JPH04148023A - Intake air control device for vehicle engine - Google Patents

Abstract

PURPOSE:To improve a volumetric efficiency of intake air when a poppet valve is fully opened for respective speed ranges by adjusting the open/close timing of a rotary valve with the rotary valve changed in rotating phase with respect to the open/close timing of the poppet valve based on engine revolution and an intake air flow rate or information on the position of an accelerator. CONSTITUTION:A rotary valve 3 which opens/closes an intake manifold 1A, is disposed within the intake manifold 1A communicated with the combustion chamber of an engine main body 1 separately from a poppet valve 2 which opens/closes an intake air port. And the rotary valve 3 is rotatably supported within a valve housing 4 provided for the intake manifold 1A, and the rotary pivot 3A of the rotary valve 3 is connected to the output shaft of a driving motor 12 via a phase changing mechanism. Furthermore, the rotating direction and the amount of rotation of the driving motor 12 are controlled by a control section 13. And in the control section, open/close timing is adjusted with the rotary valve 3 changed in rotating phase with respect to the open/close timing of the poppet valve 2 based on engine revolution and an intake air flow rate or information on the position of an accelerator.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air intake control device for an automobile engine, and more particularly to a control structure for improving volumetric efficiency.

(Prior Art) As is well known, in the intake system of an automobile engine, an intake port communicating from an intake manifold to a combustion chamber is opened and closed by a poppet valve.

The opening and closing timing of this poppet valve is set by a drive cam, and the poppet valve is opened before the piston reaches the top dead center to draw the air-fuel mixture into the combustion chamber.

(Problem to be Solved by the Invention) By the way, in the intake structure using the poppet valve described above, when the throttle valve is fully opened at high speed, low speed, and intermediate speed ranges between these, the output in each speed range is improved. One of the factors is to improve the intake efficiency, in other words, the volumetric efficiency of intake air, and it is desired to improve this efficiency.

In other words, when driving at low speeds with the accelerator fully open.

In the intake stroke using the poppet valve mentioned above, due to the low intake flow velocity, it is not possible to obtain a large amount of intake inertia, and the intake air introduced into the combustion chamber is pushed back toward the intake manifold side as the piston rises. It is necessary to prevent this phenomenon from easily occurring and reducing the volumetric efficiency of the intake air in the combustion chamber.In addition, in the medium speed range between the high speed range and the low speed range, it is necessary to prevent the filling efficiency of the intake air from increasing. Needed.

Therefore, in view of the above-mentioned requirements for the conventional intake structure, an object of the present invention is to provide a structure that improves the volumetric efficiency of intake air at full throttle in each speed range and improves the output in each speed range. An object of the present invention is to obtain an air intake control device for an automobile engine.

(Means for Solving the Problems) To achieve this object, the present invention provides a poppet valve that opens and closes an intake port communicating with a combustion chamber.

A rotary valve is located on the upstream side of the poppet valve in the intake direction and is rotatable to open and close the intake passage, and the output shaft is the support shaft of the rotary valve, and the engine crank rotational force is used as input to output the above output. a phase variable mechanism having a structure that transmits the signal to the output shaft and changes the rotational phase of the output shaft with respect to the crank rotational phase, a drive section that changes the rotational phase of the output shaft in the phase variable mechanism, and an engine. a control unit that receives the engine rotation speed, the intake flow rate 1 or the accelerator position information as input information, and outputs a drive signal for the drive unit, the control unit inputs the engine rotation speed and the intake air flow 1 or the accelerator position information. Based on this, the opening/closing timing is adjusted by changing the rotational phase of the rotary valve with respect to the opening/closing timing of the poppet valve.

Further, in the present invention, when the poppet valve is fully opened and the engine speed corresponds to a high speed range, the control unit sets the opening/closing timing for the rotary valve to overlap with the opening/closing timing of the poppet valve, and The opening/closing timing of the poppet valve is set earlier than that in the high speed range, and is further characterized in that the speed is between the high speed range and the low speed range.

(for production) According to the invention, when the poppet valve is fully open.

In the high speed range, the opening degree of the rotary valve can be set to a state where the ventilation area and overlap obtained by opening the poppet valve are maximized, and the intake time of the air-fuel mixture can be maximized.

In addition, in the low speed range, dynamic effects of intake air such as intake inertia, intake resonance, and pulsation effects are utilized.

Volumetric efficiency can be increased by closing the rotary valve when the cylinder pressure or the internal pressure of the intake manifold on the downstream side of the rotary valve in the intake direction reaches its peak. By performing intake air after the transition, it is possible to improve the filling efficiency of intake air under a large negative pressure.

