JPH09144584A - Idle engine speed controller corresponding to air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the frequency of changing over of the number of idle revolution during the operation of an air conditioner and to reduce the feeling of physical disorder given to a crewman by detecting temperature related to the actuation of an air conditioner, and controlling the number of idle revolutions through the number of different revolution according to a plurality of set temperature domain where the detected temperature exists. SOLUTION: A temperature sensor 12 for detecting temperature on the downstream side of an evaporator 8 is provided, and ECU 14 controls the actuation/stop of a compressor 1 on the temperature detected by the temperature sensor 12 and moreover the actuation of an idle adjusting means 13 for adjusting the number of idle revolutions. In this case, in ECU, a first - a third control modes for controlling the number of idle revolutions to the preset number of a first - a third revolutions with the compressor kept in a stopped state are set up according to a first - a third temperature domain where the detected temperature is positioned, and for instance at the time of controlling on the third control mode, in the case where the temperature detected by the temperature sensor 12 lowers below the specified temperature, the third control mode is changed over to the first control mode.

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 provided in the air conditioner according to the temperature condition of the air conditioner and controls the idle speed of the 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) that compresses a refrigerant that has evaporated into a high-temperature and high-pressure gas body into a high-temperature and high-pressure gas. It has become. In an automobile having such a vehicle air conditioner (hereinafter, abbreviated as an air conditioner), when the compressor is operating, the load on the engine increases 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 the idle engine speed (idle speed) that is normal (when the compressor is stopped). There is also a problem that at normal idle speed, the compressor speed is low and the cooling capacity of the cooling device is insufficient. Therefore, a technique has been developed for performing idle control at a higher idling speed than when the compressor is operating (when the compressor is stopped).

Further, if the air temperature drops too much due to cooling of the air conditioner, the evaporator or the like freezes. Therefore, in order to avoid this, the detected temperature is below a predetermined temperature while detecting the temperature in the vicinity of the evaporator. Then, a technique has been developed in which the compressor is stopped even while the air conditioner is operating to avoid the temperature drop in the evaporator.

In such a technique, the operation / stop of the compressor and the idle speed of the engine are controlled as shown in FIG. 6, for example. The horizontal axis of FIG. 6 represents the temperature near the evaporator, and the vertical axis represents 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 idle speed of the engine is controlled to a relatively high value NB as described above, and when the compressor is stopped, the idle speed of the engine is controlled to the normal value NA.

The temperature in the vicinity of the evaporator is T2.
When the temperature rises above the above, the compressor is operated to control the idle speed to a relatively high value NB, and when the temperature near the evaporator drops 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 value of the temperature range in which the freezing of the evaporator can be avoided, and the temperature T2 is set to, for example, about 3 ° C. so as to ensure the freezing avoidance control hysteresis in this evaporator. Is set.

[0006]

By the way, considering the cooling performance of the air conditioner, it is desirable to set the idle speed of the engine higher. In other words, in a vehicle air conditioner, the cooling air temperature can be lowered by the traveling air while traveling, so that the cooling capacity can be sufficiently exerted, but when the engine is idling while the vehicle is stopped, it is not possible to expect a reduction in the refrigerant temperature due to the traveling air Since the compressor rotation speed is low and the refrigerant circulation amount is also reduced, the cooling capacity is deteriorated. In particular, during the summer season, the outside air is hot, so that the cooling capacity is more likely to be insufficient.

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

As described above, there is a trade-off relationship between improving the cooling performance of the air conditioner and improving the fuel efficiency of the engine, and the idle speed during operation of the compressor is set in such a manner that they are compromised. Must be set. By the way, as an idle speed controller for an air conditioner, which considers the cooling performance of the air conditioner and the fuel consumption of the engine, for example, Japanese Patent Laid-Open No. 61-2589.
There is a technique disclosed in Japanese Patent No. 46. This technique controls the idle speed of the engine to increase in proportion to the temperature immediately after the evaporator increases.

According to this technique, if cooling performance is required, the output of the compressor can be increased to respond to this, and
If the cooling performance is not required, the idle speed can be lowered to improve fuel efficiency, but since the control is performed finely, the control logic becomes complicated, and high-speed and high-speed calculations are required, which causes an increase in cost and is unique to air conditioners. The delay in the control response causes a hysteresis between the calculation for control and the control response, which makes it difficult to realize the desired control.

Further, Japanese Utility Model Laid-Open No. 62-173533 discloses a technique for automatically controlling the output of the 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, with this technology, the idle speed is only controlled based on the outside temperature only when the air conditioner is in operation, no consideration is given to freezing of the evaporator, etc. Since the idle speed is uniquely controlled, there is a problem that the frequency of switching the idle speed is high, and the fluctuation of the engine speed and the fluctuation of the air conditioner output due to the change give a discomfort to the driver and passengers.

