JPH0942001A - Rotational speed control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a walking travel possible at a speed corresponding to the condition of the road surface according to driver's intention by controlling the quantity of intake air of an internal combustion engine corresponding to a history of the action of a car speed changing means when an accelerator pedal is fully closed in a state of a clutch engaged. SOLUTION: An idle-speed-control-velve(ISCV) 48 is provided halfway of a bypass passage 46. The ISCV 48 can optionally change its opening in accordance with an external driving signal. When a throttle valve 42 is fully closed, the air quantity is supplied to an internal combustion engine 10 in proportion to the opening of the ISCV 48. Therefore, the idling engine speed of the internal combustion engine 10 can be controlled by controlling the opening of the ISCV 48. That is, the intake air quantity of the internal combustion engine at the time when an accelerator pedal is fully closed with a clutch engaged, can be controlled corresponding to a history of the action of a car speed changing means. A walking travel at a proper speed that according to the condition of the road surface, can thus be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation speed control device for an internal combustion engine for a vehicle, and particularly to a rotation speed control of an internal combustion engine suitable for controlling the rotation speed of an internal combustion engine mounted on a vehicle equipped with a manual transmission. Regarding the device.

[0002]

2. Description of the Related Art When a four-wheel drive vehicle (hereinafter referred to as a 4WD vehicle) travels off roads such as rubble roads and rocky roads, it is necessary to keep the traveling speed low for safety. In this case, in order to prevent unstable running of the vehicle due to large unevenness of the road surface, low speed running, stopping, and starting are performed with the clutch engaged. In order to obtain good runnability during such off-road running, it is necessary to perform stable walking running, that is, low-speed running due to idle rotation of the internal combustion engine with the clutch engaged.

By the way, as a technique for maintaining the idle rotation of an internal combustion engine in a stable manner, there is a conventional technique disclosed in JP-A-6-15912.
The internal combustion engine control device disclosed in Japanese Patent Laid-Open Publication No. 2 (1994) is known. The internal combustion engine control device disclosed in the above publication discloses an idling speed control (hereinafter referred to as ISC control) when the engine speed falls below a target idle speed during traveling with a clutch engaged. In this way, the intake air amount of the internal combustion engine is increased to stabilize the operation of the internal combustion engine, and the increase of the engine speed due to the increase of the intake air amount is suppressed by delaying the ignition timing of the internal combustion engine. .

[0004]

When traveling off-road, the load on the vehicle may vary greatly due to the unevenness of the road surface. Therefore, the vehicle speed is not always constant even if the rotation speed of the internal combustion engine is maintained constant. Therefore, when the above conventional internal combustion engine control device is applied to a 4WD vehicle to perform off-road walking traveling, it is not possible to maintain a constant walking vehicle speed. Further, during off-road walking, it is preferable that the speed intended by the driver is realized rather than the constant vehicle speed. However, the above-mentioned conventional device does not have a function of reflecting the driver's intention in the low speed vehicle speed due to idle rotation. The conventional device described above is also unsuitable as a device for controlling off-road walking running in this respect as well.

Further, in the above-described conventional internal combustion engine control device, when the accelerator is depressed during low speed running due to idle rotation, the ignition timing delay control is stopped and the ignition timing is returned to the normal timing. As a result, a discontinuous change in the ignition timing may occur and a traveling shock may occur. Also,
The above-described conventional internal combustion engine control device is configured to suppress the increase in the engine speed by using the ignition timing delay control as described above, but the ignition timing delay control is a control for deteriorating the combustibility. Therefore, in a region where the delay amount is large, there is a problem that misfire easily occurs in the internal combustion engine and it becomes difficult to maintain good drivability.
As described above, the above-described conventional internal combustion engine control device is not necessarily an optimal configuration for walking.

The present invention has been made in view of the above-mentioned points, and enables walking traveling at a speed according to the road surface condition according to the driver's intention, and also shows the operating state of the internal combustion engine during walking traveling. An object of the present invention is to provide a rotation speed control device for an internal combustion engine, which can be stably maintained.