(Embodiments) Hereinafter, details of five embodiments of the present invention will be explained with reference to FIGS. 1 to 6.

FIG. 1 is a diagram showing a schematic configuration of an automobile engine to which an air intake control device according to an embodiment of the present invention is applied, and in the figure, reference numeral 1 indicates an engine body.

That is, in the intake manifold IA that communicates with the combustion chamber of the engine body 1, there is a valve on the upstream side of the intake port in the intake direction shown by the arrow for opening and closing the intake manifold IA separately from the poppet valve 2 that opens and closes the intake port. A rotary valve 3 is rotatably provided.

The rotary valve 3 described above is connected to the intake manifold IA.
The rotary valve 3 is rotatably supported in a valve housing 4 provided therein, and a rotational support shaft 3A of the rotary valve 3 is rotationally driven by a driving force transmission mechanism from the engine attached to a phase variable mechanism, which will be described later. be done.

That is, the phase variable mechanism 5 is constructed by a planetary gear mechanism in FIG. It is provided integrally with the shaft of the pulley 6A.

This sun gear 6 meshes with a planetary gear 7 at equally divided positions on the outer peripheral surface, in this embodiment, at three equally divided positions, and the planetary gear 7 is rotated by a wall wheel 8 provided as a carrier. freely supported.

The planetary gear 7 mentioned above meshes with the internal teeth 9A of the ring gear 9 located on the outer periphery thereof, and the external teeth 9B formed on the outer periphery of the ring gear 9 have a drive gear 10 integrated with the drive shaft of the rotary valve 3. are engaged. Therefore, the rotation of the crankshaft is transmitted to the planetary gear 7 via the sun gear 6, and the planetary gear 7 rotates the ring gear 9, thereby rotating the drive gear 10 and transmitting the rotational force to the rotary valve 3. be exposed.

On the other hand, a worm gear 11 meshes with the worm wheel 8 described above, and this worm gear 11 is provided integrally with the output shaft of the drive motor 2.

The drive motor 2 is a stepping motor capable of forward and reverse rotation, and its rotation direction and rotation amount are set by a control unit 13, which will be described later. The phase variable control of the rotation start position is performed, in other words, the rotation phase is adjusted and controlled.

That is, in the system configuration diagram shown in FIG. 3, the above-mentioned control section 13 is constituted by, for example, a microcomputer, and an input side via an I10 interface (not shown) attached to this microcomputer. The information includes engine speed information from the engine speed sensor, intake flow rate information from the air flow sensor, water temperature information, atmospheric pressure information, accelerator depression amount information from the accelerator position sensor, braking information from the brake sensor, and information from the ignition switch. Starter information is entered individually.

And on the output side of the microcomputer mentioned above,
A drive circuit (driver) for a drive motor 12 is connected, and a drive motor 12 having a built-in phase sensor 12A is connected to this drive circuit.

The phase sensor 12A of the drive motor 12 described above outputs phase information to the microcomputer described above to determine the state of phase control.

In the control unit 13 in this embodiment, the accelerator fully open region and each speed range when the air flow sensor is used are shown in FIG. 4 (A) using the signal from the air flow sensor (AFS) and the signal from the rotation speed sensor. Distinguish from the map,
In addition, the map shown in Figure 4 CB) determines the full-open accelerator range and each speed range when using the accelerator position sensor based on the signal from the accelerator position sensor (APS) and the signal from the rotational speed sensor. The phase of the opening/closing timing of the rotary valve 3 relative to the poppet valve 2 is changed in each speed range.

In other words, FIG. 5 shows the opening/closing timing of the rotary valve 3 relative to the opening/closing period of the poppet valve 2 based on the crank angle. So, in the high speed range,
The phases should be set so that the entire opening/closing period of the poppet valves overlaps (see Figure 5 (A)). In the low speed range, the intake starts earlier than the opening timing of the poppet valve 3, and the closing timing of the poppet valve 3 (See Figure 5 (B))), and in the medium speed range, the phase should be set so as to obtain a period in which the introduction of intake air ends earlier than the opening timing of the poppet valve 3. This is to set the phase (see FIG. 5(C)).

