JPH05106482A - Engine speed control device - Google Patents

Abstract

PURPOSE:To prevent walking surge by positively preventing a variation in rotation generated at an idle return stage caused by excessive feedback correc tion when running resistance is low and by securing sufficient engine speed feedback controlled variable when the running resistance is high. CONSTITUTION:There are provided an ISC valve provided on a bypass path for bypassing a throttle valve and an idle engine speed feedback control means RI for driving time ISC valve so that actual engine speed may converge into idle target engine speed at the time of running a vehicle under fully closed throttle valve condition. There are provided a detecting means for detecting a parameter relevant to the running resistance of the vehicle, and correction means 36, 37 for correcting the control range of idle engine speed feedback in the expanding direction as the running resistance detected by the detecting means is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine speed control device for preventing a walking surge when a vehicle runs at a very low speed.

[0002]

2. Description of the Related Art Generally, when a road is congested by a vehicle and the vehicle is traveling at a low accelerator opening with a gear engaged, the accelerator opening is small and the amount of intake air is small, so that combustion does not occur. The instability causes combustion fluctuations, and the combustion fluctuations result in a walking surge that appears as vehicle vibration.

In order to prevent such a walking surge, in an engine in which an ISC valve is provided in a bypass passage that bypasses a throttle valve, the above-mentioned ISC valve is used so that the actual rotation speed converges to an idle target rotation speed. When the engine is driven and the idle speed feedback is executed, the combustion state of the engine is stabilized in a certain state, so that the above-mentioned walking surge can be prevented.

However, in order to execute the above-mentioned idle speed feedback, generally, a guard is set in which the upper limit value and the lower limit value of the feedback control range are limited as described in Japanese Patent Publication No. 62-32340. Therefore, the following problems occur.

That is, unlike the simple idle state (the stopped state of the vehicle) while the vehicle is traveling, a factor that the traveling resistance changes is added. Therefore, when the traveling resistance becomes large,
Although the required intake air amount required to maintain the predetermined idle target speed becomes large, the feedback correction amount is limited by the feedback guard described above.
The actual intake air amount is insufficient with respect to the required intake air amount, and the walking surge cannot be suppressed sufficiently.

In order to solve such a problem, when the control range of the idle speed feedback is uniformly expanded, when the required intake air amount is small and the running resistance is small (for example, 1
Feedback over-correction occurs during high-speed running), and rotation fluctuation occurs during idling return. That is, when the rotation drops due to surging, the intake air amount increases excessively due to the feedback command, and even if the rotation increases due to this increase in the intake air amount, it takes time for the feedback to chase to converge to the target rotation speed. , The engine speed rises. On the contrary, when the rotation rises due to surging, the intake air amount decreases too much due to the feedback command, and even if the rotation decreases due to this decrease in the intake air amount, it takes time to converge to the target rotation speed due to the feedback chasing. Therefore, the engine speed drops. When the feedback guard is uniformly expanded in this way, there is a problem in that, when the running resistance is small, rotation overshooting or rotation dip occurs due to overcorrection of the feedback.

In any case, when running resistance is large, ensure a sufficient idle speed feedback control amount,
Moreover, when the running resistance is small, it is difficult to prevent the rotation fluctuation at the time of returning to the idle state by appropriate feedback, and such a conventional problem is not limited to the running resistance, but the driving resistance of the engine (external The same applies when the load) fluctuates, and when the engine external load is large, the idle speed feedback control amount becomes insufficient, making it difficult to maintain the target speed, and the engine external load is small. In this case, there is a problem in that rotation fluctuation occurs.

[0008]

The invention (first invention) according to claim 1 of the present invention is such that when the running resistance is small,
It is possible to reliably prevent the rotation fluctuation that occurs at the time of idling return due to the feedback overcorrection, and when the running resistance is large, it is possible to secure a sufficient rotation speed feedback control amount, and the walking surge It is an object of the present invention to provide an engine speed control device capable of preventing the above.

According to the second aspect of the present invention, when the gear position is on the low speed side, it is possible to reliably prevent the above-mentioned rotation fluctuation, and when the gear position is on the high speed side, By securing a sufficient rotation speed feedback control amount,
An object of the present invention is to provide an engine speed control device capable of preventing a walking surge.

According to a third aspect of the present invention (the second invention), when the external load resistance of the engine is small, it is possible to reliably prevent the engine speed from fluctuating due to the feedback overcorrection. Further, when the external load resistance of the engine is large, a sufficient engine speed feedback control amount can be secured, and a target engine speed can be maintained. To aim.

