JP2010030326A - Air conditioner for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner for a vehicle capable of certainly suppressing production of off-odor while performing fuel consumption-saving control to which favor of an occupant is reflected. <P>SOLUTION: A first threshold value (Y1) indicating an upper limit in a comfortability range in the comfortability index (IR) indicating comfortability of an occupant and a second threshold value (Y2) set to a value of the first threshold value (Y1) or higher are set to a value corresponding to a fuel consumption-saving mode selected by a fuel consumption-saving mode selection means. It is determined that a temperature (TE) of an evaporator (16) is not more than a first predetermined temperature (Twet-A) set to a wet bulb temperature (Twet) or lower of the evaporator (16) and that the comfortability index (IR) is the first threshold value (Y1) or lower, and a compressor (32) is turned OFF. When the temperature (TE) of the evaporator (16) becomes higher than a second predetermined temperature (Twet-B) set lower than the wet bulb temperature (Twet) of the evaporator (16) or when the comfortability index (IR) becomes the second threshold value (Y2) or higher, the compressor (32) is turned ON. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle air conditioner.

  Odor components (perfume odor, interior odor, cigarette odor, etc.) are attached to the surface of the evaporator (evaporator) constituting the refrigeration cycle of the vehicle air conditioner, and the surface of the evaporator is covered with condensed water. If so, those off-flavor components do not scatter toward the passenger compartment. However, when the condensed water adhering to the surface of the evaporator dries out, the off-flavor component blows out into the passenger compartment together with the air-conditioning wind, causing discomfort to the passenger.

  In order to solve such a problem, for example, in the vehicle air conditioner described in Patent Document 1, the air temperature after passing through the evaporator (hereinafter referred to as “post-evaporation temperature TE”) is equal to or lower than the wet bulb temperature Twet. In this case, the compressor is turned on / off (intermittent operation). As a result, the speed at which the surface of the evaporator dries is reduced, and most of the off-flavor components adhering to the surface of the evaporator are prevented from splashing into the passenger compartment in a short time, resulting in discomfort due to off-flavor components. Is trying to reduce.

And it was supposed that the fuel-saving of a vehicle can be aimed at by setting the off time of a compressor by intermittent operation (fuel-saving mode).
JP 2002-248933 A

  However, in the vehicle air conditioner configured as described above, the post-evaporation temperature TE may rise from a temperature lower than the wet bulb temperature Twe over the wet bulb temperature Twe during operation of the vehicle air conditioner. In such a case, off-flavor components are released into the passenger compartment. In addition, even when the intermittent operation is performed, the off-flavor component is gradually released into the vehicle interior, and there is a problem that the off-flavor reduction effect is insufficient.

  Another vehicle air conditioner is also known in which an economy switch is provided so that the occupant can select a fuel saving mode. However, even in such a device, the timing for executing the fuel saving mode is limited to a predetermined system setting, and the execution threshold cannot be changed, so it is not possible to respond to the passenger's preference. There may also be a problem that fuel consumption cannot be saved without using it.

  In view of the above problems, an object of the present invention is to provide a vehicle air conditioner that can reliably suppress the generation of a strange odor while performing fuel-saving control that reflects passenger preference.

  In order to achieve the above object, the present invention employs the following technical means.

  In the first aspect of the invention, the compressor (32) that compresses the refrigerant, the evaporator (16) that cools the air by evaporating the refrigerant, and the temperature (TE) of the evaporator (16) are detected. The operation of the evaporator temperature detecting means (43), the wet bulb temperature detecting means (44) for detecting the wet bulb temperature (Twet) of the evaporator (16), and the operation of the compressor (32) are controlled, and at the time of cooling operation The control means (36) having a fuel saving mode for intermittent operation while switching the operation of the compressor (32) between on and off, and the fuel saving mode are set to a plurality of levels with different conditions for executing the intermittent operation, A fuel saving mode selection means (45) that is operated by a passenger to select a fuel saving mode of a predetermined level, and the control means (36) is a comfort range in a comfort index (IR) indicating the comfort level of the passenger. Indicates the upper limit of The first threshold value (Y1) and the second threshold value (Y2) set to a value equal to or greater than the first threshold value (Y1) are set to values corresponding to the fuel saving mode selected by the fuel saving mode selection means (45). The temperature (TE) of the evaporator (16) is equal to or lower than a first predetermined temperature (Twet-A) set to be equal to or lower than the wet bulb temperature (Twet) of the evaporator (16), and the comfort index (IR) ) Is equal to or lower than the first threshold value (Y1), the compressor (32) is turned off, and the temperature (TE) of the evaporator (16) is changed to the wet bulb temperature (Twet) of the evaporator (16). ) Turn on the compressor (32) when the temperature is higher than the second predetermined temperature (Twet-B) set lower or when the comfort index (IR) exceeds the second threshold (Y2). It is characterized by doing.

