JPH0932614A - Engine speed controller for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of malfunction such as rough idle by stabilizing a combustion condition for a period leading from just after starting to a steady condition. SOLUTION: An electronic control unit(ECU) 41 executes the open loop control of the solenoid 11a of an idle speed control valve (ISCV) 11 as intake air quantity adjusting means until a cooling water temperature reaches a predetermined degree after an engine 1 is started. After the cooling water temperature is reached the predetermined temperature, the ECU 41 continues the open loop control for delay time, and executes normal feedback control after lapse of the delay time. The delay time is set more longer the more the intake temperature is lower. Therefore, the delay time, that is, convergent time until the opening of the ISCV 11 reaches a target opening is lengthened in case that the temperature of the combustion chamber 1a of the engine 1 is yet lower although the cooling water temperature has reached the predetermined temperature. Therefore, at a point of time when the temperature of the combustion chamber 1a of the engine 1 is sufficiently raised, the real opening of the ISCV 11 is lowered to the target opening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotational speed control device for an internal combustion engine, and more particularly to a rotational speed control for an internal combustion engine in which intake air amount adjusting means such as an idle speed control valve is provided in the middle of an intake passage. It relates to the device.

[0002]

2. Description of the Related Art Generally, as an engine idling speed control device, for example, in the middle of a bypass passage provided to bypass a throttle valve separately from the intake passage,
It is known that an idle speed control valve (ISCV) is provided. In this technique, the intake air amount of the internal combustion engine is controlled and the idle speed is controlled by adjusting the opening degree of the ISCV.

By the way, in such an idle speed control device, it is necessary to warm up the engine when the engine is started, because the engine friction is large. Therefore, for a predetermined time after the start, so-called first idle up, in which the control rotation speed is increased for the warm-up, is performed by the open loop control. Then, when the temperature of the cooling water for the engine reaches or exceeds the predetermined temperature, the ISCV is feedback controlled so that the engine speed becomes the target speed thereafter.

However, in reality, the cooling water temperature does not always give the corresponding data in the combustion chamber of the engine. For example, immediately after the cooling water temperature reaches a predetermined temperature,
In the case where the warm-up is completed and the control is shifted to the feedback control, the idle speeds for engine friction do not match, and there is a possibility that rough idle occurs.

As a technique for solving such a problem, for example, a technique disclosed in Japanese Patent Laid-Open No. 59-173534 is known. In this technology, when the cooling water temperature reaches or exceeds a predetermined temperature, only a predetermined time (delay time)
The idle up state is maintained. Then, thereafter, the engine speed is controlled so as to be gradually reduced toward the target speed. The delay time is set based on the cooling water temperature at the time of starting. That is, the lower the cooling water temperature at the time of starting, the longer the delay time is set.

[0006]

As described above, in the above prior art, the delay time is set only by the cooling water temperature at the time of starting. That is, the time from the start to the completion of the idle-up was dependent on the cooling water temperature at the start. By the way, for example, when the engine is restarted in a cold region after traveling is stopped, the cooling water temperature is relatively high although the outside air temperature (intake air temperature) is relatively low.

However, in the above-mentioned conventional technique, since the temperature of the cooling water at the time of restart is relatively high, the warm-up is completed in a relatively short time after restart. For this reason, even if the temperature in the cylinder head port or the combustion chamber is not sufficiently high, the control may shift to the feedback control, and the engine speed may decrease.
As a result, the combustion state may be deteriorated and rough idle may occur.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to stabilize a combustion state in a rotation speed control device of an internal combustion engine from immediately after starting to a steady state. Another object of the present invention is to provide a rotation speed control device for an internal combustion engine, which can prevent occurrence of problems such as rough idle.

[0009]

In order to achieve the above object, in the present invention, as shown in FIG.
Actuator M3 provided in the middle of the intake passage M2
The intake air amount adjusting means M4 that is driven to open and close by the operation state, the operating state detecting means M5 that detects the operating state of the internal combustion engine M1 including the cooling water temperature, and the operating state detecting means M5 at least during idling of the internal combustion engine M1. Based on the detection result, the target opening degree calculating means M6 for calculating the target opening degree of the intake air amount adjusting means M4, and the target calculated by the target opening degree calculating means M6 at least during idling of the internal combustion engine M1. Feedback control means M7 for feedback controlling the actuator M3 based on the opening degree, and at least the internal combustion engine M1
From the start of the engine until the cooling water temperature detected by the operating state detecting means M5 reaches a predetermined temperature, the intake air amount adjusting means M4 for warming up the internal combustion engine M1.
Is held at a predetermined opening larger than the target opening and a first idle up control means M8 for performing open loop control of the actuator M3. After the combustion room temperature detecting means M11 for detecting a value corresponding to the temperature in the combustion chamber of the engine M1 and the cooling water temperature detected by the operating state detecting means M5 reach a predetermined temperature, the intake air amount adjusting means M4 is opened. The convergence time until the degree changes to the target opening,
The gist is to provide a convergence time setting means M10 for setting the temperature to be longer as the temperature detected by the combustion room temperature detection means M9 is lower.

Further, in the invention described in claim 2, in the invention described in claim 1, the convergence time setting means M10 is provided.
After the cooling water temperature detected by the operating state detecting means M5 reaches a predetermined temperature, the opening degree of the intake air amount adjusting means M4 is set to a predetermined opening degree larger than the target opening degree for a predetermined delay time. To hold the actuator M
3 includes an idle up continuation control means for performing open loop control of No. 3, and a delay time setting means for setting the delay time so that the lower the temperature detected by the combustion room temperature detection means M9, the longer the delay time setting means. There is.

Further, in the invention described in claim 3, in the invention described in claim 1 or 2, in the convergence time setting means M10, the cooling water temperature detected by the operation state detecting means M5 reaches a predetermined temperature. After that, the transitional feedback control means for gradually approaching the opening degree of the intake air amount adjusting means M4 to the target opening degree by the feedback control constant, and the feedback control constant are detected by the combustion room temperature detecting means M9. The gist of the invention is to include feedback control constant setting means for setting the temperature to be smaller as the temperature is lower.

