JP3055445B2 - Idle speed controller for air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner which controls the operation and stop of a compressor mounted on the air conditioner in accordance with the temperature condition of the air conditioner and the idle speed of an engine. The present invention relates to an idle speed control device.

[0002]

2. Description of the Related Art Generally, in an air conditioner installed in an automobile, an engine drives a compressor (air compressor) for compressing a refrigerant which has been evaporated by an evaporator and turned into a high-temperature and high-pressure gaseous substance again to be liquefied. It has become. In a vehicle having such a vehicle air conditioner (hereinafter abbreviated as air conditioner), when the compressor is operating, the load on the engine is increased by the amount of driving the compressor. For this reason, when the compressor is operating when the vehicle is stopped, stable idling cannot be performed at an idling engine speed (idling speed) such as during normal times (when the compressor is stopped). In addition, there is also a problem that the rotation speed of the compressor is low and the cooling capacity of the cooling device is insufficient at the idle rotation speed in the normal state. Accordingly, a technology has been developed in which idle control is performed at a higher idle speed than when the compressor is operating (when the compressor is stopped).

[0003] Further, if the air temperature is too low due to cooling of the air conditioner, the evaporator or the like will be frozen. To avoid this, while detecting the temperature in the vicinity of the evaporator, the detected temperature is kept below a predetermined temperature. In such a case, a technology has been developed in which the compressor is stopped even during the operation of the air conditioner to avoid a decrease in the temperature of the evaporator.

In such a technique, for example, as shown in FIG. 6, the operation / stop of the compressor and the idle speed of the engine are controlled. The horizontal axis in FIG. 6 indicates the temperature in the vicinity of the evaporator, and the vertical axis indicates the operating state (ON or OFF) of the compressor and the idle speed state of the engine. As shown, when the compressor is operating, the engine idle speed is controlled to a relatively high value NB as described above, and when the compressor is stopped, the engine idle speed is controlled to the normal value NA.

The temperature near the evaporator is T2
When the temperature rises above, the compressor is operated to control the idle speed to a relatively high value NB, and when the temperature near the evaporator falls below T1, the compressor is stopped and the idle speed is controlled to the normal value NA. . The temperature T1 is set to, for example, about 2 ° C. based on the lower limit of the temperature range in which freezing of the evaporator can be avoided, and the temperature T2 is set to, for example, about 3 ° C. so as to secure the hysteresis of the freezing avoidance control by this evaporator. Is set.

[0006]

By the way, considering the cooling performance of the air conditioner, it is desired to set the engine idle speed higher. In other words, in the vehicle air conditioner, the cooling temperature can be sufficiently exhibited because the refrigerant temperature can be reduced by the traveling wind during traveling.However, when the engine is idling while the vehicle is stopped, the refrigerant temperature cannot be expected to decrease due to the traveling wind. Since the rotation speed of the compressor is low and the amount of circulating refrigerant is also reduced, the cooling capacity is reduced. In particular, in summer or the like, since the outside air is at a high temperature, the cooling capacity is more likely to be insufficient.

[0007] Therefore, if the value of the idle speed during operation of the compressor is made higher, the amount of circulating refrigerant from the compressor is also increased, and sufficient cooling performance can be ensured even in summer or the like. However, on the other hand, considering the fuel efficiency of the engine, it is naturally desirable to set the engine idle speed lower.

As described above, there is a trade-off between improving the cooling performance of the air conditioner and improving the fuel efficiency of the engine, and the idle speed during the operation of the compressor is reduced in such a way that they are compromised with each other. Must be set. Incidentally, as an idle speed control device for an air conditioner taking into consideration the cooling performance of the air conditioner and the fuel efficiency of the engine, for example, Japanese Unexamined Patent Publication No. 61-2589
There is a technique disclosed in Japanese Patent Publication No. 46-46. According to this technique, when the temperature immediately after the evaporator rises, the idle speed of the engine is controlled to increase in proportion to the rise.

According to this technique, if cooling performance is required, the output of the compressor can be increased to respond to the demand.
If cooling performance is not required, idling speed can be lowered to improve fuel efficiency, but control is complicated, control logic becomes complicated, high-speed calculations are required, and costs are increased. There is a problem that it is difficult to realize desired control because a delay in the control response causes hysteresis between the control calculation and the control response.

