JP3525642B2 - Idle speed control device for internal combustion engine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an idle speed control device for an internal combustion engine, and more particularly to an idle speed control device for an internal combustion engine for adjusting the intake air amount to control the idle speed. It is about.

[0002]

2. Description of the Related Art Generally, an idle speed control device for an engine is often provided with an idle speed control valve (ISCV) in the middle of a bypass passage that bypasses the throttle valve in addition to the intake passage. . By adjusting the opening of this ISCV, the intake air amount of the internal combustion engine is controlled independently of the throttle valve, and the idle speed is controlled.

In particular, when the engine is warmed up, idle up is performed. This is because the intake amount is increased by increasing the opening degree of the ISCV, and by this increase, the engine speed during idling is increased. For example, when the engine is warming up, a target idle-up rotation speed higher than the normal idle rotation speed is separately determined, and the target opening degree of ISCV (the operation amount of the actuator that drives the ISCV) is set in accordance with the rotation speed. Controlled.

Conventionally, the operation amount of the actuator at this time is constant regardless of the shift position. For example, when the actuator that drives the ISCV is a step motor, the target number of steps is set according to the N range (including the P range). Therefore, when the engine is warmed up, the number of steps of the step motor is uniquely adjusted to the target number of steps,
Idle up was running.

Here, when the shift position is switched from the N range to the D range, a load is applied to the engine, and the engine speed becomes lower than that in the N range. However, in the past, although the number of rotations decreased in the D range, the degree of the decrease was not uniform, and was left to the extent of becoming. for that reason,
For the D range, the number of rotations may be rather high, and there is a risk that a torque not requested by the driver may be produced.

On the other hand, the technique disclosed in Japanese Patent Laid-Open No. 5-171975 is known. According to this technique, during warm-up, it is determined whether it is a warm-up state (corresponding to the N range) or a warm-up state (corresponding to the D range). Then, in the case of warm-up while left standing, the opening degree of ISCV is set to be larger than that in the case of warm-up during running. Therefore, at the time of warming up for a while, the idling speed is increased, and the warming-up time can be shortened. In addition, since the opening degree of ISCV is set to a relatively small value when the vehicle is warming up, an increase in rotational speed is suppressed. As a result, it is possible to suppress an increase in torque and improve the driving feeling during traveling.

[0007]

However, the technique disclosed in the above publication has a problem when switching the shift position. More specifically, if the idle rotation speed convergence time is constant during switching of the shift position, the following problems may occur. For example, when the shift position is changed from N range to D range, ISC
The opening degree of V is switched so as to be small. At this time, if the closing speed of the ISCV is too slow for the system, the decrease in rotation speed becomes slow and the torque becomes large. There was a fear.

On the contrary, the shift position is changed from D range to N range.
When switching to the range, the ISCV opening is switched to a large opening. At this time, if the ISCV closing speed is too fast for the system, a rapid increase in the number of revolutions (overshoot) is caused. There was a risk of leaving.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide an idle speed control device for an internal combustion engine which performs idle-up during warm-up, even when a shift position is switched. It is an object of the present invention to provide an idle speed control device for an internal combustion engine, which is capable of suppressing unstable rotation speed and torque.

[0010]

In order to achieve the above object, in the invention described in claim 1, as shown in FIG. 1, intake air for adjusting the flow rate of intake air introduced into the internal combustion engine M1. The state is switched between the quantity adjusting means M2 and the neglected state or the running state according to the shift position, and when the running state is switched, the internal combustion engine M1.
Automatic transmission M3 that can be a load on the internal combustion engine M
Warm-up determination means M4 for determining whether or not the warm-up of 1 is necessary;
When the warm-up determination means M4 determines that warm-up is necessary, the target operation amount of the intake air amount adjustment means M2 is calculated to increase the idle speed of the internal combustion engine M1, and the calculation result is calculated. Based on the intake air amount adjusting means M2
And an operation amount variable control device M6 for varying the operation amount of the intake air amount adjusting device M2 controlled by the idle up control device M5 according to the shift position. In the idle speed control device for an internal combustion engine, when the shift position is switched and the state is switched between the idle state and the running state, the idle-up control means M5 controls the intake air amount adjusting means M2. An operating speed of the intake air amount adjusting means M2 is provided by providing speed change control means M7 for changing the operating speed.
Is when the state is switched from the neglected state to the running state.
When the state is switched from the running state to the neglected state
It is said that it is larger than .

