JP2000274276A - Idle speed control device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent sudden changes of the engine speed with a sudden change of the operating condition of an air conditioner, when a difference is generated between the target idle speed set in response to the vehicle operating condition and the air conditioner operating condition and the present idle speed by controlling the engine speed so as to gradually eliminate the difference. SOLUTION: Each parameter (cooling water temperature, engine speed, outside air temperature, car speed, turn-on/off of air conditioner, range position or the like) is detected by corresponding sensors and switching means 12-19, and these output signal are input to a control device 20. When an idle condition is determined, a correction value to be added to the minimum target idle speed is set in response to the range position. When an air conditioner is turned on, the last set value of the minimum target idle speed is set at a small value at the only first time. When a difference is generated between the target idle speed and the present idle speed, engine speed is variably changed so that the real idle speed gradually converges to the target idle speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine idle speed control device for appropriately controlling an idle speed during operation of an air conditioner.

[0002]

2. Description of the Related Art Generally, in a vehicle equipped with an air conditioner, a compressor of a refrigeration cycle of the air conditioner is connected to an engine and driven by an engine output. For this reason, when the air conditioner is operated in an idle state of the engine, the idle speed of the engine is appropriately increased to cope with the load of the air conditioner, and the idle speed is stabilized.

As described above, as a technique for controlling the idling speed of the engine in consideration of the operation of the air conditioner in an idle state, for example, in Japanese Patent Application Laid-Open No. 62-111138, the load increase by the air conditioner is not constant. Technology that raises the idle speed of the engine when the refrigerant pressure in the high-pressure line of the refrigeration cycle is equal to or higher than a predetermined value to prevent the idle speed from increasing more than necessary because it also fluctuates due to the heat load of the air conditioner. Is disclosed.

[0004]

However, in the above prior art, although the idling speed is controlled by the compressor discharge pressure, the compressor discharge pressure sharply decreases especially when the air conditioner changes from an operating state to a stopped state. The idle speed drops sharply,
The engine speed may fluctuate.

On the other hand, the cooling capacity required for an air conditioner varies depending on environmental conditions. For example, a large cooling capacity is required at a time when the outside air temperature is high, but a very large cooling capacity is required at a time when the outside air temperature is not so high. No ability is required. If the idling speed of the engine can be controlled in consideration of the cooling capacity required for such an air conditioner, a more appropriate engine speed can be realized at the time of idling, which is comfortable for the occupant and eliminates unnecessary engine rotation. Thus, it is possible to reduce noise and improve fuel efficiency.

The present invention has been made in view of the above circumstances, and it is possible to prevent a sudden change in the engine speed even when the operating state of the air conditioner changes suddenly in an idle state. The engine idle speed can be finely set according to the cooling capacity required of the air conditioner, realizing a natural and comfortable air conditioner in the cabin space, preventing excessive engine rotation and reducing noise and improving fuel efficiency. It is an object of the present invention to provide an engine idle speed control device that can be realized.

[0007]

According to a first aspect of the present invention, there is provided an engine idling speed control apparatus for detecting a driving state of a vehicle, comprising: detecting a driving state of the vehicle; And an air conditioner operating state detecting means for detecting an operating state of the in-vehicle air conditioner, wherein an idle speed of the engine is varied by a control means according to the vehicle operating state and the operating state of the air conditioner. In the idle speed control device for the engine to be controlled, the control means may determine whether there is a difference between the target idle speed set in accordance with the vehicle operating state and the operating state of the air conditioner and the current idle speed. The present invention is characterized in that the idling speed is variably controlled by gradually converging the current idling speed to the target idling speed. That. That is, in the engine idle speed control device according to the first aspect of the present invention, the vehicle operating state detecting means detects the vehicle operating state, the idle state detecting means detects the engine idle state, and the air conditioner operating state detecting means detects the engine idle state. Detects the operating state of the vehicle air conditioner. Then, when there is a difference between the target idle speed set in accordance with the vehicle driving state and the operating state of the air conditioner and the current idle speed, the control unit gradually sets the current idle speed as the target. The idle speed is converged to the idle speed and variably controlled.

