JP3122204B2 - Engine intake control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake control device for controlling the amount of intake air supplied to an engine.

[0002]

2. Description of the Related Art Conventionally, in order to allow an engine to rotate at a constant speed when idling, for example, the opening of a throttle valve is feedback-controlled so that the engine speed (idling speed) is constant. It is known.

In controlling such idle speed, Japanese Patent Laid-Open Publication No. 55-57639 discloses that the actual idle speed is compared with a target speed by comparing the actual idle speed with the target speed. When the rotational speed is lower than the target rotational speed, the control gain of the feedback control is increased, and when the rotational speed is higher than the target rotational speed, the control gain is set to be small, so that the exhaust gas is reduced and the fuel efficiency is improved. Has been proposed.

[0004]

However, in the prior art described above, the actual engine speed is compared with the target engine speed, and the control gain is changed according to the magnitude of the target engine speed. When the rotation speed is higher than the target rotation speed, the control gain is the same regardless of the amount of intake air being supplied to obtain the actual engine rotation speed at that time. For this reason, even if the difference between the actual engine speed and the target engine speed is the same, if the intake air amount for obtaining the same engine speed is high, such as at high altitude, it is the same as at low altitude. The intake inertia is large compared to the case where the intake air amount for obtaining the engine rotation speed is small, so even if the intake air amount is reduced by lowering the opening of the throttle valve to converge to the target rotation speed, The decrease in the air amount is delayed, and the time required to decrease to the target number of revolutions increases. Conversely, when the difference between the actual engine speed and the target speed is small, the amount of intake air is small and the intake inertia is small. The rotation speed decreases to the target rotation speed in a short time.

A similar situation occurs when the actual engine speed is lower than the target speed. Even when the difference between the actual engine speed and the target speed is the same, the same occurs at low altitude. When the amount of intake air to obtain the engine speed is small, the intake inertia is smaller than when the intake air amount is large, such as at high altitudes. Even if is increased, the increase of the air amount is delayed due to the intake inertia, and the time required to increase to the target rotational speed becomes longer.

[0006] The present invention has been made in view of the above problems, its object is, to control the idle speed of the engine by the intake air amount of the idle during engine, the control speed at the time of the intake air amount changing By changing the speed, the convergence time of the idle speed to the target speed is shortened irrespective of the variation of the intake air amount, and the convergence is improved.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, the opening / closing speed of a throttle valve or the like for changing the intake air amount of the engine is changed according to the intake air amount of the engine.

More specifically, as shown in FIG. 1, the present invention relates to an intake air amount changing means 18 for opening and closing an intake passage 16 of the engine 1 to change an intake air amount, and an intake air amount for detecting an intake air amount of the engine 1. When the output of the intake amount detecting means 14 and the output of the intake amount detecting means 14 are received, the opening / closing speed of the intake amount changing means 18 is changed according to the intake amount.
As the closing speed of the intake air amount changing means 18 increases,
When increasing the air volume, change the intake volume as the intake volume increases
Control means 36 for controlling the opening speed of the means 18 to be slow , and the control means 36 changes the intake air amount.
As a result, the idle speed of the engine 1 is adjusted to the target speed.
Feedback control, and the control gain of the feedback control.
It is configured to change the in according to the amount of intake air
And said that you are.

According to the second aspect of the present invention, the intake passage 16 is a bypass passage that bypasses the throttle valve 15, and the intake air amount changing means 18 opens and closes the bypass passage to change the intake air amount during idling. It is characterized by having.

[0010]

With the above arrangement, according to the first aspect of the present invention, the intake air amount of the engine 1 is detected by the intake air amount detecting means 14,
The control means 36 receiving the output of the intake air amount detecting means 14 changes the opening / closing speed of the intake air amount changing means 18 according to the intake air amount, and the actual idle speed of the engine 1 is higher than the target speed. When the intake air amount is controlled to decrease, the closing speed of the intake air amount changing means 18 is controlled to increase as the intake air amount increases, while the actual idle speed is lower than the target engine speed. When the intake air amount is controlled to be low and the intake air amount is increased, the intake air amount changing means 1 increases as the intake air amount increases.
8 is controlled so as to decrease the opening speed. this thing
In, regardless of the magnitude of some clogging intake inertia of the intake air quantity can be the same convergence time to the end <br/> Jin idle speed target speed 1, improvement in convergence is achieved.

Further , the amount of intake air is directly detected, and the amount of intake air is detected.
The target number of idle rotations of the engine 1 according to the size
To change the control gain of the feedback control
Therefore, even if there are various variations in the engine 1 etc.,
Irrespective of the idle speed feedback control
Control accuracy can be improved.

