimal opening/closing timing based on predetermined conditions of the internal combustion engine, thereby preventing fluctuations in engine torque, vibration, intake noise, etc.

[Means to solve the problem]

In order to solve the above problems, the intake control device of the present invention includes a plurality of intake control valves that are arranged for each of a plurality of intake passages communicating with each cylinder of an internal combustion engine and open and close the intake passages; an opening/closing driving means for independently driving each intake control valve to open and close, and a pressure regulating valve for adjusting the pressure of intake air reaching each cylinder via the intake control valve by the opening degree of a valve body, The invention is characterized in that the opening/closing timing of each of the plurality of intake control valves is independently corrected and controlled by the opening/closing driving means based on the condition.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the system configuration of an engine equipped with the intake control device of this embodiment.

In FIG. 1, this system includes a four-cylinder engine 1, an intake control unit 3 disposed in an intake system 1a of the engine 1, and an electronic control unit (hereinafter simply ECU) that controls these.
4) has been admonished since 4.

The engine 1 includes four cylinders 5, 6, 7.8, and each cylinder 5, 6, 7.8 is provided with an intake valve 9, 10, 11, 12 that is opened and closed by a high-speed adaptive cam. ,
Exhaust valves 13, 14, 15.16 are also provided. A throttle valve 40 as a pressure regulating valve is disposed in the intake system 1a of the engine 1, and the opening degree of the throttle valve 40 is drive-controlled by a throttle actuator 4l.

Further, intake bows 17, 18, 19, 20 are provided which branch from the intake system 1a and communicate with each cylinder 5, 67, 8. The intake boats 17.1B, 19.20 are each provided with intake control valves 21, 22, 23, 24, and each of these intake control valves 21, 22, 23.24 is connected to an actuator 25 as an opening/closing drive means. , 26, 27, and 28, each cylinder is independently driven to open and close.

The engine l has a detector for each cylinder 5, 6, 7.8
A crank angle sensor 29 outputs a pulse signal when the piston (not shown) is located at top dead center (TDC), a rotation speed sensor 30 outputs a pulse signal at every predetermined crank angle, and detects torque or combustion for each cylinder. Means 3
1 (for example, cylinder pressure sensor, torque sensor, knock sensor), 1,000 stages 32 (for example, intake pipe pressure sensor) that detects the air amount for each cylinder, and 1,000 stages of load detection 33 that detects the load state.
(e.g. throttle sensor, accelerator sensor), noise/vibration detection means 34 for detecting noise or vibration,
It is provided with a mechanism detection stage 35 for detecting the state of the engine.

The engine 1 also includes a control means 36 for controlling and injecting the amount and timing of injection by the injector, an ignition timing control means 37 for controlling the ignition timing, a supercharging means 38 for supercharging intake air, and learning according to the operating state. A learning control stage 39 for controlling, an intake air heating stage 42 for heating the intake air, and a cooling water temperature adjustment means 43 for adjusting the temperature of the cooling water are provided.

The ECU 4 is configured as a logic operation circuit mainly including a CPU 4A, a ROM 4B, and a RAM 4C, and is connected to an input/output section 4E via a common bus 4D to perform input/output with the outside.

Detection signals from each sensor and signals from each control means are manually inputted from the human output section 4E to the CPU 4A. On the other hand, C.P.
U4A connects the actuator 25 via the input/output section 4E.
, 26, 27.2B, throttle actuator 41,
A control signal is output to the supercharging means 38 and the intake air heating means 42.

Next, the control method of this embodiment will be explained.

Regarding the amount of intake air for each cylinder, input signals from means 32 for detecting the amount of air for each cylinder and actuators 25, 2 are used.
Intake control valves 21, 22, 23, 24 to 6, 27, 28
The injection control means 36 determines the injection amount of the injector for each cylinder based on the calculation result.

Next, basic control of the opening timing of the intake control valves 21, 22, 23, and 24 is performed based on the input signal of the rotation speed sensor 30, as shown in Table 1, as the rotation speed increases. The driving means 2
5, 26, 27, . 28. In Table 1, the valve opening timing indicates the amount of advance relative to top dead center.