Japanese Utility Model Laid-Open Publication No. Sho 62-173533 discloses a technique for automatically controlling the output of an air conditioner based on the temperature and the amount of solar radiation when the air conditioner is turned on, and controlling the idle speed of the engine in two stages. ing. However, in this technology, only the idle speed is controlled based on the outside air temperature only in the state of the air conditioner, and no consideration is given to freezing of the evaporator or the like, and depending on whether the output of the air conditioner is strong or weak. Since the idling speed is uniquely controlled, there is a problem that the frequency of switching the idling speed is high, and the fluctuation of the engine speed and the fluctuation of the air-conditioner output resulting therefrom give a driver or a passenger an uncomfortable feeling.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its main object to provide an air conditioner-compatible idle speed control device capable of ensuring both air conditioner output and fuel efficiency. I do. Also, the present invention
It is a further object to prevent freezing of the evaporator and the like.

It is a further object of the present invention to provide a device capable of suppressing the switching frequency of the idle speed during operation of the air conditioner to reduce the discomfort given to the driver and the occupant due to the switching of the idle speed. I do. Still another object of the present invention is to provide an inexpensive device. It is a further object of the present invention to provide a device suitable for promoting warm-up when the warm-up of the engine is not completed and stabilizing the idle speed.

Still another object of the present invention is to provide a device suitable for coping with engine overheating in a vehicle provided with an engine-driven radiator fan. Still another object of the present invention is to make it possible to suppress creep while ensuring both air conditioner output and fuel efficiency when applied to a vehicle with an automatic transmission.

It is a further object of the present invention to provide an apparatus which can achieve both air-conditioning output securing and fuel efficiency improvement when applied to a vehicle with a manual transmission.

[0015]

According to the present invention, there is provided an air conditioner-compatible idle speed control apparatus according to the present invention, comprising: a vehicle air conditioner having a compressor driven by an engine provided in the vehicle; Temperature detecting means for detecting a temperature related to the operation of the air conditioner, and control means for controlling the operation and stop of the compressor based on the temperature detected by the temperature detecting means and controlling the idle speed of the engine. When the detected temperature is in the first temperature range, the compressor is stopped and the idle speed is controlled to a preset first speed as a control mode by the control means. Control mode, and when the detected temperature is in a second temperature region having a temperature region portion higher than the first temperature region, the comp A second control mode in which the idler speed is controlled to a predetermined second speed as a value higher than the first speed by operating the air conditioner, and the detected temperature is the second temperature. In a third temperature range having a temperature range portion higher than the range, the compressor is operated and the idle speed is set to a third speed set in advance as a value higher than the second speed. And a third control mode for controlling the first, second, and third temperatures.
To define a temperature range, a first temperature T1 and the first temperature T1.
A second temperature T2 higher than the temperature T1;
And a third temperature T3 which is higher than the temperature T2.
And the detected temperature during the control in the first control mode.
Rises from below the second temperature T2 to above the second temperature T2.
When the first control mode is raised, the second control mode is switched from the first control mode.
Mode, and control is performed in the second control mode.
Sometimes, the detected temperature is lower than the third temperature T3 to the third temperature T3.
When the temperature rises to T3 or higher, the second control mode
Switching to the third control mode is performed, and the third control mode is set.
When the control is performed in the mode, the detected temperature is equal to the first temperature T1.
From the above, when the temperature falls below the first temperature T1, the third temperature
From the first control mode to the first control mode
It is characterized by having such a configuration .

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

According to a second aspect of the present invention, there is provided an air conditioner-compatible idle speed control device according to the first aspect , wherein at least the second control mode and the third control mode are set.
The above-mentioned control mode is characterized in that the idle speed is gradually changed when switching to the control mode.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. First, an air conditioner-compatible idle speed control device according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a schematic diagram showing a main part of a vehicle air conditioner according to the present embodiment and a hardware configuration of an idle speed control device for an air conditioner. The hardware configuration is the same as that conventionally used, but first, the hardware configuration will be described.

