JPH07246857A - Cruise control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To detect a acceleration demand without specially installing a means for detecting it, when the acceleration demand is made during the cruise control. CONSTITUTION:In the middle of an intake passage 2, a subthrottle valve 3 which is opened and closed by the operation of a step motor 8 and a main throttle valve 4 which is interlocked with an accelerator pedal 5 are arranged in series in succession from the upstream side of the intake passage 2. In the main throttle valve 4, an actuator 11 for cruise control which is equipped with a diaphragm type actuator 12, etc., is installed. During the cruise control, an electronic controller (ECU) 41 controls the actuator 11 for cruise control, and the main throttle opening degree is kept within a specific orange from the value which is obtained by adding a specific constant to the subthrottle opening degree. Accordingly, even if the acceleration demand is transmitted from a driver during the cruise control, the main throttle opening degree is increased, and such an increase is detected by a main throttle sensor 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cruise control device for an internal combustion engine, and more particularly to a first throttle valve that interlocks with an accelerator pedal and a second throttle valve that is driven and controlled by an electric actuator. The present invention relates to a cruise control device for an internal combustion engine provided in a passage.

[0002]

2. Description of the Related Art Conventionally, as this type of technique, for example, one disclosed in Japanese Patent Application Laid-Open No. 2-130229 is known. In this technique, a first throttle valve that interlocks with an accelerator pedal and a second throttle valve that is located in series with the throttle valve and that is driven by an electric motor are provided in the intake passage of the engine. . Further, in the above technique, the actuator for driving the first throttle valve irrespective of the operation of the accelerator pedal is provided. This actuator includes a diaphragm and a solenoid valve, and by switching the solenoid valve, negative pressure or atmospheric pressure is introduced into the negative pressure chamber of the diaphragm, so that the first throttle valve is opened and closed.

When the driver instructs cruise control (automatic driving control), the actuator is driven. That is, the solenoid valve is turned on,
Negative pressure is introduced into the negative pressure chamber of the diaphragm. Therefore, the diaphragm is driven, and the first throttle valve is fully opened regardless of the operation of the accelerator pedal. Then, during this period, the electric motor is drive-controlled to control the valve opening degree of the second throttle valve. By this control, a slight adjustment of the intake air amount during cruise control is performed.

[0004]

However, in the above-mentioned prior art, during cruise control, the first throttle valve was in the fully open state regardless of the operation of the accelerator pedal. Therefore, when the above technique is applied in the case where the acceleration determination is performed by changing the opening degree of the first throttle valve that is interlocked with the accelerator pedal, the acceleration determination cannot be performed during the cruise control. . Therefore, in such a case, a means for determining the acceleration based on the operation amount of the accelerator pedal or the like is additionally provided,
It was necessary to control the valve opening based on the determination means.

If such a determination means is not separately provided, the operation of the accelerator pedal is not reflected in the valve opening, so that even when the driver requests acceleration, the driver himself once releases the cruise control. Had to be performed (manually turning off the cruise control switch, etc.). As a result, the operation becomes complicated and there is a possibility that quick control cannot be performed.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to detect an acceleration request even if an acceleration request is made during cruise control without providing a separate means for detecting it. An object of the present invention is to provide a cruise control device for an internal combustion engine, which is capable of quickly performing appropriate control according to the situation.

[0007]