  Normally, when the compressor (32) is turned on and operated, the refrigerant flows through the evaporator (16), so that the temperature (TE) of the evaporator (16) decreases, so the surface of the evaporator (16) is condensed. It is kept covered with water. On the other hand, when the compressor (32) is turned off, the refrigerant does not flow through the evaporator (16), the temperature (TE) of the evaporator (16) rises, and the surface of the evaporator (16) is gradually dried. To go. At this time, the off-flavor components adhering to the surface of the evaporator (16) are released into the passenger compartment.

  According to this configuration, after the air-conditioning operation is started, the surface of the evaporator (16) is determined by determining that the temperature (TE) of the evaporator (16) is equal to or lower than the first predetermined temperature (Twet-A). Is confirmed to be wet with condensed water, and then the compressor (32) is turned off. Further, after the compressor (32) is turned off, the compressor (32) is turned on when the temperature (TE) of the evaporator (16) becomes higher than the second predetermined temperature (Twet-B). .

  That is, in this configuration, during the intermittent operation of switching the compressor (32) between on and off, the temperature (TE) of the evaporator (16) does not rise across the wet bulb temperature (Twet) and always evaporates. Since the surface of the vessel (16) is covered with condensed water, the off-flavor components adhering to the surface of the evaporator (16) are not scattered into the passenger compartment. Moreover, fuel saving can be achieved by providing the time to turn off the compressor (32) in the intermittent operation mode.

  Furthermore, the compressor (32) is turned off after determining that the comfort index (IR) is equal to or less than the first threshold (Y1), and cooling (cooling) is sufficiently performed from the viewpoint of passenger comfort. Since the compressor (32) is turned off after the air conditioning is performed, the air conditioning is not turned off with insufficient cooling, and the comfort index (IR) is equal to or greater than the second threshold (Y2). Since the compressor (32) is turned on, the cooling function is not stopped more than necessary, and passenger comfort can be maintained.

  The first threshold value (Y1) that is the timing to turn off the compressor (32) and the second threshold value (Y2) that is the timing to turn on the compressor (32) are determined by the fuel saving mode selection means (45). Since the value corresponding to the fuel saving mode selected according to the preference is set, it is possible to provide a fuel saving mode that suits the passenger's preference.

  As described above, according to this configuration, it is possible to reliably suppress the generation of a strange odor while performing fuel saving control that reflects the passenger's preference.

  The comfort index (IR) is an occupant's skin temperature (IR), and is characterized by comprising skin temperature detecting means (42) for detecting the skin temperature (IR).

  According to this configuration, the comfort of the occupant can be suitably determined by detecting the occupant's skin temperature (IR) by the skin temperature detecting means (42).

  In the invention according to claim 3, the control means (36) is configured such that the first threshold value (Y1) in the high-level fuel saving mode, which is a level for achieving further fuel savings, is the first threshold value (Y1) in the low-level fuel saving mode ( Y1) is set to a higher value.

  According to this configuration, in the high-level fuel saving mode, the first threshold value of the occupant's skin temperature (IR) that is turned off is set higher than that in the low-level fuel saving mode. Intermittent operation is executed at an early stage in which the engine is advanced, and a time for turning off the compressor (32) is secured, so that the fuel saving effect can be enhanced.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description later mentioned.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram illustrating a configuration of a vehicle air conditioner 1 according to the present embodiment. As shown in FIG. 1, a vehicle air conditioner 1 (hereinafter also simply referred to as “air conditioner 1”) that air-conditions a vehicle interior (air conditioner interior) has an air conditioning casing 10 in which an air flow path is formed. In addition, an inside / outside air switching device 11 is provided in an air upstream side portion of the air conditioning casing 10. The inside / outside air switching device 11 is formed with an inside air introduction port 12 for introducing inside air and an outside air introduction port 13 for introducing outside air, and these introduction ports 12 and 13 are selectively provided. An inside / outside air switching door 14 that opens and closes is provided. By rotating the inside / outside air switching door 14, the inlets 12 and 13 are selectively opened and closed.