In FIG. 2, reference numeral 1 denotes a compressor of an air conditioner for a vehicle (air compressor), which includes a compressor pulley 2 mounted on a rotating shaft (not shown), and a crankshaft of an engine through a crankshaft pulley 3 and an air conditioner drive belt 4. (Not shown), and the compressor 1 is driven by the crankshaft.

Reference numeral 5 denotes a tension pulley for properly holding the tension of the air conditioner drive belt 4. Reference numeral 6 denotes a condenser, which cools the refrigerant pressurized by the compressor 1 with outside air to liquefy. Reference numeral 7 denotes a refrigerant flow path, which supplies the refrigerant cooled and liquefied through the compressor 1 and the condenser 6 to an evaporator (air cooling unit) 8 via a receiver or the like (not shown) and cools the air while evaporating by the evaporator 8. The refrigerant, which has become a high-temperature and high-pressure gaseous body, is arranged to be returned to the compressor 1 again.

Naturally, the on / off operation (generally an artificial operation) of an air conditioner switch (not shown) controls the operation / stop of the vehicle air conditioner itself. On the other hand, in the ventilation system in which the evaporator 8 is arranged, a blower 9, an evaporator 8, an air mixing unit 10, and a bench duct 11 are arranged from the upstream side, and the air cooled by the evaporator 8 is supplied to the air mixing unit. After the temperature is adjusted by mixing with warm air at 10, the air is supplied from the bench duct 11 into the vehicle interior.

The idle speed controller for the air conditioner controls the idle speed of the engine corresponding to such an air conditioner for a vehicle. However, the temperature related to the operation of the air conditioner (air conditioner) is controlled. A temperature sensor (temperature detecting means) 12 for detecting the temperature on the downstream side of the evaporator 8, an idle adjusting means 13 for adjusting the idle speed, and the operation and stop of the compressor 1 based on the temperature detected by the temperature sensor 12. Control means (electronic control unit = ECU) 14 for controlling the idling speed of the engine by controlling the operation of the idle adjusting means 13 is provided.

The idle adjusting means 13 includes an idle speed controller having an idle adjusting valve separate from the throttle valve. The idle adjusting means 13 can maintain a predetermined idle speed by adjusting the opening of the idle adjusting valve. Then, the intake air amount, that is, the mixture amount is set. In addition, the temperature related to the operation of the air conditioner is an air temperature that can be cooled by the evaporator 8, and a temperature on the downstream side of the evaporator 8 (the closer to the evaporator 8 is better) as in the present embodiment is suitable. I have.

The ECU 14 has the following first to third control modes. The first control mode is a control mode in a case where the temperature detected by the temperature sensor 12 (evaporator downstream temperature) is in a first temperature range. In this control mode, the compressor 1 is stopped and the idle speed is set in advance. Set first rotation speed NA
To control.

The second control mode is a control mode when the downstream temperature of the evaporator detected by the temperature sensor 12 is in the second temperature range. In this control mode, the compressor 1 is operated and the idle The rotational speed is set to a second value higher than the first rotational speed NA.
At the rotation speed NB. The third control mode is a control mode in which the evaporator downstream temperature detected by the temperature sensor 12 is in a third temperature range. In this control mode, the compressor 1 is operated and the idle speed is reduced. , The control is performed to a third rotational speed NC which is set in advance as a value higher than the second rotational speed NB.

The first, second, and third temperature ranges include a first temperature T1 and a second temperature T2, which is higher than the first temperature T1. , And a third temperature T3 which is higher than the second temperature T2. The first temperature T1 is set based on the lower limit of a temperature range in which freezing of the evaporator can be avoided, and is set to, for example, about 2 ° C. The second temperature T2 is set to provide hysteresis in the first control mode for avoiding freezing of the evaporator, and is set to, for example, about 3 ° C. The third temperature T3 is set based on the upper limit of the temperature at which the evaporator is desired to cool at the minimum even when the outside air temperature is high in summer or the like, and is set to, for example, about 6 ° C.

As shown in FIG. 1, the first temperature region is defined in a region where the evaporator downstream temperature is lower than the second temperature T2, and the second temperature region is where the evaporator downstream temperature is the second temperature T2. The third temperature range is defined so as to include a region where the temperature is equal to or higher than the temperature T2 and lower than the third temperature T3, and the evaporator downstream temperature includes a region equal to or higher than the third temperature T3.