In addition, in the invention described in claim 4, in the invention described in any one of claims 1 to 3, the convergence time setting means M10 is the cooling water temperature detected by the operation state detecting means M5. Initial opening setting means for setting the opening of the intake air amount adjusting means M4 to be larger than at least the target opening by a predetermined initial opening when a predetermined temperature is reached; and the operating state detecting means. After the cooling water temperature detected by the temperature reaches a predetermined temperature, the opening degree of the intake air amount adjusting means M4 is gradually increased from the state of being raised by the initial opening degree to the target opening degree by the feedback control constant. And a feedback control means at the time of transition, and an initial opening adjustment means for increasing the set initial opening as the temperature detected by the combustion room temperature detecting means M9 becomes lower. Has as its gist that Dale.

(Operation) According to the configuration of the invention described in claim 1, as shown in FIG. 1, the intake air amount adjusting means M4 provided in the middle of the intake passage M2 of the internal combustion engine M1 is opened and closed. As a result, the amount of intake air supplied to the internal combustion engine M1 can be adjusted, and thus the rotational speed of the internal combustion engine M1 can be adjusted.

The operating state detecting means M5 detects the operating state of the internal combustion engine M1 including the cooling water temperature. Then, at least during idling of the internal combustion engine M1, the target opening degree of the intake air amount adjusting means M4 is calculated by the target opening degree calculating means M6 based on the detection result of the operating state detecting means M5. Further, at least when the internal combustion engine M1 is idling, based on the target opening calculated by the target opening calculating means M6, the feedback control means M7 is provided.
Thus, the actuator M3 is feedback-controlled. By this feedback control, the intake air amount during idling can be adjusted appropriately.

Further, the actuator M3 is open-loop controlled by the fast idle up control means M8 at least from the start of the internal combustion engine M1 until the cooling water temperature detected by the operating state detection means M5 reaches a predetermined temperature. The opening of the intake air amount adjusting means M4 is maintained at a predetermined opening larger than the target opening. As a result, the rotation speed of the internal combustion engine M1 is increased, and the internal combustion engine M1 is warmed up.

In the present invention, the combustion room temperature detecting means M9
Thus, a value corresponding to the temperature inside the combustion chamber of the internal combustion engine M1 is detected. Then, after the cooling water temperature reaches a predetermined temperature, the convergence time until the opening degree of the intake air amount adjusting means M4 shifts to the target opening degree is detected by the combustion room temperature detecting means M9 by the convergence time setting means M10. The lower the temperature, the longer it is set. Therefore, even if the cooling water temperature reaches the predetermined temperature, if the temperature of the combustion chamber of the internal combustion engine M1 is still low, the opening degree of the intake air amount adjusting means M4 shifts to the target opening degree. It takes a long time to converge. Therefore, when the temperature of the combustion chamber of the internal combustion engine M1 rises sufficiently, feedback control by the feedback control means M7 becomes possible in a state where the opening of the intake air amount adjusting means M4 converges near the target opening, and combustion is performed. The deterioration of the condition can be avoided.

According to the invention described in claim 2, in addition to the operation of the invention described in claim 1, the convergence time setting means M10 includes an idle-up continuation control means and a delay time setting means. Is included. Then, after the cooling water temperature detected by the operating state detection means M5 reaches the predetermined temperature by the idle-up continuation control means, the actuator M3 is open-loop controlled for a predetermined delay time to open the intake air amount adjustment means M4. Is maintained at a predetermined opening degree that is larger than the target opening degree. Here, the delay time is
The delay time setting means sets the temperature to be longer as the temperature detected by the combustion room temperature detection means M9 is lower.

Therefore, even when the temperature of the cooling water reaches the predetermined temperature, if the temperature of the combustion chamber of the internal combustion engine M1 is still low, the convergence time (delay time) becomes long, and the above-mentioned operation is performed. Will be played.

Further, according to the third aspect of the present invention,
In addition to the operation of the invention described in claim 1 or 2, the convergence time setting means M10 includes a transition feedback control means and a feedback control constant setting means.
Then, after the detected cooling water temperature reaches the predetermined temperature, the transition feedback control means gradually brings the opening degree of the intake air amount adjusting means M4 closer to the target opening degree by the feedback control constant. This feedback control constant is set by the feedback control constant setting means so that it becomes smaller as the temperature detected by the combustion room temperature detecting means M9 becomes lower.

Therefore, even when the temperature of the cooling water reaches the predetermined temperature, if the temperature of the combustion chamber of the internal combustion engine M1 is still low, the rate of approaching the target opening with respect to time becomes small. . Therefore, as a result, the convergence time until the opening degree of the intake air amount adjusting means M4 shifts to the target opening degree becomes long, and the above-mentioned operation is achieved. Further, in particular, in the present invention, since the opening degree is reduced at a speed according to the operating state at that time, the opening degree of the intake air amount adjusting means M4 does not become too large for the operating state at that time.

In addition, according to the invention described in claim 4,
In addition to the action of the invention according to any one of claims 1 to 3,
The convergence time setting unit M10 includes an initial opening setting unit, a transition feedback control unit, and an initial opening adjustment unit. Then, when the detected cooling water temperature reaches a predetermined temperature, the opening degree of the intake air amount adjusting means M4 becomes larger than the target opening degree by a predetermined initial opening degree by the initial opening degree setting means. To be done. Further, after the cooling water temperature reaches the predetermined temperature, the transition feedback control means gradually increases the opening degree of the intake air amount adjusting means M4 from the state of being raised by the initial opening degree by the feedback control constant. It gets closer to the opening. At this time, the initial opening adjusting means makes the set initial opening larger as the temperature detected by the combustion room temperature detecting means M9 is lower.

Therefore, even when the temperature of the cooling water reaches the predetermined temperature, if the temperature of the combustion chamber of the internal combustion engine M1 is still low, the feedback control constant is increased from the state in which the initial opening is raised. However, the target opening is gradually approached. Therefore, as a result, the convergence time until the opening degree of the intake air amount adjusting means M4 shifts to the target opening degree becomes long, and the above-mentioned operation is achieved.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment in which the engine speed control device for an internal combustion engine according to the present invention is embodied in a gasoline engine will be described in detail below with reference to FIGS.