[0007]

The above-mentioned object is operated for the purpose of changing the vehicle speed in an internal-combustion-engine speed control device for controlling the speed of the internal-combustion engine mounted on a vehicle equipped with a manual transmission. Vehicle speed changing means, and an air amount control means for controlling the intake air amount of the internal combustion engine when the accelerator pedal is fully closed with the clutch engaged, according to the history of the operation of the vehicle speed changing means. This is achieved by the rotation speed control device of the internal combustion engine provided.

In the present invention, the vehicle speed changing means is operated for the purpose of changing the vehicle speed. Therefore, the history reflects the driver's intention of acceleration or deceleration. It can be estimated that the driver wants a higher vehicle speed if the vehicle is frequently accelerated even at idle speed while traveling. On the other hand, if deceleration is frequently performed, it can be estimated that the driver wants a lower vehicle speed. In the present invention, the air amount control means controls the intake air amount of the internal combustion engine according to the history of the vehicle speed changing operation. Therefore, the intake air amount of the internal combustion engine when the clutch is engaged and the accelerator is fully closed will be controlled according to the driver's intention, and the engine speed will achieve the vehicle speed according to the driver's intention. The number of rotations is controlled.

[0009]

FIG. 1 shows a system configuration diagram of an embodiment of the present invention. The present embodiment is an example in which the rotation speed control device is applied to an internal combustion engine 10 mounted on a part-time 4WD vehicle. In FIG. 1, the cylinder block 12 constitutes the main body of the internal combustion engine 10. In the wall of the cylinder block 12, a water jacket 14 through which cooling water circulates
Is provided. In addition, the cylinder block 12 includes
A water temperature sensor 16 that detects the temperature of the cooling water flowing through the water jacket 14 is provided.

A piston 18 is housed in the cylinder block 12 in a liquid-tight manner and in a slidable manner. The internal combustion engine 10 of the present embodiment is a multi-cylinder internal combustion engine, and in the cylinder block 12, a plurality of pistons (not shown) are housed in addition to the piston 18. Further, inside the cylinder block 12, above the piston 18, the combustion chamber 20
Are formed. An ignition plug 22 is arranged in the combustion chamber 20, and an intake manifold 28 and an exhaust manifold 30 communicate with each other via an intake valve 24 or an exhaust valve 26, respectively.

The intake manifold 28 is provided with a plurality of branch pipes that connect each cylinder of the internal combustion engine 10 and the surge tank 32. Each branch pipe is provided with a solenoid valve type injector 34. In the internal combustion engine 10, the fuel injection amount can be changed by changing the time length of the drive signal supplied to the injector 34.

An intake pipe 40 is provided upstream of the surge tank 32.
Are in communication. Inside the intake pipe 40, a main throttle valve (hereinafter simply referred to as a throttle valve) 4
2 are provided. The throttle valve 42 is a valve that operates in conjunction with the accelerator pedal, and is configured to have an opening degree according to the amount of depression of the accelerator pedal. A throttle sensor 44 that detects the opening of the throttle valve 42 is provided near the throttle valve 42.

The intake pipe 40 and the surge tank 32 are connected by a bypass passage 46 that bypasses the throttle valve 42. Therefore, the throttle valve 42
Even if is fully closed, the internal combustion engine 10 is supplied with air if the bypass passage 46 is in the conductive state. An idle speed control valve (hereinafter referred to as ISCV) 48 is provided in the middle of the bypass passage 46.
Is provided. The ISCV 48 is a valve mechanism including a step motor as a drive mechanism, and its opening can be arbitrarily changed according to a drive signal supplied from the outside. When the throttle valve 42 is fully closed, IS
The amount of air corresponding to the opening degree of the CV 48 is supplied to the internal combustion engine 10. Therefore, the idle speed of the internal combustion engine 10 can be controlled by controlling the opening degree of the ISCV 48.