However, a hysteresis is provided for switching between these control modes. That is, as shown in FIG. 1, when the evaporator downstream temperature rises, the control mode is switched as follows. That is, when the evaporator downstream temperature detected by the temperature sensor 12 rises from a temperature lower than the second temperature T2 to a temperature equal to or higher than the second temperature T2 during the control in the first control mode, the second control mode is switched from the first control mode to the second control mode. Switch to. Further, at the time of control in the second control mode, the temperature downstream of the evaporator detected by the temperature sensor 12 is equal to the third temperature.
Rises from below the temperature T3 to above the third temperature T3,
Switching from the second control mode to the third control mode is performed.

On the other hand, when the evaporator downstream temperature decreases, the control mode is switched as follows. That is, when the evaporator downstream temperature detected by the temperature sensor 12 drops from the first temperature T1 or more to less than the first temperature T1 during the control in the third control mode, the third control mode switches to the first control mode. Switch to. Further, at the time of control in the second control mode, the temperature downstream of the evaporator detected by the temperature sensor 12 is equal to the first temperature.
When the temperature falls from the temperature T1 or more to less than the first temperature T1,
Switching from the second control mode to the first control mode is performed.

As described above, with respect to the idle speed switching (switching between NA and NB) for turning on / off the compressor 1, a hysteresis of a temperature difference is provided as described in FIG. In regard to the switching of the idle speed (switching between NB and NC) according to the cooling capacity requirement at the time of turning on, a hysteresis of a large temperature difference described as a variable control hiss in FIG. 1 is provided.

Therefore, if the downstream temperature of the evaporator is kept lower than the second temperature T2 during the control in the first control mode, the first control mode is continued. Further, at the time of control in the second control mode, the evaporator downstream temperature is equal to or higher than the first temperature T1 and the third temperature T
If a value less than 3 is maintained, the second control mode is continued. Then, if the downstream temperature of the evaporator keeps the first temperature T1 or more during the control in the third control mode, the third control mode is continued.

Since the idle speed control device for an air conditioner according to the first embodiment of the present invention is configured as described above, for example, as shown in FIG. Idle control routine)
The control of the air conditioner and the idle speed is performed as follows. That is, first, in step S10, it is determined whether or not the air conditioner switch is on. If the air conditioner switch is not on, idle control during air conditioner operation is not performed, and the state where the compressor is off and the idle speed is NA is maintained. However, if the air conditioner switch is on,
Proceeding to step S20, the detected temperature (air thermo temperature) downstream of the evaporator detected by the temperature sensor 12 is read, and in step S30, it is determined whether or not the detected temperature is equal to or higher than the third temperature T3.

If the detected temperature is equal to or higher than the third temperature T3, the process proceeds to step S40, and the third control mode is executed. That is, the compressor 1 is operated (turned on), and the idle speed is controlled to the third speed NC. Then, in step S50, the flag F is set to 3, and the process returns.
The flag F takes one of 1, 2, and 3. If the flag F is 1, it means that the first control mode is selected, and if the flag F is 2, the second control mode is selected. The control mode is selected, and if the flag F is 3, it means that the third control mode is selected.

On the other hand, if it is determined in step S30 that the detected temperature is not higher than the third temperature T3, the process proceeds to step S60 to determine whether the detected temperature is lower than the first temperature T1.
Here, if the detected temperature is lower than the first temperature T1, the process proceeds to step S70, and the first control mode is executed. That is,
The compressor 1 is stopped (turned off), and the idle speed is controlled to the first speed NA. Then, step S80
Then, the flag F is set to 1 and the process returns.

If it is determined in step S60 that the detected temperature is not lower than the first temperature T1, the process proceeds to step S90, and it is determined whether or not the flag F is 2. Step S
When the process proceeds to 90, the detected temperature is equal to or higher than the first temperature T1 and lower than the third temperature T3. If the flag F is 2, the process proceeds to step S100 and the second control mode is continued. . That is, the compressor 1 is operated (turned on),
The idle speed is controlled to the second speed NB. Then, in step S110, the flag F is set to 2, and the process returns.

