JPH10299549A - Engine idle-up control method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress large fluctuation of engine speed so as to correspond to change of all loads by increasing an injection rate of fuel when engine speed is lower than idling rotational speed, and stopping the injection rate to increase when idling upper limit rotational speed is larger than idling lower limit rotational speed. SOLUTION: Fluctuation of a load on idling operation is detected by a signal detected by engine speed detecting means 41, and a rate of fuel injected to an engine 1 is increased/decreased so as to set engine speed to be between idling lower/upper limit rotational speed A, B. In this time, the idling lower limit rotational speed A is set smaller than the idling upper limit rotational speed B. Those lower/upper limits are set, and thereby, the lowest lower limit rotational speed A is ensured when a load is small, idling is carried out, stop of the engine 1 on idling is prevented, and also a fuel consumption rate is suppressed to the lowest limit. When the load is large, it can correspond to the load with rotational speed between the lower/upper limits, and idling is carried out having a margin in load fluctuation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine idle-up control method for controlling the number of revolutions during idle operation of an engine and a device thereof.

[0002]

2. Description of the Related Art In an idling operation of a car or the like, even if the idling operation with a constant fuel is performed, a load of power generation is applied to an engine using an air conditioner or the like.
When other loads are applied to the engine, the engine speed during idling decreases, and in the worst case, the engine stops, or when these loads disappear, the engine speed increases, resulting in waste. Therefore, it is necessary to control the engine rotation during the idling operation in order to perform the idling operation with the minimum necessary engine rotation.

Conventional methods and devices for controlling an engine during idling operation include the operating load of an air conditioner for air conditioning in a driver's seat and a cargo compartment, the load by an intake / exhaust throttle that uses exhaust air for warm-up, and the power for power steering. When a specific load such as a load is operated, the operation of the load is detected, and based on this detection signal, the first idle in the injection pump is operated to increase the fuel injection amount,
It was a method of controlling the rotation of the engine.

[0004] Therefore, when a load other than the load having the operation detecting means is generated, there is a problem that the number of revolutions of the engine is reduced. In order to solve this problem, the operation and generation state of each load are reduced. Providing a sensor for detection increases the cost and complicates the control method and device. For example, the load other than the above may be an electric load that appears as an increase in the driving torque of the generator due to the use of a headlight, a car stereo, or the like, or an engine load that is generated at low temperatures due to an increase in the viscosity of the lubricating oil. There is an increase in the frictional resistance of each sliding part. In addition, as a cause of the decrease in engine output, when the temperature of the fuel or the atmosphere rises, the density of the fuel or the air decreases and the intake efficiency into the cylinder decreases, and the injection amount of the injection pump is adjusted. Control sleeve (control rack) may move to a position in the injection amount reduction or non-injection amount range due to inertia force during sudden braking, and the output may extremely decrease. .

For this reason, Japanese Patent Application Laid-Open No. 58-131337 proposes an engine idle adjusting device that controls the engine by detecting the idle speed of the engine instead of detecting the operation and generation state of each load. . In this idle adjusting device, when the rotation speed is higher than the set rotation speed, the throttle valve is set to the first opening position with a low opening to lower the engine rotation speed. Degree position and raise the engine speed,
An engine that controls an idle speed to a set speed has been proposed.

[0006]

However, since the operating condition of the throttle valve is set by only one rotation speed, the opening change of the throttle valve is repeated around this set rotation. There is a problem that rotation fluctuations due to hunting cause not only discomfort to the occupant but also decrease durability of components such as an electromagnetic three-way switching valve and a negative pressure actuator for moving the throttle valve.

[0007] Further, if the set rotation speed is reduced, the engine stops when the load suddenly fluctuates, and if the set rotation speed is increased on the assumption that the load is large, the fuel consumption increases when idling with a small load. There is. In addition, in this control, when the vehicle is running in an idle state, such as in the case of creep running on a congested road or the like, the fuel injection amount to the engine is increased or decreased by a change in load such as a gradient change during running. Since only a certain amount is intermittently increased / decreased, there is a problem that running is not smooth and a sense of incongruity is caused to deteriorate running feeling.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. It is an object of the present invention to directly detect a load applied to an engine based on an engine speed and determine the engine speed as an idle lower limit speed. It is an object of the present invention to provide an idle-up control method and apparatus capable of controlling the engine speed so as to fall between the engine upper limit engine speed and the engine speed so as to cope with all load changes while suppressing large fluctuations in the engine speed.