Further, according to the second aspect of the present invention, between the intake air amount adjusting means M2 for adjusting the flow rate of the intake air introduced into the internal combustion engine M1, and the standing state and the traveling state depending on the shift position. The automatic transmission M3, which can switch the state of the internal combustion engine M1 when the running state is switched, and the warm-up determination means for determining whether or not the internal combustion engine M1 needs to be warmed up. M4, and when the warm-up determination means M4 determines that warm-up is necessary, the target operation amount of the intake air amount adjustment means M2 is calculated in order to increase the idle speed of the internal combustion engine M1. Idle up control means M5 for controlling the intake air amount adjusting means M2 based on the calculation result, and the intake air amount adjusting hand controlled by the idle up control means M5 according to the shift position. In an idle speed control device for an internal combustion engine, which is provided with an operation amount variable control means M6 for changing the operation amount of M2, the shift position is switched and the state is switched between a standing state and a running state. In this case, speed change control means M for changing the operating speed of the intake air amount adjustment means M2 by the idle-up control means M5.
7, said shift position is switched, since the state is switched between the use state and the traveling state, after the constant time Tokoro has elapsed, according to the speed change control unit M7, the intake amount adjusting means M2 The gist of the invention is to provide a speed change forcibly ending means for forcibly ending the change of the operating speed of.

Further, in the invention described in claim 3, in the idle speed control device for an internal combustion engine according to claim 1 or 2, the intake air amount adjusting means M2 is provided with the internal combustion engine M.
1, an electronically controlled throttle mechanism including a throttle valve provided in the intake passage and an actuator for opening and closing the throttle valve, and an idle speed provided in a bypass intake passage bypassing the throttle valve provided in the intake passage The gist of the invention is that it is configured by at least one of an ISC mechanism including a control valve and an actuator for opening and closing the valve.

In addition, in the invention described in claim 4, in the idle speed control device for an internal combustion engine according to any one of claims 1 to 3, the target operation amount of the intake air amount adjusting means M2 is the internal combustion engine. Its gist is that it is calculated according to the engine temperature of the engine M1.

[0014]

[0015]

In addition , in the invention described in claim 5 , in the idle speed control device for an internal combustion engine according to any one of claims 1 to 4 , the operation amount variable control means M6 is
The gist of the invention is that the operation amount of the intake air amount adjusting means is made variable so that the rotation speed of the internal combustion engine becomes higher in the left state than in the traveling state.

(Operation) According to the configuration of the invention described in claim 1, as shown in FIG. 1, the intake air amount adjusting means M2 adjusts the flow rate of the intake air introduced into the internal combustion engine M1. . In addition, the automatic transmission M3 is switched between a neglected state and a running state according to the shift position, and when the running state is switched, the internal combustion engine M1.
Can be a burden on

The warm-up determination means M4 determines whether or not the internal combustion engine M1 needs to be warmed up. If it is determined that warm-up is necessary, idle-up control means M5
The target operation amount of the intake air amount adjusting means M2 is calculated by
The intake air amount adjusting means M2 is controlled based on the calculation result. As a result, the idling speed of the internal combustion engine M1 is increased and the internal combustion engine M1 is warmed up. Further, in the operation amount variable control means M6, the operation amount of the intake air amount adjusting means M2 controlled by the idle up control means M5 is made variable according to the shift position. Therefore, the idle rotation speed is different between when the vehicle is warmed up for a while and when it is warmed up when the vehicle is running, and the rotation speed, the warm-up performance, and the torque according to each state can be secured.

In the present invention, when the shift position is switched and the state is switched between the neglected state and the running state, the speed change control means M7 causes the idle up control means M5 to take in the intake air amount. The operating speed of the adjusting means M2 is changed. Therefore, when converging to the above different idling speeds, it converges quickly or slowly depending on the shift position (state). Therefore, stable rotation speed fluctuation and torque fluctuation are ensured for the system.

Further, the operating speed of the intake air amount adjusting means M2 is higher when the state is switched from the standing state to the running state than when the state is switched from the running state to the standing state. Therefore, when the state is switched from the neglected state to the running state, the rotation speed fluctuates and converges relatively quickly. On the contrary, when the state is switched from the running state to the neglected state, the rotation speed changes relatively slowly. Furthermore, according to the invention described in claim 2, wherein the switched shift position, the switched state between the standing state and the traveling state, after the constant time Tokoro has elapsed, the speed change forced The ending unit forcibly ends the change of the operating speed of the intake air amount adjusting unit M2 by the speed changing control unit M7. Therefore, if the rotational speed does not converge too long after the shift position is switched, the operating speed of the intake air amount adjusting means M2 is forcibly returned to the original speed, and in some cases, the rotational speed Smooth convergence will be achieved.