The present invention was devised in view of the above problems, and a main object of the present invention is to provide an idle speed control device for an air conditioner, which is capable of both ensuring an air conditioner output and improving fuel efficiency. To do. Also, the present invention
It is a further object to prevent freezing of the evaporator and the like.

Further, it is a further object of the present invention to provide an apparatus capable of suppressing the switching frequency of the idle speed during the operation of the air conditioner to reduce the discomfort felt by the driver or the passenger due to the switching of the idle speed. To do. Furthermore, it is a further object of the invention to provide an inexpensive device. Another object of the present invention is to provide a device suitable for coping with acceleration of warm-up when the engine is not warmed up and stabilization of idle speed.

A further object of the present invention is to provide a vehicle equipped with an engine-driven radiator fan, which is suitable for coping with engine overheat when the engine overheats. Still another object of the present invention is to make it possible to suppress creep while achieving compatibility between securing air conditioner output and improving fuel efficiency when applied to a vehicle with an automatic transmission.

It is a further object of the present invention to provide an apparatus capable of achieving both air conditioner output assurance and fuel efficiency improvement when applied to a vehicle with a manual transmission.

[0015]

Therefore, an idle speed control device for an air conditioner according to the present invention according to claim 1 is a vehicle air conditioner having a compressor driven by an engine provided in the vehicle. A temperature detection means for detecting a temperature related to the operation of the air conditioner, and a control means for controlling the operation and stop of the compressor based on the temperature detected by the temperature detection means and the idle speed of the engine In the control mode by the control means, when the detected temperature is in the first temperature region, the compressor is stopped and the idle speed is controlled to a preset first speed. Of the control mode and the detected temperature in the second temperature region having a temperature region portion higher than the first temperature region, A second control mode in which the idle speed is set to a second speed that is preset as a value higher than the first speed, and the detected temperature is the second temperature. When in the third temperature range having a temperature range higher than the range, the compressor is operated and the idle speed is set to a third speed that is preset as a value higher than the second speed. A third control mode for controlling is provided.

According to a second aspect of the present invention, in the idle speed control device for an air conditioner according to the first aspect of the present invention, in the device according to the first aspect, the temperature detecting means sets the air conditioner as a temperature related to the operation of the air conditioner. It is characterized in that the temperature on the downstream side of the evaporator for cooling the working air is detected. An idle speed control device for an air conditioner according to a third aspect of the present invention is the device according to the first or second aspect, wherein the first, second, third
A first temperature T1, a second temperature T2 higher than the first temperature T1, and a third temperature T3 higher than the second temperature T2 in order to define the temperature range of And a fourth temperature T4 that is lower than the third temperature T3 and is equal to or higher than the first temperature T1 are set, and the detected temperature is set to the second temperature when the control is performed in the first control mode. When the temperature rises from below the temperature T2 to above the second temperature T2, the control mode is switched from the first control mode to the second control mode, and the detected temperature is controlled to the When the temperature rises from below the third temperature T3 to above the third temperature T3, the second control mode is switched to the third control mode, and the detected temperature is controlled during the control in the third control mode. Falls below the fourth temperature T4 from above the fourth temperature T4 In this case, switching from the third control mode to the second control mode is performed, and the detected temperature is reduced from the first temperature T1 or more to less than the first temperature T1 during the control in the second control mode. It is characterized in that it is configured to switch from the second control mode to the first control mode when descending.

According to a fourth aspect of the present invention, in the idle speed control device for an air conditioner of the present invention, in the device according to the third aspect, a temperature difference (T3-T3) between the third temperature T3 and the fourth temperature T4. T4) is the above-mentioned first temperature T1 and second
It is characterized in that it is set to be larger than the temperature difference (T2-T1) from the temperature T2. Claim 5
An air conditioner-compatible idle speed control device according to the present invention described in the above is the device according to claim 1 or 2, in which the first, second, and third temperature regions are defined.
Temperature T1 and the second temperature T1 higher than the first temperature T1.
Temperature T2 and the third temperature T2 higher than the second temperature T2.
Temperature T3 is set, and when the detected temperature rises from less than the second temperature T2 to not less than the second temperature T2 during the control in the first control mode, the temperature from the first control mode is changed to the above. After switching to the second control mode,
When the detected temperature rises from less than the third temperature T3 to not less than the third temperature T3 during control in the control mode, the second control mode is switched to the third control mode. When the detected temperature falls 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 is switched to the first control mode. It is characterized by being configured as follows.

According to a sixth aspect of the present invention, there is provided an idle speed control device for an air conditioner according to any one of the first to fifth aspects, wherein when the engine is in a cold state,
When the detected temperature is in the second temperature range, the idle speed is controlled to be higher than the second speed. Here, the rotation speed higher than the second rotation speed corresponds to, for example, the third rotation speed, and if set in this way, the control system of the apparatus can be configured at a lower cost.