FIG. 2 is a schematic configuration diagram showing an engine speed control device mounted on a vehicle in this embodiment. As shown in the figure, an engine 1 as an internal combustion engine takes in outside air from an air cleaner 3 through an intake passage 2. Further, the engine 1 takes in the fuel injected from the injector 4 provided for each cylinder in the vicinity of the intake port 2a at the same time as taking in the outside air. Then, a mixture of the taken-in fuel and the outside air is introduced into the combustion chamber 1a through the intake valve 5 provided for each cylinder, and exploded and burned in the combustion chamber 1a to obtain a driving force. Further, the exhaust gas after the explosion and combustion is led out of the combustion chamber 1a via the exhaust valve 6 to the exhaust passage 7 where the exhaust manifold for each cylinder is gathered, and is discharged to the outside.

In the middle of the intake passage 2, there is provided a throttle valve 8 which opens and closes in conjunction with the operation of an accelerator pedal (not shown). And this throttle valve 8
Is opened and closed, the amount of air taken into the intake passage 2 is adjusted. On the downstream side of the throttle valve 8,
A surge tank 9 for smoothing the pulsation of the intake air is provided.

A bypass intake passage 10 is provided in the middle of the intake passage 2 as a bypass passage that bypasses the throttle valve 8, that is, connects the upstream side and the downstream side of the throttle valve 8. . In the middle of the bypass intake passage 10, a linear solenoid type idle engine for adjusting the flow rate of air flowing through the passage 10 is provided.
A speed control valve (ISCV) 11 is provided. The ISCV 11 basically has a solenoid 11a constituting an actuator when the throttle valve 8 is closed and the engine 1 is in an idle state.
Is duty controlled. The duty ratio is controlled to open and close (drive) the ISCV 11 as appropriate. By this opening and closing, the air flow rate (intake air amount) of the bypass intake passage 10 is adjusted. The adjustment of the intake air amount controls the engine speed NE during idling. In the present embodiment, this ISCV1
1 constitutes an intake air amount adjusting means.

An intake air temperature sensor 21 for detecting the intake air temperature THA is provided near the air cleaner 3 in the intake passage 2. This intake air temperature THA can correspond to the temperature in the combustion chamber 1a. In the vicinity of the throttle valve 8, a throttle sensor 22 for detecting the opening (throttle opening) θ is provided, and when the throttle valve 8 is fully closed, it is turned on to detect an idle state. An idle switch 23 is provided. Further, the surge tank 9 is provided with an intake pressure sensor 24 that communicates with the tank 9 and detects an intake air pressure (intake pressure) PiM.

On the other hand, an oxygen sensor 25 for detecting the oxygen concentration OX in the exhaust gas is provided in the exhaust passage 7. Further, the engine 1 is provided with a water temperature sensor 26 for detecting the temperature (cooling water temperature) THW of the cooling water.

An ignition signal distributed by a distributor 13 is applied to an ignition plug 12 provided for each cylinder of the engine 1. The distributor 13 distributes the high voltage output from the igniter 14 to each of the ignition plugs 12 in synchronization with the crank angle of the engine 1. The ignition timing of each of the ignition plugs 12 is the high voltage output timing from the igniter 14. Is determined by

The distributor 13 is provided with a rotation speed sensor 27 for detecting the rotation speed (engine speed) NE of the engine 1 from the rotation of a rotor (not shown) built in the distributor 13. The distributor 13 is also provided with a crank angle sensor 28 for detecting a change in the crank angle of the engine 1 at a predetermined rate according to the rotation of the rotor.

In addition, the automatic transmission 15 drivingly connected to the engine 1 is provided with a vehicle speed sensor 29. The vehicle speed sensor 29 is capable of detecting the vehicle speed (vehicle speed) SPD at that time and outputting a signal indicating the value.

In addition, inside the automatic transmission 15,
A neutral start switch 30 is provided.
The neutral start switch 30 detects that the current shift position ShP is in a neutral range [N range (including P range)]. That is, it is possible to detect whether the current shift position ShP is in the N range or the drive range (D range).

Then, each of the sensors 21, 22, 24 ...
The operating state and the like of the engine 1 are appropriately detected by the engine 29, the idle switch 23, the neutral start switch 30, and the like, and these constitute an operating state detecting means. Further, for example, by the intake air temperature sensor 21,
Combustion room temperature detection means is configured.

Further, each injector 4, the solenoid 11a for the ISCV 11 and the igniter 14 are electrically connected to an electronic control unit (hereinafter, simply referred to as "ECU") 41, and their drive timing is controlled by the operation of the ECU 41. It The ECU 41 constitutes a target opening calculation means, a feedback control means, a fast idle up control means, and a convergence time setting means (including an idle up continuation control means and a delay time setting means).

The ECU 41 includes an intake air temperature sensor 21, a throttle sensor 22 and an idle switch 2 as described above.
3, intake pressure sensor 24, oxygen sensor 25, water temperature sensor 2
6, a rotation speed sensor 27, a crank angle sensor 28, a vehicle speed sensor 29, and a neutral start switch 30 are connected to each other. Therefore, the ECU 41 controls the sensors 21, 22, 24 to 29 and the idle switch 2
3 and the output signal from the neutral start switch 30, etc., the injector 4 and the solenoid 11a.
(ISCV11), the igniter 14, etc. are controlled suitably.

Next, the structure of the ECU 41 will be described with reference to the block diagram of FIG. The ECU 41 includes a central processing unit (CPU) 42, a read-only memory (ROM) 43 in which a predetermined control program, a map, and the like are stored in advance, a CPU 42
A random access memory (RAM) 44 for temporarily storing the calculation results of the above, a backup RAM 45 for storing previously stored data, and the like. The ECU 41
Are the external input circuit 46 and the external output circuit 47
And the like are connected by a bus 48 to constitute a logical operation circuit.

The external input circuit 46 includes the intake air temperature sensor 21, the throttle sensor 22, and the idle switch 2 described above.
3, intake pressure sensor 24, oxygen sensor 25, water temperature sensor 2
6, a rotation speed sensor 27, a crank angle sensor 28, a vehicle speed sensor 29, a neutral start switch 30, and the like are connected to each other. Then, the CPU 42 reads output signals from the sensors 21, 22, 24 to 29, the idle switch 23 and the neutral start switch 30 via the external input circuit 46 as input values. Then, the CPU 42 suitably controls the injector 4, the solenoid 11a, the igniter 14, and the like connected to the external output circuit 47 based on these input values. The learning values and flags in this embodiment are stored in the backup RAM 45 described above.