Further, according to the invention of claim 3,
In addition to the actions of the invention described in claims 1 and 2, the intake air amount adjusting means M2 is an electronically controlled type that includes a throttle valve provided in an intake passage of the internal combustion engine M1 and an actuator for opening and closing the throttle valve. At least one of a throttle mechanism, an ISC mechanism including an idle speed control valve provided in a bypass intake passage that bypasses a throttle valve provided in the intake passage, and an actuator for opening and closing the valve is provided. . Therefore, the above-described operation can be easily achieved with a generally installed mechanism.

In addition, according to the invention of claim 4,
In addition to the operation of the invention described in claims 1 to 3, the target operation amount of the intake air amount adjusting means M2 is calculated according to the engine temperature of the internal combustion engine M1. Therefore, when the warm-up state of the internal combustion engine M1 is still insufficient, a larger idle-up is ensured and the warm-up is promoted.

[0023]

[0024]

In addition , according to the invention of claim 5 ,
In addition to the actions of the invention described in claims 1 to 4 ,
The operation amount variable control means M6 makes the operation amount of the intake air amount adjusting means M2 variable so that the rotation speed of the internal combustion engine M1 is higher in the left state than in the traveling state.
Therefore, when the shift position is switched, for example, when the state changes from the neglected state to the running state, the rotation speed becomes lower than before. Therefore, in the traveling state, it is possible to prevent the torque from being excessively generated due to the rotation speed being too high.

In particular, in the combination with the invention described in claim 1 , when the vehicle is left in the running state and the vehicle is in the running state, the decrease in the rotational speed is slowed down, resulting in a large torque. Suppressed. Further, when the running state is changed to the neglected state, the rapid increase in the rotational speed, which prevents the rotational speed from rapidly increasing (overshooting), is suppressed.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which an idle speed control device for an internal combustion engine according to the present invention is embodied in a gasoline engine will now be described in detail with reference to the drawings.

FIG. 2 is a schematic configuration diagram showing an idle speed control device for an engine mounted on a vehicle in the present embodiment. As shown in FIG. 1, an engine 1 as an internal combustion engine takes in outside air from an air cleaner 3 via an intake passage 2. Further, the engine 1 takes in the outside air and at the same time takes in fuel injected from an injector 4 provided for each cylinder near the intake port 2a. Then, the mixture of the taken-in fuel and the outside air is introduced into the combustion chamber 1a via the intake valve 5 provided for each cylinder, and the combustion chamber 1a is exploded and burned to obtain a driving force. Further, the exhaust gas after the explosion and combustion is led from the combustion chamber 1a through the exhaust valve 6 to the exhaust passage 7 where the exhaust manifold for each cylinder gathers, and is exhausted 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
The amount of intake air to the intake passage 2 is adjusted by opening and closing. Also, on the downstream side of the throttle valve 8,
A surge tank 9 for smoothing the pulsation of intake air is provided.

In the middle of the intake passage 2, the bypass intake passage 1 that bypasses the throttle valve 8, that is, connects the upstream side and the downstream side of the throttle valve 8 with each other.
0 is provided. And this bypass intake passage 1
In the middle of 0, an idle speed control valve (ISC) that adjusts the flow rate of the air flowing through the passage 10
V) 11 is provided. The ISCV 11 is basically controlled to open / close when the throttle valve 8 is closed and the engine 1 is in an idle state. ISCV11
Is opened and closed by a step motor 11a as an actuator.
The air flow rate (intake air amount) of the bypass intake passage 10 is adjusted. The engine speed NE during idling is controlled by adjusting the intake air amount. In the present embodiment, the ISCV 11 and the step motor 11a and the like constitute 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. In addition, in the vicinity of the throttle valve 8,
A throttle sensor 22 that detects the opening degree (throttle opening degree) θ is provided, and an idle switch 23 that “turns on” to detect an idle state when the throttle valve 8 is fully closed is provided. Further, the surge tank 9 is provided with an intake pressure sensor 24 that communicates with the surge tank 9 and detects the 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 that detects the temperature (cooling water temperature) THW of the cooling water. In the present embodiment, this cooling water temperature THW is adopted as the temperature corresponding to the engine temperature.

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 is for distributing the high voltage output from the igniter 14 to each spark plug 12 in synchronization with the crank angle of the engine 1. The ignition timing of each spark plug 12 is the high voltage output timing from the igniter 14. 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) incorporated in the distributor 13. Further, the distributor 13 is also provided with a crank angle sensor 28 that detects a change in the crank angle of the engine 1 at a predetermined rate according to the rotation of the rotor.

At the same time, an automatic transmission 15 which can be a load on the engine 1 is drivingly connected to the engine 1. The automatic transmission 15 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 the 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 (leaving state) or in the drive range [D range (running state)].

Then, each of the sensors 21, 22, 24 ...
The operating state and the like of the engine 1 are appropriately detected by 29, the idle switch 23, the neutral start switch 30, and the like.