According to a second aspect of the present invention, there is provided an engine idling speed control device for detecting a driving state of a vehicle, an idling state detecting means for detecting an idling state of the engine, and a vehicle air conditioner. Air conditioner operating state detecting means for detecting an operating state of the air conditioner, and temperature information detecting means for detecting temperature information of an outside air temperature or a vehicle interior temperature. In an engine idle speed control device variably controlled by a control means according to a state, an air conditioner variably setting a cooling capacity required by the air conditioner according to at least one of the temperature information and a value selectively set. Capacity setting means, wherein the control means controls the vehicle operating state, the operation state of the air conditioner, and the air conditioner capacity. Characterized by variably controlling the idle speed according to the setting of a constant section. That is, in the engine idle speed control device according to the second aspect, the vehicle operating state detecting means detects the vehicle operating state, the idle state detecting means detects the engine idle state, and the air conditioner operating state detecting means detects the engine idle state. The operating state of the on-vehicle air conditioner is detected, and the temperature information detecting means detects the temperature information of the outside air temperature or the vehicle interior temperature. The air conditioner capacity setting means variably sets a cooling capacity required by the air conditioner according to at least one of the temperature information and a value selectively set. The control means variably controls the idle speed in accordance with the vehicle operating state, the operating state of the air conditioner, and the setting of the air conditioner capacity setting means.

Further, the engine idling speed control device according to the third aspect of the present invention includes a vehicle operating state detecting means for detecting a driving state of the vehicle, an idle state detecting means for detecting an idling state of the engine, and a vehicle air conditioner. Air conditioner operating state detecting means for detecting an operating state of the air conditioner, and temperature information detecting means for detecting temperature information of an outside air temperature or a vehicle interior temperature. In an engine idle speed control device variably controlled by a control means according to a state, an air conditioner variably setting a cooling capacity required by the air conditioner according to at least one of the temperature information and a value selectively set. Capacity control means, wherein the control means controls the vehicle operating state and the air condition according to the operating state of the air conditioner. When there is a difference between the target idle speed set according to the operating state of the air conditioner and the setting of the air conditioner capacity setting means and the current idle speed, the current idle speed is gradually reduced to the target idle speed. It is characterized in that the idle speed is variably controlled by converging to the speed. That is, in the engine idle speed control device according to the third aspect, the vehicle operating state detecting means detects the driving state of the vehicle, the idle state detecting means detects the engine idle state, and the air conditioner operating state detecting means detects the engine idle state. The operating state of the on-vehicle air conditioner is detected, and the temperature information detecting means detects the temperature information of the outside air temperature or the vehicle interior temperature. Also,
The air conditioner capacity setting means variably sets a cooling capacity required by the air conditioner according to at least one of the temperature information and a value selectively set. Then, the control means determines whether or not there is a difference between the target idle speed set in accordance with the setting of the vehicle operating condition, the operating condition of the air conditioner, and the air conditioner capacity setting device, and the current idle speed. Variably controls the idle speed by converging the current idle speed gradually to the target idle speed.

According to a fourth aspect of the present invention, there is provided the engine idle speed control device according to the first or third aspect, wherein the operating state of the vehicle and the operation of the air conditioner are controlled. A plurality of target idle speeds are set for each operating region determined by the state, and when shifting to a different operating region, the current idle speed is converged in a stepwise manner to the target idle speed determined by the operating region to which the shift is made. It is characterized by the following.

Further, the engine idle speed control apparatus according to the invention described in claim 5 is an engine speed control apparatus according to claims 1 to 4.
In the engine idle speed control device according to the above,
The operating state of the air conditioner is detected at least based on a compressor discharge pressure of the air conditioner.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 show an embodiment of the present invention, FIG. 1 is an overall explanatory diagram of an engine idle speed control device, FIG. 2 is an explanatory diagram of an example of a target idle speed,
3 is an explanatory diagram of a discharge pressure reference value, FIG. 4 is a flowchart of an idle speed control program, FIG. 5 is a flowchart continued from FIG. 4, FIG. 6 is a flowchart continued from FIG.
7 is a flowchart continued from FIG. 4, and FIG. 8 is a flowchart continued from FIG. 4, FIG. 5, FIG. 6, or FIG.