According to a fourth aspect of the present invention, when the load of the vehicle air conditioner (air conditioner) is small, it is possible to reliably prevent the engine speed from fluctuating due to the feedback overcorrection. In addition, when the load of the vehicle-mounted air conditioner is large, a sufficient engine speed feedback control amount can be secured and the target engine speed can be maintained. For the purpose of provision.

[0012]

According to a first aspect of the present invention, an ISC valve is provided in a bypass passage that bypasses a throttle valve, and the vehicle is in a fully closed state of the throttle valve. An engine speed control device comprising an idle speed feedback control means for driving the ISC valve so that the actual speed converges to an idle target speed during traveling, which is a parameter related to vehicle running resistance. Is a rotation speed control device for an engine, which is provided with a detection means for detecting and a correction means for correcting the control range of the idle speed feedback in the expansion direction as the running resistance detected by the detection means increases. And

The invention according to claim 2 of the present invention is, in addition to the configuration of the invention according to claim 1, an engine revolution speed control device in which a parameter related to the running resistance is set to a gear position of a transmission. It is characterized by being.

According to a third aspect of the present invention (the second invention), the bypass passage for bypassing the throttle valve is I
An engine speed control device provided with an idle speed feedback control means for driving the ISC valve so that the actual speed converges to an idle target speed under the throttle valve fully closed condition with an SC valve interposed. A detection means for detecting a parameter related to the external load resistance of the engine, and a correction means for correcting the control range of the idle speed feedback in the expanding direction as the external load resistance detected by the detection means is larger. It is characterized in that it is an engine rotation speed control device provided with.

According to a fourth aspect of the present invention, in addition to the configuration of the third aspect of the present invention, engine speed control in which a parameter related to the external load of the engine is set to the load of the vehicle air conditioner It is a device.

[0016]

According to the invention (first invention) of the first aspect of the present invention, when the detecting means detects the parameter relating to the running resistance of the vehicle, the correcting means has a larger running resistance, Since the control range of the idle speed feedback is corrected in the expansion direction, when the running resistance is small, the feedback overcorrection is eliminated, and as a result, it is possible to reliably prevent the rotation fluctuation that occurs at the time of idling return, Further, when the running resistance is large, there is an effect that a sufficient rotational speed feedback control amount can be secured and a walking surge can be prevented.

According to the second aspect of the present invention,
When the detecting means detects the gear position (shift position), the correcting means corrects the control range of the idle speed feedback in the expanding direction as the gear position is on the higher speed side, so that the gear position is on the lower speed side. In the case of, the feedback overcorrection is eliminated, and as a result, it is possible to reliably prevent the rotation fluctuation that occurs at the time of idling return, and when the gear position is on the high speed side, sufficient rotation speed feedback control is performed. There is an effect that a sufficient amount can be secured and a walking surge can be prevented.

According to the third aspect of the present invention (the second invention), when the detecting means detects a parameter related to the external load resistance of the engine, the correcting means has a large external load resistance. As the idle speed feedback control range is expanded, the feedback overcorrection is eliminated when the external load is small, and as a result, it is possible to reliably prevent the engine speed from changing. In addition, when the external load resistance is large, there is an effect that a sufficient rotation speed feedback control amount can be secured and the target rotation speed can be maintained.

According to the invention of claim 4 of the present invention,
When the above-mentioned detecting means detects the load of the vehicle-mounted air conditioner, the larger the load, the more the correction means corrects the control range of the idle speed feedback toward the expansion direction, so the load of the vehicle-mounted air conditioner is small. In this case, overcorrection of the feedback is eliminated, and as a result, it is possible to reliably prevent the engine speed from fluctuating, and when the load of the vehicle air conditioner is large, there is a sufficient speed feedback control amount. It is possible to secure the target rotation speed and maintain the target rotation speed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. The drawing shows an engine speed control device, and FIG.
In the above, the air flow sensor 2 is connected to the rear of the air cleaner 1 for purifying the intake air, and the air flow sensor 2 is configured to detect the intake air amount.

A throttle body 3 is connected to the rear of the air flow sensor 2 described above, and a throttle chamber 5 in the throttle body 3 is provided with a throttle valve 5 for controlling the amount of intake air. And this throttle valve 5
A surge tank 6 as an expansion chamber having a predetermined volume is connected to the downstream intake passage, an intake manifold 8 communicating with the intake port 7 is connected downstream of the surge tank 6, and an injector 9 is connected to the intake manifold 8. Are installed.