Next, of the various processes executed by the ECU 41, the opening control of the ISCV 11 will be described.
As described above, in the ISCV 11, the solenoid 11a is basically duty-controlled when the throttle valve 8 is closed and the engine 1 is in the idling state. Here, when the engine is not started, the above-mentioned sensors etc. 2
Based on the detection signals from 1 to 30, the operating state of the engine 1 is determined, and the learning value is appropriately updated based on the determination result. Then, the learned value is set as the target opening, and the solenoid 11a of the ISCV 11 is set so that the actual opening of the ISCV 11, that is, the actual engine speed NE becomes the opening (rotation speed) corresponding to the target opening. It is feedback controlled. On the other hand, when the engine 1 is not idling, the IS is basically
The opening degree of the CV 11 is open-loop controlled so as to reach the latest target opening degree.

Now, when the engine 1 is in the idling state, the control of the ISCV 11 as described below is executed. Hereinafter, a process for performing the control will be described with reference to a flowchart of FIG.

FIG. 4 shows the "ISC" executed by the ECU 41 when the engine 1 is operating, particularly when idling.
5 is a flowchart showing a "V control routine", which is executed by a regular interrupt every predetermined time.

When the processing shifts to this routine, first, at step 101, the ECU 41 causes the sensors 21
Detection signals (for example, intake air temperature THA, throttle opening θ, intake air pressure PiM, oxygen concentration OX, cooling water temperature T)
HW, engine speed NE, vehicle speed SPD, shift position S
hP, an air conditioner operation signal, etc.), a flag (for example, a start control flag XST described later), and the like are read.

Next, at step 102, the ECU 4
1 determines whether or not the start-time control flag XST read in step 101 is "1". Here, the start time control flag XST is set to "1" when the open loop control at the time of idling is executed,
If not, it is set to "0". When the start control flag XST is "1", it is determined that the open loop control is being performed, and the process jumps to step 106. Also, control flag X at start
If ST is “0”, the process proceeds to step 103.

In step 103, the ECU 41
Based on a signal from a starter (not shown) or the like, it is determined whether or not the current time is immediately after starting. Then, when it is determined that the present time is immediately after the start, the process proceeds to step 104 to execute the open loop control thereafter.

Then, at step 104, the delay time KDLY is based on the intake air temperature THA read this time.
(Corresponding to the count value) is set. Here, when calculating the delay time KDLY, a map as shown in FIG. 5 is referred to. That is, when intake air temperature THA is high (combustion room temperature is high), delay time KDLY is set to a small value, and when intake air temperature THA is low (combustion room temperature is low), delay time KDLY is set to a large value. . Also,
In the following step 105, the ECU 41 sets the start control flag XST to "1".

In step 106 after the step 105 or 102, the count value CDIFB of the counter is incremented by "1".
Further, in step 107, the cooling water temperature THW read this time is set to a predetermined temperature T1 (eg 80
℃) or above. Then, if the cooling water temperature THW has not reached the predetermined temperature T1 or higher, the process proceeds to step 108.

In step 108, the open opening DOP is calculated based on the various operating states read this time. However, the open degree DOP is set to a relatively large value in order to warm up the engine 1. Further, in the following step 109, the opening degree of the solenoid 11a, that is, the ISCV 11 is open-loop controlled based on the calculated open opening degree DOP. As a result, the intake air amount becomes relatively large, the engine speed NE increases, and the engine 1 can be warmed up. Then, the ECU 41 once ends the subsequent processing.

On the other hand, in step 107, when the cooling water temperature THW is equal to or higher than the predetermined temperature T1,
Move to step 110. In step 110, it is determined whether or not the current count value CDIFB of the counter is equal to or longer than the delay time KDLY set in step 104. Then, the count value CDIFB
If is not longer than the delay time KDLY, it is determined that the open loop control needs to be continued for a while, and the process proceeds to step 108. Step 108
In the same manner as above, the open opening DOP is calculated, and in the subsequent step 109, the solenoid 11a, that is, the solenoid 11a, is calculated based on the calculated open opening DOP.
Open loop control of the opening of ISCV11. Then, the subsequent processing is temporarily terminated.

When the count value CDIFB is equal to or longer than the delay time KDLY in step 110, the temperature in the combustion chamber 1a is sufficiently high, and the combustion state is hindered even if the open loop control is completed. It is determined that the above does not occur, and the process proceeds to step 111. In step 111, the start-time control flag X is set to prevent the open loop control from being executed thereafter.
Set ST to "0". Further, in the following step 112, the count value CDIFB of the counter is cleared to "0".

Further, in step 113, the target opening for feedback control of the ISCV 11 is calculated based on the operating state at that time. And step 11
In 4, the opening degree of the solenoid 11a, that is, the ISCV 11 is feedback-controlled based on the calculated target opening degree.

When it is determined in step 103 that the current time is not immediately after the start, it is determined that the open loop control has already been completed and the normal fordback control may be executed. Step 11
Jump to 1. Then, the above-mentioned step 111
~ The processing of step 114 is executed, and the subsequent processing is once ended.

As described above, according to the "ISCV control routine" of the present embodiment, basically, after the start, until the cooling water temperature THW reaches the predetermined temperature T1, the open opening degree D
Open loop control is executed based on OP. Then, the open loop control is continued for a predetermined time (delay time KDLY) after the cooling water temperature THW reaches the predetermined temperature T1. Then, after the delay time KDLY has elapsed, normal feedback control is executed.

Now, in the present embodiment, the intake air temperature sensor 2
1 detects a value (intake air temperature THA) corresponding to the temperature in the combustion chamber 1a of the engine 1. Then, the delay time KDLY, that is, the time until the control content of the opening degree of the ISCV 11 shifts to the feedback control after the cooling water temperature THW reaches a predetermined temperature is variable according to the intake air temperature THA. More specifically, the delay time KDLY
Is set to be longer as the intake air temperature THA is lower.