  A blower 15 that blows air sucked from both the inlets 12 and 13 is disposed at a downstream side portion of the inside / outside air switching device 11. The blower 15 is driven by a blower motor M1. An evaporator 16 that cools the air blown into the room is disposed on the air downstream side of the blower 15.

  A heater core 17 that heats air is disposed on the air downstream side of the evaporator 16. The heater core 17 heats air using the coolant of the traveling vehicle engine 18 as a heat source. A bypass flow path 19 that bypasses the heater core 17 is formed on the downstream side of the evaporator 16, and the air volume ratio between the air volume passing through the heater core 17 and the air volume passing through the bypass flow path 19 is adjusted on the air upstream side of the heater core 17. An air mix door 21 is disposed.

  And in the most downstream site | part of the air-conditioning casing 10, the face blower outlet 22 for blowing off air-conditioning air to a passenger | crew interior passenger | crew's upper body, the foot blower outlet 23 for blowing air to a passenger | crew passenger's foot, and windshield A defroster air outlet 24 for blowing air toward the inner surface of the air outlet is formed, and air outlet mode switching doors 25a to 25c for switching the air outlet mode are disposed at the air upstream side portions of the air outlets 22 to 24, respectively. It is installed.

The evaporator 16 is a heat exchanger on the low-pressure side of a vapor compression refrigeration cycle Rc (hereinafter simply referred to as “refrigeration cycle Rc”) that exhibits refrigeration capacity by evaporating the refrigerant. The refrigeration cycle Rc includes a compressor 32, a radiator 33, and an accumulator 34 that are driven by the vehicle engine 18 via the electromagnetic clutch 31. An expansion valve 35 is provided on the refrigerant upstream side of the evaporator 16 (the refrigerant flow path on the refrigerant inlet side) as decompression means for the refrigerant radiated by the radiator 33. The compressor 32 is, for example, a fixed capacity type compressor in which the discharge capacity per one rotation becomes a predetermined value.

Furthermore, the air conditioner 1 has an air conditioner ECU 36 as control means. The air conditioner ECU 36 includes a well-known microcomputer including a CPU, a ROM, a RAM (all not shown), and peripheral circuits. The ROM stores a control program for air conditioning control, and performs various calculations and processes based on the control program. Further, the air conditioner ECU 36 has a known timer function.

  The air conditioner ECU 36 is electrically connected to the blower 15, the air mix door 21, the outlet mode switching doors 25 a to 25 c, the compressor 32, and the like. Further, the sensor group includes an outside air temperature sensor 41 that detects the outside air temperature TAM, a skin temperature sensor 42 (skin temperature detecting means) that spot-detects the skin temperature IR of the occupant, and a temperature TE (hereinafter referred to as “evaporator”) of the evaporator 16. Sensors such as a post-evaporation temperature sensor 43 (evaporator temperature detection means) for detecting the post-temperature TE and a wet bulb temperature sensor 44 (wet bulb temperature detection means) for detecting the wet bulb temperature Twet of the evaporator 16 In addition, an economy level changeover switch 45 (fuel saving mode selection means) for switching the level in the fuel saving control by an operation by the occupant is electrically connected.

  Skin temperature IR is an embodiment of the “comfort index” of the present invention. The wet bulb temperature Twet is the surface temperature of the evaporator 16 in a state where the surface of the evaporator 16 is wet with condensed water, and the post-evaporation temperature TE is maintained while the surface of the evaporator 16 is wet with condensed water. Is below the wet bulb temperature Twet. Incidentally, the wet bulb temperature Twe is determined from the temperature (dry bulb temperature) of the air (suction air) flowing into the evaporator 16 and the humidity (relative humidity). The wet bulb temperature sensor 44 converts the change amount of the moisture sensitive film in the sensor into an electric signal and sends it to the air conditioner ECU 36. When the air conditioner 1 is activated, the air conditioner ECU 36 controls the operation of the blower 15 and various motors (not shown) for driving various doors as well as controlling the compressor 32.