In FIG. 1, reference numeral 1 denotes an engine,
The cooling water of the engine 1 is cooled by passing through a radiator 2 disposed on the front side of the engine 1 behind a front grill (not shown) of the vehicle.

Reference numeral 3 denotes a refrigeration unit of an air conditioner. The refrigeration unit 3 draws a gas refrigerant, compresses the gas refrigerant to a high temperature and a high pressure, and discharges the refrigerant. And a condenser 5 for temporarily storing the refrigerant from the condenser 5 and constantly sending out the liquid refrigerant, removing the dust and water in the system, and the liquid refrigerant from the receiver dryer 6 by the thermosensitive cylinder 7a. It mainly comprises an expansion valve 7 for atomizing to low temperature and low pressure while adjusting the opening based on the detected evaporator outlet temperature, and an evaporator 8 for vaporizing the refrigerant from the expansion valve 7 and removing heat.

The compressor 4 is, for example, a vane rotary compressor driven by the output of the engine 1 and is connected to the engine 1 via a magnet clutch 9 composed of a magnet coil, a clutch plate and the like.
The magnet clutch 9 is connected to a control device 2 described later.
0, and when the magnetic clutch 9 is released, the output from the engine 1 is not transmitted, and the compressor 4 is stopped. Conversely, when the magnet clutch 9 is engaged, the output from the engine 1 is transmitted, and the compressor 4 is driven.

The condenser 5 is disposed immediately before the radiator 2 and, together with the radiator 2, a main cooling fan 10a and a sub cooling fan 10b disposed behind the radiator 2.
And cooling air by a pair of cooling fans 10 (both electric motor fans) and traveling wind from a front grill.

The expansion valve 7 and the evaporator 8 are both disposed in a hood as a cooling unit 11, and the cool air sucked from the cooling unit 11 by a fan (not shown) passes through an air mixing chamber (not shown) in the vehicle interior. Is selectively blown out from each outlet.

On the engine 1 side, a water temperature sensor 12 for detecting an engine cooling water temperature and an engine speed sensor 13 for detecting an engine speed are provided as vehicle operating state detecting means. Further, on the refrigeration unit 3 side of the air conditioner, a discharge pressure sensor 14 for detecting the pressure of the refrigerant discharged from the compressor 4 is provided as an air conditioner operating state detecting means, and an evaporator air temperature for detecting the temperature of the cool air passing through the evaporator. A sensor 15 is provided. Further, an outside air temperature sensor 16 for detecting an outside air temperature AT is provided in front of the condenser 5 as temperature information detecting means.

The control device 20 includes the above-described sensors 1
2, 13, 14, 15, and 16 are connected, a vehicle speed sensor 17 for detecting a vehicle speed V constituting an idle state detecting means is connected, and an air conditioner switch 18 for ON / OFF operation of the air conditioner is also operated. It is connected as state detection means. Further, the control device 20 includes:
Range position (drive (D) range or neutral (N) range) of transmission (not shown) (automatic transmission in this embodiment)
Is input from the range position switch 19. The range position switch 19 is provided as one of the vehicle operating state detecting means. Other necessary sensors and switches (not shown) are connected.

The control device 20 is composed of a microcomputer or the like, and based on input signals from the above-described sensors and switches, controls for the engine 1 such as idle speed control (fuel injection control, ignition timing control, etc.). Executing the control for the air conditioner and the control for the cooling fan 10,
Necessary output signals are output from the idle speed control valve 21, engine parts, the magnetic clutch 9,
And output to the cooling fan 10.

The controller 20 controls the air conditioner, for example, when the occupant sets the cooling capacity with the air conditioner switch 18 (for example, slides it sideways and sets the amount by the amount of the slide). This is executed by setting the ON point and the OFF point of the compressor 4 at the temperature and outputting the drive or stop of the compressor 4 to the magnet clutch 9 based on the evaporator air temperature.