An air flow meter 50 is connected to the intake pipe 40 upstream of the throttle valve 42. The air flow meter 50 generates an output signal according to the amount of air flowing inside. An intake air temperature sensor 52 is incorporated in the air flow meter 50. Intake air temperature sensor 52
Generates an output signal according to the temperature of the air flowing inside the air flow meter 50, that is, inside the intake pipe 40.
An air filter 54 is connected to the upstream side of the air flow meter 50. Therefore, the clean air that has been filtered by the air filter 54 flows into the intake pipe 40.

The water temperature sensor 16 and the spark plug 2 described above.
2, injector 34, throttle sensor 44, ISC
The V48, the air flow meter 50, and the intake air temperature sensor 52 are connected to an electronic control unit (ECU) 72. ECU
Reference numeral 72 denotes a fuel injection amount and ignition timing for realizing a stable operating state based on the outputs of the water temperature sensor 16, the throttle sensor 44, the air flow meter 50, the intake air temperature sensor 52, etc.
The ISC opening and the like are calculated to control the ignition plug 22, the injector 34, the ISCV 48, and the like.

The ECU 72 also includes a 4WD / 2WD changeover switch 60 and a Hi / Lo changeover switch 62.
Is connected. 4WD / 2WD selector switch 6
0 is 4WD drive system of the vehicle equipped with the internal combustion engine 10
To 2WD or from 2WD to 4WD. The Hi / Lo changeover switch 62 is a switch used when changing the gear ratio of the transmission during 4WD traveling from the Hi mode to the Lo mode or from the Lo mode to the Hi mode. The Hi mode is used during normal traveling. Also, Lo
The mode can be selected only during 4WD traveling, and is used in a situation where the vehicle speed is low and large torque is required, such as during off-road traveling.

When 2WD is selected by the 4WD / 2WD selector switch 60, the output of the internal combustion engine 10 is decelerated at a predetermined speed reduction ratio by transmission and then transmitted to the rear axle via a transfer. On the other hand, when 4WD is selected, the power decelerated by the transmission is transmitted to the front axle as well as the rear axle via the transfer, and the power is reduced to 4WD.
Running is performed. When the Lo mode is selected by the Hi / Lo switch 62 during 4WD traveling, the output of the transmission is further decelerated and transmitted to the rear axle and the front axle.

As shown in FIG. 1, the ECU 72 includes a vehicle speed sensor 64, in addition to the various sensors and actuators described above.
The NE sensor 66 and the brake switch 68 are connected. The vehicle speed sensor 64 is a sensor that detects the traveling speed of the vehicle, and the NE sensor 66 is a sensor that detects the rotational speed of the internal combustion engine 10. Also, the brake switch 68
Is a sensor that detects whether or not the brake pedal 69 is depressed.

The internal combustion engine speed control system of this embodiment is characterized by a method of controlling the opening of the ISCV 48 during walking. Hereinafter, referring to FIG. 2 and FIG. 3, the ECU
The contents of the process of the ISCV48 control routine executed by 72 will be described. FIG. 2 is an ISC executed by the ECU 72.
An example of the flowchart of the control routine of the opening degree of V48 is shown. This routine is started at the same time as the operation of the internal combustion engine 10 is started, and is repeatedly executed at a predetermined time interval (every 100 ms in this embodiment) during the operation of the internal combustion engine 10.

When the routine shown in FIG. 2 is started, first, at step 111, it is judged if the drive system is the 4WD / Lo mode. This determination is 4WD / 2
This is performed based on the outputs of the WD changeover switch 60 and the Hi / Lo changeover switch 62. There is a difference in the ratio between the engine speed NE and the vehicle speed V when the Hi mode is selected and when the Lo mode is selected. Therefore, it is possible to distinguish between the Hi mode and the Lo mode based on the ratio of NE and V. Further, in this embodiment, the Lo mode is realized only in the 4WD mode as described above. Therefore, if it can be determined that the mode is the Lo mode, it can be estimated that the driving method is 4WD. Therefore, in step 111, the determination of 4WD and 2WD is omitted, and H
It is also possible to determine only i / Lo.