  Next, the economy level changeover switch 45 will be described. FIG. 2 is a diagram showing an economy level changeover switch 45 (economy level change screen 51) in the present embodiment. The vehicle according to the present embodiment includes a multi-display 50 that displays audio information, a navigation screen, and an air conditioner mode screen at a substantially central portion (not shown) of an instrument panel (instrument panel portion). The economy level switching screen 51 constituting one screen of the air conditioner mode screen can be displayed on the multi-display 50 by selecting the air conditioner mode with a predetermined panel switch (hard switch) or touch switch. In the present embodiment, a three-stage economy level changeover switch 45 is provided as a touch switch, and includes a low economy level switch 45a, a middle economy level switch 45b, and a high economy level switch 45c in order from the left toward the screen. ing.

  Here, “low”, “medium”, and “high” indicate the level of fuel saving, the degree of fuel saving is lower as the low economy level switch 45a is lower, and the degree of fuel saving is higher as the high economy level switch 45c is lower. Is large, that is, it is a level that achieves further fuel saving. The occupant can select a desired economy level (fuel saving mode) by touching desired level switches 45a, 45b, 45c on the economy level switching screen 51. The selected operation signal is input to the air conditioner ECU 36, and the air conditioner ECU 36 performs air conditioner control according to the input switch signal (details will be described later).

  Next, the control method of the vehicle air conditioner 1 in this embodiment is demonstrated. FIG. 3 is a flowchart showing an example of a control procedure (main flow) of the vehicle air conditioner 1 executed by the air conditioner ECU 36 in the present embodiment. In FIG. 3, only the steps in the characteristic part of this embodiment are shown for simplicity, and general flows such as calculation of the target outlet temperature TAO, determination of the inlet mode, and determination of the outlet mode are omitted. It is what.

  As shown in FIG. 3, first, in step S10, an occupant is identified based on communication information from a body ECU (not shown) based on a key ID (information on a door lock release key) and a seat position (occupant authentication). Next, in step S20, it is determined whether or not the outside air temperature TAM detected by the outside air temperature sensor 41 is within a predetermined range. In the present embodiment, it is determined whether or not the outside air temperature TAM is in the range of the temperature T1 or higher and the temperature T2 or lower (T1 ≦ TAM ≦ T2). Here, the temperature T1 is set lower than the temperature T2 (T1 <T2). If the outside air temperature TAM is within this range, the process proceeds to step S30, and fuel saving control (intermittent operation mode) is executed. This fuel saving control is an intermittent operation control in which the operation of the compressor 32 is switched between on and off, and is a main part of the present invention, and details thereof will be described later.

  On the other hand, if the outside air temperature TAM is outside the predetermined range in step S20, that is, if the outside air temperature TAM is lower than the temperature T1 or higher than the temperature T2, the process is performed without performing the fuel saving control in step S30. finish. This is because, when the outside air temperature TAM is lower than the temperature T1, if the fuel saving control, that is, the intermittent operation of the compressor 32, is performed, the window of the vehicle is likely to be cloudy when the compressor 32 is turned off. This is because driving is not appropriate. The temperature T1 can be set to a temperature within the range of 5 ° C to 10 ° C, for example.

  Further, when the outside air temperature TAM is higher than the temperature T2, if the compressor 32 is intermittently operated, the ambient temperature immediately rises when the compressor is turned off. This will be repeated (the off timing will be described in detail later), and in this case also, intermittent operation is not appropriate. The temperature T2 can be set to a temperature within a range of 30 ° C. to 40 ° C., for example. That is, in step S20, it is determined whether or not the outside air temperature TAM is suitable for intermittent operation of the compressor 32, and the intermittent operation is performed only when it is suitable.

  Next, details of the fuel saving control will be described. FIG. 4 is a flowchart showing details of the fuel saving control in step S30 of FIG. As shown in FIG. 4, when the fuel economy control is started, first, economy level information is input in step S31, and in accordance with the input economy level (low, medium, or high) in step S32. Set threshold for skin temperature IR.

  FIG. 5 shows the threshold value of the skin temperature IR corresponding to each economy level. Here, the first threshold Y1 is a value for viewing the timing at which the compressor 32 is turned off, and indicates the upper limit of the comfort range. That is, if the skin temperature IR is equal to or lower than the first threshold value Y1, it means that the skin temperature IR has fallen to a comfortable range due to sufficient cooling. On the other hand, the second threshold Y2 is a value for checking the timing when the compressor 32 is turned on, and is set to a temperature higher than the first threshold Y1. That is, when the skin temperature IR is equal to or higher than the second threshold Y2, it means that the skin temperature IR has increased due to the passage of time since the cooling was stopped, and the feeling of comfort has been impaired. To do.