The control device 20 controls the cooling fan 10 by controlling the operation state of the air conditioner (signal from the air conditioner switch 18), the signals from the water temperature sensor 12, the engine speed sensor 13, the vehicle speed sensor 17, and the discharge. In accordance with the compressor discharge pressure Pco from the pressure sensor 14, variable control is performed with reference to a preset map or the like.

Further, the control device 20 controls the idle speed of the engine 1 by controlling the engine cooling water temperature, the engine speed, the compressor discharge pressure, the outside air temperature AT, the vehicle speed V, the on / off of the air conditioner switch 18, the range position ( (D or N range), a target idle speed is set according to an idle speed control program described later, and output to the idle speed control valve 21 to perform variable control.

The idling speed control program has a function to constitute an idling state detecting means for judging an idling state based on the vehicle speed V, and a cooling capacity required by the air conditioner to determine the outside air temperature A.
It is formed to include a function as an air conditioner capacity setting means variably set according to T, and is a program for variably controlling the idle speed of the engine 1. That is, the control device 20 is configured to include a function as a control unit in the idle speed control device.

Next, the idle speed control by the control device 20 will be described with reference to flowcharts of idle speed control programs shown in FIGS. The idle speed control program is repeatedly executed at predetermined time intervals when an ignition switch (not shown) is turned on. First, step (hereinafter abbreviated as “S”) 101
Then, each parameter (engine cooling water temperature, engine speed, compressor discharge pressure, outside air temperature AT, vehicle speed V, on / off of the air conditioner switch 18, range position (D or N range), etc.) is read.

Next, in S102, the vehicle speed V = 0 is determined (processing constituting the idle state detecting means). If the vehicle speed V ≠ 0, it is determined that the vehicle is not in the idle state, and the program exits. Conversely, if the vehicle speed V = 0, it is determined that the vehicle is in the idle state, and the process proceeds to S103, where it is added to the minimum target idle speed (predetermined basic idle speed) according to the range position (D or N range). The correction value (ISCATD) to be set.

Thereafter, the process proceeds to S104, where it is determined whether the air conditioner switch 18 is ON or OFF.
If 8 is OFF and the air conditioner is stopped, S105
Proceed to. In S105, the minimum target idle speed when the air conditioner is turned off is set. Although the setting method will be described later, in S105, a delay (delay) process for suppressing a rapid change in the idle speed when the air conditioner is switched from the ON state to the OFF state, and setting of the minimum target idle speed in the OFF state. Perform processing.

Here, the reason why the minimum target idle speed is used instead of simply the target idle speed is that a correction value (ISCATD) corresponding to the above-described range position is added.

On the other hand, in S104, the air conditioner switch 1
If the air conditioner 8 is ON and the air conditioner is operating, the process proceeds to S106, and the previous setting value of the minimum target idle speed is set as a small value only for the first time (first time only processing).

Next, the routine proceeds to S107, where a discharge pressure reference value is set according to the outside air temperature AT. This is as an air conditioner capacity setting means for variably setting the cooling capacity required by the air conditioner.

Specifically, as shown in FIG. 3, the reference value of the compressor discharge pressure Pco is set in advance in accordance with the outside air temperature in accordance with the "larger compressor discharge pressure reference value" and the "small compressor discharge pressure reference value. Is set. And
If the detected compressor discharge pressure Pco is a value larger than the "larger compressor discharge pressure reference value", the compressor discharge pressure Pco is larger than the "larger compressor discharge pressure reference value" and larger than the "larger compressor discharge pressure reference value". The compressor discharge pressure Pco is classified as “medium” if the value is in a region below the “compressor discharge pressure reference value”, and “compressed” if the value is in a region below the “small compressor discharge pressure reference value”. .

The two compressor discharge pressure reference values are both set lower as the outside air temperature AT rises, and are determined so that the region where the compressor discharge pressure Pco is "large" increases. This is because the cooling capacity of the air conditioner is required to be improved as the outside air temperature AT is higher, particularly in summer.