If it is determined in step 111 that the control is not in the 4WD / Lo mode, the L4 control flag indicating whether or not the control in the 4WD / Lo mode is being executed is reset in step 133. Next, step 13
At 4, the flag processing is performed to allow the feedback control of the ISCV 48. The feedback control of the ISCV48 is performed so that the deviation between the rotational speed NE of the internal combustion engine 10 and the target idle rotational speed becomes "0".
It is realized by controlling the opening (hereinafter, referred to as ISC opening). At this time, the ECU 72 updates the learning value reflecting the ISC opening degree that achieves the target idle speed at any time,
And remember. This learned value is used as a basic ISC opening during feedback control, and the internal combustion engine 10
Is used as the initial value of the ISC opening when the engine is stopped and then restarted.

When it is determined in step 111 that the mode is 4WD / Lo mode, 4W after step 112
Control in the D / Lo mode (hereinafter referred to as L4 control) is executed. At step 112, it is judged if the L4 control flag is set. This time,
After the condition of step 111 is satisfied, in the case of the first process, the L4 control flag is determined to be in the reset state. In such a case, in step 113, ISCV
After the flag processing is performed to stop the feedback control of 48, the L4 control flag is set in step 114. As a result, when the step 112 is executed from the next time onward, it is determined that the L4 control flag is in the set state. In this case, steps 113 and 114 are skipped and the process proceeds to step 115.

In step 115, the internal combustion engine 10
It is determined whether or not the rotation speed NE is equal to or higher than the predetermined rotation speed A. The predetermined rotation speed A is a lower limit value of the rotation speed at which the internal combustion engine 10 can operate stably. When it is determined in step 115 that the rotational speed NE is smaller than the lower limit value A, the routine of this time is ended without performing the process of changing the ISC opening. On the other hand, if the condition of step 115 is satisfied, the process proceeds to step 116 and the subsequent processing is continued.

In step 116, the internal combustion engine 10
It is determined whether or not the rotation speed NE is less than or equal to the predetermined rotation speed B. The predetermined rotation speed B is an upper limit value of the idling rotation speed of the internal combustion engine 10, which is provided to prevent the vehicle from jumping out. If it is determined in step 116 that the rotational speed NE is larger than the upper limit value B, the routine of this time is ended without performing the process of changing the ISC opening degree. On the other hand, when the condition of step 116 is satisfied, the routine proceeds to step 117, and the subsequent processing is continued.

At step 117, it is judged if the vehicle speed SPD is smaller than the predetermined speed C or not. The predetermined speed C is a threshold value for determining whether or not the vehicle is walking by the vehicle speed, and in the present embodiment, C is used.
Is set to 5 km / h. If it is determined that the vehicle speed SPD is equal to or higher than the predetermined speed C, it is determined that the vehicle is not walking, and the routine of this time is ended. On the other hand, when the condition of step 117 is satisfied, it is determined that the vehicle is walking, and the process of step 118 is executed.

At step 118, it is judged if the accelerator pedal is depressed. Whether or not the accelerator pedal is depressed is determined based on whether or not the opening degree of the throttle valve 42 measured by the throttle valve sensor 44 is in the fully closed state. If it is determined in step 118 that the accelerator pedal is depressed, the process proceeds to step 128 to detect the frequency of accelerator operation. On the other hand, if it is determined that the pedal is not depressed, the process proceeds to step 119.

At step 119, it is judged if the brake pedal 69 is depressed. Whether or not the brake pedal 69 is depressed is determined by the output of the brake switch 68. When it is determined in step 119 that the brake pedal 69 is depressed, the process proceeds to step 120 to detect the frequency of brake operation. The determination results in steps 118 and 119 are stored in the ECU until the next processing.