According to a seventh aspect of the present invention, there is provided an idle speed control device for an air conditioner according to any one of the first to sixth aspects, wherein the vehicle is a radiator cooling fan which is rotationally driven by the engine. When the detected temperature is in the second temperature range when the engine overheats, the idle speed is controlled to be higher than the second speed.

Also here, the rotation speed higher than the second rotation speed corresponds to, for example, the third rotation speed, and if set in this way, the control system of the apparatus can be constructed at a lower cost. You can Further, when the overheat is further deteriorated (that is, the engine temperature, particularly the engine cooling water temperature is further increased), the compressor is configured to switch from the operating state to the non-operating state, so that the air conditioner cooling unit ( It is possible to obtain the effects of ensuring the maintenance of the operation of the cooler and promoting the engine cooling.

According to an eighth aspect of the present invention, there is provided an idle speed control device for an air conditioner according to any one of the first to seventh aspects, wherein the vehicle is equipped with an automatic transmission. The difference between the first rotation speed and the second rotation speed is larger than the difference between the second rotation speed and the third rotation speed. An idle speed control device for an air conditioner according to a ninth aspect of the present invention is the device according to any one of the first to seventh aspects, wherein the vehicle is equipped with a manual transmission, and the first rotational speed is the same. The difference between the rotational speed and the second rotational speed is smaller than the difference between the second rotational speed and the third rotational speed.

According to a tenth aspect of the present invention, there is provided the idle speed control device for an air conditioner according to any one of the first to fifth aspects, wherein at least the second control mode and the third control mode are used. It is characterized in that the idle speed is gradually changed when switching between and.

[0023]

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

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

Numeral 5 is a tension pulley for properly holding the tension of the air conditioner drive belt 4. Further, 6 is a condenser, which cools the refrigerant pressurized by the compressor 1 by the outside air to liquefy it. Reference numeral 7 denotes a refrigerant flow path, which supplies the liquefied refrigerant that has been cooled 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 in the evaporator 8. The refrigerant, which has become a high-temperature and high-pressure gas, is returned to the compressor 1 again.

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

The air conditioner-compatible idle speed control device controls the idle speed of the engine corresponding to such a vehicle air conditioner, and the temperature related to the operation of the air conditioner (air conditioner) is controlled. As 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 an operation and a stop of the compressor 1 based on the temperature detected by the temperature sensor 12. The control means (electronic control unit = ECU) 14 controls the operation of the idle adjusting means 13 and controls the idle speed of the engine.

As the idle adjusting means 13, there is an idle speed controller or the like having an idle adjusting valve separate from the throttle valve, so that a predetermined idle speed can be maintained by adjusting the opening of the idle adjusting valve. In addition, the intake air amount, that is, the air-fuel mixture amount is set. The temperature related to the operation of the air conditioner is the temperature of the air that can be cooled by the evaporator 8 here, and the temperature on the downstream side of the evaporator 8 (which should be as close as possible to the evaporator 8) is suitable as in the present embodiment. There is.

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

The second control mode is a control mode in the case where the temperature downstream 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 idled. The second speed preset with the rotation speed as a value higher than the first rotation speed NA
The rotation speed is controlled to NB. Further, the third control mode is a control mode in the case where the evaporator downstream temperature detected by the temperature sensor 12 is in the third temperature region. In this control mode, the compressor 1 is operated and the idle rotation speed is changed. , The third rotation speed NC that is set in advance as a value higher than the second rotation speed NB.

By the way, the above-mentioned first temperature region, second temperature region, and third temperature region include a first temperature T1 and a second temperature T2 which is higher than the first temperature T1. , And a third temperature T3 that is higher than the second temperature T2. The first temperature T1 is set based on the lower limit value of the 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 give a hysteresis related to the first control mode for avoiding the freezing of the evaporator, and is set to, for example, about 3 ° C. The third temperature T3 is set on the basis of the upper limit value of the temperature to be cooled at the evaporator unit even when the outside air temperature is high such as in summer, and is set to, for example, about 6 ° C.

As shown in FIG. 1, the first temperature range is defined within a range where the evaporator downstream temperature is lower than the second temperature T2, and the second temperature range is defined when the evaporator downstream temperature is below the second temperature T2. It is defined to include a region that is equal to or higher than the temperature T2 and lower than the third temperature T3, and the third temperature region is defined such that the evaporator downstream temperature includes a region that is equal to or higher than the third temperature T3.