It is still another object of the present invention to provide an idle-up control method and apparatus capable of obtaining a good running feeling by smoothing the rotation of the engine during running without increasing or decreasing the fuel during idling.

[0010]

SUMMARY OF THE INVENTION An idle-up control method for achieving the above-mentioned object comprises an engine speed detecting device, an engine fuel injection amount increasing device, and an engine speed detecting device. An idle-up control device comprising a control means for inputting the set engine speed and controlling the injection amount increasing means, wherein the control means reduces the fuel injection amount when the engine speed falls below an idle lower limit speed. The method is a method of controlling the injection amount increasing means to stop increasing the injection amount when the engine speed exceeds an idle upper limit rotation speed that is larger than the idle lower limit rotation speed.

Further, in addition to the above control, the vehicle further comprises a transmission gear position detecting means and a clutch state detecting means, wherein the control means detects the gear position detected by the gear position detecting means and the clutch state detecting means. The clutch state detected by the means is input, and when the gear position is a position other than the neutral position and the clutch state is in the connected state, the injection amount increasing means is deactivated and the injection amount is not increased. To control.

An engine idle-up control device for implementing the above method includes an engine speed detecting means, an injection amount increasing means for increasing an engine fuel injection amount in response to an operation signal, and the engine The engine speed detected by the speed detecting means is input, and when the engine speed falls below the idling lower limit speed, an operation signal is output to the injection amount increasing means, and the engine speed becomes the idling lower limit speed. A control means for stopping the output of the operation signal when the idling upper limit rotational speed exceeds a larger value.

The transmission further includes a transmission gear position detecting means and a clutch state detecting means, wherein the control means detects a gear position other than the neutral position by the gear position detecting means, and When the clutch state detected by the state detecting means is in the connected state, the control means stops the output of the operation signal.

That is, the present invention does not operate the first idle by detecting the operation state of the device for applying a load to the engine, but directly detects the amount of load applied to the engine only by the engine speed to perform the injection. A method and a device for operating a quantity increasing means, and a method and a device for preventing hunting of an engine speed by controlling between a lower limit speed and an upper limit speed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the apparatus of the idle-up control method of the present invention includes an engine speed detecting unit 41 for detecting an engine speed N, a transmission gear position detecting unit 42, a clutch state detecting unit 43,
An engine control unit (ECU) 1 which is a control means for inputting detection signals from the detection means 41, 42, 43 and outputting an operation signal and a non-operation signal to the injection amount increasing means 3; Receiving means for increasing the amount of fuel injected into the engine.

The injection amount increasing means 3 includes a vacuum pump (V
P) 31, a negative pressure actuator 33 called "first idle", and a vacuum switching valve (VSV) 32 provided therebetween. The negative pressure actuator 33 switches the vacuum switching valve 32 according to the operation signal to connect the vacuum pump 31 and the negative pressure actuator 33. As a result, when a negative pressure is applied to the diaphragm 33a of the negative pressure actuator 33, the negative pressure actuator 33 is connected to the diaphragm 33a. The rod 33b moves, and the movement of the rod 33b moves the control lever 34 at the idling position to increase the fuel injection amount, thereby supplying fuel to the injection pump 2.

In addition, the non-operation signal causes the vacuum switching valve 32
Is switched to connect the negative pressure actuator 33 to the atmosphere open side, the atmospheric pressure is applied to the diaphragm 33a of the negative pressure actuator 33, and the diaphragm 33a and the rod 33b return,
The control lever 34 is also configured to return to the original idling position, stop increasing the fuel injection amount, and operate the engine with the original fuel injection amount for idling.

