JPH11324687A - Engine intake system - Google Patents

Abstract

(57) [Summary] [Problem] To enable a suitable intake air amount control in an entire use area of an engine by using a rotary valve instead of a throttle valve. SOLUTION: In an intake passage 15 of an engine 10, two rotary valves 1 and 2 which rotate in synchronization with engine rotation and open / close the intake passage 15 by the rotation are provided in series.
Then, the rotational phases of the rotary valves 1 and 2 are controlled in accordance with the engine operating conditions to control the overlap position and the open period of the rotary valves 1 and 2. When the load is high, the rotation of one rotary valve 2 is stopped at the open position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a rotary valve in an intake passage of an engine which rotates in synchronization with engine rotation and opens and closes the intake passage by the rotation. The present invention relates to an intake device for an engine that controls a phase to control an intake amount.

[0002]

2. Description of the Related Art In a conventional general engine, a throttle valve is provided in an intake passage to control the amount of intake air. As a result, pumping loss occurred and engine efficiency was reduced.

Accordingly, as disclosed in Japanese Patent Application Laid-Open Nos. Hei 7-97939 and Hei 8-218829, a rotary valve is provided in the intake passage which rotates in synchronization with the engine rotation and opens and closes the intake passage by the rotation. There has been proposed an apparatus that controls the amount of intake air by controlling the phase of the opening period of the rotary valve with respect to the opening period of the intake valve.

[0004]

However, such an intake system for an engine using a rotary valve satisfies the required valve-opening characteristics corresponding to the entire operating range of the engine for the following reasons. There was a problem that it was not possible. That is, in general, a rotary valve needs to have an opening period of each rotary valve longer than an opening period of an intake valve in consideration of a full load in terms of structure. However, in such a valve opening setting, when the required air amount is small at the time of idling or the like, the phase of the opening period of the rotary valve is advanced with respect to the opening period of the intake valve. If the intake valve is controlled to close quickly, the rotary valve will be opened again when the intake valve closes, so that it is not possible to perform suitable intake air amount control.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to enable a suitable intake air amount control in an entire use area of an engine.

[0006]

According to the present invention, a rotary valve is provided in an intake passage of an engine, the rotary valve being rotated in synchronization with engine rotation and opening and closing the intake passage by the rotation. In an intake system for an engine capable of controlling an intake air amount by controlling a phase of an opening period of a rotary valve with respect to an opening period, two rotary valves are provided in series, and rotation of these rotary valves is controlled according to engine operating conditions. Control means for controlling the phase to control the overlap position and the period of the open period of the rotary valve is provided.

According to a second aspect of the present invention, the control means includes a rotation stopping means for stopping rotation of at least one of the rotary valves at an open position under a predetermined operating condition. The invention according to claim 3 is characterized in that the control means stops the rotation of one of the rotary valves at the open position when the load is high.

[0010] In the invention according to claim 4, the control means operates at a partial load in a period when the intake valve starts to open.
The opening periods of the two rotary valves are overlapped. The invention according to claim 5 is characterized in that the control means overlaps the open periods of the two rotary valves near the maximum lift position of the intake valve at the time of partial load.

In the invention according to claim 6, a failure detecting means for detecting a failure of each rotary valve is provided, and when a failure of one of the rotary valves is detected, the failure occurs when the failed rotary valve is fixed at the open position. A fail-safe means for controlling the intake air amount by a rotary valve not provided is provided.

[0010]

According to the first aspect of the present invention, two rotary valves are provided in series in the intake passage of the engine, and the rotational phases of these rotary valves are controlled in accordance with the engine operating conditions. By controlling the overlap position and the period of the open period, the intake air amount can be suitably controlled. In particular, even if one of the rotary valves is closed early, and the intake valve is closed and the rotary valve is opened again, if the other rotary valve is closed, no suction is performed. Becomes possible.

According to the second aspect of the present invention, by providing the rotation stopping means for at least one of the rotary valves, when the rotation of the rotary valve is unnecessary, the rotation of the rotary valve is stopped to thereby drive the drive device (for example, a motor). Energy consumption can be reduced, sound vibration performance can be improved, and the life of a rotary valve component (for example, a bearing) can be extended.

