JPH04148024A - 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 providing a rotary valve with open/close timing by which the poppet valve is closed, for example, earlier when an engine is low in revolution than when the engine is high in revolution during the time when the poppet valve is kept fully open. 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. In addition, the rotating pivot 3A of the rotary valve 3 is connected to the output shaft of a driving motor 12 via a phase change mechanism. Furthermore, the rotating direction and the amount of rotation of the driving motor 12 is controlled by a control section 13. And the control section 13 provides the rotary valve 3 with open/close timing by which the poppet valve 2 is closed, for example, earlier when an engine is low in revolution than when the engine is high in revolution, based on engine revolution and an intake air flow rate or information on the position of an accelerator during the time when the poppet vale 2 is kept fully open.

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, a poppet valve is used to open and close an intake port communicating from an intake manifold to a combustion chamber.

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 particular, when driving at low speeds with the accelerator fully open, the intake stroke by the poppet valve described above cannot have a large amount of intake inertia due to the low intake flow velocity.
It is necessary to prevent the intake air introduced into the combustion chamber from being pushed back toward the intake manifold side as the piston rises, which tends to reduce the volumetric efficiency of intake air within the combustion chamber.

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

(Means for Solving the Problems) In order to achieve this object, the present invention provides a poppet valve that opens and closes an intake port that communicates with a combustion chamber, and a poppet valve that is located upstream of the poppet valve in the intake direction and rotates. The output shaft is a rotary valve that opens and closes the intake passage, and 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, and the output shaft a phase variable mechanism having a structure that changes the rotational phase of the output shaft; a drive unit that changes the rotational phase of the output shaft in the phase variable mechanism;
a control section that takes in the intake air flow rate or accelerator position information as input information and outputs a drive signal to the drive section, and the control section is configured to:
When the poppet valve is fully open and the engine speed corresponds to a high speed range, the rotary valve is set to open/close timing that overlaps with the poppet valve's open/close timing, and at low speeds, the engine speed is set to overlap the poppet valve's open/close timing. It is characterized by setting the opening/closing timing to close earlier than in the high-speed range.

(Function) According to the present invention, when the poppet valve is fully opened, 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 in the high speed range, and the air-fuel mixture is Inhalation time can be maximized.

In addition, in low-speed ranges, dynamic effects of intake air such as intake inertia, intake resonance, and pulsation effects are used to reduce the pressure when the in-cylinder pressure or the internal pressure of the intake manifold downstream of the rotary valve in the intake direction reaches its peak. Volumetric efficiency can be increased by closing the rotary valve.

(Embodiment) Hereinafter, details of an embodiment of the present invention will be described 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.

In other words, the 1-phase variable mechanism 5 is constituted 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 The phase is set so as to obtain a period in which the introduction of intake air ends earlier than the above (see FIG. 5(B)).

Therefore, in the high speed range when the accelerator is fully open, the rotary valve 3
By overlapping the open period of the poppet valve 2 with the open period of the poppet valve 2, the ventilation area can be overlapped and the intake air introduction time can be maximized, thereby increasing the volumetric efficiency. By utilizing intake effects such as intake inertia, resonance, and pulsation effects, the valve closes when the cylinder pressure or the intake manifold pressure downstream of the rotary valve reaches its peak, or immediately after the piston passes the bottom dead center. The push-out effect of the intake air that causes the rising process is prevented, thereby suppressing a decrease in volumetric efficiency.

Since this embodiment has the above-described configuration, its operation will be explained below 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 dynamic motor 12 rotates in the direction indicated by the symbol α in FIG. For example, when the drive motor 12 is advanced in the direction indicated by , and the drive motor 12 rotates in the opposite direction to this case (direction indicated by the symbol β), the drive gear 10 is in the high-speed range phase, which is the symbol γ. The angle is retarded in the direction indicated by the symbol β from the position indicated by .

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

(Effects of the Invention) 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. At high speeds, 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.
In addition, in the low speed range, by closing the rotary valve when the cylinder pressure or the pressure in the intake manifold downstream of the rotary valve reaches its peak, or immediately after that, it is possible to suppress the decrease in the volumetric efficiency of the intake air, and to reduce the intake air blowout. By suppressing the return, it is possible to prevent a decrease in 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, IA... Intake manifold, 2... Poppet valve, 3... Rotary valve, 5...
... Phase variable mechanism, 10... Immediate action gear for rotary valve,
12... Drive motor. Figure 5 (A) High speed (B) a compliance

Claims (1)

[Scope of Claims] A poppet valve that opens and closes an intake port that communicates with the 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 the intake passage; The support shaft of the rotary valve is used as the 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 takes in the intake flow rate or accelerator position information as input information and outputs a drive signal to the drive section, and the control section controls the poppet valve based on the engine speed and the intake flow rate or accelerator position information. When the engine is fully open and the engine speed is in the high speed range, the rotary valve is set to open/close timing that overlaps with the poppet valve opening/closing timing, and in the low speed range, the opening/closing timing is set to overlap with the poppet valve opening/closing timing. An intake control device for an automobile engine characterized by setting an opening/closing timing that closes earlier than in the case of an air intake control device for an automobile engine.