On the other hand, if it is determined in step 119 that the brake pedal 69 is not depressed,
It is determined that neither the accelerator pedal nor the brake pedal is depressed, and the process proceeds to step 123 without performing the process of detecting the frequency of accelerator operation and brake operation.

At step 128, it is judged if the accelerator pedal was depressed in the previous processing. Whether or not the accelerator pedal was depressed at the time of the previous processing is determined based on the accelerator pedal depression state stored in the previous step 118. When it is determined that the accelerator pedal has not been depressed in the previous processing, it is determined that the accelerator pedal has been depressed between the previous processing and the current processing. In this case, in step 129, the accelerator counter AC indicating the number of times the accelerator pedal is stepped up is incremented, and in step 130, the brake pedal 69
The brake counter BC, which indicates the number of times the vehicle is stepped on, is counted down.

If it is determined in step 128 that the accelerator pedal was also depressed during the previous processing, the accelerator pedal is kept depressed from the previous processing to the current processing, that is, ,
It is determined that no new stepping action has been performed. In this case, steps 121 and 122 are skipped and the process proceeds to step 123.

At step 120, it is judged if the brake pedal 69 was depressed in the previous processing. Whether or not the brake pedal 69 was depressed at the time of the previous processing is determined based on the state of the brake pedal 69 stored in the previous step 119.

Then, after the processing for the brake counter BC is performed in the same manner as the operation for the accelerator counter AC in steps 129 and 30, step 123 is performed.
Proceed to. At step 123, it is judged if the brake counter BC is greater than or equal to the predetermined value α. The predetermined value α is a threshold value for determining whether the driver intends to decelerate by the number of times the brake pedal 69 is depressed,
In this embodiment, α is set to 3. Step 1
In 23, when it is determined that the brake counter BC is equal to or greater than α, the driver can determine that the driver intends to decelerate. In this case, next step 12
At 4, the target opening degree of the ISCV 48 is decreased. On the other hand, when it is determined in step 123 that the brake counter BC is smaller than the predetermined value α, the process of step 131 is executed.

At step 131, it is judged if the accelerator counter AC is greater than or equal to a predetermined value β. The predetermined value β is a threshold value for determining whether or not the driver intends to accelerate by the number of depressions of the accelerator pedal,
In this embodiment, β is set to 3. Step 1
When it is determined in 31 that the accelerator counter AC is β or more, the driver can determine that the driver intends to accelerate. In this case, step 13
At 2, the target opening degree of the ISCV 48 is increased. On the other hand, when the above conditions are not satisfied, it is determined that the driver does not intend to accelerate or decelerate, and ISCV48
The process proceeds to step 126 without changing the target opening degree.

After the processing of step 124 or 132 is completed, the process proceeds to step 125. Then, in step 125, the brake counter BC and the accelerator counter AC are both cleared, and then the process of step 126 is executed. In step 126, a process for keeping the target opening degree of the ISCV 48 between a predetermined upper limit value and a predetermined lower limit value is performed. That is, in step 126, it is first determined whether or not the target opening degree set in step 124 or 132 is within the predetermined upper / lower limit guard. As a result, when it is determined that the target opening degree of the ISCV 48 exceeds the upper limit value, the target opening degree is set to a predetermined upper limit value, and when it is determined that it is below the lower limit value. , The target opening is set to a predetermined lower limit. Then, in order to match the opening of the ISCV 48 with the target opening, I
After the control signal is given to the SCV 48, the current processing of this routine ends.

By the way, for example, when the accelerator pedal and the brake pedal 69 are alternately and repeatedly depressed, the driver should judge that neither acceleration nor deceleration is intended. In this case, steps 121 and 12
9, the accelerator counter AC and the brake counter B
C and C are counted up alternately. Therefore, if no action is taken to decrement these counters, they both continue to increment. As a result, the condition of step 123 or 131 is eventually satisfied, and the driver makes an erroneous determination that the driver intends to accelerate or decelerate.