  In the present embodiment, as shown in FIG. 5, at the low economy level, the first threshold Y1 is set to 26 ° C. and the second threshold Y2 is set to 27 ° C., and at the middle economy level, the first threshold Y1 is set to 27 ° C. The second threshold Y2 is set to 28 ° C., and at the high economy level, the first threshold Y1 is set to 28 ° C. and the second threshold Y2 is set to 29 ° C. The first threshold value Y1 and the second threshold value Y2 are both set higher as the higher economy level than the lower economy level.

  For example, when the low economy level is selected by the passenger, in step S32, the first threshold Y1 is set to 26 ° C. and the second threshold Y2 is set to 27 ° C. based on FIG. In step S33, the compressor 32 is turned off and on at a predetermined timing. This is performed by off / on control of the electromagnetic clutch 31 of the compressor 32.

  Returning to FIG. 4, the off timing will be described first. In the present embodiment, two conditions (first off condition and second off condition) are observed, and the compressor 32 is turned off when these two conditions are satisfied.

  First, the first off condition is that the post-evaporation temperature TE detected by the post-evaporation temperature sensor 43 is equal to or lower than the wet bulb temperature Twe-A (= the temperature at which the surface of the evaporator 16 can be kept wet). That is (TE ≦ Twet-A). A is an arbitrary coefficient of 0 or more, and can be set, for example, in a range of about 0 ° C to 5 ° C. By satisfying the first OFF condition, it can be confirmed that the evaporator 16 has been cooled to some extent and that the surface of the evaporator 16 is wet with condensed water because it is equal to or lower than the wet bulb temperature Twet. The wet bulb temperature Twet-A is an embodiment of the first predetermined temperature of the present invention.

  The second off condition is that the skin temperature IR detected by the skin temperature sensor 42 is not more than the first threshold value Y1 (IR ≦ Y1). By setting the value of the first threshold value Y1 to an appropriate temperature, it can be confirmed that the occupant's body temperature has become an appropriate temperature, and cooling has been sufficiently performed to such an extent that a comfortable feeling can be obtained. Further, it is conceivable that the temperature of the evaporator 16 decreases immediately after the start of cooling, and the first off condition is satisfied. However, the compressor 32 cannot be turned off immediately by looking at the second condition together. In addition, since the vehicle interior is waited until the vehicle interior is cooled to some extent, the time between on and off of the compressor 32 is not extremely shortened. In the present embodiment, the range where the skin temperature IR is equal to or lower than the first threshold Y1 corresponds to the “comfortable range”.

  Next, on-timing will be described. In the present embodiment, two conditions (first on condition and second on condition) are observed, and the compressor 32 is turned on when any one of these two conditions is satisfied. ing.

  First, the first ON condition is that the post-evaporation temperature TE is higher than the wet bulb temperature Twet-B (TE> Twet-B). B is a coefficient, which may be the same value as the coefficient A of the first off condition, and can be set as appropriate within a range of greater than 0 ° C. and less than 5 ° C., for example. The value that can be taken by the coefficient B does not include 0. Under this first ON condition, it can be confirmed that the post-evaporation temperature TE is certainly lower than the wet bulb temperature Twe, and the surface of the evaporator 16 is wet with condensed water. Conversely, if the post-evaporation temperature TE rises above Twet-B and exceeds Twet-B, there is a risk that off-flavor components adhering to the surface of the evaporator 16 will be scattered toward the vehicle interior. The wet bulb temperature Twet-B is an embodiment of the second predetermined temperature of the present invention.

  The second ON condition is that the skin temperature IR is equal to or higher than the second threshold Y2 (IR ≧ Y2). The second threshold Y2 is set to a higher temperature than the first threshold Y1 (Y2> Y1). By setting the value of the second threshold Y2 to be larger than the first threshold Y1, it is possible to prevent the on / off control from being repeated in a short cycle. And by considering this condition, it can be confirmed that the skin temperature IR of the occupant rises and feels uncomfortable. For example, when the passenger's skin temperature IR rises and becomes uncomfortable before the post-evacuation temperature TE becomes equal to or higher than Twet-B, the compressor 32 is turned on, so that the passenger's comfort is not impaired. .