If it is determined in step S100 that the flag F is not 2, the flow advances to step S120 to determine whether the flag F is 1. Here, if the flag F is not 1, the flag F is 3, and the detected temperature is equal to or higher than the first temperature T1 and lower than the third temperature T3. In this case, the process proceeds to step S40. , The third control mode is continued.

On the other hand, if the flag F is 1, step S1
Proceeding to 30, it is determined whether the detected temperature is equal to or higher than the second temperature T2. Here, if the detected temperature is equal to or higher than the second temperature T2, the process proceeds to step S100 and switches from the first control mode to the second control mode. That is, the compressor 1
Is operated (turned on), and the idle speed is changed to the second speed N.
B is controlled. Then, in step S110, the flag F
And returns.

If it is determined in step S130 that the detected temperature is not equal to or higher than the second temperature T2, the process proceeds to step S70.
Continue with the first control mode. In this way, even when the compressor 1 is operating, if necessary, the idle speed is increased from the second speed NB to the third speed N higher than the second speed NB.
C, the idle speed is switched to the third speed NC and the output of the compressor 1 is increased even when the cooling capacity by the condenser 6 is reduced, for example, when the outside air temperature is high in summer or the like. Thus, there is an effect that the cooling performance can be improved.

If the temperature downstream of the evaporator does not increase, the idle speed is controlled to the relatively low second speed NB even when the compressor 1 is operating,
Fuel efficiency can be improved while ensuring the required cooling capacity. For example, FIGS. 4A and 4B show a case in which the present apparatus is based on idle speed control (see a dashed line with “switching control” in the figure) and a case in which the idle speed is fixed to a second speed NB (see FIG. It is a figure which shows the effect of this device by comparing and showing the cooling performance of the evaporator part in the case where it is fixed to the third number of revolutions NC (see the solid line) (see the solid line in the figure). As shown in the figure, in the present apparatus, the cooling performance of the evaporator section near the third rotation number NC fixed can be obtained.
Of course, although not shown, the fuel efficiency can be sufficiently improved as compared with the case where the engine speed is fixed at the third rotational speed NC.

In addition, a problem that the vicinity of the evaporator is frozen due to excessive cooling by the operation of the compressor 1 can be avoided. In addition, a large hysteresis described as a variable control hysteresis is provided, and the second temperature range when the second control mode is performed is such that the temperature downstream of the evaporator is equal to or higher than the first temperature T1 and the third temperature T3.
The third temperature range when performing the third control mode is a wide temperature range in which the temperature downstream of the evaporator is equal to or higher than the first temperature T1. It is possible to avoid a decrease in which the switching between the control mode and the third control mode is repeated, so that the switching frequency of the control mode is greatly reduced. And the frequency of giving a feeling of strangeness to the driver and the occupant can be greatly reduced.

Of course, the provision of the air thermohis reduces the switching frequency of the control mode, and has the same effect. In addition, the target idle speed is three stages, and the target idle speed is not set in detail. Therefore, the control logic becomes relatively simple, and the cost can be reduced simply by changing the software part of the conventional technology. In addition to this, the device can be constituted by the above, and the hysteresis between the calculation for control and the control response is less likely to be affected, and the idle control can be made stable and reliable.

Next, an air conditioner-compatible idle speed control device according to a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in a third temperature range according to a third control mode, and the other portions are configured in the same manner as the first embodiment. Therefore, the parts different from the first embodiment will be described.

That is, in the second embodiment, as shown in FIG. 5, the temperature at which the control mode is switched from the third control mode to another control mode, that is, the lower limit of the third temperature range is set to the fourth temperature T4. Is set. The fourth temperature T4 is at least a value higher than the first temperature T1 and lower than the third temperature T3. Here, in particular, the third temperature T3 and the fourth temperature T4
Is set so that the temperature difference (T3-T4) from the temperature T4 is larger than the temperature difference (T2-T1) between the first temperature T1 and the second temperature T2.