In order to achieve the above object, in the present invention, as shown in FIG.
1, which is provided in the middle of the intake passage M2
3 and a first throttle valve M4 interlocked with the first throttle valve M4, and a second throttle valve M5 provided upstream or downstream of the first throttle valve M4 in the middle of the intake passage M2.
An electric actuator M6 for driving the second throttle valve M5, and the first throttle valve M4
First valve opening degree detection means M7 for detecting the opening degree of
Second valve opening degree detection means M8 for detecting the opening degree of the second throttle valve M5, and the first throttle valve M
A cruise control actuator M9 for driving 4 regardless of the operation of the accelerator pedal M3;
An automatic driving judging means M10 for judging whether or not there is a need for automatic driving of the internal combustion engine M1 based on a driver's instruction, and the automatic driving judging means M10 judges that the automatic driving of the internal combustion engine M1 is necessary. When the first and second
Drive for driving the cruise control actuator M9 and drivingly controlling the electric actuator M6 to control the opening of the second throttle valve M5 based on the detection results of the valve opening detection means M7, M8. A cruise control device for an internal combustion engine, comprising: a control means M11, wherein when the automatic operation determination means M10 determines that the automatic operation of the internal combustion engine M1 is necessary, the first throttle valve M4 is opened. The gist is that adjustment control means M12 for adjusting and controlling the cruise control actuator M9 is provided so that the degree becomes larger than the opening degree of the second throttle valve M5 by an opening degree within a predetermined range. .

[0008]

According to the above construction, as shown in FIG. 1, the first throttle valve M4 provided in the middle of the intake passage M2 of the internal combustion engine M1 works in conjunction with the accelerator pedal M3. Also,
In the middle of the intake passage M2, the first throttle valve M4
Second throttle valve M provided upstream or downstream of the
5 is driven by an electric actuator M6. Here, the opening degree of the first throttle valve M4 is detected by the first valve opening degree detecting means M7, and the second valve opening degree detecting means M is detected.
The opening degree of the second throttle valve M5 is detected by 8. Also, the cruise control actuator M9
Accordingly, the first throttle valve M4 causes the accelerator pedal M3 to
Driven independently of the operation. Further, the automatic driving determination means M10 determines whether or not the automatic driving of the internal combustion engine M1 is necessary based on the driver's instruction. When the automatic operation determination means M10 determines that the automatic operation of the internal combustion engine M1 is necessary, the drive control means M11 is based on the detection results of the first and second valve opening degree detection means M7, M8.
As a result, the cruise control actuator M9 is driven and the electric actuator M6 is drive-controlled to control the opening degree of the second throttle valve M5. Therefore, during cruise control, the opening degree of the second throttle valve M5 is mainly controlled by the electric actuator M6. By this control, the intake air amount is adjusted and the automatic running is executed.

Further, in the present invention, the automatic driving judging means M
When it is determined by 10 that the automatic operation of the internal combustion engine M1 is necessary, the adjustment control means M12 causes the opening degree of the first throttle valve M4 to fall within a predetermined range from the opening degree of the second throttle valve M5. The cruise control actuator M9 is adjusted and controlled so that the opening degree becomes larger. Therefore, the opening of the first throttle valve M4 is changed even when the accelerator pedal M3 is operated by the driver requesting acceleration during the cruise control, and the first valve opening is changed. It can be detected by the detection means M7. Therefore, it is possible to detect the acceleration request during cruise control without separately providing a means for detecting the acceleration request such as the accelerator pedal operation amount.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the cruise control device for an internal combustion engine according to the present invention will be described in detail below with reference to FIGS.

FIG. 2 is a schematic configuration diagram showing a cruise control device for a gasoline engine mounted on a vehicle in this embodiment. An engine 1 as an internal combustion engine mounted on a vehicle includes an intake passage 2 and an exhaust passage (not shown). In the above structure, the engine 1 takes in outside air from an air cleaner (not shown) through the intake passage 2. Further, at the same time as the intake of the outside air, fuel is injected from each injector to the vicinity of the intake manifold, so that the mixture of the fuel and the outside air is taken into the combustion chamber of each cylinder. Then, the taken-in air-fuel mixture explodes and burns in each combustion chamber due to the operation of the spark plug, and the piston, the crankshaft, and the like (not shown) are actuated to obtain the driving force of the engine 1, that is, the engine output. . Further, the burned gas after being burned in each combustion chamber is guided to the exhaust passage as exhaust gas, purified by the catalytic converter, and then discharged to the outside.