According to the second aspect of the present invention, the intake air amount changing means 18
Is an idle speed control valve in a bypass passage that bypasses the throttle valve 15, so that the existing idle speed control valve can be effectively used to improve the convergence of the idle speed of the engine 1 .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. FIG. 6 shows an overall configuration of an embodiment of the present invention. Reference numeral 1 denotes a rotary engine mounted on a vehicle. The engine 1 has a rotor housing 2 having a trochoid surface on an inner periphery, and the rotor housing 2 is hermetically sealed from both sides. And a rotor 5 for partitioning the space into three working chambers 4, 4,... In a space surrounded by the two housings 2, 3.
Is housed. The rotor 5 is supported by the output shaft 6 so as to be capable of eccentric rotation. The eccentric rotation of the rotor 5 causes the respective working chambers 4 to perform suction, compression, and exhaust strokes in order, thereby driving the output shaft 6 to rotate. I am trying to do it.

The side housing 3 has an intake port 7 communicating with the working chamber 4 in the intake stroke, and the rotor housing 2 has an exhaust port 8 communicating with the working chamber 4 in the exhaust stroke. . The intake port 7 is connected to a downstream end of an intake passage 9 that supplies intake air (air) to the working chamber 4 in an intake stroke. The intake passage 9 is an independent intake passage 1 having a downstream end connected to the intake port 7.
0, and the upstream end of the independent intake passage 10 is connected to the surge tank 11. The surge tank 11 is connected to a downstream end of a collective intake passage 12, and an upstream end of the collective intake passage 12 is connected to an air cleaner 13. An air flow meter 14 as an intake air amount detecting means for detecting an intake air amount Qa (intake air amount) is disposed in the collective intake passage 12 immediately downstream of the air cleaner 13.
A throttle valve 15 interlocked with an accelerator pedal (not shown) is provided in the collective intake passage 12 on the downstream side of the fourth side.

One end of a bypass passage 16 is connected to the collective intake passage 12 immediately upstream of the throttle valve 15, and the other end of the bypass passage 16 passes through the rotor housing 2 of the engine 1 and is in the working chamber in the intake stroke. When the throttle valve 15 is fully closed when the engine 1 is idling, the air upstream of the throttle valve 15 is supplied directly to the working chamber 4 in the intake stroke of the engine 1 via the bypass passage 16. I have.

The bypass passage 16 has a throttle valve 1
The boost tank 17 for storing the intake air in order from the fifth side
And an ISC valve 18 (idle speed control valve) composed of a proportional control type electromagnetic valve, and controls the opening of the ISC valve 18 when the engine 1 is idling when the throttle valve 15 is fully closed. Thus, the amount of air directly supplied to the engine 1 bypassing the throttle valve 15 is adjusted, and the idle speed of the engine 1 is controlled. In this embodiment, the above ISC
The valve 18 constitutes an intake air amount changing unit that opens and closes the bypass passage 16 which is one of the intake air passages of the engine 1 to change the intake air amount.

In the independent intake passage 10, a primary injector 19 for fuel injection is provided in the vicinity of the intake port 7 of the engine 1, and a secondary injector 2 is provided upstream thereof.
0 is provided. 21 is the working chamber 4 in the compression stroke
The ignition plug ignites the intake air in the inside, and is connected to an igniter 23 via an ignition coil 22. Reference numeral 24 denotes an assist air passage having one end connected to the collective intake passage 12 immediately upstream of the throttle valve 15. The assist air passage 24 is branched into two in the middle, and one end thereof is connected to the primary injector 19. The other end is opened to a nearby independent intake passage 10 and the other end is opened to a working chamber 4 in an intake stroke through the rotor housing 2 of the engine 1. An oil passage 25 for supplying lubricating oil is connected to the other passage 24 via a valve 26, and a small amount of air is supplied from the upstream of the throttle valve 15 by utilizing a pressure difference of air by the assist air passage 24. Supply to the independent intake passage 10 near the primary injector 19,
The vaporization / atomization of the fuel from the injector 19 is promoted, and the lubricating oil from the oil passage 25 is sucked into the working chamber 4 in the intake stroke.

The collective intake passage 12 immediately upstream of the throttle valve 15 and the surge tank 11 are connected by another assist air passage 27 having an orifice 28.
When the engine 1 is idling, the assist air passage 27
Thus, a small amount of air is supplied to the independent intake passage 10 to create an air flow for carrying the fuel injected from the injectors 19 and 20.

The exhaust port 8 is connected to an upstream end of an exhaust passage 29 for exhausting the exhaust gas in the working chamber 4.