According to the third aspect of the invention, when one of the rotary valves stops rotating at the open position when the load is high, it is possible to reduce the intake resistance and the energy consumption of the driving device. According to the fourth aspect of the present invention, at the time of partial load, the opening period of the two rotary valves is overlapped with the opening period of the intake valve so that the intake air amount can be effectively controlled.

According to the fifth aspect of the present invention, the opening period of the two rotary valves is overlapped in the vicinity of the maximum lift position of the intake valve at the time of partial load, so that when the boost in the cylinder is maximized, the intake air is exhausted. Air flow can be improved. According to the invention according to claim 6, when the failure of one of the rotary valves is detected, the intake amount control is performed by the non-failed rotary valve in a state where the failed rotary valve is fixed at the open position, so that the fail-safe operation is performed. And limp home.

[0014]

Embodiments of the present invention will be described below. FIG. 1 is a system diagram of an engine showing an embodiment of the present invention, and FIG. 2 is a control block diagram. Here, the engine 10 is a four-cylinder engine. An ignition plug 12 is mounted substantially at the center of the combustion chamber 11 of each cylinder on the cylinder head side, and the intake valve 13 and the exhaust valve 1 surround the ignition plug 12.
4 are arranged to face each other.

A first rotary valve 1 and a second rotary valve are provided for each cylinder in the intake passage 15 to the intake valve 13 without providing a throttle valve and upstream of the intake valve 13 downstream of the branch to each cylinder. 2 are interposed in series. Although not shown, the fuel injection valve is provided so as to be directly injected into the combustion chamber 11 or is disposed in an intake passage 15 between the first rotary valve 1 and the intake valve 13.

The first and second rotary valves 1 and 2 are
A valve chamber 1a formed by expanding the intake passage 15 in an arc shape.
2a is a valve plate attached to the rotating shafts 1b and 2b and arranged at a predetermined rotation angle θ (9
The valve opens in the section of (0 ° or more), then fully closed in the section of (180 ° −θ), opens again in the section of θ, and then fully closed in the section of (180 ° −θ).

The rotary shafts 1b and 2b are common to all cylinders, and the rotary valves (valve plates) 1 and 2 of the respective cylinders are changed by 90 ° with respect to the rotary shafts 1b and 2b. The rotating shafts 1b and 2b are
The motors 21 and 22 are controlled by a motor controller 23. The motor controller 23 is controlled by the engine control unit 24.

The engine control unit 24 includes:
Signals are input from an accelerator sensor 26 that detects the amount of depression of an accelerator pedal 25 (accelerator opening), a crank angle sensor 27 that detects engine rotation, and the like. Here, the engine control unit 24 basically synchronizes with the engine rotation, and
While rotating the first and second rotary valves 1 and 2 at a speed of, the first
And controlling the rotation phase of the second rotary valves 1 and 2 (phase difference control) so as to control the overlap position and the period of the open period of the rotary valves 1 and 2.
A command signal is output to the motor controller 23. Therefore, the engine control unit 24 has a function as control means.

The motor controller 23 outputs a drive signal to the motors 21 and 22 while detecting the rotational positions (rotary valve positions) of the motors 21 and 22 in accordance with a command signal from the engine control unit 24. The rotation of the first and second rotary valves 1 and 2 is controlled via the control valve 22. Next, the phase difference control of the first and second rotary valves 1 and 2 (the intake air amount control using the first and second rotary valves 1 and 2) according to the engine operating conditions by the engine control unit 24 will be described with reference to FIG. This will be described with reference to the timing chart of FIG.

At the time of high load, as shown in FIG.
While the rotation of the second rotary valve 2 farther from the intake valve 13 is stopped and held at the fully opened position, the opening period of the first rotary valve 1 closer to the intake valve 13 is delayed to open the second valve 2. Is controlled in the direction to match, and completely matches at the time of full load. Therefore, the control means constituted by the engine control unit 24 includes a rotation stopping means.