As shown in FIG. 2, in the middle of the intake passage 2, a sub-throttle valve 3 as a second throttle valve and a main throttle valve 4 as a first throttle valve are arranged in series from the upstream side thereof. It is installed in. The main throttle valve 4 is an accelerator pedal 5 provided in the driver's seat.
, Which are mechanically connected by an accelerator link via a wire 6, and are opened and closed in conjunction with the operation of the accelerator pedal 5. The main throttle valve 4 is always biased by the return spring 7 in the closing direction. Basically, in this embodiment, the opening of the main throttle valve 4, that is, the main throttle opening TAM is set so as to have a unique linear opening characteristic with respect to the operation amount of the accelerator pedal 5. .

On the other hand, the sub-throttle valve 3 is opened and closed by the operation of a step motor 8 as an electric actuator provided in the vicinity thereof. The support shaft of the sub-throttle valve 3 is connected to the output shaft of the step motor 8. The sub-throttle valve 3 is constantly urged by the return spring 9 in the opening direction. And
By opening and closing the main throttle valve 4 and the sub-throttle valve 3, respectively, the amount of intake air taken into each cylinder through the intake passage 2 is adjusted, thereby controlling the engine output.

In the present embodiment, in order to improve the operability of the vehicle, under various driving conditions, the engine output with respect to the operation amount of the accelerator pedal 5 is optimized by the cooperation of the opening characteristics of the throttle valves 3 and 4. Is set to. That is, while the engine 1 is operating, the sub throttle valve 3
Is controlled in the closing direction by the step motor 8, so that the intake amount uniquely adjusted by the main throttle valve 4 that is interlocked with the accelerator pedal 5 is further reduced.
As a result, the engine output is suppressed, the engine output characteristic for the operation of the accelerator pedal 5 is appropriately set under various operating conditions, and good accelerator controllability is realized over the entire operating range. Further, in this embodiment, since the throttle is a two-valve type, even if the sub-throttle valve 3 fails (fails), the driver returns the accelerator pedal 5 to close the main throttle valve 4. It is possible to decelerate the engine 1 without delay. When the sub-throttle valve 3 fails in the fully open position, the driver can operate the accelerator pedal 5
It is possible to arbitrarily open the main throttle valve 4 and arbitrarily control the engine output. As a result, the vehicle can be evacuated when the vehicle fails.

A main throttle sensor 31 as a first valve opening detecting means for detecting the main throttle opening TAM is provided near the main throttle valve 4. In addition, a sub-throttle sensor 32 is provided near the sub-throttle valve 3 as a second valve opening detection means for detecting the sub-throttle opening TAS.

Further, a vehicle speed sensor 33 is provided in a transmission (not shown) drivingly connected to the engine 1. With this vehicle speed sensor 33, the vehicle speed,
That is, the vehicle speed V is detected.

In the present embodiment, the main throttle valve 4 is provided with the cruise control actuator 1
1 is connected. That is, the cruise control actuator 11 includes a diaphragm type actuator 12 and a vacuum switching valve (V
SV) 13 is provided. The diaphragm type actuator 12 is a lever 12a for opening and closing the main throttle valve 4.
And a diaphragm 12b connected to the lever 12a,
It is composed of a negative pressure chamber 12c partitioned by a diaphragm 12b, a spring 12d arranged in the negative pressure chamber 12c and biasing the diaphragm 12b, and the like. Then, in the state where the negative pressure is not introduced into the negative pressure chamber 12c, the diaphragm 12b is biased by the spring 12d, and the lever 1
2a is held at a position where the main throttle valve 4 is not driven. That is, the main throttle valve 4 is closed unless the accelerator pedal 5 is operated. On the other hand, the negative pressure chamber 12c
When the negative pressure is introduced into the diaphragm 12, the diaphragm 12b is pulled by the negative pressure and displaced, and the lever 12a is held at the position where the main throttle valve 4 is opened. That is, the main throttle valve 4 is opened regardless of the operation amount of the accelerator pedal 5.