Therefore, in the high speed range when the accelerator is fully open, the rotary valve 3
By overlapping the opening period of the poppet valve 2 with the opening period of the poppet valve 2, it is possible to overlap the ventilation area and maximize the intake air introduction time, thereby increasing the volumetric efficiency. In this system, the piston passes through bottom dead center by closing when or immediately after the cylinder pressure or the intake manifold pressure downstream of the rotary valve reaches its peak by utilizing intake effects such as intake inertia, resonance, and pulsation effect. This prevents the push-out action of the intake air that later causes a rising process, thereby suppressing a decrease in volumetric efficiency. In addition, in the medium speed range, by opening late, the volumetric efficiency is increased by increasing the flow rate of intake air using the negative pressure in the downward stroke of the piston6. The operation of the control section will be explained as follows using the flowchart shown in FIG. 5 to explain the operation of the control section.

That is, when intake air amount information from the air flow sensor (AFS) or accelerator depression amount information from the accelerator pedal sensor (APS) and engine rotation speed information from the rotation speed sensor are input, the map shown in FIG. 4 is input. Select one of these to determine whether it corresponds to fully opening the accelerator, and if it is fully open, determine the high speed range, low speed range, and medium speed range based on the rotation speed information. .

Then, according to the result of this speed range discrimination, a rotational drive signal is outputted to the drive motor 12 so that the opening/closing timing of the rotary valve 3 in the state shown in FIG. 4 is obtained.

In other words, when the drive motor 12 rotates in the direction indicated by the symbol α in FIG. For example, if the angle is advanced in the direction indicated by the symbol α and the drive motor 12 rotates in the opposite direction to this case, then (
(in the direction indicated by symbol β), the drive gear 10 is retarded in the direction indicated by symbol β from the position indicated by symbol γ, which is the phase in the high speed range.

The amount and direction of rotation of the drive motor 12 based on the rotational drive signal described above are checked by the phase sensor 12A in the drive motor 12, and feedback control is performed until a predetermined state is obtained.

(Effects of the Invention) As described above, according to the present invention, a poppet valve and a rotary valve are combined in the intake passage, and the opening/closing timing of the rotary valve can be adjusted in the high speed range and the low speed range when the accelerator is fully opened. In high-speed ranges, the volumetric efficiency of intake air can be increased by maximizing the intake time when the poppet valve is opened to ensure a sufficient amount of intake air. Also.

In the low speed range, the rotary valve is closed when or immediately after the cylinder pressure or the pressure in the intake manifold downstream of the rotary valve reaches its peak, thereby suppressing the drop in intake volumetric efficiency.

By suppressing the blowback of intake air, it is possible to prevent a decrease in volumetric efficiency. In the medium speed range, by promoting negative pressure in the combustion chamber, it is possible to increase the intake air flow velocity and increase the intake air filling efficiency, thereby improving the volumetric efficiency.

Therefore, when the accelerator is fully opened in each speed range, a decrease in output can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the overall configuration of an intake control device according to an embodiment of the present invention, FIG. 2 is a schematic perspective view showing main parts of the intake control device shown in FIG. 1, and FIG. A system configuration diagram showing the control section of the intake control device shown in the figure.
Figure 5 is a diagram to explain the map used in the control unit shown in Figure 3. Figure 6 is a diagram to explain the characteristics of the control unit shown in Figure 3. 3 is a flowchart for explaining the operation of the control section. 1... Engine body, LA... Intake manifold, 2... Poppet valve, 3... Rotary valve, 5...
... Phase variable mechanism, 10... Drive gear for rotary valve,
12... Drive motor. Figure 5 (A) High speed (B) Race (C) To LP speed

Claims (1)

[Claims] 1. A poppet valve that opens and closes an intake port that communicates with a combustion chamber; A rotary valve that is rotatable and located upstream in the intake direction with respect to the poppet valve that opens and closes an intake passage; , The support shaft of the rotary valve is used as an output shaft, and the crank rotational force of the engine is transmitted to the output shaft as input,
a phase variable mechanism having a structure that changes the rotational phase of the output shaft with respect to the crank rotational phase; a drive section that changes the rotational phase of the output shaft in the phase variable mechanism; a control section that receives the flow rate or accelerator position of the poppet as input information and outputs a drive signal to the drive section; An intake control device for an automobile engine, characterized in that the opening/closing timing is adjusted by changing the rotational phase of the rotary valve with respect to the opening/closing timing of the valve. 2. In the intake control device for an automobile engine according to claim 1, the control unit causes the opening and closing timing of the poppet valve to overlap when the engine rotation speed corresponds to a high speed range when the poppet valve is fully opened. The opening/closing timing is set to the rotary valve, and in the low speed range, the opening/closing timing of the poppet valve is set earlier than in the high speed range, and further, in the speed range between the high speed range and the low speed range, the poppet valve is closed. An air intake control device for an automobile engine, characterized in that the opening/closing timing is set to open later than in the case of a high speed range.