That is, the idle rotation speed of the engine 1 is set higher as the compressor discharge pressure Pco increases. For this reason, the compressor discharge pressure Pco is varied so that the region on the “large” side increases as the outside air temperature AT increases, and the compressor discharge pressure Pco is varied in a direction to increase the idle speed of the engine 1. I have. When the compressor 4 of the air conditioner is operated, the compressor 4 is connected to the engine 1 via the magnetic clutch 9. When the engine speed increases, the rotational speed of the compressor 4 also increases, and the refrigerant in the refrigeration cycle The amount of circulation is also increased, and the cooling capacity in the passenger compartment is increased.

Conversely, when the outside air temperature AT is low, the cooling capacity of the air conditioner is not so required. For this reason, the region where the compressor discharge pressure Pco is “large” is reduced, the idle speed of the engine 1 is reduced, and the fuel efficiency is improved.

In the present embodiment, the two compressor discharge pressure reference values are automatically variably set in accordance with the outside air temperature AT, but are automatically variably set in accordance with the vehicle interior temperature. The configuration may be set. Furthermore, the occupant may be allowed to variably set the value through a slide switch or the like so that the occupant can use the air conditioner for selecting the cooling capacity.

Thereafter, the program proceeds to S108, in which it is determined whether the compressor discharge pressure Pco is a large value. As a result, if the value is large, the process proceeds to S109, where the minimum target idle speed is set to a large value (a value set in advance corresponding to a large value of the compressor discharge pressure Pco), and the process proceeds to S110.

In S110, it is determined whether or not the previously set minimum target idle speed is a large value. If the previous value is also a large value and there is no change, the process proceeds to S111, and the currently set minimum target idle speed is increased. Value.

If it is determined in step S110 that the previously set minimum target idle speed is not a large value, the process proceeds to step S112, where the previously set minimum target idle speed is an intermediate value (the compressor discharge pressure Pco corresponds to the intermediate value). Is determined in advance.

As a result, if the previously set minimum target idle speed is an intermediate value, the process proceeds to S113, and a predetermined time (for example, 3 seconds) has elapsed since the previous intermediate value was set as the minimum target idle speed. It is determined whether or not it has been performed.

If the predetermined time has elapsed, S114
Then, the minimum target idle speed set this time is set to the large value set in S109. If the predetermined time has not elapsed, the process proceeds to S115, and the minimum target idle speed set this time remains at the intermediate value of the previous time.

In step S112, the previously set minimum target idle speed is not an intermediate value, that is, the previously set minimum target idle speed is a small value (corresponding to a small compressor discharge pressure Pco in advance). In the case of (set value), the process proceeds to S116, and it is determined whether or not a predetermined time (for example, 3 seconds) has already elapsed since the previous small value was set as the minimum target idle speed.

If the predetermined time has elapsed, S117
Then, the minimum target idle speed set this time is set to an intermediate value so as to approach a large minimum target idle speed. If the predetermined time has not yet elapsed, the process proceeds to S118, and the minimum target idle speed set this time remains at the previous small value.

That is, the processing of the above-mentioned steps S109 to S118 is performed when the result of setting the minimum target idle speed to a large value this time is the delay of the delay corresponding to the previously set minimum target idle speed. Processing.

On the other hand, if the compressor discharge pressure Pco is not a large value in S108, the flow advances to S119 to determine whether the compressor discharge pressure Pco is an intermediate value. If it is determined in S119 that the compressor discharge pressure Pco is an intermediate value, the process proceeds to S120, the minimum target idle speed is set to an intermediate value, and the process proceeds to S121.

In S121, it is determined whether or not the previously set minimum target idle speed is an intermediate value. If the previous time is also an intermediate value and there is no change, the process proceeds to S122, and the currently set minimum target idle speed is set. Is an intermediate value.

If it is determined in step S121 that the previously set minimum target idle speed is not an intermediate value, the flow advances to step S123 to determine whether the previously set minimum target idle speed is small.

As a result, if the previously set minimum target idle speed is a small value, the process proceeds to S124, and whether a predetermined time (for example, 3 seconds) has already elapsed since the previous small value was set as the minimum target idle speed. Determine whether or not.