The negative pressure chamber 12c of the diaphragm type actuator 12 is connected to the VSV 13 through a pipe 14. The VSV 13 is a three-way solenoid valve having an input port, an output port, and an atmosphere port, and is duty-controlled. One end of a pipe 14 communicating with the negative pressure chamber 12c is connected to the output port of the VSV 13. The input port of the VSV 13 is connected to a negative pressure generation source (for example, in the middle of the intake passage 2 because of the gasoline engine in this embodiment) through the negative pressure pipe 15.

When the VSV 13 is turned on (for example, duty ratio = “100%”), the negative pressure chamber 12c of the diaphragm type actuator 12 is connected to the pipe 14,
The air is communicated with the intake passage 2 through the VSV 13 and the like. Therefore, the intake negative pressure in the intake passage 2 is supplied into the negative pressure chamber 12c of the diaphragm actuator 12.
On the other hand, VSV13 is turned off (for example, duty ratio =
By "0%"), the negative pressure chamber 12c of the diaphragm actuator 12 is opened to the atmosphere.

Further, in this embodiment, a cruise control switch 17 as shown in FIG. 3 is provided in the vicinity of a steering wheel (not shown). The cruise control switch 17 is provided with a lever switch body 18 having a lever shape and a push-type main switch 19 provided at the tip thereof. The cruise control switch 17 is appropriately operated by the driver to execute cruise control (automatic traveling or constant speed traveling). In other words, each time the main switch 19 is pushed in the direction of arrow A, the power is turned on / off. Further, while the lever switch main body 18 is being pushed up in the direction of arrow B in the figure, the control of "return" or "acceleration" is performed. Furthermore, while the lever switch main body 18 is being pushed down in the direction of arrow C in the figure, control of "set" or "deceleration" is performed. At the same time, when the lever switch main body 18 is pulled in the direction of arrow D in the figure, "cancel" control is performed and the cruise control is released. In this embodiment, the control of "cancel" is also performed when the brake pedal (not shown) is depressed by a predetermined amount or more.

As shown in FIG. 2, the above-mentioned control is performed by an electronic control unit (hereinafter referred to as "ECU") provided via a cruise control computer (not shown) near the base end of the cruise control switch 17. 41) based on the operation signal of each switch.

In this embodiment, the main throttle sensor 31, the sub throttle sensor 32, the vehicle speed sensor 33,
The cruise control switch 17 and the like are electrically connected to the ECU 41. More specifically,
The ECU 41 is a read-only memory (RO) in which a central processing unit (CPU), a predetermined control program and the like are stored in advance.
M), a random access memory (RAM) for temporarily storing the calculation results of the CPU, a backup RAM for storing prestored data, and the like. And the ECU
Reference numeral 41 is configured as a logical operation circuit in which these units and external input / output circuits are connected by a bus. The main throttle sensor 31, the sub-throttle sensor 32, the vehicle speed sensor 33, the cruise control switch 17 and the like are connected to the external input circuit. Further, the stepper motor 8 is provided in the external output circuit of the ECU 41.
And VSV13 and the like are connected to each other. And
The ECU 41 performs cruise control of the engine 1 or override (during cruise control) based on various signals input from the various sensors 31 to 33 and the cruise control switch 17 and other signals (a signal indicating that the brake pedal is depressed). Step motor 8 and VS to execute control such as acceleration)
The operation of V13 and the like is preferably controlled. In this example,
The ECU 41 constitutes an automatic driving determination means, a drive control means, and an adjustment control means.

In the present embodiment, during normal traveling, the main throttle valve 4 is opened and closed by operating the accelerator pedal 5, and the main throttle opening TAM detected by the main throttle sensor 31 is read by the ECU 41. Be done. The ECU 41, based on the main throttle opening TAM and signals indicating the operating states of various vehicles,
The step motor 8 is drive-controlled so that the sub-throttle opening TAS has an optimum value. With such control,
As described above, the engine output is equal to both throttle valves 3 and 4.
It is controlled to be optimum by the cooperation of the respective opening characteristics.