The fourth temperature T4 may be lower than the second temperature T2 as shown by a solid line in FIG. 5 or higher than the second temperature T2 as shown by a chain line in FIG. . Since the second embodiment of the present invention is configured as described above,
During the third control mode, the temperature downstream of the evaporator becomes the fourth temperature.
When the temperature falls below the temperature T4, the control mode is switched from the third control mode to the second control mode, and the switching frequency is slightly increased as compared with the first embodiment, but the second fuel mode has a lower fuel consumption.
Since the use frequency of the control mode becomes higher, the fuel efficiency can be improved accordingly. The temperature difference (T3-T4) between the third temperature T3 and the fourth temperature T4 is the temperature difference (T2-T4) between the first temperature T1 and the second temperature T2.
By taking the value larger than 1), the frequency of control switching when the compressor is on can be significantly reduced.
Such a temperature difference setting may be performed as needed.

In the above embodiment, the switching between the second control mode and the third control mode, that is, the switching of the rotation speed when switching between the second rotation speed NB and the third rotation speed NC is performed. Although the case where the switching is performed in a stepwise manner is shown, for the switching of the rotation speed when the mode switching occurs, a ramp control is introduced to change the idle rotation speed from the second rotation speed NB to the second rotation speed NB as shown in FIG. 3 so as to gradually increase to the rotation speed NC,
Alternatively, the configuration may be such that the idle speed gradually decreases from the third speed NC to the second speed NB.

Introducing the ramp control at the time of switching the rotation speed in this manner not only eliminates the feeling of rising speed and uncomfortable feeling of the rotation speed at the time of switching, but also has the effect of suppressing frequent switching of modes. it can. In addition, the lamp control
When switching from the second rotation speed NB to the third rotation speed NC,
At the time of the reverse switching (from the third rotational speed NC to the second rotational speed N
B at the time of switching to B).

The lamp control can be introduced at the time of switching between the first control mode and the second control mode or the third control mode. If it is necessary to quickly turn off the compressor at the time of switching to the first control mode, introducing the above-mentioned ramp control may lead to a rise in the engine speed rather than the first control mode. It is conceivable to introduce the lamp control only when switching from the control mode to the second control mode.

In the above embodiment, the first, second, and third modes are switched without any particular consideration of the engine temperature state. May be detected and this result may be used as a control factor when performing the mode switching. That is, when the engine cooling water temperature is not completed at the first set water temperature (for example, 80 ° C.) or lower, the idle speed at the time of the air-con on is increased from the viewpoint of promoting warm-up and stabilizing the idle speed. It is preferable to set the engine cooling water temperature in a vehicle having an engine-driven radiator fan.
In the case of an overheat state of 10 ° C. or more, it is preferable to set the idle speed at the time of turning on the air conditioner high from the viewpoint of increasing the cooling capacity of the radiator. For this reason,
In the configuration shown in FIG. 2, a modification in which the output of the engine cooling water temperature sensor is input to the ECU 14 and control is performed according to a flowchart shown in FIG.

The flowchart shown in FIG. 8 is obtained by adding steps 200 and thereafter to the flowchart of FIG. 3. As shown in FIG. 8, after reading in step S20, first, in step S200, engine cooling is performed. The detection value of the water temperature is read, and it is determined whether the detected water temperature (that is, the engine temperature) is lower than the first set water temperature TL and whether the detected water temperature is higher than the second set water temperature TH. The flag FTW is set to 1 (step S240) when both are determined in steps S210 and S220, and when neither is satisfied (that is, when warm-up is completed and overheating is not performed). , The flag FTW is set to 0 (step S2
30). Then, the flag FTW in step S250
Only when the flag FTW is 1, the control is performed such that the idle speed is set to the second speed NB in step S100 of the flowchart of FIG. 3 so that the idle speed becomes the third speed NC higher than this. (Step S26)
0).

As a result, when the air conditioner is turned on at the time of completion of warm-up or overheating, the idle speed is always controlled to a higher speed NC, so that warm-up is promoted, the speed is stabilized, and the cooling capacity of the radiator is secured. The effect can be achieved. In the modification shown in FIG.
It goes without saying that one of steps S210 and S220 may be omitted, and only one of the warm-up countermeasures and the overheat countermeasures may be adopted.