Then, if the predetermined time has elapsed, S125
Then, the minimum target idle speed set this time is set to an intermediate value. If the predetermined time has not yet elapsed, the process proceeds to S126, and the minimum target idle speed set this time remains at the previous small value.

If the previously set minimum target idle speed is not a small value in step S123, that is, if the previously set minimum target idle speed is a large value, the process proceeds to step S127, where the previously large value is set. It is determined whether or not a predetermined time (for example, 3 seconds) has elapsed since the setting of the minimum target idle speed.

Then, if the predetermined time has elapsed, S128
Then, the minimum target idle speed set this time is set to an intermediate value. If the predetermined time has not elapsed, the process proceeds to S129, and the minimum target idle speed set this time remains at the previous large value.

That is, in the processing of S120 to S129, the delay according to the minimum target idle speed set up to the previous time when the result of setting the minimum target idle speed to an intermediate value this time is obtained. Processing.

If it is determined in step S119 that the compressor discharge pressure Pco is not an intermediate value, that is, if the compressor discharge pressure Pco is determined to be small, the process proceeds to step S130, and the minimum target idle speed is set to a small value. , S
Proceed to 131.

In S131, it is determined whether or not the previously set minimum target idle speed is a small value. If the previous time is also a small value and there is no change, the process proceeds to S132, and the currently set minimum target idle speed is set to a small value. Value.

If it is determined in step S131 that the previously set minimum target idle speed is not a small value, the flow advances to step S133 to determine whether the previously set minimum target idle speed is an intermediate value.

As a result, if the previously set minimum target idle speed is an intermediate value, the process proceeds to S134, and a predetermined time (for example, 3 seconds) has already elapsed since the previous intermediate value was set as the minimum target idle speed. It is determined whether or not it has been performed.

If the predetermined time has elapsed, the flow proceeds to S135.
Then, the minimum target idle speed set this time is set to a small value. If the predetermined time has not yet elapsed, the process proceeds to S136, and the minimum target idle speed set this time remains at the intermediate value of the previous time.

If the previously set minimum target idle speed is not an intermediate value in S133, that is, if the previously set minimum target idle speed is a large value, the process proceeds to S137, where the previously set minimum target idle speed is increased. It is determined whether or not a predetermined time (for example, 3 seconds) has already elapsed after setting the minimum target idle speed.

Then, if the predetermined time has elapsed, S138
Then, the minimum target idle speed set this time is set to an intermediate value. If the predetermined time has not yet elapsed, the process proceeds to S139, and the minimum target idle speed set this time remains at the previous large value.

That is, the processes of S130 to S139 are performed in the case where the result of setting the minimum target idle speed to a small value is obtained this time, and the delay corresponding to the previously set minimum target idle speed is set. Processing.

Thereafter, S105, S111, S114,
S115, S117, S118, S122, S125,
S126, S128, S129, S132, S135
S140 from any of S136, S138 and S139
Then, the final target idle speed is set. That is, the correction value (ISCATD) based on the range position obtained in S103 is added to each of the minimum target idle speeds, and a correction value according to the engine coolant temperature is added. Set the number. FIG. 2 shows an example of the target idle speed of the engine 1 obtained in this manner.

Then, the program proceeds to S141, in which the program is output to the idle speed control valve 21 based on the set target idle speed to exit the program.

Next, the processing of S105 will be described with reference to FIG. In S201, it is determined whether the previously set minimum target idle speed is a large value. If the value is large, the process proceeds to S202; if not, S2
Go to 03. In S202, the minimum target idle speed is set to an intermediate value, and the routine exits.

In S203, it is determined whether or not the previously set minimum target idle speed is an intermediate value. If the value is an intermediate value, the process proceeds to S204. If the value is not an intermediate value, the process proceeds to S207. In S204, the minimum target idle speed is set to an intermediate value, and it is determined whether a predetermined time has elapsed. If the predetermined time has elapsed, the process proceeds to S205, where the minimum target idle speed is set to a small value. If not, the process proceeds to S206, and the minimum target idle speed is set to an intermediate value until the predetermined time has elapsed, and the routine is started. Exit.