On the other hand, during cruise control (automatic traveling or constant speed traveling), the ECU 41 controls the cruise control actuator 11 described later (more specifically, the duty control of the VSV 13),
The main throttle opening TAM is controlled to a value within a predetermined target range, and the step motor 8 is feedback-controlled so that the vehicle can travel at the target vehicle speed.

Next, the processing operation for the opening / closing control of the main throttle valve 4 during the cruise control control executed by the ECU 41 will be described with reference to the flowchart shown in FIG.

By the way, the flow chart shown in FIG.
An actuator target opening TT, which is the target opening of the diaphragm type actuator 12 executed by the ECU 41
The "actuator target opening degree setting routine" for setting AM is shown. That is, this flowchart shows how to adjust the opening degree of the diaphragm actuator 12 (and thus the duty ratio of the VSV 13). This routine is executed by a regular interrupt every predetermined time.

If the process first moves to this routine, the ECU 41 determines in step 101 based on the detection results of the main throttle sensor 31, the sub-throttle sensor 32, the vehicle speed sensor 33, the cruise control switch 17, etc. Various signals related to TAM, sub throttle opening TAS, vehicle speed V and cruise control are read. Further, the ECU 41
Read the various flags that are currently set.

Next, in step 102, the ECU 41 determines whether or not the main switch 19 of the cruise control switch 17 is turned on based on various signals relating to the cruise control read this time. If the main switch 19 of the cruise control switch 17 is not currently turned on, it is determined that the cruise control is not necessary, and the step 1
03, the target actuator opening TTAM
_i is set to "0", and the subsequent processing is temporarily terminated.

If the main switch 19 is turned on, it is determined in step 104 whether or not the set switch is turned on based on various signals regarding the cruise control read this time. This set switch is turned on when the above-mentioned lever switch body 18 is pushed down in the direction of arrow C in FIG. Then, when the set switch is turned on, it is determined in step 105 whether the override flag ORF is "1". The override flag ORF is a flag indicating whether or not the driver depresses the accelerator pedal 5 to temporarily request acceleration (this is called override) during cruise control. Then, when the override is performed, the override flag ORF is set to "1", and otherwise it is set to "0". Then, if the override flag ORF is not "1" in step 105, it is determined that the override is not currently performed and the cruise control needs to be performed, and the process proceeds to step 106.

At step 106, the ECU 41
It is determined whether or not the main throttle opening TAM read this time is less than or equal to a value obtained by adding a predetermined constant T1 to the sub throttle opening TAS read this time. If the main throttle opening TAM is less than or equal to the value obtained by adding the constant T1 to the sub throttle opening TAS, step 107
At this time, the main throttle opening TAM read this time
However, it is determined whether or not the value is greater than or equal to a value obtained by adding a predetermined constant T2 (where 0 <T2 <T1) to the sub-throttle opening TAS read this time. When the main throttle opening TAM is greater than or equal to the value obtained by adding the constant T2 to the sub throttle opening TAS, the main throttle opening TAM is obtained by adding the constant T2 to the sub throttle opening TAS and the sub throttle opening TAS. And a value obtained by adding a constant T1 to (TAS + T2 ≦ TAM ≦ TAS + T1). That is, it is determined that the main throttle opening TAM is within the target range, and the routine proceeds to step 108. Then, in step 108, the previous actuator target opening TTAM _i-1 is set as the current actuator target opening TTAM _i . That is,
The current actuator target opening TTAM _i is set to the same value as the previous actuator target opening TTAM _i-1 . Then, the subsequent processing is temporarily terminated.