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 the drive timing of these is controlled by the operation of the ECU 41. It The ECU 41 constitutes warm-up determination means, idle-up control means, operation amount variable control means, speed change control means, speed change prohibition means, and speed change forced termination means.

The ECU 41 includes the intake air temperature sensor 2 described above.
1, throttle sensor 22, idle switch 23, intake pressure sensor 24, oxygen sensor 25, water temperature sensor 26, rotation speed sensor 27, crank angle sensor 28, vehicle speed sensor 2
9 and a neutral start switch 30 are connected to each other. Therefore, the ECU 41 uses each of these sensors 2
1, 22, 24 to 29, the idle switch 23, the neutral start switch 30, and the like based on the output signals from the injector 4, the solenoid 11a (ISC
V11) and the igniter 14 and the like are preferably controlled.

Next, the configuration 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, maps, etc. are stored in advance, and a CPU 42.
Random access memory (RAM) 44 for temporarily storing the calculation results and the like, backup RAM 45 for storing previously stored data, and the like. In addition, the ECU 41
Is an external input circuit 46 and an external output circuit 47.
And the like are connected as a logical operation circuit by a bus 48.

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. 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 as input values via the external input circuit 46. 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 various processes executed by the ECU 41, control of the idle speed will be described. That is, after the engine 1 is started, the control of the ISCV 11 (step motor 11a) as described below is executed. Then, the processing for performing the control will be described below with reference to the flowchart of FIG.

FIG. 4 is a flow chart showing the "idle rotation speed control routine" executed by the ECU 41 after the engine 1 is started, and is executed by interruption every predetermined crank angle.

When the processing shifts to this routine, first, at step 101, the ECU 41 causes the sensors 21
Detection signals from 30 to 30 (for example, intake temperature THA, throttle opening θ, intake pressure PiM, oxygen concentration OX, cooling water temperature THW, engine speed NE, vehicle speed SPD, shift position ShP, etc.) are read.

In the following step 102, it is determined whether or not the current shift position ShP is in the N range. When the current shift position ShP is in the N range,
In step 103, the control determination lower limit rotation speed KPNE
MN is calculated based on map A shown in FIG. Also,
The current shift position ShP is not in the N range, that is, D
In the case of the range, in step 104, the control determination lower limit rotation speed KPNEMN is calculated based on the map B shown in FIG.

In step 105, the engine rotational speed NE read this time is the lower limit rotational speed KPNEM of the control determination in step 105 after shifting from step 103 or step 104.
It is determined whether N or more. Then, when the engine speed NE is not equal to or higher than the control determination lower limit speed KPNEMN, this control is not performed, and the subsequent processing is temporarily terminated.

On the other hand, when the engine speed NE is equal to or higher than the control determination lower limit speed KPNEMN, the routine proceeds to step 106. In step 106, it is determined whether the engine 1 is currently warming up. In other words, the warm-up control has already been completed,
It is determined whether or not the feedback control of the normal ISCV11 has been made. Then, if the engine 1 is not currently warming up, that is, if the feedback control of the normal ISCV 11 has been completed, this control is not performed, and the subsequent processing is temporarily terminated.

If the engine 1 is currently warming up, the process proceeds to step 107. In step 107, it is determined whether or not the warm-up control speed up flag XPTUP calculated in a separate routine described later is "0". Then, the warm-up control speed up flag XPTU
When P is “0”, it is determined that it is not necessary to increase the control speed (or it is necessary to prohibit the increase of the control speed), and the process proceeds to step 108. In step 108, the warm-up control execution speed KCEGRV is set to "a".
Set to.

On the other hand, in step 107, when the warm-up control speed up flag XPTUP is not "0", that is, when it is "1", the control speed is increased as compared with the case where the flag XPTUP is "0". Control goes to step 109. In step 109, it is determined again whether the current shift position ShP is in the N range. Then, when the current shift position ShP is in the N range, in step 110, the warm-up control execution rotational speed KCEG is performed.
RV is set to "b" (where b <a). Further, when the current shift position ShP is not in the N range, that is, in the D range, in step 111, the warm-up control execution rotational speed KCEGRV is set to "c" (however, c <
b <a).

Further, step 108 and step 11
0, the process proceeds from step 111, and in step 112, the step number PMT of the step motor 11a is increased or decreased by "1 step" for each warm-up control execution rotational speed KCEGRV. More specifically, when the current step number PMT of the step motor 11a is larger than the target step number PT during warm-up, the step number PMT
Is increased by "one step". Here, the target number of steps PT during warm-up is the number of learning steps PG after completion of warm-up (the number of steps learned after completion of warm-up, in the N range, and when the air conditioner is off). Therefore, during the warm-up, the learning step number PG becomes a constant value) and the sum of the step-number raised amount PTB during the warm-up (this will be described later) (PT = PG + PTB)
However, basically, control is performed so that the current step number PMT converges to the target step number PT during warming up.