This makes it possible to cope with high load and full load by extending the intake period. Further, by stopping the rotation of one of the second rotary valves 2 at the open position, it is possible to reduce the drive energy. In this case, responsiveness and the like are improved by holding the second rotary valve 2 farther from the intake valve 13 at the fully open position and controlling the intake air amount by the first rotary valve 1 closer to the intake valve 13. At the time of full load, both the first and second rotary valves 1 and 2 may be stopped at the full open position.

At the time of partial load, as shown in FIG. 3B, the opening period of the second rotary
Of the first rotary valve 1
Of the first and second rotary valves 1 and 2
The overlap period of the opening period of the intake valve 13 is reduced to make a part thereof coincide with the start of opening of the intake valve 13.
The intake period is shortened so that intake can be performed only at the beginning of opening of No. 3.

At this time, if only the first rotary valve 1 is used, when the first rotary valve 1 is controlled to close early, the first rotary valve 1 is opened again when the intake valve 13 closes, and air is taken in. However, if the second rotary valve 2 is provided and closed, no air is sucked. Alternatively, as shown in FIG. 3 (C), the overlap period between the open periods of the first and second rotary valves 1 and 2 is reduced to control the intake valve to coincide with the intake valve maximum lift with the highest boost. Airflow can also be improved.

By shortening the intake period in this way, it is possible to cope with a partial load. The engine control unit 24 further includes a failure detecting means for detecting a failure of each rotary valve, and a failure-free rotary valve fixed to an open position when one of the rotary valves is detected to have failed. It has a function as a fail-safe means for controlling the intake air amount by a valve, and the flow of the intake air amount control including this function is
This will be described with reference to a flowchart.

FIGS. 4 and 5 are flowcharts of the intake air amount control routine. In step 1 (referred to as S1 in the figure, the same applies hereinafter), the accelerator opening is detected based on a signal from the accelerator sensor. In step 2, the engine rotation is detected based on the signal from the crank angle sensor.

In step 3, the intake passage opening period (overlap position and period of the opening period of the first and second rotary valves) is calculated by referring to a map based on the accelerator opening and the engine speed. In step 4, the operating conditions of the first and second rotary valves are determined based on the calculated intake passage opening period.

In step 5, a drive signal is output to the motor controller according to the determined operating conditions. In step 6, it is determined whether the motor of the first rotary valve is operating according to the required output. If it is operating according to the required output, the process proceeds to step 7. In step 7, it is determined whether or not the motor of the second rotary valve is operating according to the required output.
Returning to step 1, the above control is continued.

If the motor of the first rotary valve is not operating according to the required output, it is determined in step 8 whether or not the motor of the second rotary valve is operating according to the required output. If not, go to step 9. In step 9, it is diagnosed that both rotary valves are out of order and the driver is warned of the outage. Then, in step 10, it is determined whether or not both rotary valves are stuck. If both rotary valves are stuck, in step 11, the ignition switch is turned off, the engine is stopped, and the process is terminated. finish. If at least one of the rotary valves is not stuck, in step 12, the operated rotary valve is operated to the fully closed position and held at the fully closed position (idle state), and the process ends.

If the motor of one of the rotary valves is not operating as required, the process proceeds to step 13 in FIG. In step 13, it is diagnosed that one of the rotary valves is out of order and the driver is warned of the outage. Then, in step 14, it is determined whether or not the failed rotary valve is operable.

If the failed rotary valve is inoperable, step 15 determines whether the failed rotary valve is stuck in the fully closed position. If it is fixed in the fully closed position, in step 16, the non-failed operating rotary valve is operated to the fully closed position and held at the fully closed position (idle state), and the process is terminated.

If the failed valve is not stuck at the fully closed position, the opening of the failed rotary valve is read, and the routine proceeds to step 18 and subsequent steps. If the failed rotary valve is operable, in step 17, the failed rotary valve is fixed at a predetermined opening (opening = a), and the process proceeds to step 18 and subsequent steps.