On the other hand, in step 107, if the main throttle opening TAM is smaller than the value obtained by adding the constant T2 to the sub throttle opening TAS, it is determined that the main throttle opening TAM is smaller than the target range. Then, the process proceeds to step 109. Then, in order to increase the actuator target opening TTAM, in step 109, a value obtained by adding a predetermined constant T0 [for example, T0 = (T1-T2) / 2] to the previous actuator target opening TTAM _i-1 Actuator target opening TTAM _i
Set as. Then, the subsequent processing is temporarily terminated.

In step 106, when the main throttle opening TAM is larger than the value obtained by adding the constant T1 to the sub throttle opening TAS, it is determined that the main throttle opening TAM is larger than the target range. After making a determination, the process proceeds to step 110. Step 11
At 0, it is determined whether the vehicle speed V _i read this time is larger than the value obtained by adding a predetermined vehicle speed constant V _m to the vehicle speed V _i-1 read last time. And this vehicle speed V
_{When i} is larger than the value obtained by adding a predetermined vehicle speed constant V _m to the previous vehicle speed V _i-1, it is determined that the vehicle speed has increased due to traveling on a downhill road. Then, in order to reduce the main throttle opening TAM, step 1
11, the previous actuator target opening TTAM
A value obtained by subtracting a predetermined constant T0 (this constant T0 may be different from the value in step 109) from _i-1 is set as the current actuator target opening TTAM _i . Then, the subsequent processing is temporarily terminated.

On the other hand, in step 110, if the current vehicle speed V _i is not larger than the value obtained by adding the predetermined vehicle speed constant V _m to the previous vehicle speed V _i-1 , it is determined that there is an override. . That is, it is determined that the driver depresses the accelerator pedal 5 to temporarily request acceleration. Then, in step 112, the ECU 41 sets the override flag ORF to "1".
Further, in the following step 113, the previous actuator target opening TTAM _i-1 is stored as the opening before opening override TTOA.

Further, the ECU 41 executes the next step 11
In 4, because it is currently overriding,
The actuator target opening TTAM _i this time is set to “0”. Therefore, during this period, the main throttle valve 4 is opened by depressing the accelerator pedal 5, and the vehicle is accelerated. Then, the subsequent processing is temporarily terminated.

If the override flag ORF is "1" at the step 105, it is determined that the override is currently being performed, and the step 115 is performed.
Move to. In step 115, it is determined whether or not the main throttle opening TAM read this time is larger than the stored pre-override determination opening TTAO. Then, when the main throttle opening TAM is larger than the pre-override determination opening TTAO, it is determined that the overriding is still in progress, and the routine proceeds to step 114. Then, the actuator target opening TTAM _i of this time is set to “0”, and the subsequent processing is once ended. On the other hand, in step 115, the main throttle opening TAM is set to the pre-override determination opening TTAO.
If the following occurs, it is determined that the override has been completed. That is, when the driver finishes depressing the accelerator pedal 5, the main throttle opening T
It is determined that AM has become equal to or less than the opening TTAO before the override determination. Then, in step 116, the override flag ORF is set to "0", and the subsequent processing is temporarily terminated.

If the set switch is not turned on in step 104, step 1
Go to 17. In step 117, it is determined whether or not the return switch is on. The return switch is turned on when the lever switch body 18 described above is pushed up in the direction of arrow B in the drawing.
If the return switch is on, it is determined in step 118 that the cruise control is required again, and it is assumed that the set switch is on to prepare for the next process. At the same time, the ECU 41 proceeds to step 109 to increase the actuator target opening TTAM for the time being.
A value obtained by adding a predetermined constant T0 to the previous actuator target opening TTAM _i-1 is the current actuator target opening T
Set as TAM _i . Then, the subsequent processing is temporarily terminated. If the return switch is not turned on in step 117, it is determined that cruise control is not necessary, and the process proceeds to step 103. Then, in step 103, the current actuator target opening TTAM _i is set to “0”, and the subsequent processing is temporarily terminated.