Therefore, the cooling water temperature THW is equal to the predetermined temperature T1.
If the temperature of the combustion chamber 1a of the engine 1 is still low, the delay time KDLY, and thus the actual opening of the ISCV 11 after shifting to the feedback control, becomes the target opening. It takes a long time to converge. Therefore, when the temperature of the combustion chamber 1a of the engine 1 is sufficiently increased, the actual opening degree of the ISCV 11 is reduced to the target opening degree. As a result, the deterioration of the combustion state can be avoided, the combustion state can be stabilized immediately after the start of the engine 1 to the steady state, and the occurrence of problems such as rough idle can be prevented. be able to.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. However, since the configuration and the like of this embodiment are the same as those of the above-described first embodiment, the same members and the like are denoted by the same reference numerals and description thereof is omitted. The following description focuses on the differences from the first embodiment. In the present embodiment, E
The CU 41 constitutes a target opening calculation means, a feedback control means, a fast idle up control means, and a convergence time setting means (transition feedback control means and feedback control constant setting means).

As in the first embodiment, FIG. 6 shows the ECU 41 when the engine 1 is operating, particularly when it is idling.
It is a flow chart which shows the "ISCV control routine" performed by.

When the processing shifts to this routine, first, at step 201, the ECU 41 causes the sensors 21
The detection signals from 30 are read. Next, step 2
In 02, the ECU 41 determines that the cooling water temperature THW read in step 201 is a predetermined temperature T1.
It is determined whether (for example, 80 ° C.) or higher. Then, if the cooling water temperature THW has not reached the predetermined temperature T1 or higher, the process proceeds to step 203.

In step 203, the open opening DOP is calculated based on the various operating states read this time. However, the open degree DOP is set to a relatively large value in order to warm up the engine 1. Further, in the following step 204, the opening degree of the solenoid 11a, that is, the ISCV 11 is open-loop controlled based on the calculated opening degree DOP. Then, the subsequent processing is temporarily terminated.

On the other hand, when the cooling water temperature THW is equal to or higher than the predetermined temperature T1 in step 202,
Move to step 205. In step 205, it is determined whether or not the cooling water temperature THW read this time is equal to or greater than a value (for example, 90 ° C.) obtained by adding a predetermined value α (for example, “10 ° C.”) to a predetermined temperature T1 that is set in advance. If the cooling water temperature THW is not equal to or higher than the value obtained by adding the predetermined value α to the predetermined temperature T1, the actual ISC is set.
In order to delay the opening of V11 from reaching the target opening, the routine proceeds to step 206.

In step 206, an integration constant KDITHA as a feedback control constant is set based on the intake air temperature THA read this time. Here, when calculating the integration constant KDITHA, a map as shown in FIG. 7 is referred to. That is, when the intake air temperature THA is high (the combustion room temperature is high), the integration constant KDITHA
Is large and the intake air temperature THA is low (combustion room temperature is low), the integration constant KDITHA is set to a small value.

Then, in the following step 207,
Integral constant K set this time to the previous basic target opening DI
A value obtained by subtracting (or possibly adding) DITHA is set as a new basic target opening DI.

Further, in step 208, the solenoid 11 is opened based on the basic target opening degree DI set this time.
a, that is, the opening degree of the ISCV 11 is feedback-controlled. Then, the subsequent processing is temporarily terminated.

On the other hand, in step 205, when the cooling water temperature THW is still equal to or more than the value obtained by adding the predetermined value α to the predetermined temperature T1, the temperature in the combustion chamber 1a has risen sufficiently and the opening degree of the ISCV 11 is increased. Even if the normal feedback control is performed so that the value becomes the target opening degree, it is determined that the combustion state will not be hindered, and the process proceeds to step 209. In step 209, the previous basic target opening D
A new basic target opening degree DI is obtained by adding or subtracting a predetermined constant value tDITHA (the constant value tDITHA may be variable depending on the deviation between the actual opening and the target opening) to I. Set as. Step 2
In step 08, the solenoid 11a, that is, the opening of the ISCV 11 is feedback-controlled based on the basic target opening DI set this time. Then, the subsequent processing is temporarily terminated.

As described above, according to the "ISCV control routine" of the present embodiment, basically, after the start, until the cooling water temperature THW reaches the predetermined temperature T1, the open opening degree D
Open loop control is executed based on OP. Then, until the cooling water temperature THW reaches a value obtained by adding the predetermined value α to the predetermined temperature T1, special feedback control based on the integration constant KDITHA is executed. After that, after the cooling water temperature THW reaches the value obtained by adding the predetermined value α to the predetermined temperature T1, normal feedback control is executed.

Now, in the present embodiment, the intake air temperature sensor 2
1 detects a value (intake air temperature THA) corresponding to the temperature in the combustion chamber 1a of the engine 1. The integration constant KDITHA is made variable according to the intake air temperature THA. More specifically, the integration constant KDITHA is set to be smaller as the intake air temperature THA is lower.

Therefore, the cooling water temperature THW is equal to the predetermined temperature T1.
If the temperature of the combustion chamber 1a of the engine 1 is still low, the integration constant KDITHA becomes small as shown by the broken line in FIG. Transition to ISCV11
The convergence time for the actual opening to reach the target opening is long. Therefore, when the temperature of the combustion chamber 1a of the engine 1 is sufficiently increased, the actual opening degree of the ISCV 11 is reduced to the target opening degree. As a result, similarly to the first embodiment, deterioration of the combustion state can be avoided, the combustion state can be stabilized immediately after the start of the engine 1 to the steady state, and the rough state can be achieved. It is possible to prevent the occurrence of problems such as idle.

In particular, in the present embodiment, the opening degree is reduced by the integral constant KDITHA corresponding to the operating state at that time. Therefore, the opening degree of the ISCV 11 does not become too large for the driving state at that time, and as a result, the fuel consumption can be improved.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. However, since the configuration and the like of the present embodiment are also the same as those of the above-described first embodiment, the same members and the like are designated by the same reference numerals and the description thereof will be omitted. Then, in the following, differences from the first and second embodiments will be mainly described. It should be noted that in the present embodiment, the ECU 41 controls the target opening degree calculation means, the feedback control means, the fast idle up control means, and the convergence time setting means (the initial opening degree setting means, the transition feedback control means, and the initial opening degree adjusting means). Is included).

As in the first and second embodiments, FIG. 9 shows the EC when the engine 1 is operating, particularly when idling.
It is a flow chart which shows an "ISCV control routine" performed by U41, and is performed by a regular interruption every predetermined time.