On the other hand, an intake valve 12 and an exhaust valve 13 which are opened and closed by a valve operating mechanism (not shown) are attached to the above-mentioned intake port 7 and exhaust port 11 which are in proper communication with the combustion chamber of the engine 10. Further, an ignition plug (not shown) having a spark gap facing the combustion chamber is attached to the cylinder head.

An O ₂ sensor 15 is arranged in the exhaust passage 14 communicating with the above-mentioned exhaust port 11, and a catalytic converter, called a catalyst, for detoxifying harmful gases is connected to the rear of the exhaust passage 14. ..

By the way, a bypass passage 16 for bypassing the above-mentioned throttle valve 5 is provided.
While an ISC valve 17 as an ISC (idle speed control) mechanism is installed in the air cleaner 1,
An intake air temperature sensor 19 is provided downstream of the element 18, a throttle sensor 20 is provided on the throttle body 3, and a water temperature sensor 21 is provided on the water jacket.

FIG. 2 shows a control circuit of the engine speed control device. The CPU 30 has an intake air amount Q from the air flow sensor 2, an engine speed Ne from the crank angle sensor 22, and an engine cooling water from the water temperature sensor 21. The water temperature t, the TVO fully closed signal from the idle switch 23 formed integrally with the throttle sensor 20, and the shift position from the shift switch 24 for detecting the gear position of the transmission as an example of the parameter related to the running resistance of the vehicle. The ISC valve 17 is driven and controlled in accordance with a program stored in the ROM 25 based on each signal input from the RAM 25, and the RAM 26 is stored in the RAM 26 by the first map shown in FIG. 3, the second map shown in FIG. 4, and the third map shown in FIG. , Necessary maps such as the fourth map shown in FIG. 6 and the fifth map shown in FIG. 7 are stored.

Here, the above-mentioned first map (see FIG. 3) is a map in which the basic flow rate gb (base value of the amount of air flowing through the ISC valve 17) with respect to the change in the water temperature t is set.
Since the lower the value, the worse the combustibility, the basic flow rate gb is set to increase.

The above-mentioned second map (see FIG. 4) is the first speed, the second
The basic flow rate gb, the upper limit guard value FBMAX of the feedback correction flow rate gfb, and the lower limit card value FBMIN of the feedback correction flow rate gfb corresponding to the respective shift positions of the third speed, the fourth speed, and the shift position are set, and hatched in the same figure. The range indicated by this shows the control range of the idling speed feedback, and the control range of the idling speed feedback is set to increase as the running resistance becomes higher on the high speed shift side.

The above-mentioned third map (see FIG. 5) is a map in which the horizontal axis represents the engine speed Ne and the vertical axis represents the load CE, and the idle speed feedback zone is set. The area surrounded by the fully closed throttle line and the engine speed (No + α) line is the idle speed feedback zone. Here, the above-mentioned No shows a target rotation speed, and this target rotation speed No is variable depending on the water temperature t.

The above-mentioned fourth map (see FIG. 6) is a map in which the target number of revolutions No corresponding to the change in the water temperature t is set.
Since the lower the value, the worse the combustibility, the target rotational speed is set to increase.

The above-mentioned fifth map (see FIG. 7) is a feedback correction amount TM for each rotation deviation ΔNe obtained by subtracting the target rotation speed No from the current engine rotation speed Ne.
It is a map in which the value of PGFB is set.

Further, the CPU 30 described above increases the control range of the idle speed feedback in the direction of expansion as the running resistance detected by the shift switch 24 as a detecting means for detecting the parameter related to the running resistance of the vehicle increases. It also serves as a correcting means (see steps 36 and 37 in the flowchart of FIG. 8) for correcting.

The operation of the engine speed control device thus constructed will be described below with reference to the flowchart of FIG.

In the first step 31, the CPU 30 reads the engine cooling water temperature t from the water temperature sensor 21,
In the next second step 32, the CPU 30 determines whether or not the gear is in. And when gearing in, the next third step 3
On the other hand, when it is in neutral, the process proceeds to another fourth step 34.

In the fourth step 34, the CPU 30 determines from the first map shown in FIG. 3 the basic flow rate gb during neutral.
Read, set, and in the next fifth step 35, the CPU
Reference numeral 30 denotes an upper limit guard value FBMAX and a lower limit guard value F of the feedback correction flow rate gfb at the time of neutral.
Set BMIN.