As described above, in this "actuator target opening setting routine", various conditions and various parameters (whether cruise control is necessary, whether override is required, main throttle opening TA)
M, sub throttle opening TAS, etc.), the actuator target opening TTAM is set.

As described above, according to the cruise control device of the present embodiment, during the cruise control, the sub-throttle valve 3 is mainly driven and controlled by the step motor 8, so that the intake air amount is adjusted and the vehicle speed is increased. V is held almost constant. At this time, the main throttle opening TAM controlled by the cruise control actuator 11 is equal to the sub throttle opening T
Feedback control is performed so that the value is maintained between a value obtained by adding a predetermined constant T2 to AS and a value obtained by adding a predetermined constant T1 to the sub throttle opening TAS (TAS + T2 ≦ T
AM ≦ TAS + T1). More specifically, as shown in FIG. 5, when the sub-throttle opening TAS at a certain time point is “α”, the main throttle opening TAM at that time point is “β (where α + T2 ≦ β ≦ α +
T1) ”.

Therefore, even when the driver requests an acceleration during cruise control and the accelerator pedal 5 is operated, the main throttle valve is fully opened, unlike the prior art in which the main throttle valve is fully opened. The opening degree of 4 increases (becomes larger than “α + T1”), and the fact that the vehicle speed V is increasing on a slope or the like is excluded and the fact can be detected by the main throttle sensor 31. it can. Therefore, it is possible to reliably detect an acceleration request during cruise control, that is, an override, without separately providing a means (accelerator opening detection sensor) for detecting an acceleration request such as an accelerator pedal operation amount. As a result, it is possible to promptly perform accurate control depending on the situation from during cruise control to overriding control.

Further, in the present embodiment, during the override control, the previous actuator target opening TTAM _i-1 immediately before the entry into the override control is stored as the pre-override determination opening TTAO, and the current main target opening TTAM _i-1 is stored. The throttle opening TAM is always compared. Therefore, even when the depression of the accelerator pedal 5 is ended during the override control, the end of the override can be detected promptly and reliably. Therefore, cruise control can be resumed again in response to a subsequent request.

Further, in this embodiment, the main throttle opening TAM is maintained between a value obtained by adding a predetermined constant T2 to the sub throttle opening TAS and a value obtained by adding a predetermined constant T1 to the sub throttle opening TAS. I was made to do it. Here, by setting the constant T1 as small as possible,
Even if the accelerator pedal 5 is slightly depressed, the read main throttle opening TAM deviates from the target range. Therefore, the override can be detected promptly.

The present invention is not limited to the above-described embodiments, but may be implemented as follows with a part of the structure appropriately changed without departing from the spirit of the invention. (1) In the "actuator target opening degree setting routine" of the above-described embodiment, after the processing of step 116 in which it is determined that the overriding is finished, the subsequent processing is once finished, but thereafter, step 116-B. As an alternative, a process of setting the pre-override determination opening TTao as the current actuator target opening TTAM _i may be added. By performing such processing, it becomes possible to quickly and smoothly return to the main throttle opening TAM at the time of the initial cruise control.

(2) In the above embodiment, the embodiment is applied to a vehicle equipped with a gasoline engine, but it may be applied to a vehicle equipped with a diesel engine. In such a case, a vacuum pump (not shown) can be preferably used as the negative pressure generation source. That is, through the pipe 14 to the negative pressure chamber 12c of the diaphragm type actuator 12, the VSV1
3 is connected and its input port is connected to the vacuum pump. This vacuum pump is drivingly connected to the crankshaft of the diesel engine body,
It is driven in conjunction with the operation.

(3) In the above embodiment, the lever type cruise control switch 17 is adopted, but a switch other than the above type such as a button operating system may be used.

(4) In the above embodiment, the sub throttle valve 3 is arranged upstream of the main throttle valve 4, but the sub throttle valve 3 may be arranged downstream of the main throttle valve 4. . The technical idea which is not described in each claim of the claims and which can be grasped from the above-described embodiment will be described below together with its effect.