When the current step number PMT of the step motor 11a is smaller than the target step number PT during the warming up, the step number PMT is set to "1 step".
Reduce. Further, when the current step number PMT of the step motor 11a is the same as the target step number PT during warm-up, the step number PMT is not changed and is set as it is. Then, the ECU 41 once ends the subsequent processing.

As described above, in the "idle speed control routine", the number of steps of the step motor 11a is set for each warm-up control execution speed KCEGRV while the engine 1 is warming up. That is, when the warm-up control speed up flag XPTUP is "0", the warm-up control execution speed KCEGRV is set to "a", and the step number of the step motor 11a is controlled at a relatively slow speed. . When the warm-up control speed up flag XPTUP is "1" and the shift position ShP is in the N range, the warm-up control execution rotational speed KCEGRV is set to "b", and the speed is medium. Step motor 11
The number of steps in a is controlled. Further, when the warm-up control speed up flag XPTUP is "1" and the shift position ShP is in the D range, the warm-up control execution rotational speed K
CEGRV is set to "c", and the step number of the step motor 11a is controlled at a relatively high speed.

Next, the target number of steps PT during the above warm-up
A process for calculating the step number increase amount PTB in the middle of warming up, which is variable during warming up, will be described among the parameters constituting the above. That is, FIG.
It is a flow chart which shows a "step number raising amount calculation routine" performed by U30, and is performed by interruption for every predetermined crank angle.

When the processing shifts to this routine, the ECU
First, in step 201, the control unit 30 determines whether or not the current shift position ShP is in the N range. If the shift position ShP is in the N range, step 202
Move to. In step 202, the number of steps PT increased during warming up based on the map C shown in FIG.
Calculate B. As shown in the figure, in this case, the higher the cooling water temperature THW, the smaller the step number raising amount PTB is set. Then, the ECU 30 once ends the subsequent processing.

In step 201, when the current shift position ShP is not in the N range, that is, in the D range, the process proceeds to step 203. Step 203
In, the step number increase amount PTB during warm-up is calculated based on the map D shown in FIG. As shown in the figure, also in this case, the higher the cooling water temperature THW, the smaller the step number raising amount PTB is set. further,
In this case, if the cooling water temperature THW is the same, the step number raising amount PTB is set to a value smaller than that in the N range. Then, the ECU 30 once ends the subsequent processing.

As described above, in the "step number raising amount calculation routine", the shift position S at the end
The step number raising amount PTB is calculated according to hP and the cooling water temperature THW.

Next, the warm-up control speed up flag X
A process for setting PTUP will be described. That is, FIG. 6 is a flowchart showing the "warm-up control speed up flag setting routine" executed by the ECU 30, which is executed by interruption every predetermined crank angle.

When the processing shifts to this routine, the ECU
30 is the first step in step 301.
Step number PMT of data 11a_i-1From the above warm-up
The absolute value of the value obtained by subtracting the target step number PT is set in advance.
Less than or equal to the predetermined number of steps d (for example, d = 2 steps)
It is determined whether or not there is a history of. Here, the implementation
In the form of, when starting the engine 1,
Several PMT is forced to the maximum value (eg 250 steps)
It is set (see FIG. 9). And then on
The number of steps PM with an earlier cycle than the above-mentioned "c"
Control so that T becomes equal to the target number of steps PT during warm-up.
Controlled. Therefore, if a predetermined time elapses after starting,
By the light control, the number of steps PMT_i-1From above warm up
The absolute value of the value obtained by subtracting the target step number PT
The number of steps is less than or equal to d (PMT _i-1And PT are almost equal
The time should come. In this embodiment
Until this time comes, the number of steps PMT and warm
Items that need to be close to the target number of steps PT on board
As a result, the control according to the present invention is prohibited. Therefore, on
If the condition in step 301 is not satisfied, the step
Move to step 304.

Then, at step 304, the warm-up control speed up flag XPTUP is set to "0",
The subsequent process is once ended. On the other hand, when the condition of step 301 is satisfied, that is, the absolute value of the value obtained by subtracting the target step number PT during warm-up from the previous step number PMT _i-1 of the step motor 11a is the predetermined step number d. If the history below is even once, the process proceeds to step 302. In step 302, the elapsed time TASPC after the switching of the shift position ShP (switching from the N range to the D range or from the D range to the N range) is equal to or longer than a predetermined time e, and It is determined whether or not it is the second predetermined time f (however, f> e) or less. Then, the shift position ShP
When the elapsed time TASPC after the switching of is not less than the predetermined time e and not more than the second predetermined time f, the control according to the present invention is permitted in step 303.
The warm-up control speed up flag XPTUP is set to "1", and the subsequent processing is temporarily terminated.