On the other hand, in the above third step 33, the CPU
30 reads the shift position by the signal from the shift switch 24, and in the next sixth step 36, the CPU 3
For 0, the basic flow rate gb corresponding to the shift position is read from the second map shown in FIG. 4 and set. Then the seventh step 37
Then, the CPU 30 determines from the above-described second map that the upper limit guard value FB of the feedback correction flow rate gfb according to the shift position.
MAX and lower limit guard value FBMIN are read and set.

Next, in the eighth step 38, the CPU 30 reads the current engine speed Ne from the crank angle sensor 22, and in the next ninth step 39, the CPU 30 determines whether or not the idle switch 23 is ON. Then, when the TVO with the idle switch 23 OFF is not fully closed, the process skips to the fifteenth step 45, while when the TVO with the idle switch 23 ON is fully closed, the process proceeds to the next tenth step 40.

In the tenth step 40 described above, the CPU 30
Calculates the load CE on the basis of the calculation formula CE = Q / Ne, and from the load CE and the current engine speed Ne, the idle speed feedback zone (see FIG. 5).
No. 3 map), and if the operating state of the engine is within the feedback zone, the following 11th map is performed.
On the other hand, if it is outside the feedback zone, the routine proceeds to the above-mentioned fifteenth step 45, while proceeding to step 41.

That is, in each of the above steps 39 and 40,
Whether or not the feedback condition is satisfied is determined. When the feedback condition is satisfied, the process proceeds to the eleventh step 41, and when the feedback condition is not satisfied, the process proceeds to the fifteenth step 45.

In the above-described fifteenth step 45, the CPU 30
After setting the basic flow rate gb to the final control amount ga, in the next sixteenth step 46, the CPU 30 drives the ISC valve 17 based on the final control amount ga described above, and performs a series of processing when the feedback condition is not satisfied. finish.

On the other hand, in the eleventh step 41 described above, the CP
U30 calculates the rotation deviation ΔNe based on the calculation formula of ΔNe = Ne−No, and in the next twelfth step 42, the CPU
Reference numeral 30 reads the feedback correction amount TMPGFB per rotation based on the rotation deviation ΔNe from the fifth map shown in FIG. 7.

Next, in a thirteenth step 43, the CPU 30 obtains the final feedback correction amount gfb based on the following equation.

Gfb = clip (gfb _[i-1] + TMP
GFB, FBMIN, FBMAX) where clip means guarding gfb _[i-1] is the previous feedback correction amount TMPGFB is the feedback correction amount per time FBMIN is the lower limit guard value FBMAX is the upper limit guard value When the calculated feedback correction amount gfb is less than or equal to the lower limit guard value FBMIN, this lower limit guard value FBMIN is set as the feedback correction amount gfb, and when the feedback correction amount gfb is equal to or more than the upper limit guard value FBMAX, this upper limit guard value FBMAX is corrected by feedback. The calculated feedback correction amount gfb is the lower limit guard value FBMIN and the upper limit guard value FBM.
When the value is in the middle of AX, the calculated value gfb _[i-1] + TMP
This means that GFB is used as the feedback correction amount gfb.

Next, in a fourteenth step 44, the CPU 30 calculates the final control amount ga by adding the above-mentioned feedback correction amount gfb to the basic flow rate gb, and in the next sixteenth step 46, the CPU 30 performs the above-mentioned final control. The ISC valve 17 is driven based on the amount ga.

In short, when the shift switch 24 as the detecting means detects the gear position (shift position), the above-mentioned correcting means (see the sixth step 36 and the seventh step 37) is arranged so that the gear position is on the higher speed side. Since the control range of idle speed feedback (see the hatched portion in FIG. 4) is corrected in the expansion direction, when the gear position is on the low speed side, overcorrection of feedback is eliminated, and as a result,
It is possible to reliably prevent the rotational fluctuation that occurs when returning to idle, and when the gear position is on the high speed side, it is possible to secure a sufficient rotational speed feedback control amount and prevent a walking surge. There is an effect that can be done.