(A) In the cruise control device for an internal combustion engine according to claim 1, the cruise control actuator comprises at least a diaphragm type actuator driven by negative pressure based on a negative pressure source. And

With such a structure, it is not necessary to separately provide an actuator that is mechanically or electrically driven, and the cost can be reduced. (B) In the cruise control device for the internal combustion engine according to claim 1, the adjustment control means, when the automatic operation determination means determines that the automatic operation of the internal combustion engine is necessary, the first throttle The valve opening is
It is characterized in that the cruise control actuator is adjusted and controlled so as to be larger than the opening of the second throttle valve by an opening within a predetermined range of "20 °" or less.

With such a structure, it is possible to eliminate the discomfort for the driver when the accelerator pedal is operated during the cruise to accelerate (at the time of overriding).

(C) In the cruise control device for an internal combustion engine according to claim 1, claim (a) or (b),
When it is determined by the automatic driving determination means that the internal combustion engine needs to be automatically driven, the opening degree of the first throttle valve is changed to "5" as the opening degree of the second throttle valve.
The cruise control actuator is adjusted and controlled so as to be within a range of a value obtained by adding "°" to a value obtained by adding "30 °" to the opening degree of the second throttle valve.

With such a structure, it is possible to eliminate the discomfort for the driver at the time of overriding.

[0051]

As described above in detail, according to the cruise control device for an internal combustion engine of the present invention, even if an acceleration request is made during cruise control, the acceleration request can be sent without separately providing a means for detecting it. This has an excellent effect that detection can be performed and appropriate control can be promptly performed according to the situation.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing a cruise control device for an internal combustion engine in one embodiment embodying the present invention.

FIG. 3 is a partial perspective view showing a cruise control switch according to an embodiment.

FIG. 4 is a flowchart showing an “actuator target opening degree setting routine” executed by an ECU in one embodiment.

FIG. 5 is a graph showing the relationship between the main throttle opening and the sub-throttle opening for explaining the function and effect in one embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as internal combustion engine, 2 ... Intake passage, 3 ... Sub-throttle valve as second throttle valve, 4 ... 1st
Main throttle valve as a throttle valve, 5 ... Accelerator pedal, 8 ... Step motor as an electric actuator, 11 ... Cruise control actuator, 12 ... Diaphragm actuator, 13 ... V that constitutes a part of the cruise control actuator
SV, 31 ... Main throttle sensor, 32 ... Sub-throttle sensor, 41 ... ECU that constitutes automatic driving determination means, drive control means, and adjustment control means.

Claims (1)

[Claims] 1. An internal combustion engine is provided with a midway of an intake passage,
A first throttle valve that operates in conjunction with an accelerator pedal; a second throttle valve that is provided upstream or downstream of the first throttle valve in the middle of the intake passage; and a second throttle valve that drives the second throttle valve For controlling the opening of the first throttle valve, a first valve opening detecting means for detecting the opening of the first throttle valve, and a second valve for detecting the opening of the second throttle valve. An opening degree detection means, a cruise control actuator for driving the first throttle valve irrespective of the operation of the accelerator pedal, and a determination as to whether or not there is a need for automatic operation of the internal combustion engine based on a driver's instruction. And a detection result of the first and second valve opening degree detection means when the automatic operation determination means determines that the automatic operation of the internal combustion engine is necessary. A cruise control device for an internal combustion engine, comprising: a drive control means for driving the cruise control actuator based on the result, and drivingly controlling the electric actuator to control the opening degree of the second throttle valve. When the automatic operation determination means determines that the internal combustion engine needs to be automatically operated, the opening degree of the first throttle valve is within a predetermined range from the opening degree of the second throttle valve. A cruise control device for an internal combustion engine, comprising adjustment control means for adjusting and controlling the cruise control actuator so as to increase the opening degree thereof.