The above ISC valve 18 and each injector 1
9, 20, and the igniter 23 are the control unit 3
1 is controlled. The control unit 31 includes an output signal of the air flow meter 14, an output signal of a throttle sensor 32 for detecting an opening of the throttle valve 15, an output signal of a water temperature sensor 33 for detecting a temperature of cooling water of the engine 1, An output signal of a rotation speed sensor 34 for detecting an engine rotation speed N1 based on a rotation angle of an output shaft 6 of the engine 1 and an output signal of an atmospheric pressure sensor 35 for detecting an atmospheric pressure for high altitude correction are inputted. I have.

Here, in the control unit 31, the ISC valve 18 and the injectors 19, 2
A control procedure for controlling 0 will be described with reference to FIG. First, in the first step S1 after the start, it is determined from the output signal of the throttle sensor 32 whether or not the throttle opening (TVO) is fully closed, that is, whether or not the engine 1 is in an idle state. If this determination is NO, step S12
To store the feedback correction coefficient I in the memory,
In step S13, the correction coefficient I is output, and in step S14
After the ISC valve 18 is driven with the correction coefficient I, the process returns to step S1. The feedback correction coefficient I is a coefficient when the opening degree of the ISC valve 18 is feedback-controlled so that the engine speed N1 (idling speed) becomes the target speed N0 during idling.

If it is determined in step S1 that the throttle opening is fully closed (YES), the actual engine speed N is determined based on the output signal of the speed sensor 34 in step S2.
1. The engine water temperature and the like are detected based on the output signal of the water temperature sensor 33, and in step S3, the target rotational speed N0 of the engine 1 corresponding to the engine water temperature is read. The target engine speed N0 of the engine 1 corresponding to the engine water temperature is as shown in FIG. 3, and is basically set such that the lower the engine water temperature, the higher the target engine speed N0. Also,
The characteristics vary depending on ON / OFF of an in-vehicle air conditioner (not shown) driven by the engine 1. When the air conditioner is turned on, the target rotation speed N0 increases by a certain value as compared with the OFF state. It is supposed to.

After step S3, the process proceeds to step S4, where the actual engine speed N1 is compared with the target engine speed N0. If this determination is YES, that is, N1> N0, the intake air amount Qa is detected from the output signal of the air flow meter 14 in step S5, and a control gain α corresponding to the intake air amount Qa is set in the next step S6. This gain α is used when the engine speed N1 is higher than the target speed N0, and is set so as to increase proportionally with an increase in the intake air amount Qa as shown in FIG. I have. Further, in step S7, a new correction coefficient I is obtained by subtracting the control gain α from the previous feedback correction coefficient I, and then the process proceeds to steps S12 to S14.

On the other hand, if the determination in step S4 is N1 ≦ N0
If NO, it is determined in step S8 whether N1 <N0. When the determination is YES, the intake air amount Qa is detected based on the output signal of the air flow meter 14 in step S9, and the intake air amount Qa is detected in the next step S10.
Is set in accordance with the control gain β. The gain β is used when the engine speed N1 is lower than the target speed N0, and is set so as to decrease proportionally as the intake air amount Qa increases as shown in FIG. You. Thereafter, in step S11, the control gain β is added to the previous feedback correction coefficient I to obtain a new correction coefficient I, and then the process proceeds to steps S12 to S14.

In step S8, NO, that is, N1
= N0, if it is determined in step S12-
Proceed to S14.

In this embodiment, at steps S4 to S14 in the above algorithm, the output of the air flow meter 14 is received, and the opening / closing speed of the ISC valve 18 is changed according to the intake air amount Qa detected thereby, and the engine speed N1 Is higher than the target rotational speed N0 and the intake air amount Qa is reduced, the closing speed of the ISC valve 18 is increased as the intake air amount Qa increases, and conversely, the engine rotational speed N1 becomes larger than the target rotational speed N0. When increasing the intake air amount Qa at a low value, the larger the intake air amount Qa, the more the ISC valve 1
Control means 36 for controlling the opening speed of the shutter 8 to be slow is constituted.

Therefore, in the above embodiment, the ISC valve 18 is set so that the engine speed N1 (idling speed) becomes the target speed N0 when the engine 1 is idling.
Is feedback-controlled. At the same time, the intake air amount Qa at that time is detected by the air flow meter 14, and according to the detected intake air amount Qa, the IS
The opening / closing speed of the C valve 18 can also be changed.

That is, for example, the actual engine speed N
Since 1 is higher than the target rotation speed N0, the target rotation speed N0
When the intake air amount Qa is controlled to decrease in order to lower the engine speed N1, the closing speed of the ISC valve 18 is set to be high when the intake air amount Qa is large, and when the intake air amount Qa is small. The closing speed of the ISC valve 18 is reduced.