Table 1: Basic Interval Valve Timing Also, the basic control of the closing timing of the intake control valves 21, 22, 23, 24 is set as follows. In other words, the amount of intake air is determined by multiplying the air density by the intake time, and conventionally, air I#A adjustment at partial load was handled by keeping the intake time constant and changing the air density using the throttle valve. In this embodiment, in order to reduce pump loss, not only the air density but also the intake time are adjusted, so the intake control valves 21.22, 23.2
The valve closing time of No. 4 is controlled according to the load as shown in Table 2. The relationship between the opening degree of the throttle valve 40 and the amount of depression of the accelerator at this time is set as shown in FIG. In Table 2, the valve closing time indicates the amount of advance relative to the bottom dead center.

Table 2 Basic Valve Closing Timing Figures 3 and 4 show the opening/closing profile of the intake control valve at the basic opening timing and closing timing mentioned above.
Figure 3 shows the profile at low rotation, and Figure 4 shows the profile at high rotation.

In FIG. 4, the intake control valve opens earlier and closes later than the intake valve, but the intake control valve may always be fully open.

Further, in this embodiment, the valve closing timing is determined by calculating the basic valve closing control with various correction terms depending on the operating state. Since this correction term is provided for each cylinder, the intake air amount for each cylinder is determined to be the optimum value depending on the operating situation.

Equation (1) shows an example of calculation of the valve closing timing.

TC=TCBSE+TTC+FTC+TRTC+BTC
+NTC+NETC+TI)C・・・・・・・・・(1
) In equation (1), TC is the advance amount of valve closing timing TCBSE is the basic valve closing advance amount shown in Table 2 TTC is the A/F correction advance amount during transition FTC is the combustion temperature correction advance amount The amount TRTC is the acceleration slip (traction) control advance amount BTC. The intake brake control advance amount NTC during deceleration, the correction advance amount NETC during knocking, and the correction advance amount TDC during equal air amount control indicate the actuator aging correction advance amount.

In this correction control, in this embodiment, equal air scent correction control shown in NETC is performed to prevent variations in intake air amount between cylinders due to the layout of the intake system. That is, each intake control valve 21, 22, 23 .
24, the valve closes at the closing timing of L (G), so that the amount of intake air taken into each cylinder 5, 6, and 7.8 is equal, and the engine torque and vibration due to variations in intake air , fluctuations in intake noise, etc. can be suppressed.Moreover,
With this correction control, as shown in Fig. 4, the primary power, the
The sound quality of the next and third part and the adjacent part will be reduced, resulting in an improvement in tone and eliminating unpleasant noise for the driver or passengers. disappears.

〔Effect of the invention〕

As described above, according to the present invention, since each intake control valve is independently corrected and controlled, optimal control can be performed for each cylinder. In addition to improving torque and fuel efficiency, this can also improve engine torque, vibration, intake noise, etc. due to variations in intake air volume by correcting and controlling the amount of intake air taken into each cylinder to be equal. It is possible to prevent this from happening, and also improve the tone, which can cause discomfort to the driver and passengers. I can't get enough of it.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing the overall structure of an embodiment of the present invention;
Fig. 2 is a characteristic diagram showing the relationship between the accelerator depression amount and the throttle valve opening in this embodiment, Fig. 3 is a diagram showing the opening/closing profile of the intake control valve at low speed in this embodiment, and Fig. 4
FIG. 5 is a diagram showing the opening and closing profile of the intake control valve at high speed according to this embodiment, FIG. 5 is a diagram showing intake noise characteristics of this embodiment, and FIG. 6 is a diagram showing conventional intake noise characteristics. 21, 22, 23. 24... Intake control valve. 2526,
27.28... Actuator (opening/closing drive means), 4
0...Throttle valve (pressure adjustment valve).

Claims (1)

[Scope of Claims] A plurality of intake control valves that are arranged for each of a plurality of intake passages communicating with each cylinder of an internal combustion engine and open and close the intake passages, and a plurality of intake control valves that are independently driven to open and close. an opening/closing drive means; and a pressure regulating valve that adjusts the pressure of intake air reaching each cylinder via the intake control valve by the opening degree of a valve body, and the opening/closing drive means An intake control device, wherein the opening/closing timing of the plurality of intake control valves is independently corrected and controlled.