FIG. 9 is a control circuit block diagram showing another embodiment of the engine speed control device. The CPU 30 has an intake air amount Q from the air flow sensor 2 and a crank angle sensor 2
2, the engine speed Ne from 2, the engine cooling water temperature t from the water temperature sensor 21, the TVO fully closed signal from the idle switch 23 formed integrally with the throttle sensor 20, and an example of parameters related to the external load resistance of the engine. Based on each signal input of the air conditioner load from the air conditioner switch 27 that detects the load of the on-vehicle air conditioner (hereinafter simply referred to as an air conditioner), the ISC valve 17 is driven and controlled according to the program stored in the ROM 25. The RAM 26 has a sixth map shown in FIG.
Necessary maps and data such as the third map shown in FIG. 4, the fourth map shown in FIG. 6 and the fifth map shown in FIG. 7 are stored.

Here, the above-mentioned sixth map (see FIG. 11)
Is the basic flow rate gb with respect to changes in the water temperature t (ISC valve 17
A base value of the amount of air flowing through the air conditioner switch 27 is set separately for when the air conditioner switch 27 is OFF and when it is ON.
Is set to be large.

Further, the above-mentioned CPU 30 corrects the control range of the idle speed feedback in the expanding direction as the engine external load resistance (air conditioner load) detected by the air conditioner switch 27 as the detecting means becomes larger (FIG. 10). Steps 53 and 5 of the flowchart shown in FIG.
(See 6).

The operation of the engine speed control device thus constructed will be described below with reference to the flowchart of FIG.

In the first step 51, the CPU 30 reads the engine cooling water temperature t from the water temperature sensor 21 and the air conditioner load signal from the air conditioner switch 27, and in the next second step 52, the CPU 30 turns on the air conditioner switch 27. If the air conditioner is on, the process proceeds to the next third step 53, while if the air conditioner is off, the process proceeds to another fourth step 54.

At the fourth step 54, the CPU 30 reads the basic flow rate gb when the air conditioner switch is OFF from the sixth map shown in FIG. 11 and sets it, and then at the next fifth step 3
5, the CPU 30 determines the upper limit guard value FBMA of the feedback correction flow rate gfb when the air conditioner switch is OFF.
Set X and the lower limit guard value FBMIN.

On the other hand, in the above-mentioned third step 53, the CPU
30 is the air conditioner switch O from the sixth map shown in FIG.
The basic flow rate gb at the time of N is read and set. Next, in a sixth step 56, the CPU 30 causes the air conditioner switch O described above.
The upper limit guard value FBMAX and the lower limit guard value FBMIN of the feedback correction flow rate gfb corresponding to the FF time are read and set. The guard value described above may be either a linear one having a tendency almost equal to that of the map shown in FIG. 4 or one in which the guard value is gradually increased as the air conditioner load increases.

Next, in the seventh step 57, the CPU 30 reads the current engine speed Ne from the crank angle sensor 22, and in the next eighth step 58, the CPU 30 determines whether or not the idle switch 23 is ON. Then, when the TVO with the idle switch 23 OFF is not fully closed, the process skips to the 14th step 64, while when the TVO with the idle switch 23 ON is fully closed, the process shifts to the next step 59.

In the above-mentioned ninth step 59, the CPU 30 calculates the load CE based on the calculation expression CE = Q / Ne, and at the same time, the idle speed feedback zone is calculated from both the load CE and the current engine speed Ne. (See the third map in FIG. 5), and if the operating state of the engine is within the feedback zone, the process proceeds to the next tenth step 60, while if it is outside the feedback zone, the above-mentioned The process proceeds to the 14th step 64.

That is, in each of the above steps 58 and 59,
Whether or not the feedback condition is satisfied is determined. When the feedback condition is satisfied, the process proceeds to the tenth step 60, and when the feedback condition is not satisfied, the process proceeds to the fourteenth step 64.

In the above-mentioned fourteenth step 64, the CPU 30
After setting the basic flow rate gb to the final control amount ga, in the next fifteenth step 65, the CPU 30 drives the ISC valve 17 based on the above-mentioned final control amount ga, and performs a series of processing when the feedback condition is not satisfied. finish.

On the other hand, in the tenth step 60 described above, the CP
U30 calculates the rotation deviation ΔNe based on the calculation formula of ΔNe = Ne−No, and in the next eleventh step 61, the CPU
Reference numeral 30 reads the feedback correction amount TMPGFB per rotation based on the rotation deviation ΔNe from the fifth map shown in FIG. 7.

Next, in a twelfth step 62, the CPU 30 obtains the final feedback correction amount gfb based on the following equation.