However, hysteresis is provided for switching between these control modes. That is, as shown in FIG. 1, when the temperature downstream of the evaporator rises, the control mode is switched as follows. That is, when the temperature downstream of the evaporator detected by the temperature sensor 12 rises from below the second temperature T2 to above the second temperature T2 during the control in the first control mode, the first control mode changes to the second control mode. Switch to. Further, during the control in the second control mode, the temperature downstream of the evaporator detected by the temperature sensor 12 becomes the third temperature.
When the 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 temperature downstream of the evaporator drops, the control mode is switched as follows. That is, when the evaporator downstream temperature detected by the temperature sensor 12 falls 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 changes to the first control mode. Switch to. Further, during the control in the second control mode, the temperature downstream of the evaporator detected by the temperature sensor 12 becomes the first temperature.
When the temperature drops from above the temperature T1 above to below the first temperature T1,
Switching from the second control mode to the first control mode is performed.

As described above, regarding the idle speed switching (switching between NA and NB) for turning on / off the compressor 1, a hysteresis of a temperature difference as described as air thermohis in FIG. Regarding the idle speed switching (switching between NB and NC) required for the cooling capacity requirement at the time of ON, a large temperature difference hysteresis described as a variable control hiss in FIG. 1 is provided.

Therefore, when the temperature downstream of the evaporator is kept below the second temperature T2 during the control in the first control mode, the first control mode is continued. Further, during the 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 the time period less than 3 is maintained, the second control mode is continued. Then, when the temperature downstream of the evaporator is maintained at or above the first temperature T1 during the control in the third control mode, the third control mode is continued.

The idle speed controller for an air conditioner according to the first embodiment of the present invention is configured as described above, and therefore, for example, as shown in FIG. Idle control routine)
As a control of the air conditioner and the idle speed. That is, first, in step S10, it is determined whether the air conditioner switch is on. If the air conditioner switch is not on, idle control is not performed when the air conditioner is operating, and the compressor is off and the idle speed is maintained at NA. 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 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 to execute the third control mode. 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 any 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. This means that 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 the detected temperature is not equal to or higher than the third temperature T3 in the determination in step S30, the process proceeds to step S60 and it is determined whether or not 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. And step S80
Then, the flag F is set to 1, and the process returns.

If the detected temperature is not lower than the first temperature T1 in the determination in step S60, the process proceeds to step S90 and it is determined whether 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. Therefore, if the flag F is 2, the process proceeds to step S100 to continue the second control mode. . 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 the flag F is not 2 in step S100, the process proceeds to step S120, and it is determined whether the flag F is 1. 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, therefore, the process proceeds to step S40. , The third control mode is continued.

On the other hand, if the flag F is 1, step S1
In step 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 the first control mode is switched to the second control mode. That is, the compressor 1
Is activated (turned on), and the idle speed is set to the second speed N
Control to B. Then, in step S110, the flag F
Return 2 and return.

If the detected temperature is not equal to or higher than the second temperature T2 in step S130, the process proceeds to step S70.
Continue with the first control mode. In this way, even when the compressor 1 is operating, the idle speed is increased from the second speed NB to the third speed N higher than the second speed NB, if necessary.
Since it is possible to switch to 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 of the condenser 6 is lowered due to high temperature of outside air such as in summer. Therefore, there is an effect that the cooling performance can be improved.

If the temperature downstream of the evaporator does not rise, the idle speed is controlled to the second speed NB which is a relatively low speed even when the compressor 1 is operating.
Fuel efficiency can be improved while ensuring the required cooling capacity. For example, FIG. 4 shows a case in which the idle speed control of the present apparatus is performed (see a broken line labeled “In the case of switching control” in the figure) and a case where the idle speed is fixed to the second rotation speed NB (in the figure, It is a figure which shows the effect of this apparatus by comparing and showing the cooling performance of the evaporator part by a case (refer to a solid line in a figure) when fixing to 3rd rotation speed NC (refer to a solid line). As shown in the figure, in this device, the cooling performance of the evaporator portion close to the third rotation speed NC fixation can be obtained,
Of course, although not shown, in terms of fuel consumption, it is possible to sufficiently improve the fuel efficiency as compared with the case where the third rotational speed NC is fixed.

Of course, as in the conventional case, it is possible to avoid the problem that the vicinity of the evaporator is frozen due to excessive cooling due to the operation of the compressor 1. Further, a large hysteresis described as a variable control hysteresis is provided, and in the second temperature range when the second control mode is performed, the temperature downstream of the evaporator is equal to or higher than the first temperature T1 and the third temperature T3.
Since the temperature range of the evaporator downstream is equal to or higher than the first temperature T1, the third temperature range when the third control mode is performed is particularly wide. It is possible to avoid a decrease that repeats switching between the control mode and the third control mode, the switching frequency of the control mode is significantly reduced, and engine speed fluctuations and air conditioner output fluctuations due to the switching of the control modes. It is possible to significantly reduce the frequency of giving an uncomfortable feeling to a driver or an occupant.