As a countermeasure for overheating when the air conditioner is turned on, the following control structure can be considered. That is, when the engine cooling water temperature becomes equal to or higher than the second set temperature, the idle speed is changed from the second speed NB to the third speed NC while maintaining the air conditioner ON state. When the engine cooling water temperature further rises to reach a third set temperature higher than the second set temperature, the air conditioner is turned on from off while maintaining the idle speed at the third speed NC. Control to switch to may be performed.

Further, any or all of the idle speeds NA, NB, and NC corresponding to each control mode are separately set for a traveling range and a neutral range in a vehicle with an automatic transmission. It is also conceivable to set differently for (especially the traveling range of) the vehicle with the automatic transmission. That is, the idle speed in the first control mode is NAN for a neutral range of the automatic transmission (or a vehicle with a manual transmission), NAD for a travel range of the automatic transmission, and In the case of the neutral range of the automatic transmission (or the vehicle with the manual transmission), the idle speed in the second control mode is NBN.
NBD for the traveling range of the automatic transmission, and NCN for the idle speed in the third control mode for the neutral range of the automatic transmission (or a vehicle with a manual transmission). NCD in the case of the traveling range of the automatic transmission.

In this way, at least NCN>
In a state that satisfies NCD (if necessary, NBN> NB
D is satisfied), and in the case of a neutral range of the automatic transmission (or a vehicle with a manual transmission), NCN-NBN
In the case of the traveling range of the automatic transmission, it is desirable to set the rotation speed so as to satisfy the relationship of NCD-NBD <NBD-NAD.

With this setting, in the case of the former [neutral range of the automatic transmission (or a vehicle with a manual transmission)], the rotational speed NBN becomes relatively low and the fuel efficiency is improved. Since the rotation speed NCN is set relatively high, it is possible to prioritize ensuring the air conditioner performance. In the latter case (running range of the automatic transmission), while operating the air conditioner corresponding to low fuel consumption at the rotational speed NBD, the rotational speed NCD can be kept relatively low, so that the creep amount can be reduced. There is an effect that can be done.

[0060]

As described in detail above, according to the idle speed control apparatus for an air conditioner according to the present invention, a vehicle air conditioner having a compressor driven by an engine provided in a vehicle is provided. With Shona,
Temperature detection means for detecting a temperature related to the operation of the air conditioner; control means for controlling the operation and stop of the compressor based on the temperature detected by the temperature detection means and for controlling the idle speed of the engine; When the detected temperature is in a first temperature range, a first mode in which the compressor is stopped and the idle speed is controlled to a preset first speed is provided as a control mode by the control means. When the control mode and the detected temperature are in a second temperature range having a temperature range higher than the first temperature range, the compressor is operated and the idle speed is set to be lower than the first speed. A second control mode for controlling the rotation speed to a second value set in advance as a high value, and a third temperature region having a temperature region portion where the detected temperature is higher than the second temperature region. If in a third control mode for controlling the idle speed to a third rotation speed set in advance as a value higher than the second rotational speed is provided the compressor as the working conditions, the 1st, 2nd, 3rd temperature
To define a temperature range, a first temperature T1 and the first temperature T1.
A second temperature T2 higher than the temperature T1;
And a third temperature T3 which is higher than the temperature T2.
And the detected temperature during the control in the first control mode.
Rises from below the second temperature T2 to above the second temperature T2.
When the first control mode is raised, the second control mode is switched from the first control mode.
Mode, and control is performed in the second control mode.
Sometimes, the detected temperature is lower than the third temperature T3 to the third temperature T3.
When the temperature rises to T3 or higher, the second control mode
Switching to the third control mode is performed, and the third control mode is set.
When the control is performed in the mode, the detected temperature is equal to the first temperature T1.
From the above, when the temperature falls below the first temperature T1, the third temperature
From the first control mode to the first control mode
By being configured, while allowing the required cooling capacity can be sufficiently secured, it is possible to make improved fuel economy. In addition, the required cooling capacity can be accurately detected.
To secure the cooling capacity and improve fuel efficiency as described above.
In addition to being able to achieve a good balance,
Reduced as much as possible the switching frequency of the idle speed during down operation
Less likely to cause discomfort to drivers and occupants
Become. Furthermore, the control logic is extremely simple and lower
The device can be configured at a cost. Also idol
The target value of the control is set to the first rotation speed, the second rotation speed, and the third rotation speed.
Idle control to control to any fixed number of turns
Calculation and control compared to setting the target value of
Hysteresis between the response and the
Control can be made stable and reliable.