Gfb = clip (gfb _[i-1] + TMP
GFB, FBMIN, FBMAX) where clip means guarding gfb _[i-1] is the previous feedback correction amount TMPGFB is the feedback correction amount per time FBMIN is the lower limit guard value FBMAX is the upper limit guard value When the calculated feedback correction amount gfb is less than or equal to the lower limit guard value FBMIN, this lower limit guard value FBMIN is set as the feedback correction amount gfb, and when the feedback correction amount gfb is equal to or more than the upper limit guard value FBMAX, this upper limit guard value FBMAX is corrected by feedback. The calculated feedback correction amount gfb is the lower limit guard value FBMIN and the upper limit guard value FBM.
When the value is in the middle of AX, the calculated value gfb _[i-1] + TMP
This means that GFB is used as the feedback correction amount gfb.

Next, in a thirteenth step 63, the CPU 30 calculates the final control amount ga by adding the above-mentioned feedback correction amount gfb to the basic flow rate gb, and in the next fifteenth step 65, the CPU 30 causes the above-mentioned final control amount gb to be calculated. The ISC valve 17 is driven based on the amount ga.

In summary, when the air conditioner switch 27 as the detecting means detects the load of the air conditioner, the above-mentioned correcting means (see the third step 53 and the sixth step 56 in the flowchart of FIG. 10) has a larger air conditioner load, Since the control range of idle speed feedback is corrected in the expanding direction, overcorrection of feedback is eliminated when the air conditioner load is small, and as a result, it is possible to reliably prevent the engine speed from changing. When the load on the air conditioner is large, there is an effect that a sufficient rotation speed feedback control amount can be secured and the target rotation speed can be maintained.

In the correspondence between the configuration of the present invention and the above-described embodiment, the idle speed feedback control means according to claim 1 of the present invention starts from steps 41, 42, 43 and 44 of the flow chart shown in FIG. In the same manner, the detecting means described in claim 1 corresponds to the shift switch 24, and the correcting means described in claim 1 corresponds to each step 36 of the flowchart shown in FIG.
Corresponding to 37, the idle speed feedback control means according to claim 3 is a second routine R comprising steps 60, 61, 62, 63 of the flowchart shown in FIG.
10, the detecting means according to claim 3 corresponds to the air conditioner switch 27, and the correcting means according to claim 3 corresponds to FIG.
Although it corresponds to the respective steps 53 and 56 of the flowchart shown in FIG. 5, the present invention is not limited to the configuration of the above-described embodiment.

[Brief description of drawings]

FIG. 1 is a system diagram showing an engine speed control device of the present invention.

FIG. 2 is a block diagram of a control circuit.

FIG. 3 is an explanatory diagram of a first map.

FIG. 4 is an explanatory diagram of a second map.

FIG. 5 is an explanatory diagram of a third map.

FIG. 6 is an explanatory diagram of a fourth map.

FIG. 7 is an explanatory diagram of a fifth map.

FIG. 8 is a flowchart.

FIG. 9 is a control circuit block diagram showing another embodiment of the present invention.

FIG. 10 is a flowchart.

FIG. 11 is an explanatory diagram of a sixth map.

[Explanation of symbols]

5 ... Throttle valve 16 ... Bypass passage 17 ... ISC valve 24 ... Shift switch 27 ... Air conditioner switch 36, 37 ... Correction means 53, 56 ... Correction means R1 ... First routine (idle speed feedback control means) R2 ... Second routine (Idle speed feedback control means)

Claims (4)

[Claims] 1. An ISC valve is provided in a bypass passage that bypasses a throttle valve, and the ISC valve is configured so that the actual rotational speed converges to an idle target rotational speed when the vehicle is running under the throttle valve fully closed state. A rotation speed control device for an engine having an idle rotation speed feedback control means for driving, a detection means for detecting a parameter related to a running resistance of a vehicle, and a running resistance detected by the detecting means being larger, An engine rotation speed control device comprising: a correction unit that corrects a control range of idle speed feedback in an expansion direction. 2. The engine speed control device according to claim 1, wherein the parameter relating to the running resistance is set to the gear position of the transmission. 3. An idle rotation driving an ISC valve in a bypass passage that bypasses the throttle valve, and driving the ISC valve so that the actual rotation speed converges to an idle target rotation speed when the throttle valve is fully closed. An engine speed control device comprising a number feedback control means, wherein the detection means for detecting a parameter related to an external load resistance of the engine and the larger the external load resistance detected by the detection means, the idle speed An engine speed control device, comprising: a correction unit that corrects a feedback control range in an expansion direction. 4. The engine speed control device according to claim 3, wherein the parameter related to the external load of the engine is set to the load of the vehicle air conditioner.