Of course, the provision of the air thermohis also reduces the frequency of switching the control modes, and has the same effect. In addition, the target idle speed is three stages, and the target idle speed is not set finely, so the control logic becomes relatively simple, and the cost can be reduced by changing the software part of the conventional technology. In addition to being able to configure the device, the hysteresis between the calculation for control and the control response is less likely to affect, and the idle control can be made stable and reliable.

Next, an idle speed controller for an air conditioner as a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in the third temperature region related to the third control mode, and the other parts are configured similarly to the first embodiment. Therefore, the part different from the first embodiment will be described.

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

The fourth temperature T4 may be equal to or lower than the second temperature T2 as shown by a solid line in FIG. 5, or may be equal to 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,
In the third control mode, the temperature downstream of the evaporator is the fourth
When the temperature drops below the temperature T4 of the second control mode, the third control mode is switched to the second control mode.
Since the control mode is used more frequently, the fuel consumption can be improved accordingly. Further, the temperature difference (T3-T4) between the third temperature T3 and the fourth temperature T4 is equal to the temperature difference (T2-T4) between the first temperature T1 and the second temperature T2.
By taking a value larger than 1), it is possible to significantly reduce the control switching frequency when the compressor is on.
Such temperature difference setting may be performed as necessary.

In the above embodiment, the rotation speed is switched when switching between the second control mode and the third control mode, that is, when switching between the second rotation speed NB and the third rotation speed NC. Although the case of performing the operation stepwise is shown, regarding the switching of the rotational speed when the mode switching occurs, the ramp control is introduced to change the idle rotational speed from the second rotational speed NB to the second rotational speed NB as shown in FIG. So as to gradually increase up to the rotational speed NC of 3,
Alternatively, the idle speed may be gradually decreased from the third speed NC to the second speed NB.

Introducing the ramp control at the time of switching the rotational speed in this way eliminates the feeling of incongruity and discomfort of the rotational speed at the time of switching, and also has the effect of suppressing frequent switching of the modes. it can. The lamp control is
At the time of switching from the second rotation speed NB to the third rotation speed NC,
At the time of this reverse switching (from the third rotation speed NC to the second rotation speed N
Or (when switching to B)).

This lamp control can be introduced at the same time when switching between the first control mode and the second control mode or the third control mode, but from the viewpoint of prioritizing the prevention of icing of the evaporator or the like. If it is necessary to quickly turn off the compressor when switching to the 1 control mode, the introduction of the above lamp control may rather cause the engine speed to rise, so in this case, It is possible 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 taking into consideration the engine temperature state. However, the engine temperature state is changed from the engine cooling water temperature. May be detected and this result may be used as a control factor when performing the above mode switching. That is, when the engine cooling water temperature is not higher than the first set water temperature (for example, 80 ° C) and the warming-up is not completed, the idle speed at the time of the air conditioner turn-on is increased from the viewpoint of promoting warm-up and stabilizing the idle speed. It is preferable to set it. In a vehicle or the like having an engine-driven radiator fan, the engine cooling water temperature is the second set water temperature (for example, 1
In the case of an overheat condition of 10 ° C. or more, it is preferable to set the idle rotation speed to a high value when the air conditioner is turned on from the viewpoint of increasing the cooling capacity of the radiator. For this reason,
In the configuration shown in FIG. 2, a modified example in which the engine cooling water temperature sensor output is input to the ECU 14 and control is performed according to the flowchart shown in FIG. 8 is also conceivable.

The flow chart shown in FIG. 8 is obtained by adding steps 200 and subsequent steps to the flow chart of FIG. 3, and as shown in the figure, after the reading in step S20, the engine cooling is performed in step S200. The detection value of the water temperature is read, and whether the detected water temperature (that is, the engine temperature) is lower than the first set water temperature TL or higher than the second set water temperature TH, respectively. When it is determined in step S210 and step S220 that either of the conditions is satisfied, the flag FTW is set to 1 (step S240), and none of the conditions is satisfied (that is, when warm-up is completed and overheat is not generated). The flag FTW is set to 0 (step S2).
30). Then, the flag FTW in step S250
If the flag FTW is 1, it is determined that the idle rotation speed is set to the second rotation speed NB in step S100 of the flowchart of FIG. 3 so that the third rotation speed NC is higher than this. Yes (step S26
0).

As a result, at the time of completion of warm-up or when the air conditioner is turned on at the time of overheating, the idle speed is always controlled to a higher speed NC, and the warm-up promotion / stabilization of the speed and the cooling capacity of the radiator are secured. The effect of can be achieved. In the modification shown in FIG. 8,
It goes without saying that either one of steps S210 and S220 may be omitted and only one of the warm-up countermeasure and the overheat countermeasure may be adopted.

As a countermeasure against overheating when the air conditioner is turned on, the following control structure can be considered. That is, when the engine cooling water temperature is 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, Further, when the engine cooling water temperature rises and reaches the third set temperature which is higher than the second set temperature or higher, the idle speed is kept at the third speed NC and the air conditioner is turned off. You may perform control which switches to.