The gear position detecting means 42 is, for example,
The clutch state detecting means 43 is formed by a limit switch or the like which is turned on when the gear becomes a nutrature and turned off at other positions. The clutch state detecting means 43 is, for example, turned on at each connected position and turned off at a disconnected position.
It is formed by a limit switch or the like which becomes as follows. And
When the engine speed N detected by the engine speed detecting means 41 falls below a preset idle lower limit speed A, the engine control unit 1 outputs an operation signal to the injection amount increasing means 3 to operate the engine, and the fuel injection is performed. When the engine speed N is increased by a preset increase and the engine speed N exceeds a preset idle upper limit speed B larger than the idle lower limit speed A, a non-operation signal is output to the injection amount increasing means 3. Then, the injection amount increasing means 3 is controlled so as to stop increasing the injection amount.

Further, when the gear position detected by the gear position detecting means 42 is a position other than the neutral position and the clutch state detected by the clutch state detecting means 43 is in the connected state, that is, when the vehicle is running, The injection amount increasing means 3 is controlled so as not to operate. This idle lower limit rotation speed A is
For example, it is set at a slightly higher rotation speed with a margin than the minimum rotation speed at which the engine does not stop, and the idle upper limit rotation speed B takes into account, for example, the maximum load expected to be applied during idling and the average load. Then, even if there is some load fluctuation, the number of rotations is set to a sufficient value. Further, the fuel increase amount by the injection amount increasing means 3 is set, for example, so that the fuel amount can maintain the idling lower limit rotation speed A even when the maximum load expected to be applied at the time of idling is applied.

Specifically, this control is performed according to a flowchart of a sub-flow of engine control as shown as an example in FIG. This sub-flow is repeatedly called and executed from the main flow of the engine control during the idling operation, and continues to output either the operation signal or the non-operation signal to the injection amount increasing means 3. Here, in order to clearly indicate the output state, a non-operation signal is output. However, usually, only an operation signal is output, and a state without this operation signal is set to a non-operation state.
It is not always necessary to output the non-operation signal.

First, when this sub-flow is called and started, an engine speed N is inputted in step S1.
Next, in step S2, data of the gear position and the clutch position is input. Next, it is determined in step S3 whether the vehicle is in the traveling state.
Is confirmed in step S4. In step S3, it is determined whether or not the clutch position is at the connection position.
At step S4, it is determined whether or not the gear position is neutral. If it is not neutral, it is determined that the vehicle is running, and a non-operation signal is output at step S7, and the routine returns.

Further, when it is determined in step S3 that the clutch position is not engaged, and in step S4
When it is determined that the gear position is in the neutral position in step S5, it is determined that the vehicle is not in the running state, and the process goes to step S5 to perform control based on the rotation speed. In step S5, it is determined whether or not the operation signal is being output. If the operation signal is being output, it is determined in step S6 whether or not the engine speed N is greater than the idle upper limit speed B. If it is larger, a non-operation signal is output in step S7 and the routine returns.
If it is not larger, an operation signal is output in step S8 and the routine returns.

If the operation signal is not being output in step S5, the idling lower limit rotation speed A is determined in step S9.
If the engine speed N is smaller than the idling lower limit speed A, an operation signal is output in step S10 and the operation returns. If not, a non-operation signal is output in step S11 and the operation returns. I do. According to this control, when the engine speed N is equal to or less than the preset idle lower limit speed A according to the engine speed N during idling operation and not in the traveling state, the fuel injection amount is reduced to a predetermined amount. When the engine speed N is equal to or higher than a preset idle upper limit speed B while the engine speed N is increasing, the fuel injection amount is reduced to the original amount. , The engine speed N can be reduced, and the engine speed can be maintained between the idle lower limit speed A and the idle upper limit speed B.

According to the above-described idle-up control method, a change in load during idling operation is detected by the engine speed N, and the engine speed N is set between the idle lower limit speed A and the idle upper limit speed B. As a result, the amount of fuel injected into the engine can be increased or decreased, so that the idle operation can be performed according to the load, and the operation of the engine can be suitably maintained.