On the other hand, according to the routine described above, when one of the counters is counted up in steps 121, 122 and 129, 131,
The processing is performed so that the other counter is always counted down. Thus, according to the routine described above,
Even in the case as described above, it is possible to correctly judge the driver's intention.

According to the above-mentioned routine, 4WD.Lo
In the state where the mode is selected, the feedback control of the ISCV 48 is stopped and the L4 control is performed. Then, the rotational speed NE of the internal combustion engine 10 is within a predetermined range,
Further, when the vehicle is traveling at the walking traveling speed, the driver's intention to accelerate or decelerate is determined by the number of accelerator operations and the number of brake operations of the driver, and the opening degree of the ISCV 48 is controlled. As a result, it is possible to carry out walking traveling at a speed intended by the driver according to the road surface condition.

By the way, when the ISCV 48 is feedback-controlled during off-road walking, the learning value of the ISC opening gradually increases due to a great traveling load accompanying traveling on a road surface having a lot of unevenness. When the internal combustion engine is stopped and restarted in such a state, the idle speed is controlled with the increased learning value as the target value.
In this case, if the internal combustion engine is started with the clutch engaged as described above, a large torque will be transmitted to the drive wheels as the internal combustion engine is started. As described above, when the large torque is transmitted to the drive wheels, a vehicle pop-out phenomenon may occur when the internal combustion engine is restarted. On the other hand, according to the above-described routine, the learning of the ISC opening is not performed during walking, and therefore, the target value of the idle speed does not increase. Therefore, according to the system of the present embodiment, it is possible to effectively prevent the vehicle from popping out when the internal combustion engine is restarted.

Next, a second example of the ISCV48 control routine according to this embodiment will be described with reference to FIG. This routine is characterized in that the driver's intention to accelerate or decelerate is judged based on the cumulative depression time of the accelerator pedal or the brake pedal 69. In addition,
In this routine, the same steps as those in the routine shown in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

Similar to the routine of the first embodiment shown in FIG. 2, the routine shown in FIG. 3 is started at the same time as the operation of the internal combustion engine 10 is started, and a predetermined time interval (10
It is repeatedly executed every 0 ms. In this routine, if it is determined at step 118 that the accelerator pedal is depressed, then the routine proceeds to step 178. When it is determined in step 119 that the brake pedal 69 is depressed, the process proceeds to step 170. When it is determined in steps 118 and 119 that neither the accelerator pedal nor the brake pedal is depressed, neither the brake counter BT nor the accelerator counter AT is operated and the process proceeds to step 173.

At step 178, it is judged if the accelerator pedal was depressed in the previous processing. As a result, when it is determined that the brake pedal has been depressed in the previous processing, it is determined that the brake pedal has been kept depressed from the previous time to this time. In this case, the routine proceeds to step 179, where the accelerator counter AT indicating the cumulative depression time of the accelerator pedal is counted up, and then the routine proceeds to step 180 where the brake counter BT indicating the cumulative depression time of the brake pedal 69 is counted down. In addition, the cumulative depression time is actually
(Counter value) * (time interval for executing routine (100 ms)).

On the other hand, if it is determined in step 178 that the brake pedal has not been depressed in the previous processing, the brake pedal has been depressed between the previous time and this time, that is, the elapsed time since the depression. Is determined to be insufficient to count up the brake counter BT. In this case, the brake counter BT is not operated and the process proceeds to step 173.

In steps 170 to 172, the accelerator counter AT in steps 178 to 180
Similarly to the operation for, the operation for the brake counter BT is performed and the process proceeds to step 173. Step 173
At, it is determined whether the brake counter BT is greater than or equal to the predetermined value γ. The predetermined value γ is the brake pedal 69
It is a threshold value for determining whether or not the driver intends to decelerate based on the cumulative stepping time. When it is determined in step 173 that the brake counter BT is equal to or greater than the predetermined value γ, the driver can determine that the driver intends to decelerate. In this case, the subsequent step 12
At 4, the target opening degree of the ISCV 48 is decreased. In this example, γ is set to 200. Therefore,
When the cumulative depression time of the brake pedal 69 is 20 seconds or more, it is determined that the driver intends to decelerate. On the other hand, when it is determined in step 173 that the brake counter BT is smaller than the predetermined value γ, the process proceeds to step 181.