When the processing shifts to this routine, first, at step 301, the ECU 41 causes the sensors 21
The detection signals from 30 are read. Next, step 3
In 02, the ECU 41 determines that the cooling water temperature THW read in step 301 is a predetermined temperature T1.
It is determined whether (for example, 80 ° C.) or higher. Then, if the cooling water temperature THW has not reached the predetermined temperature T1 or higher, the process proceeds to step 303.

In step 303, the open opening DOP is calculated based on the various operating states read this time. Further, in the subsequent step 304, the opening degree of the solenoid 11a, that is, the ISCV 11 is open-loop controlled based on the calculated open opening degree DOP. Then, the subsequent processing is temporarily terminated. On the other hand, in step 302, when the cooling water temperature THW is equal to or higher than the predetermined temperature T1, the process proceeds to step 305. In step 305, the cooling water temperature TH read last time is read.
It is determined whether W has a value smaller than the predetermined temperature T1. The previous cooling water temperature THW is equal to the predetermined temperature T
If it is smaller than 1, the cooling water temperature T
Judging that the HW has reached the predetermined temperature T1, step 3
Move to 06.

In step 306, the initial opening KDITHAI for feedback control is calculated based on the intake air temperature THA read this time. Here, when calculating the initial opening degree KDITHAI, a map as shown in FIG. 10 is referred to. That is, the intake air temperature THA
Is high (combustion room temperature is high), the initial opening KDIT
When the intake air temperature THA is low (the combustion room temperature is low) when the HAI is small, the initial opening KDITHAI is set to a large value.

Then, in the following step 307,
The initial opening KDITHAI calculated this time is set as the basic target opening DI. Further, in step 308, the opening degree of the solenoid 11a, that is, the ISCV 11 is feedback-controlled based on the basic target opening degree DI set this time. Then, the subsequent processing is temporarily terminated.

On the other hand, in step 305, when the previous cooling water temperature THW is also equal to or higher than the predetermined temperature T1, the process proceeds to step 309. In step 309,
Similar to the second embodiment, the previous basic target opening degree DI is set.
Predetermined constant value tDITHA (this constant value t
(DITHA may be variable depending on the deviation between the actual opening and the target opening) is added or subtracted to set as a new basic target opening DI. Further, the process proceeds to step 308, and the opening degree of the solenoid 11a, that is, the ISCV 11 is feedback-controlled based on the basic target opening degree DI set this time. Then, the subsequent processing is temporarily terminated.

As described above, according to the "ISCV control routine" of the present embodiment, basically, after the engine is started, the opening degree D is increased until the cooling water temperature THW reaches the predetermined temperature T1.
Open loop control is executed based on OP. When the cooling water temperature THW reaches the predetermined temperature T1,
The basic target opening DI is set to the initial opening KDITHAI, and thereafter the feedback control is executed.

Now, in the present embodiment, the intake air temperature sensor 2
1 detects a value (intake air temperature THA) corresponding to the temperature in the combustion chamber 1a of the engine 1. Then, the initial opening degree KDITHAI is made variable according to the intake air temperature THA. More specifically, the initial opening KDITHAI is
The intake air temperature THA is set to increase as it decreases.

Therefore, the cooling water temperature THW is equal to the predetermined temperature T1.
Even if the temperature reaches the combustion chamber 1a of the engine 1 when the temperature is still low, the initial opening KDITHAI
Is set to a large value, the basic target opening degree DI becomes large as shown by the broken line in FIG. for that reason,
After shifting to normal feedback control, ISCV11
The convergence time for the actual opening to reach the target opening is long. Therefore, when the temperature of the combustion chamber 1a of the engine 1 is sufficiently increased, the actual opening degree of the ISCV 11 is reduced to the target opening degree. As a result, similarly to the first and second embodiments, the deterioration of the combustion state can be avoided, and the combustion state can be stabilized immediately after the engine 1 is started to the steady state. At the same time, it is possible to prevent the occurrence of problems such as rough idle.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. However, since the configuration and the like of the present embodiment are also the same as those of the above-described first embodiment, the same members and the like are designated by the same reference numerals and the description thereof will be omitted. And
In the following, differences from the first to third embodiments will be mainly described. In the present embodiment as well, E
The CU 41 constitutes target opening calculation means, feedback control means, fast idle up control means, and convergence time setting means (including initial opening setting means, transition feedback control means, and initial opening adjustment means). .

FIG. 12 is similar to the first to third embodiments.
E when the engine 1 is running, especially when idling
It is a flow chart which shows an "ISCV control routine" performed by CU41, and is performed by a regular interruption for every predetermined time.

When the processing shifts to this routine, first, in step 401, the ECU 41 causes the sensors 21
The detection signals from 30 to 30 are read, and in step 402, it is determined whether or not the cooling water temperature THW read in step 401 is equal to or higher than a predetermined temperature T1 (for example, 80 ° C.) that is set in advance. If the cooling water temperature THW has not reached the predetermined temperature T1 or higher, step 4
At 03, the open opening DOP is calculated based on the various operating states read this time. Also, the following step 40
In step 4, based on the calculated opening degree DOP,
The solenoid 11a, that is, the opening degree of the ISCV 11 is open-loop controlled. Then, the subsequent processing is temporarily terminated.

On the other hand, in step 402, when the cooling water temperature THW is equal to or higher than the predetermined temperature T1,
Control goes to step 405. In step 405, it is determined whether or not the intake air temperature THA read this time is smaller than a predetermined reference temperature T2.
Here, the reference temperature T2 is a temperature at which a sufficiently good combustion state can be obtained even if the normal feedback control is performed, and is a temperature empirically set in advance. And
When the intake air temperature THA is lower than the reference temperature T2, it is assumed that the combustion state may be deteriorated if the opening degree of the ISCV 11 is suddenly lowered, and the process proceeds to step 406.

In step 406, a predetermined raised initial opening DGINT is set as the basic target opening DG. This raised initial opening degree DGINT is a value larger than a normal learning opening degree DGOLD which will be described later.

Then, in the following step 407,
The lifted initial opening DGINT calculated this time is set as the basic target opening DI. Further, in step 408, the opening degree of the solenoid 11a, that is, the ISCV 11 is feedback-controlled based on the basic target opening degree DI set this time. Then, the subsequent processing is temporarily terminated.