In S207, it is determined whether or not the previously set minimum target idle speed is a small value. When the value is small, the process proceeds to S208. When the value is not small, that is, when the value does not correspond to any of the large value and the intermediate value, the process proceeds to S211. In S208, it is determined whether a predetermined time has elapsed after setting the minimum target idle speed to a small value. If the predetermined time has elapsed, the process proceeds to S209, and the minimum target idle speed is set to a value without correction of the compressor discharge pressure. If the predetermined time has not elapsed, the minimum target idle speed is set to a small value in S210, Exit the routine.

In S211, the minimum target idle speed is set to a value without the compressor discharge pressure correction as in S209, and the routine exits.

That is, when the air conditioner is switched from ON to OFF, the idle speed is reduced while performing the delay process, so that a rapid change in the idle speed can be suppressed.

As described above, according to the embodiment of the present invention, as shown in the processing of S108 to S139, the difference between the target idle speed and the current idle speed (idle speed previously set) is obtained. Is large, the target idle speed is converged stepwise with time. Further, in S105, when the air conditioner changes from the operating state to the stopped state, control is performed to gradually decrease the idle speed. Thus, even if the compressor discharge pressure suddenly drops when the air conditioner changes from the operating state to the stopped state, the idle speed does not drop sharply and the engine speed does not fluctuate greatly.

Further, in an automobile equipped with an automatic transmission, even if the air conditioner switch is turned on when the vehicle is stopped in the D range, a sharp increase in the idle speed is suppressed. The pop-out phenomenon caused by switching the air conditioner switch can be reduced.

Further, as shown in the process of S107, the cooling capacity required by the air conditioner can be variably set and controlled according to the outside air temperature. As a result, it is possible to finely set the optimal engine idle speed according to the cooling capacity required of the air conditioner, realize a natural and comfortable air conditioner interior space, prevent excessive engine rotation, reduce noise and reduce fuel consumption. An improvement can be realized.

[0070]

As described above, according to the first aspect of the present invention, there is provided an engine idle speed control apparatus for variably controlling an engine idle speed in accordance with a vehicle operating state and an air conditioner operating state. When there is a difference between the target idle speed set in accordance with the operating state and the operating condition of the air conditioner and the current idle speed, the current idle speed is gradually converged to the target idle speed. Therefore, even if the operating condition of the air conditioner fluctuates suddenly in the idle state, it is possible to prevent the engine speed from fluctuating abruptly. Can be.

According to the second aspect of the present invention, there is provided an engine idle speed control device for variably controlling an engine idle speed in accordance with a vehicle operating state and an air conditioner operating state. Since the capacity is variably set in accordance with at least one of the temperature information and the value selectively set, and the cooling capacity required by the air conditioner is taken into consideration when calculating the idle speed, the required air conditioner is required. It is possible to finely set the optimal engine idle speed in accordance with the cooling capacity, realize a natural and comfortable air conditioner in the vehicle compartment, prevent excessive engine rotation, and reduce noise and improve fuel efficiency.

Further, according to the third aspect of the present invention, an air conditioner is required in an idle speed control device for an engine that variably controls an idle speed of an engine according to a vehicle operating state and an operating state of the air conditioner. The cooling capacity is variably set in accordance with at least one of the temperature information and the value selectively set, so that the cooling capacity required by the air conditioner is taken into consideration in determining the idle speed, and the target idle When there is a difference between the rotation speed and the current idle rotation speed, the current idle rotation speed is gradually converged to the target idle rotation speed.
It is possible to obtain the effects of both the first and second aspects. That is, even in the idle state, even if the operating state of the air conditioner fluctuates rapidly, it is possible to prevent the engine speed from fluctuating rapidly, and it is possible to finely optimize the engine speed according to the cooling capacity required for the air conditioner. It is possible to set the idle speed of the engine, to realize a natural and comfortable air conditioner in the vehicle compartment, to prevent excessive engine rotation, and to reduce noise and improve fuel efficiency.

[Brief description of the drawings]

FIG. 1 is an overall explanatory diagram of an engine idle speed control device.

FIG. 2 is a diagram illustrating an example of a target idle speed.