At step 181, it is judged if the accelerator counter AT is greater than or equal to a predetermined value δ. The predetermined value δ is a threshold value for determining whether or not the driver intends to accelerate based on the cumulative depression time of the accelerator pedal. In step 181, the accelerator counter AT
If it is determined that is greater than or equal to δ, the driver can determine that the driver intends to accelerate. in this case,
In step 132, the target opening degree of ISCV 48 is increased. In this embodiment, δ is set to 200. Therefore, the cumulative depression time of the accelerator pedal is 20
When the time exceeds 2 seconds, it is determined that the driver intends to accelerate.

On the other hand, when the above conditions are not satisfied, it is determined that the driver does not intend to accelerate or decelerate, and the routine proceeds to step 126 without changing the target opening of the ISCV 48. When the processing of step 124 or 132 is completed, the routine proceeds to step 175, where both the brake counter BT and the accelerator counter AT are cleared and then the routine proceeds to step 126.

Then, in step 126, as in the routine of the first example, the target opening degree of the ISCV 48 is guarded within a predetermined range, then a control signal is given to the ISCV 48, and the routine of this time is ended. According to the above routine, the driver's intention to accelerate or decelerate is determined based on the depression times of the brake pedal 69 and the accelerator pedal. Then, based on the result of the determination, the walking traveling at an appropriate speed according to the road surface condition is realized as in the routine of the first embodiment described above.

By the way, the above-mentioned embodiment aims to control the walking speed on the off-road,
The scope of application of the present invention is not limited to this, and the present invention can be applied to a device that controls a walking speed on road. In the above embodiment, the brake pedal 69 and the accelerator pedal correspond to the vehicle speed changing means described above. The air amount control means is realized by the ECU 72 executing the processes of steps 118 to 126 and steps 170 to 180 in the first and second examples of the ISCV48 control routine.

The air amount control means is not limited to the ISCV control, and the air amount may be adjusted by controlling an electronically controlled throttle, for example.

[0049]

As described above, according to the present invention, the number of revolutions of the internal combustion engine in the state where the clutch is connected and the accelerator pedal is fully closed depends on the driver's intention to accelerate or decelerate. Can be controlled. Therefore, according to the present invention, it is possible to realize walking traveling at an appropriate speed according to the road surface condition. Further, in the present invention,
The engine speed control by the ignition timing is not required. Therefore, the operating state of the internal combustion engine during walking can be stably maintained.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a rotation speed control device for an internal combustion engine that is an embodiment of the present invention.

FIG. 2 is a first example of a flowchart of an ISCV control routine executed to control the idle speed of the internal combustion engine in the embodiment of the present invention.

FIG. 3 is a second example of a flowchart of an ISCV control routine executed to control the idle speed of the internal combustion engine in the embodiment of the present invention.

[Explanation of symbols]

10 Internal Combustion Engine 44 Throttle Sensor 48 Idle Speed Control Valve (I
SCV) 60 4WD / 2WD selector switch 62 Hi / Lo selector switch 68 Brake switch 72 Electronic control unit (ECU)

Claims (1)

[Claims] 1. A rotation speed control device for an internal combustion engine for controlling the rotation speed of an internal combustion engine mounted on a vehicle equipped with a manual transmission, wherein a vehicle speed changing means operated for the purpose of changing the vehicle speed is connected to a clutch. In this state, the intake air amount of the internal combustion engine when the accelerator pedal is fully closed is controlled according to the history of the operation of the vehicle speed changing means, and an internal combustion engine is provided. Speed controller