On the other hand, the elapsed time TASPC after the shift position ShP is switched is the predetermined time e or more,
If it is not the second predetermined time f or less, the warm-up control speed up flag XPTUP is set to "0" in step 304 in order to prohibit the control according to the present invention, and the subsequent processing is temporarily ended. This is the elapsed time TA
If the control speed of the number of steps is switched when the SPC is less than the predetermined time e, the engine speed NE may suddenly change, which is intended to be avoided. In addition, it may not be appropriate to execute the control according to the present invention until the elapsed time TASPC exceeds the second predetermined time f, and this is to avoid this.

As described above, in the above-mentioned "warm-up control speed up flag setting routine", the history of the number of steps PMT _i-1 and the target number of steps PT during warm _- up being substantially equal to each other after starting is provided even once. In some cases, and the elapsed time TASP after the shift position ShP is switched
The warm-up control speed up flag XPTUP is set to "1" only when C is within the predetermined range, and the warm-up control speed up flag XPTUP is set to "0" otherwise. It

Next, the operation and effect of this embodiment will be described with reference to FIG.
It will be described based on the timing chart shown in FIG. As shown in the figure, it is assumed that the engine 1 is started at the timing t1 (when cold) (shift position ShP.
Of course, in the N range), as described above, first, the step number PMT is forcibly set to the maximum value (for example, 250 steps). Then, after that, the number of steps PMT is controlled to be equal to the target number of steps PT during warm-up in a quick cycle. Then, after a predetermined time has elapsed after the start, at the timing t2, the number of steps P
The absolute value of the value obtained by subtracting the target step number PT during warm _- up from MT _i-1 becomes equal to or less than the predetermined step number d (PMT _i-1
And PT become substantially equal), and one condition (condition of step 301) for setting the warm-up control speed up flag XPTUP to "1" will be satisfied thereafter.

After that, the step number PMT is controlled so as to match the target step number PT during warm-up.
At this time, the warm-up control speed up flag XPTUP is still
Is "0" and the shift position ShP is in the N range, the warm-up control execution rotational speed KCEGRV is set to "a" (step 108). Therefore, the matching control is executed at a relatively slow cycle "a" (step 112).

Further, it is assumed that the shift position ShP is switched from the N range to the D range at the timing t3. Along with this, the target number of steps PT during warm-up (PT =
PG + PTB) is the number of steps during warming up
Since TB decreases (because map C is switched to map D), it greatly decreases (broken line in the figure).
However, after that, until the predetermined time e elapses, the warm-up control speed up flag XPTUP remains set to "0" (steps 302 and 304). The control is executed in the cycle of.

Then, at the timing t4 when the predetermined time e has elapsed, the warm-up control speed up flag XPTUP is set.
Is set to "1". Therefore, thereafter, the warm-up control execution rotational speed KCEGRV is set to "c" (steps 107, 109, 111). Therefore, the matching control is executed at a relatively short cycle "c" (step 112). The number of steps P
Even after the timing t5 when MT matches the target step number PT during warm-up, there are only many occasions where the step number is not increased / decreased, and the control is performed at a relatively early cycle "c". It will continue to run.

Further, at the timing t6 when the second predetermined time f has elapsed, the warm-up control speed up flag XPT is set.
UP will be set to "0" again (step 3).
02, 304). Therefore, after that, the control is executed in the relatively slow cycle "a".

Next, it is assumed that the shift position ShP is switched from the D range to the N range at the timing t7. Along with this, the target number of steps PT during warm-up (PT =
PG + PTB) is the number of steps during warming up
Since TB increases (because map C is switched to map D), it greatly increases (broken line in the figure).
However, after that, until the predetermined time e elapses, the warm-up control speed up flag XPTUP remains set to "0" (steps 302 and 304). The control is executed in the cycle of.

Then, at a timing t8 when the predetermined time e has elapsed, the warm-up control speed up flag XPTUP is set.
Is set to "1" again. Therefore, thereafter, the warm-up control execution speed KCEGRV is set to "b" (steps 107, 109, 110). For this reason, the above-mentioned control to be matched is executed with a medium cycle of "b" (step 112). Even after the timing t9 when the number of steps PMT matches the target number of steps PT during warm-up, the number of steps does not increase or decrease, and the control is continuously executed in the medium cycle of "b". To be done. Further, at the timing t10 when the second predetermined time f has elapsed, the warm-up control speed up flag XPTUP is set to "0" again (steps 302 and 304). Therefore, thereafter, as in the above case, the control is executed in the relatively slow cycle of "a".