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

According to the idle speed control apparatus for an air conditioner according to the present invention described in claim 2, in the apparatus described in claim 1 , at least at the time of switching between the second control mode and the third control mode. With the configuration in which the change of the idle speed is gradually performed, the effect of removing the feeling of rising and unnaturalness of the speed at the time of switching,
There is also an effect that frequent switching of modes can be suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram showing control contents of an air conditioner-compatible idle speed control device as a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a main part of a vehicle air conditioner and a hardware configuration of an idle speed control device for an air conditioner according to an embodiment of the present invention.

FIG. 3 is a flowchart showing control contents of an air conditioner-compatible idle speed control device as a first embodiment of the present invention.

FIG. 4 is a graph showing an effect of the idle speed control device for an air conditioner according to the first embodiment of the present invention.

FIG. 5 is a diagram showing control contents of an air conditioner-compatible idle speed control device as a second embodiment of the present invention.

FIG. 6 is a diagram showing control contents of a conventional air conditioner-compatible idle speed control device.

FIG. 7 is a characteristic diagram showing a modified example of the switching control by introducing the ramp control of the idle speed control device for an air conditioner according to the embodiment of the present invention.

FIG. 8 is a flowchart showing control contents of a modification of the idle speed control device for an air conditioner according to the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 compressor (air compressor) 2 compressor pulley 3 crankshaft pulley 4 air conditioner drive belt 5 tension pulley 6 condenser 7 refrigerant flow path 8 evaporator (air cooling unit) 9 blower 10 air mix unit 11 bench duct 12 temperature sensor (temperature detecting means) 13 Idle adjustment means 14 Control means (Electronic control unit = ECU)

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Eiji Nomura 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Masaru Kado 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Tetsuo Suzuki 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Tsuyoshi Tadanaga 5-33-8 Shiba, Minato-ku, Tokyo No. Mitsubishi Motors Corporation (56) References JP-A-61-258946 (JP, A) JP-A-3-54014 (JP, A) JP-A-62-138841 (JP, U) JP-A-62 -173533 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 41/00-41/40 F02D 29/04

Claims (2)

(57) [Claims] 1. An air conditioner for a vehicle having a compressor driven by an engine provided in a vehicle, temperature detecting means for detecting a temperature associated with operation of the air conditioner, and a temperature detected by the temperature detecting means. And control means for controlling the operation and stop of the compressor based on the idle speed of the engine based on the detected temperature in a first temperature range as a control mode by the control means. A first control mode in which the compressor is stopped to control the idle speed to a preset first speed, and a second control mode having a temperature range portion in which the detected temperature is higher than the first temperature range. When the compressor is in the temperature range, the compressor is operated and the idle speed is set to a value higher than the first speed. A second control mode for controlling the number of rotations, and when the detected temperature is in a third temperature range having a temperature range higher than the second temperature range, the compressor is operated and the idle speed is reduced. a third control mode is provided for controlling the third rotational speed which is previously set as a value higher than the second rotational speed, the first, second, in order to define a third temperature area of the To
The first temperature T1 and higher than the first temperature T1
The second temperature T2 and higher than the second temperature T2
A third temperature T3 is set, and the detected temperature is set at the time of the control in the first control mode.
The temperature rises from below the second temperature T2 to above the second temperature T2.
From the first control mode to the second control mode
And the detected temperature is changed to the second temperature during the control in the second control mode.
3 has risen from below the temperature T3 to above the third temperature T3
From the second control mode to the third control mode.
Is switched, and when the control is performed in the third control mode, the detected temperature is changed to the second control mode.
The temperature has dropped from the first temperature T1 or more to the first temperature T1 or less.
From the third control mode to the first control mode.
Characterized in that it is configured to perform switching .
An idle speed controller for air conditioners. 2. The apparatus according to claim 2, wherein at least the second control mode and the
When switching to the third control mode, the idle rotation
The idle speed control device for an air conditioner according to claim 1, wherein the number is gradually changed .