FIG. 3 is an explanatory diagram of a discharge pressure reference value.

FIG. 4 is a flowchart of an idle speed control program.

FIG. 5 is a flowchart continued from FIG. 4;

FIG. 6 is a flowchart continued from FIG. 4;

FIG. 7 is a flowchart continued from FIG. 4;

FIG. 8 is a flowchart following FIG. 4, FIG. 5, FIG. 6, or FIG.

FIG. 9 is a flowchart of a delay process.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Engine 3 Refrigeration unit 4 Compressor 9 Magnet clutch 12 Water temperature sensor (vehicle operating state detecting means) 13 Engine speed sensor (vehicle operating state detecting means) 14 Discharge pressure sensor (air conditioner operating state detecting means) 16 Outside air temperature sensor (temperature information) Detecting means) 17 vehicle speed sensor (idle state detecting means) 18 air conditioner switch (air conditioner operating state detecting means) 19 range position switch (vehicle operating state detecting means) 20 control device (idle state detecting means, air conditioner capacity setting means, controlling means) 21 Idle speed control valve

Continued on the front page F-term (reference) 3G065 AA11 CA00 CA14 DA04 EA03 FA12 GA00 GA09 GA10 GA11 GA27 GA31 GA37 3G093 AA05 AA12 BA09 BA19 BA32 CA04 CB01 DA01 DA05 DB06 DB09 DB11 DB25 DB27 EA03 EA07 FA07 3G301 HA01 KA07 JA03 JA37 NE23 PA10Z PE01A PE01Z PE08Z PF00Z PF01Z PF08Z PF13Z

Claims (5)

[Claims] A vehicle operating state detecting means for detecting an operating state of the vehicle; an idle state detecting means for detecting an idle state of the engine; and an air conditioner operating state detecting means for detecting an operating state of the vehicle air conditioner. An idle speed control device for an engine, wherein the idle speed of the engine is variably controlled by control means in accordance with the vehicle operating state and the operating state of the air conditioner. When there is a difference between the target idle speed set according to the above and the current idle speed, the current idle speed is gradually converged to the target idle speed little by little and the idle speed is variably controlled. An idle speed control device for an engine. 2. A vehicle operating state detecting means for detecting an operating state of a vehicle, an idle state detecting means for detecting an idle state of an engine, an air conditioner operating state detecting means for detecting an operating state of an onboard air conditioner, an outside air temperature or Temperature information detecting means for detecting temperature information of the vehicle interior temperature,
An engine idle speed control device that variably controls idle speed of the engine with control means according to the vehicle operating state and the operating state of the air conditioner, wherein at least one of the temperature information and a value selectively set. Air conditioner capacity setting means for variably setting a cooling capacity required by the air conditioner in accordance with the condition of the vehicle. An engine idle speed control device for variably controlling the engine speed. A vehicle operating state detecting means for detecting an operating state of the vehicle; an idle state detecting means for detecting an idle state of the engine; an air conditioner operating state detecting means for detecting an operating state of the vehicle air conditioner; Temperature information detecting means for detecting temperature information of the vehicle interior temperature,
An engine idle speed control device that variably controls idle speed of the engine with control means according to the vehicle operating state and the operating state of the air conditioner, wherein at least one of the temperature information and a value selectively set. Air conditioner capacity setting means for variably setting a cooling capacity required by the air conditioner in accordance with the operation condition of the air conditioner, the control state of the air conditioner, and the operation state of the air conditioner. When there is a difference between the target idle speed set according to the setting and the current idle speed, the current idle speed is converged little by little to the target idle speed to vary the idle speed. An idle speed control device for an engine, wherein the control is performed. 4. A plurality of target idle speeds are set for each operating region determined by the operating condition of the vehicle and the operating condition of the air conditioner, and when shifting to a different operating condition, the target idle speed is determined based on the current idle speed. The engine idle speed control device according to claim 1 or 3, wherein the idle speed is converged in a stepwise manner to a target idle speed determined by an operation region. 5. The engine idle speed control device according to claim 1, wherein the operating state of the air conditioner is detected based on at least a compressor discharge pressure of the air conditioner.