  On the other hand, even if the skin temperature IR is lower than the second threshold Y2 and is not yet uncomfortable, if the first ON condition is satisfied (TE> Twet-B), the post-evaporation temperature will soon be Since it is considered that TE exceeds the wet bulb temperature Twe and a strange odor is generated in the passenger compartment, the compressor 32 is turned on from the viewpoint of preventing the bad odor.

  In step S33, after the compressor 32 is turned off and on at a predetermined timing, the process proceeds to step S34, and it is determined whether or not the control continuation time is shorter than a predetermined time S (for example, 25 seconds to 40 seconds). Here, the control continuation time in this embodiment refers to the time from when the compressor 32 is turned off to when it is turned on again. Note that this control duration is measured by a known timer function.

  If the control continuation time is equal to or longer than the predetermined time S (step S34: NO), the process returns to step S31 and this control is repeated. On the other hand, if the control duration is shorter than the predetermined time S (step S34: YES), the fuel saving control is canceled in step S35 until the ignition switch is turned off. If the cycle from off to on is too short (off time is too short), annoyance to the occupant will occur due to changes in the air-conditioning air, etc., which will be uncomfortable. For this reason, the measurement time from turning off once to turning on is measured, and if the time is shorter than the predetermined time S, the fuel saving control is exited and, for example, the Auto (automatic) mode is followed. .

  Although omitted in the flowchart, in this embodiment, the blower motor M1 of the blower 15 is also turned off and on at the same timing as the off and on control of the compressor 32. In this way, by turning off the blower 15 as well, a fuel saving effect can be further achieved.

  According to the embodiment, after the air conditioning operation is started, it is determined that the post-evaporation temperature TE is equal to or lower than Twet-A (first predetermined temperature), and the surface of the evaporator 16 is wet with condensed water. After confirming this, the compressor 32 is turned off (step S33).

  Further, after the compressor 32 is turned off, when the post-evaporation temperature TE becomes higher than Twet-B (second predetermined temperature), the compressor 32 is turned on (step S33). Normally, when the compressor 32 is turned off, the refrigerant does not flow through the evaporator 16, the temperature of the evaporator 16 rises, and the surface of the evaporator 16 gradually dries. On the other hand, when the compressor 32 is turned on and operated, the refrigerant flows through the evaporator 16 to lower the temperature (surface temperature) of the evaporator 16, so that the surface of the evaporator 16 is covered with condensed water. Maintained.

  In the present embodiment, the surface of the evaporator 16 is always covered with condensed water without the post-evaporation temperature TE rising across the wet bulb temperature Twe during the intermittent operation of switching the compressor 32 between on and off. It becomes a state. Thereby, the off-flavor component adhering to the surface of the evaporator 16 is not scattered in a vehicle interior, and generation | occurrence | production of off-flavor can be suppressed reliably.

  Also, when the passenger gets out of the vehicle and the vehicle air conditioner 1 is stopped, for example, the surface of the evaporator 16 is gradually dried, and then the vehicle air conditioner 1 is first operated. Then, the case where the surface of the evaporator 16 is dry is considered. However, even in this case, according to the present embodiment, the fuel consumption control is performed after the evaporator 16 becomes wet under the first off condition, so that the evaporation is performed during the operation of the vehicle air conditioner 1. The nasty smell can be reliably suppressed without drying the surface of the vessel 16. When the post-evaporation temperature TE falls from a temperature higher than the wet bulb temperature Twe so as to cross the wet bulb temperature Twe, no problem occurs because no odor is generated. The present embodiment is characterized in that after the start of operation, after the post-evaporation temperature TE is lowered to a temperature lower than the wet bulb temperature Twet, the wet bulb temperature Twe is controlled so as not to rise again.

  Then, by providing the first on condition and the second on condition that are turned on again after the compressor 32 is turned off, the off time can be ensured until either of the conditions is satisfied, so that further fuel saving effect can be achieved. it can.

  Further, the compressor 32 is turned off after determining that the occupant's skin temperature IR is equal to or lower than the first threshold value Y1, and after cooling (cooling) is sufficiently performed from the viewpoint of occupant comfort. Since the compressor 32 is turned off, the air conditioning is not turned off while the cooling is insufficient, and when the skin temperature IR is equal to or higher than the second threshold Y2, the compressor 32 is turned on. The passenger's comfort can be maintained without stopping the function more than necessary.