Further, any or all of the idle speeds NA, NB, NC corresponding to each control mode can be set separately for the running range and the neutral range in a vehicle with an automatic transmission, or with a vehicle with a manual transmission. It is also conceivable to set it separately for the vehicle with the automatic transmission (particularly the driving range). That is, the idle speed in the first control mode is NAN for the neutral range of the automatic transmission (or a vehicle with a manual transmission), NAD for the running range of the automatic transmission, and , The idle speed in the second control mode is NBN in the case of the neutral range of the automatic transmission (or the vehicle with the manual transmission).
And NBD for the drive range of the automatic transmission, and NCN for the neutral range of the automatic transmission (or a vehicle with a manual transmission) for the idle speed in the third control mode. , NCD for the drive range of the automatic transmission.

After this, at least NCN>
In a state where NCD is satisfied (if necessary, NBN> NB
D is also satisfied), in the case of the neutral range of the automatic transmission (or the vehicle with the manual transmission), NCN-NBN
In the case of the traveling range of the automatic transmission, it is desirable to set the number of revolutions so as to satisfy the relation of> NBN-NAN and the traveling range of the automatic transmission.

With this setting, in the former case (the neutral range of the automatic transmission (or the vehicle with the manual transmission)), the rotational speed NBN becomes a relatively low rotational speed, and the fuel consumption is improved. Since the rotational speed NCN is set to be relatively high, it is possible to preferentially secure the air conditioner performance. Further, in the latter case (running range of the automatic transmission), the air conditioner operation corresponding to the low fuel consumption is ensured at the rotation speed NBD, while the rotation speed NCD is 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 device for an air conditioner of the present invention as set forth in claim 1, a vehicle air conditioner having a compressor driven by an engine provided in the vehicle is provided. Shona,
Temperature detection 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 detection means and the idle speed of the engine. In the control mode by the control means, when the detected temperature is in the first temperature region, the compressor is stopped and the idle speed is controlled to a preset first speed. In the control mode and in the second temperature region having the temperature region portion in which the detected temperature is higher than the first temperature region, the idle speed is set to be higher than the first speed with the compressor operating. A second control mode for controlling to a second rotation speed preset as a high value, and a third temperature range having a temperature range portion in which the detected temperature is higher than the second temperature range. In the third control mode, the compressor is operated and the idle speed is controlled to a third speed preset as a value higher than the second speed. The fuel efficiency can be improved while ensuring the required cooling capacity.

According to the idle speed control device for an air conditioner of the present invention as set forth in claim 2, in the device as claimed in claim 1, the temperature detecting means sets the temperature related to the operation of the air conditioner as: An inexpensive configuration that detects the temperature on the downstream side of the evaporator that cools the air for air conditioning makes it possible to accurately detect the required cooling capacity, and to achieve a good balance between ensuring the cooling capacity and improving fuel efficiency. It can be compatible. Further, by setting the first temperature region based on the freezing temperature of the evaporator or the like, it is possible to effectively prevent the freezing of the evaporator or the like.

According to the idle speed control device for an air conditioner of the present invention as defined in claim 3, in the device as defined in claim 1 or 2, the first, second and third temperature regions are defined. Therefore, the first temperature T1, the second temperature T2 higher than the first temperature T1, the third temperature T3 higher than the second temperature T2, and the third temperature T3. A fourth temperature T4 that is lower than the temperature T3 and is equal to or higher than the first temperature T1 is set, and the detected temperature is less than the second temperature T2 from the second temperature T2 during the control in the first control mode. When the temperature rises above the second temperature T2, the first control mode is switched to the second control mode, and when the detected temperature is less than the third temperature T3 during the control in the second control mode. When the temperature rises above the third temperature T3, the second control mode Mode is switched to the third control mode, and when the detected temperature falls from above the fourth temperature T4 to below the fourth temperature T4 during control in the third control mode, The control mode is switched from the control mode to the second control mode, and when the detected temperature falls from the first temperature T1 or more to less than the first temperature T1 during the control in the second control mode. By being configured to switch from the second control mode to the first control mode, the required cooling capacity can be accurately detected, and the above-mentioned cooling capacity can be secured and fuel consumption can be improved. In addition to achieving a good balance, the control logic is relatively simple and the device can be constructed at low cost. In addition, the target value for idle control is set to the first speed,
Since the second rotation speed or the third rotation speed is controlled to a fixed value, the hysteresis between the calculation and the control response is less likely to affect, as compared with the case where the idle control target value is set finely. The idle control can be made stable and reliable.