As described above in detail, according to the present embodiment, (a) the target step number PT during warm-up is made variable according to the shift position ShP. In other words, the step number increase amount PTB in the N range, and thus the target step number PT during warm-up, is set to a value higher than that in the D range. Therefore, it is possible to avoid a situation in which the engine speed NE becomes high in the D range, thereby preventing a problem that a torque not requested by the driver is output. You can

(B) In this embodiment, when the shift position ShP is switched, the speed at which the step number PMT matches the target step number PT during warm-up is changed. More specifically, when the N range is switched to the D range, the step number PMT converges to the target step number PT during warm-up faster than when the D range is switched to the N range. Therefore, when the shift position ShP is switched from the N range to the D range,
The number of steps PMT (opening of ISCV11) is switched so as to be small, but at this time, the closing speed of ISCV11 does not become too slow for the system. Therefore, the decrease in the engine speed NE becomes slower,
The problem that the torque becomes large can be prevented.

Conversely, when the shift position ShP is switched from the D range to the N range, the number of steps PMT (IS
The opening degree of the CV 11 is switched to be large, but at this time, the closing speed of the ISCV 11 is not too fast for the system. Therefore, it is possible to prevent a problem that the engine speed NE is suddenly increased (overshoot).

(C) Further, in the present embodiment, it is prohibited to change the control speed until the predetermined time e elapses after the shift position ShP is switched. Therefore, a large change in the intake air amount does not occur until the actual gear change is completed and the load change is completed. As a result, the rapid fluctuation of the engine speed NE is further suppressed.

(D) In addition, in the present embodiment, after the second predetermined time f has elapsed since the shift position ShP was switched, the change of the control speed is completed (in the cycle of "a"). I put it back). Therefore, after the shift position ShP is switched, the engine speed N is too long.
When E does not converge, the fluctuation speed of the step number PMT is forcibly returned to the original speed, and in some cases, the smooth convergence of the rotation speed is achieved.

(E) In addition, in this embodiment, the ISCV 11 and the step motor 11a are adopted as means for adjusting the idle speed. For this reason, the above-mentioned action can be easily achieved by a mechanism that is generally installed, and thus a dramatic increase in cost can be suppressed.

(F) Further, in the present embodiment, the step number raising amount PTB is calculated according to the cooling water temperature THW corresponding to the temperature of the engine 1. Therefore, when the warm-up state of the engine 1 is still insufficient, a larger idle-up is secured, and the warm-up can be further promoted.

(G) Further, in this embodiment, after the engine 1 is started, the step number PMT is forcibly set to the maximum value. For this reason, it becomes easier to further promote warm-up.

Further, the above control is not executed unless the absolute value of the value obtained by subtracting the target step number PT during warm _- up from the step number PMT _i-1 is not more than the predetermined step number d. Therefore, the instability of the engine speed NE immediately after starting can be suppressed.

The present invention is not limited to the above-described embodiment, but may be implemented as follows with a part of the configuration appropriately changed without departing from the spirit of the invention. (1) In the above-described embodiment, the cooling water temperature THW is adopted as the parameter corresponding to the temperature of the engine 1 (engine temperature), but the intake air temperature TH detected by the intake air temperature sensor 21 is used.
A or an oil temperature detected by an oil temperature sensor (not shown) may be adopted as a parameter corresponding to the engine temperature.

(2) In the above-described embodiment, the gasoline engine is used as the engine, but a vehicle equipped with a diesel engine can also be used.

(3) In the above embodiment, ISCV11
The degree of opening is specified when it is controlled by the step motor, but it may be specified when, for example, a solenoid is used as an actuator and is controlled by duty control.

(4) In the above embodiment, the intake air amount adjusting means is constituted by the bypass intake passage 10, the ISCV 11 and the solenoid 11a, but it may be constituted by other means. For example, the throttle valve 8 may be controlled to be opened and closed by an actuator such as a step motor, and the throttle valve 8 and the actuator may constitute an intake air amount adjusting means. Alternatively, both may be combined.

(5) The characteristics of each map in the above embodiment are not necessarily limited to those shown in the drawings. (6) In the above embodiment, the case where the step motor 11a is controlled by open loop control has been described, but the present invention is also applied to the case where feedback control is performed so that the engine speed NE matches the target speed. can do.

(7) In the above embodiment, the warm-up control execution speed KCEGRV is made variable so that the speed at which the step number PTM is converged is made variable. The number of changing steps) may be variable.