On the other hand, when the intake air temperature THA is equal to or higher than the reference temperature T2 in step 405, it is determined that the normal feedback control may be executed, and the routine proceeds to step 408. In step 408, the normal learning opening degree DGOLD is set as the basic target opening degree DI. Further, the routine proceeds to step 407, where the solenoid 11 is opened based on the basic target opening degree DI set this time.
a, that is, the opening degree of the ISCV 11 is feedback-controlled. Then, the subsequent processing is temporarily terminated.

As described above, according to the "ISCV control routine" of the present embodiment, basically, after the start, until the cooling water temperature THW reaches the predetermined temperature T1, the open opening degree D
Open loop control is executed based on OP. When the cooling water temperature THW reaches the predetermined temperature T1,
The basic target opening degree DI is selectively set to either the raised initial opening degree DGINT or the normal learning opening degree DGOLD, and thereafter, the feedback control is executed based on the basic target opening degree DI.

Now, in the present embodiment, the intake air temperature sensor 2
1 detects a value (intake air temperature THA) corresponding to the temperature in the combustion chamber 1a of the engine 1. Then, the basic target opening degree DI is selectively made variable according to the intake air temperature THA. More specifically, when the intake air temperature THA is low, a relatively large raised initial opening DGINT is set as the basic target opening DI.

Therefore, the cooling water temperature THW is equal to the predetermined temperature T1.
Even when the temperature reaches the combustion chamber 1a of the engine 1, the basic target opening degree DI becomes large, and the actual ISCV11 is changed after the normal feedback control. The convergence time for the opening of to reach the target opening is long. Therefore, when the temperature of the combustion chamber 1a of the engine 1 is sufficiently increased, the ISC
The actual opening of V11 will fall to the target opening. As a result, similarly to the first to third embodiments, the deterioration of the combustion state can be avoided, and the combustion state can be stabilized immediately after the engine 1 is started to the steady state. At the same time, it is possible to prevent the occurrence of problems such as rough idle.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIGS. 13 and 14. However, since the configuration and the like of the present embodiment are also the same as those of the above-described first embodiment, the same members and the like are designated by the same reference numerals and the description thereof will be omitted.
Then, in the following, differences from the first to fourth embodiments will be mainly described. Note that, also in this embodiment, the ECU 41 controls the target opening degree calculation means, the feedback control means, the first idle up control means,
And convergence time setting means (including initial opening setting means, transition feedback control means and initial opening adjusting means).

FIG. 13 is similar to the first to fourth embodiments.
E when the engine 1 is running, especially when idling
It is a flow chart which shows an "ISCV control routine" performed by CU41, and is performed by a regular interruption for every predetermined time.

When the processing shifts to this routine, first, in step 501, the ECU 41 causes the sensors 21
The detection signals from 30 to 30 are read, and in step 502, it is determined whether or not the cooling water temperature THW read in step 501 is equal to or higher than a predetermined temperature T1 (for example, 80 ° C.) that is set in advance. If the cooling water temperature THW has not reached the predetermined temperature T1 or higher, step 5
At 03, the open opening DOP is calculated based on the various operating states read this time. Also, the following step 50
In step 4, based on the calculated opening degree DOP,
The solenoid 11a, that is, the opening degree of the ISCV 11 is open-loop controlled. Then, the subsequent processing is temporarily terminated.

On the other hand, in step 502, when the cooling water temperature THW is equal to or higher than the predetermined temperature T1,
Control goes to step 505. In step 505, the previously read cooling water temperature THW is the predetermined temperature T1.
It is determined whether the value is smaller than. If the previous cooling water temperature THW is lower than the predetermined temperature T1, it is determined that the cooling water temperature THW has reached the predetermined temperature T1 for the first time, and the process proceeds to step 506.

In step 506, the amount of increase KDIUP for feedback control is calculated based on the intake air temperature THA read this time. Here, a map as shown in FIG. 14 is referred to when calculating the lift amount KDIUP. That is, when the intake air temperature THA is high (combustion room temperature is high), the amount of increase KDIUP
Is small and the intake air temperature THA is low (combustion room temperature is low), the lift amount KDIUP is set to a large value.

Then, in the following step 507,
A value obtained by adding the lift amount KDIUP calculated this time to the basic target opening DI ₀ at the time of the previous feedback control stored in the ROM 43 is set as the basic target opening DI. Further, in step 508, based on the basic target opening degree DI set this time, the solenoid 11a,
That is, the opening of the ISCV 11 is feedback-controlled. Then, the subsequent processing is temporarily terminated.

On the other hand, in step 505, if the previous cooling water temperature THW is also equal to or higher than the predetermined temperature T1, the process proceeds to step 509. In step 509,
Similar to the second embodiment, the previous basic target opening degree DI is set.
Predetermined constant value tDITHA (this constant value t
(DITHA may be variable depending on the deviation between the actual opening and the target opening) is added or subtracted to set as a new basic target opening DI. Further, the process proceeds to step 508, and the opening degree of the solenoid 11a, that is, the ISCV 11 is feedback-controlled based on the basic target opening degree DI set this time. Then, the subsequent processing is temporarily terminated.

As described above, the "ISCV control routine" of the present embodiment also has the same effect as that of the third embodiment. The present invention is not limited to the above embodiments, and may be configured as follows, for example.

(1) In each of the above embodiments, the combustion chamber 1a
Although the intake air temperature THA is adopted as a parameter corresponding to the temperature of, the outside air temperature sensor for detecting the temperature of the outside air is separately provided, and the value detected by the sensor is adopted as the parameter corresponding to the temperature of the combustion chamber 1a. May be.

(2) In the above-mentioned embodiment, the engine is embodied as a gasoline engine, but it may be embodied as a vehicle equipped with a diesel engine.

(3) In the above embodiment, ISCV11
Although the opening degree is controlled by duty control of the solenoid 11a, a step motor or the like may be used as an actuator to drive and control it.

(4) In each of the above embodiments, ISCV1
1 constitutes an intake air amount adjusting means, and a solenoid 11
Although the actuator is configured by a, the throttle valve 8 may be separately opened and closed by an actuator such as a step motor, and this may be used as the intake air amount adjusting means.