At this time, the idle lower limit rotational speed A is set smaller than the idle upper limit rotational speed B and has a dead band (BA), so that hunting can be prevented. In addition, by setting the lower limit and the upper limit, when the load is small, the engine can be idled while securing the minimum rotational speed A at the lower limit, so that it is possible to prevent the engine from stopping during idling and to minimize the fuel consumption. Can be. In addition, when the load is large, the load can be handled with the rotation speed between the minimum rotation speed A and the upper limit rotation speed B, so that idling is performed with a margin for some load fluctuation. In addition, since the upper limit is suppressed, it is possible to prevent unnecessary fuel consumption from occurring.

Further, as in the case of creep running on a congested road or the like, it is determined whether or not the vehicle is running in an idle state.
Judging from the neutral gear position and the engaged clutch state, when it is judged that the vehicle is running, the fuel injection amount increasing means 1 can be deactivated, so that the running can be performed smoothly and a good running feeling can be obtained. Can be secured.

[0027]

According to the idle-up control method and the apparatus thereof according to the present invention, the load fluctuation during idling operation is detected based on the engine speed, and the engine speed is set between the idle lower limit speed and the idle upper limit speed. The amount of fuel injected into the engine can be increased or decreased so that the amount of fuel injected into the engine can be controlled in response to changes in the load during idling, and the engine speed can be maintained within a certain range. It is possible to perform idling with good fuel efficiency while preventing stoppage and rotation speed fluctuation.

Further, the operating condition of the idle-up control device is set to two rotation speeds, a lower limit and an upper limit, and a dead band is provided to prevent hunting of the engine speed.
Rotational speed fluctuation can be reduced. In addition, when the load is small, the minimum number of revolutions can be secured at the lower limit to prevent the engine from stopping during idling and to minimize the fuel consumption. Since idling can be performed at a rotation speed higher than the minimum rotation speed, it is possible to respond to fluctuations in load with a margin, and since the upper limit is suppressed, unnecessary fuel consumption can be prevented. Can be prevented.

In addition, when the vehicle is running in an idling state such as creeping on a congested road or the like, the fuel injection amount increasing means can be prevented from operating.
The running can be smooth and a good running feeling can be secured.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an idle-up control device that performs a control method of the present invention.

FIG. 2 is a flowchart showing a control method of the present invention.

[Explanation of symbols]

1 ... control means, engine control unit (E
CU) 2 Injection pump 3 Fuel injection amount increasing means 31 Vacuum pump (VP) 32 Vacuum switching valve (VSV) 33 Negative pressure actuator 4 Sensors 41 Engine speed detecting means 42 Gear Position detecting means 43… Clutch position detecting means

Claims (4)

[Claims] An engine speed detecting means, an engine fuel injection amount increasing means, and a control means for controlling the injection amount increasing means by inputting the engine speed detected by the engine speed detecting means. In the idle-up control device provided, the control means increases the fuel injection amount when the engine speed falls below the idle lower limit speed, and the engine upper speed is higher than the idle lower limit speed. An engine idle-up control method for controlling the injection amount increasing means so as to stop increasing the injection amount when the injection amount is increased. 2. A transmission gear position detecting means and a clutch state detecting means, wherein the control means detects a gear position detected by the gear position detecting means and a clutch state detected by the clutch state detecting means. The idle of the engine according to claim 1, wherein when the gear position is other than the neutral position and the clutch state is in the engaged state, the injection amount increasing means is deactivated and the injection amount is not increased. Up control method. 3. An engine speed detecting means, an injection amount increasing means for increasing an injection amount of fuel of the engine in response to an operation signal, and an engine speed detected by the engine speed detecting means. When the engine speed falls below the idle lower limit speed, an operation signal is output to the injection amount increasing means.When the engine speed exceeds the idle upper limit speed which is larger than the idle lower limit speed, the operation signal is output. An idle-up control device for an engine, comprising control means for stopping the engine. 4. A transmission gear position detecting means and a clutch state detecting means, wherein the control means detects a gear position other than a neutral position by the gear position detecting means, and When the clutch state detected by the state detection means is in the connected state,
4. The engine idle-up control device according to claim 3, wherein the control unit stops outputting the operation signal.