[0084]

As described in detail above, according to the present invention,
In an idle speed control device for an internal combustion engine that performs idle-up during warm-up, even when the shift position is switched, it is possible to suppress the instability of the rotation speed and torque.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram illustrating a conceptual configuration of an invention according to the present invention.

FIG. 2 is a schematic configuration diagram showing an idle speed control device for an engine according to an embodiment.

FIG. 3 is a block diagram showing an electrical configuration of an ECU.

FIG. 4 is a flowchart showing a “idle rotation speed control routine” executed by the ECU.

FIG. 5 is a flow chart showing a “step number raising amount calculation routine” executed by the ECU.

FIG. 6 is a flowchart showing a “warm-up control speed up flag setting routine” executed by the ECU.

FIG. 7 is a map showing a relationship between a cooling water temperature and a control determination lower limit rotation speed.

FIG. 8 is a map showing the relationship between the cooling water temperature and the step number raising amount.

FIG. 9 is a timing chart showing the relationship of cooling water temperature, shift position, number of steps, engine speed, and warm-up control speed up flag with respect to time.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as an internal combustion engine, 2 ... Intake passage, 8 ... Throttle valve, 10 ... Bypass intake passage which constitutes intake amount adjusting means, 11 ... Idle speed control valve (ISCV) which constitutes intake amount adjusting means, 11a ...
Step motors constituting the intake air amount adjusting means, 15 ... Automatic transmission, 41 ... Warm-up judging means, idle-up control means, actuation amount variable control means, speed change control means, speed change prohibition means and speed change forced termination means. ECU to configure.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-171975 (JP, A) JP-A-5-306642 (JP, A) JP-A-5-180031 (JP, A) JP-A-8- 74641 (JP, A) Tokuhyo 9-509237 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02D 29/00-29/06 F02D 41/00-45/00

Claims (5)

(57) [Claims] Claim: What is claimed is: 1. An intake air amount adjusting means for adjusting the flow rate of intake air introduced into an internal combustion engine, and a state in which the intake air amount adjusting means is switched between a neglected state and a running state and a running state. In the case of the above, an automatic transmission that may be a load on the internal combustion engine, a warm-up determination means for determining whether or not the internal combustion engine needs to be warmed up, and warm-up by the warm-up determination means are necessary. If it is determined that the target engine operation amount of the intake air amount adjusting means is calculated in order to increase the idle speed of the internal combustion engine, the idle up control means for controlling the intake air amount adjusting means based on the calculation result. And an operation amount variable control means for changing the operation amount of the intake air amount adjusting means controlled by the idle up control means according to the shift position. In the device, when the shift position is switched and the state is switched between a standing state and a running state, speed change control means for changing the operating speed of the intake air amount adjusting means by the idle-up control means. The operating speed of the intake air amount adjusting means is higher when the state is switched from the standing state to the running state than when the state is switched from the running state to the standing state. Engine idle speed control device. 2. A state is switched between an air intake amount adjusting means for adjusting a flow rate of intake air introduced into an internal combustion engine and a standing state or a running state according to a shift position, and is switched to a running state. In the case of the above, an automatic transmission that may be a load on the internal combustion engine, a warm-up determination means for determining whether or not the internal combustion engine needs to be warmed up, and warm-up by the warm-up determination means If it is determined that the target engine operation amount of the intake air amount adjusting means is calculated in order to increase the idle speed of the internal combustion engine, the idle up control means for controlling the intake air amount adjusting means based on the calculation result. And an operation amount variable control means for changing the operation amount of the intake air amount adjusting means controlled by the idle up control means according to the shift position. In the device, when the shift position is switched and the state is switched between a standing state and a running state, speed change control means for changing the operating speed of the intake air amount adjusting means by the idle-up control means. When, said shift position is switched, after the switched state between the standing state and the traveling state, has passed Jo Tokoro time by the speed change control means, operating speed of the intake air quantity adjusting means And a speed change forcible ending means for forcibly ending the change of the above. 3. The electronically controlled throttle mechanism comprising an throttle valve provided in an intake passage of the internal combustion engine and an actuator for opening and closing the throttle valve, and a throttle provided in the intake passage. The at least one of an ISC mechanism including an idle speed control valve provided in a bypass intake passage that bypasses the valve and an actuator for opening and closing the valve is configured by at least one of the two. Idle speed control device for internal combustion engine. 4. The internal combustion engine according to claim 1, wherein the target operation amount of the intake air amount adjusting means is calculated according to the engine temperature of the internal combustion engine. Idle speed control device. 5. The operation amount variable control means is in a state of being left unattended.
The internal combustion engine speed will be higher than in the running state.
The operating amount of the intake air amount adjusting means is variable.
Idle speed control apparatus for an internal combustion engine according to any of claims 1 4, characterized in that that.