According to a fourth aspect of the present invention, in the idle speed control device for an air conditioner according to the third aspect, in the device according to the third aspect, a temperature difference (T3-T3) between the third temperature T3 and the fourth temperature T4. T4) is the above-mentioned first temperature T1 and second
By setting the temperature to be greater than the temperature difference (T2-T1) from the temperature T2, it is possible to reduce the switching frequency of the idle speed particularly during the operation of the air conditioner,
The driver and passengers are less likely to feel uncomfortable.

According to the idle speed control device for an air conditioner of the present invention as defined in claim 5, in the device as defined in claim 1 or 2, the first, second and third temperature regions are defined. Therefore, a first temperature T1, a second temperature T2 that is higher than the first temperature T1, and a third temperature T3 that is higher than the second temperature T2 are set, When the detected temperature rises from less than the second temperature T2 to not less than the second temperature T2 during control in the first control mode, switching from the first control mode to the second control mode is performed. When the detected temperature rises from less than the third temperature T3 to not less than the third temperature T3 during control in the second control mode, the second control mode is switched to the third control mode. When switching is performed and control is performed in the third control mode The detected temperature of the first temperature T1
From the above, when the temperature falls below the first temperature T1, the third temperature
By being configured to switch from the control mode to the first control mode, the required cooling capacity can be accurately detected, and the above-mentioned securing of the cooling capacity and improvement of fuel efficiency are balanced. In addition to achieving good compatibility, it is possible to reduce the switching frequency of the idle speed particularly during the operation of the air conditioner as much as possible, and it is difficult for the driver and passengers to feel uncomfortable. Further, the control logic is extremely simple, and the device can be configured at a lower cost.
Further, since the target value of the idle control is controlled to a fixed value of any of the first rotation speed, the second rotation speed, and the third rotation speed, compared to the case where the target value of the idle control is set finely, The hysteresis between the calculation and the control response is unlikely to affect, and the idle control can be made stable and reliable.

According to the idle speed control device for an air conditioner of the present invention as defined in claim 6, claims 1 to 5 are provided.
In the device according to any one of claims 1 to 3, when the detected temperature is in the second temperature range when the engine is in a cold state, the idle speed is controlled to be higher than the second speed. With the configuration, there is an advantage that it is possible to easily deal with the promotion of warm-up when the engine is not warmed up and the stabilization of the idle speed.

According to the idle speed control device for an air conditioner of the present invention as defined in claim 7, claims 1 to 6 are provided.
In the device according to any one of claims 1 to 3, the vehicle includes a radiator cooling fan that is rotationally driven by the engine, and when the detected temperature is in the second temperature region when the engine overheats, the idle rotation speed is Is controlled to a higher rotational speed than the second rotational speed, there is an advantage that it is possible to easily cope with engine overheating in a vehicle equipped with an engine-driven radiator fan.

According to the idle speed control device for an air conditioner of the present invention as defined in claim 8, claims 1 to 7 are provided.
In the device according to any one of the items 1 to 3, the vehicle has an automatic transmission, and the difference between the first rotation speed and the second rotation speed is the second rotation speed and the third rotation speed. Since it is larger than the difference between, and in a vehicle with an automatic transmission, while ensuring both air-conditioner output and fuel efficiency improvement,
There is an advantage that creep can be suppressed.

According to the idle speed control device for an air conditioner of the present invention described in claim 9, claims 1 to 7 are provided.
In the device according to any one of items 1 to 5, the vehicle has a manual transmission, and the difference between the first rotation speed and the second rotation speed is the second rotation speed and the third rotation speed. Since it is smaller than the difference between and, when it is applied to a vehicle with a manual transmission, there is an advantage that it is possible to achieve both the securing of the air conditioner output and the improvement of fuel consumption.

According to the idle speed control device for an air conditioner of the present invention as set forth in claim 10,
5. The device according to any one of 5 above, wherein the idle speed is gradually changed at least when switching between the second control mode and the third control mode, whereby the rotational speed at the time of switching is changed. There is also an effect of removing a feeling of blowing up and a feeling of strangeness, and an effect of suppressing frequent switching of modes.

[Brief description of the drawings]

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

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

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

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

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

FIG. 6 is a diagram showing a control content of a conventional idle speed control device for an air conditioner.

FIG. 7 is a characteristic diagram showing a modification of the switching control by introducing the lamp control of the idle speed controller for an air conditioner according to the embodiment of the present invention.

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

[Explanation of symbols]

 1 Compressor (Air Compressor) 2 Compressor Pulley 3 Crank Shaft Pulley 4 Air Conditioner Drive Belt 5 Tension Pulley 6 Condenser 7 Refrigerant Flow Path 8 Evaporator (Air Cooling Section) 9 Blower 10 Air Mix Unit 11 Bench Duct 12 Temperature Sensor (Temperature Sensor) 13 Idle adjusting means 14 Control means (electronic control unit = ECU)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiji Nomura 5-3-8 Shiba, Minato-ku, Tokyo Within Mitsubishi Motors Corporation (72) Inventor Masaru Kadii 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Automobile Industry Co., Ltd. (72) Inventor Tetsuo Suzuki 5-3-8, Shiba, Minato-ku, Tokyo Mitsubishi Motors Corp. (72) Inventor Go Tadanaga 5-3-8, Shiba, Minato-ku, Tokyo Mitsubishi Motors Industry Co., Ltd.