In step 18, the accelerator opening is detected based on the signal from the accelerator sensor. Step 19
Then, the engine rotation is detected based on the signal from the crank angle sensor. In step 20, based on the accelerator opening and the engine rotation, the opening period of the intake passage by the non-failed operating rotary valve is calculated in consideration of the opening of the failed rotary valve.

In step 21, based on the calculated intake passage open period, the operating condition of the non-failed operating rotary valve is determined. In step 22, a drive signal is output to the motor controller according to the determined operating condition. Thereafter, the process returns to step 6 in FIG. FIG.
9 is a flowchart of an intake air amount control routine (part 2) showing another embodiment, which is used in combination with the flow of FIG. 4 instead of FIG.

In step 13, it is diagnosed that one of the rotary valves is out of order, and the driver is warned of the outage. Then, in step 14, it is determined whether or not the failed rotary valve is operable. If it is determined in step 14 that the failed rotary valve cannot be operated, the flow is the same as that in FIG. 5 (steps 15, 16, 18 to 18).
22).

If the failed rotary valve is operable, in step 23, the failed rotary valve is operated to the fully open position and held at the fully open position, and the process proceeds to step 24 and subsequent steps. In step 24, the accelerator opening is detected based on the signal from the accelerator sensor.

In step 25, a non-failed operating rotary valve is controlled in the same manner as a conventional throttle valve (electrically-controlled throttle valve) according to the accelerator opening. Thereafter, the process returns to step 6 in FIG. If a negative pressure such as a brake booster or engine emission control (EGR, evaporative purge) is required, a negative pressure is generated by closing the second rotary valve 2 to a certain opening (determined by the accelerator opening). Then, it can be taken out from the negative pressure take-out passage 28 in FIG.

[Brief description of the drawings]

FIG. 1 is a system diagram of an engine showing an embodiment of the present invention.

FIG. 2 is a control block diagram of the above.

FIG. 3 is a timing chart of intake air amount control using a rotary valve.

FIG. 4 is a flowchart of an intake air amount control routine (part 1);

FIG. 5 is a flowchart of an intake air amount control routine (part 2);

FIG. 6 is a flowchart of an intake air amount control routine (part 2) showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st rotary valve 2 2nd rotary valve 1a, 2a Valve chamber 1b, 2b Rotating shaft 10 Engine 11 Combustion chamber 12 Spark plug 13 Intake valve 14 Exhaust valve 15 Intake passage 21, 22, Motor 23 Motor controller 24 Control unit 25 Accelerator pedal 26 Accelerator sensor 27 Crank angle sensor

Claims (6)

[Claims] An intake passage of an engine is provided with a rotary valve that rotates in synchronization with engine rotation and opens and closes the intake passage by the rotation, and controls a phase of an opening period of the rotary valve with respect to an opening period of the intake valve. In an intake device for an engine capable of controlling an intake amount, two rotary valves are provided in series, and a rotation phase of these rotary valves is controlled in accordance with an engine operating condition to control an overlapping position of an opening period of the rotary valves. And a control unit for controlling a period. 2. The intake system for an engine according to claim 1, wherein said control means includes a rotation stopping means for stopping rotation of at least one of the rotary valves at an open position under predetermined operating conditions. 3. An intake system for an engine according to claim 2, wherein said control means stops the rotation of one of the rotary valves at an open position when the load is high. 4. The control means according to claim 1, wherein at the time of partial load, an opening period of the two rotary valves is overlapped with a period during which the intake valve starts to open.
An intake device for an engine according to claim 3. 5. The control device according to claim 1, wherein the control means overlaps the open periods of the two rotary valves near the maximum lift position of the intake valve at the time of partial load. An intake device for an engine according to any one of the above. 6. A failure detecting means for detecting a failure of each rotary valve, wherein when a failure of one of the rotary valves is detected, an intake is performed by a non-failed rotary valve while the failed rotary valve is fixed at an open position. 6. The intake device for an engine according to claim 1, further comprising a fail-safe means for performing a quantity control.