(5) The various control contents in the above embodiments may be combined appropriately. A technical idea which is not described in each claim of the claims and can be grasped from the above-described embodiment will be described below together with its effect.

(A) In the idle speed control device according to any one of claims 1 to 4, the combustion room temperature detecting means comprises at least one of an intake air temperature sensor and an outside air temperature sensor.

With such a structure, the value corresponding to the temperature of the combustion chamber of the internal combustion engine can be appropriately grasped, and more accurate control can be performed.

[0102]

As described in detail above, according to the present invention,
In the engine speed control device for an internal combustion engine, it is possible to stabilize the combustion state immediately after the start up to the steady state, and it is possible to prevent the occurrence of problems such as rough idle. Play.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram illustrating a conceptual configuration of an invention according to claim 1;

FIG. 2 is a schematic configuration diagram showing an idle speed control device of the first embodiment.

FIG. 3 is a block diagram showing an electrical configuration of an ECU according to the first embodiment.

FIG. 4 is a flowchart showing an “ISCV control routine” executed by the ECU in the first embodiment.

FIG. 5 is a map showing the relationship between the intake air temperature and the delay time.

FIG. 6 is a flowchart showing an “ISCV control routine” in the second embodiment.

FIG. 7 is a map showing the relationship between the intake air temperature and the integration constant.

FIG. 8: Basic target opening and ISCV over time
5 is a timing chart showing the relationship between the opening degrees of

FIG. 9 is a flowchart showing an “ISCV control routine” in the third embodiment.

FIG. 10 is a map showing a relationship between an intake air temperature and an initial opening degree.

FIG. 11: Basic target opening and ISC over time
6 is a timing chart showing the relationship between V opening degrees.

FIG. 12 is a flowchart showing an “ISCV control routine” in the fourth embodiment.

FIG. 13 is a flowchart showing an “ISCV control routine” in the fifth embodiment.

FIG. 14 is a map showing the relationship between the intake air temperature and the amount of raising.

[Description of Reference Signs] 1 ... Engine as internal combustion engine, 8 ... Throttle valve, 10 ... Bypass intake passage as bypass passage, 1
DESCRIPTION OF SYMBOLS 1 ... Idle speed control valve (ISCV) as intake air amount adjusting means, 11a ... Solenoid as actuator, 21 ... Intake temperature sensor constituting operating state detecting means and combustion room temperature detecting means, 22 ... Operating state detecting means A throttle sensor, 23 ... an idle switch that constitutes an operating state detecting means, 24 ... an intake pressure sensor that constitutes an operating state detecting means, 25 ... an oxygen sensor that constitutes an operating state detecting means, 26 ... an operating state detecting means. A water temperature sensor, 27 ... a rotation speed sensor that constitutes an operating state detecting means, 28 ... a crank angle sensor that constitutes an operating state detecting means, 29 ... a vehicle speed sensor that constitutes an operating state detecting means, 30 ... an operating state detecting means. Neutral start switch, 41 ... Target opening calculation means, feedback control hand , ECU constituting the first idling-up control unit and the convergence time setting means, and the like.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Sato 1-1-1 Kyowa-cho, Obu-shi, Aichi Aisan Industry Co., Ltd. (72) Masanori Senda 1-chome, Kyowa-cho, Obu-shi, Aichi 1 In Aisan Industry Co., Ltd. (72) Inventor Katsunao Takeuchi 1 in 1-1, Kyowa Town, Obu City, Aichi Prefecture Aisan Industry Co., Ltd.

Claims (4)

[Claims] 1. An air conditioner provided in an intake passage of an internal combustion engine,
An intake air amount adjusting means that is driven to open and close by an actuator, an operating state detecting means that detects an operating state including a cooling water temperature of the internal combustion engine, and a detection result of the operating state detecting means at least during idling of the internal combustion engine. Based on the target opening calculated by the target opening calculating means at least during idling of the internal combustion engine, the actuator is operated based on the target opening calculating means for calculating the target opening of the intake air amount adjusting means. Feedback control means for feedback control, and at least the amount of intake air for warming up the internal combustion engine until the cooling water temperature detected by the operating state detection means reaches a predetermined temperature after the internal combustion engine is started. The opening of the adjusting means is maintained at a predetermined opening larger than the target opening, and A rotation speed control device for an internal combustion engine, comprising: a fast idle up control means for performing open loop control of a user; a combustion room temperature detection means for detecting a value corresponding to a temperature in a combustion chamber of the internal combustion engine; and the operating state. After the cooling water temperature detected by the detection means reaches a predetermined temperature, the convergence time until the opening degree of the intake air amount adjusting means shifts to the target opening degree is low when the temperature detected by the combustion room temperature detecting means is low. A rotation speed control device for an internal combustion engine, comprising: a convergence time setting means for setting a longer time. 2. The convergence time setting means sets the opening of the intake air amount adjusting means to the target opening for a predetermined delay time after the cooling water temperature detected by the operating state detecting means reaches a predetermined temperature. Idle-up continuation control means for controlling the actuator in an open loop so as to maintain the opening degree larger than the predetermined temperature, and a delay time for setting the delay time to be longer as the temperature detected by the combustion room temperature detection means is lower. The rotation speed control device for an internal combustion engine according to claim 1, further comprising setting means. 3. The convergence time setting means gradually targets the opening degree of the intake air amount adjusting means by a feedback control constant after the cooling water temperature detected by the operating state detecting means reaches a predetermined temperature. And a feedback control constant setting means for setting the feedback control constant to be smaller as the temperature detected by the combustion room temperature detection means is lower. The rotation speed control device for an internal combustion engine according to claim 1 or 2. 4. The convergence time setting means sets the opening degree of the intake air amount adjusting means to be at least the target opening degree when the cooling water temperature detected by the operating state detecting means reaches a predetermined temperature. A predetermined initial opening amount,
After the initial opening setting means for setting a large state and the cooling water temperature detected by the operating state detecting means reach a predetermined temperature, the opening of the intake air amount adjusting means is raised by the initial opening. From the above state, the transition feedback control means that gradually approaches the target opening degree by the feedback control constant, and the initial opening degree that is set becomes larger as the temperature detected by the combustion room temperature detecting means becomes lower. And an initial opening degree adjusting means for controlling the initial opening degree.
4. A rotation speed control device for an internal combustion engine according to any one of 3 to 3.