Claims (10)

[Claims] 1. 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 temperature detected by the temperature detecting means. And a control means capable of controlling the operation and stop of the compressor based on the control means and controlling the idle speed of the engine. When the detected temperature is in the first temperature range as a control mode by the control means, A first control mode in which the compressor is stopped and the idle speed is controlled to a preset first speed, and a second control mode has a second temperature range part in which the detected temperature is higher than the first temperature range. When in the temperature range, the compressor is operated and the idle speed is set to a value higher than the first speed, and the second speed is preset. When the second control mode in which the number of revolutions is controlled and the detected temperature is in the third temperature region having a temperature region portion higher than the second temperature region, the idle speed is set to the operating state of the compressor. And a third control mode for controlling to a third rotation speed preset as a value higher than the second rotation speed.
Idle speed controller for air conditioners. 2. The temperature detecting means detects a temperature on a downstream side of an evaporator that cools air for air conditioning as a temperature related to the operation of the air conditioner. Idle speed controller for air conditioners. 3. A first temperature T1, a second temperature T2 higher than the first temperature T1, and a second temperature T2 for defining the first, second and third temperature regions. A third temperature T3, which is higher than the second temperature T2, and a fourth temperature T4, which is lower than the third temperature T3 and is equal to or higher than the first temperature T1, are set. When the detected temperature rises from below the second temperature T2 to above the second temperature T2 during control in the first control mode, switching from the first control mode to the second control mode is performed, When the detected temperature rises from less than the third temperature T3 to not less than the third temperature T3 during control in the second control mode, switching from the second control mode to the third control mode is performed. And the detected temperature is the fourth temperature T4 during the control in the third control mode. From the above, when the temperature falls below the fourth temperature T4, the third control mode is switched to the second control mode, and when the control in the second control mode is performed, the detected temperature is the first temperature. It is characterized in that it is configured to switch from the second control mode to the first control mode when the temperature drops from a temperature T1 or higher to a temperature lower than the first temperature T1.
An idle speed control device for an air conditioner according to claim 1 or 2. 4. The third temperature T3 and the fourth temperature T4 described above.
And a temperature difference (T3-T4) between the first temperature T1 and the second temperature T2 are set to be larger than the temperature difference (T2-T1) between the first temperature T1 and the second temperature T2. Item 3
Idle speed controller for the air conditioner described. 5. A first temperature T1, a second temperature T2 higher than the first temperature T1, and a second temperature T2 for defining the first, second, and third temperature regions. A third temperature T3, which is higher than the second temperature T2, is set, and the detected temperature during the control in the first control mode changes from less than the second temperature T2 to more than the second temperature T2. When the temperature rises, the control mode is switched from the first control mode to the second control mode, and when the control is performed in the second control mode, the detected temperature is from less than the third temperature T3 to the third temperature T3. When the temperature rises above, the second control mode is switched to the third control mode, and the detected temperature is controlled from the first temperature T1 or more to the first temperature during the control in the third control mode. When the temperature falls below T1, the third control mode is changed to the first control. It is characterized in that it is configured to switch to the control mode,
An idle speed control device for an air conditioner according to claim 1 or 2. 6. When the detected temperature is in the second temperature range when the engine is in a cold state, the idle speed is controlled to a speed higher than the second speed. The idle speed control device for an air conditioner according to any one of claims 1 to 5. 7. The vehicle includes a radiator cooling fan driven to rotate by the engine, and when the detected temperature is in the second temperature range when the engine overheats, the idle speed is set to the second speed. The idling speed control device for an air conditioner according to any one of claims 1 to 6, wherein the idling speed control device is controlled to have a higher rotation speed than the rotation speed. 8. The vehicle has an automatic transmission,
The difference between the first rotation speed and the second rotation speed is the second rotation speed.
9. The idle speed control device for an air conditioner according to any one of claims 1 to 7, characterized in that it is larger than a difference between the rotation speed and the third rotation speed. 9. The vehicle includes a manual transmission,
The difference between the first rotation speed and the second rotation speed is the second rotation speed.
8. The idle speed control device for an air conditioner according to any one of claims 1 to 7, characterized in that it is smaller than the difference between the rotation speed and the third rotation speed. 10. The method according to claim 1, wherein the idle speed is gradually changed at least when switching between the second control mode and the third control mode. Idle speed controller for the air conditioner described.