On the other hand, when the actual engine speed N1 is lower than the target engine speed N0 and the control is performed in the direction of increasing the intake air amount Qa to increase the engine speed N1 toward the target engine speed N1. The closing speed of the ISC valve 18 decreases as the intake air amount Qa increases, and the closing speed of the ISC valve 18 increases when the air amount Qa decreases. Therefore, for example, even if the intake air amount Qa changes due to a change in the atmospheric pressure or the like and the inertia of the air changes accordingly, the convergence time of the engine speed N1 to the target speed N0 can be made the same. It is possible to improve convergence of the engine speed N1 to the target speed N0 while preventing hunting due to excessive rise or fall of the engine speed N1.

Particularly, in this embodiment, the throttle valve 15
The downstream end of the bypass passage 16 for bypassing the engine 1
Is connected to the working chamber 4 in the intake stroke, and the bypass air is directly supplied to the engine 1. Therefore, compared with the case where the upstream and downstream intake passages of the throttle valve 15 are connected by the bypass passage, the downstream side of the bypass passage 16 is connected. Low volume, I
By adjusting the opening of the SC valve 18, the intake air amount Qa changes quickly, so that feedback control of the engine speed N1 to the target speed N0 can be performed with good responsiveness, and the above effect can be obtained effectively.

Although the above embodiment is directed to a rotary engine, the present invention can be applied to a reciprocating engine.

In the above-described embodiment, the bypass passage 16 and the ISC valve 18 are provided for controlling the idle speed. However, the bypass passage 16 and the ISC valve 18 are not provided. The present invention is also applicable to a system in which the opening is directly adjusted to control the idle speed .

[0033]

As described above, according to the first aspect of the present invention, the intake air amount changing means for opening and closing the intake passage of the engine to change the amount of intake air is provided. The opening / closing speed of the intake air amount changing means is changed according to the amount, and when the intake air amount is reduced, the larger the intake air amount, the more the intake air
While increasing the closing speed of the volume changing means,
Opening speed of the intake air amount changing means as the intake air amount increases
Because the degree is made slower , the convergence time of the engine idle speed to the target speed can be the same regardless of the amount of intake air, that is, the magnitude of the intake inertia. , The convergence to the target time can be improved. Also, depending on the amount of intake air, the engine idle
Control speed feedback control to the target speed
The engine, etc.
The feedback control of idle speed
Control accuracy can be improved.

According to the second aspect of the present invention, the intake amount changing means is an idle speed control valve in a bypass passage that bypasses the throttle valve. The convergence of the rotation speed can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of the present invention.

FIG. 2 is a flowchart illustrating an algorithm of idle speed control performed by a control unit according to the embodiment of the present invention.

FIG. 3 is a characteristic diagram showing a characteristic of correcting a target value of an idle speed by an engine water temperature.

FIG. 4 is a characteristic diagram for setting a control gain according to an intake air amount when an engine speed is higher than a target speed.

FIG. 5 is a characteristic diagram for setting a control gain according to an intake air amount when an engine speed is lower than a target speed.

FIG. 6 is an explanatory diagram showing a configuration of an example of the present invention.

[Explanation of symbols]

 Reference Signs List 1 engine 14 air flow meter (intake amount detection means) 15 throttle valve 16 bypass passage 18 ISC valve (intake amount change means) 31 control unit 34 speed sensor 36 control means N1 engine speed N0 target speed

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-189649 (JP, A) JP-A-59-215934 (JP, A) JP-A-55-57639 (JP, A) 192846 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F02D 41/16 F02D 41/04 315

Claims (2)

(57) [Claims] 1. An intake air amount changing means for opening and closing an intake passage of an engine to change an intake air amount, an intake air amount detecting means for detecting an intake air amount of the engine, When the opening / closing speed of the intake air amount changing means is increased, the intake air amount is decreased.
The more the intake air volume, the faster the closing speed of the intake air volume changing means
On the other hand, when increasing the intake air amount,
Control means for controlling the opening speed of the intake air amount changing means to be slower . The control means changes the intake air amount to change the intake air amount.
Feedback control of the idle speed to the target speed
The control gain of the feedback control is determined by the magnitude of the intake air amount.
An intake control device for an engine, characterized in that the intake control device is configured to change in accordance with the engine speed. 2. The intake control device for an engine according to claim 1, wherein the intake passage is a bypass passage that bypasses a throttle valve, and the intake air amount changing means opens and closes the bypass passage to reduce the intake air amount at idle. An intake control device for an engine, which is a variable idle speed control valve.