  The first threshold value Y1 that is the timing to turn off the compressor 32 and the second threshold value Y2 that is the timing to turn on the compressor 32 are set according to the occupant's preference by the economy level changeover switch 45 as the fuel saving mode selection means. Since it is set to a value corresponding to the selected fuel saving mode, it is possible to provide a fuel saving mode that suits the passenger's preference.

  Specifically, when the low economy level is selected, the skin temperature IR is low (first threshold Y1 = 26 ° C.) and the compressor 32 is turned off. On the other hand, when the high economy level is selected, the skin temperature IR is It is turned off at a higher value (first threshold Y1 = 28 ° C.). In this way, by providing a difference in the control constant for each economy level switch 45a, 45b, 45c, fuel saving control that matches the sensation of the passenger can be performed.

  In the above embodiment, the desired economy level can be easily selected by touching the economy level changeover switch 45 on the economy level change screen 51 of the multi-display 50, and the operation is very easy to understand. You can enjoy the fuel efficiency mode system. In addition, the desired level varies depending on the situation even for the same occupant. According to this embodiment, the economy level can be selected as appropriate depending on the physical condition of the day, the amount of gasoline, etc. Can be further increased.

  Further, by providing a temperature difference between the first threshold Y1 that is the threshold at the off timing and the second threshold Y2 that is the threshold at the on timing (Y2> Y1), the compressor 32 is prevented from being turned on immediately. Thus, the so-called hunting phenomenon in which the on / off switching is repeated at an extremely short cycle can be effectively suppressed.

  As described above, according to the present embodiment, in addition to the reduction in the generation of strange odors, the vehicle air conditioner 1 can be configured to ensure air conditioning comfort and further achieve fuel saving that reflects passenger preference. .

(Other embodiments)
In the above embodiment, the fixed capacity type compressor 32 is used, but it may be configured as a variable capacity type compressor.

  In the above embodiment, the temperature of the evaporator 16 (post-evaporation temperature TE) is read from the air temperature after passing through the evaporator 16, but from the everfin sensor directly attached to the fins of the evaporator 16. You may make it detect.

  In the above embodiment, the configuration has three levels of economy (low fuel consumption mode): low, medium, and high. However, even if a plurality of economy levels (fuel saving mode) of two levels, four or more levels are set. good.

  In the above embodiment, the skin temperature IR is used as the comfort index indicating the degree of comfort of the occupant. However, not only the spot temperature of the occupant is detected in a spot manner, but also, for example, the viewing angle for detecting the occupant's ambient air temperature together A wide range of skin temperature may be used as a comfort index.

  In the above embodiment, as shown in FIG. 5, the first threshold value Y1 and the second threshold value Y2 of the skin temperature IR are set in a range of approximately 26 ° C. to 29 ° C., but are limited to this numerical value (range). It is not a thing.

  In addition, for example, the first threshold value Y1 may remain the value in the above-described embodiment, and the values of the second threshold value Y2 may be common to 29 ° C. Even in this case, when the first threshold value Y1 is different, the off timing can be made different, and a plurality of economy levels having different control threshold values can be set.

  In the above embodiment, the economy level changeover switch 45 (low economy level switch 45a, medium economy level switch 45b, high economy level switch 45c) as a fuel saving mode selection means is provided as a touch switch. You may comprise by. For example, as shown in FIG. 6, a rotary dial input type switch 45B as a hard switch may be used.

It is a schematic diagram which shows the structure of the vehicle air conditioner in 1st Embodiment. It is a figure which shows an economy level change switch (economy level change screen). It is a flowchart which shows an example of the control procedure (main flow) of the vehicle air conditioner which air-conditioner ECU performs. It is a flowchart which shows the detail of the fuel-saving control in step S30 of FIG. It is a figure which shows the threshold value of skin temperature IR corresponding to each economy level. It is a figure which shows the economy level change switch in other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 10 Air conditioning case 15 Blower 16 Evaporator 32 Compressor 36 Air conditioner ECU (control means)
42 Skin temperature sensor (skin temperature detection means)
43 After-evaporation temperature sensor (Evaporator temperature detection means)
44 Wet bulb temperature sensor (wet bulb temperature detection means)
45 Economy level selector switch (fuel saving mode selection means)
45a Low economy level switch (fuel saving mode selection means)
45b Medium economy level switch (fuel saving mode selection means)
45c high economy level switch (fuel saving mode selection means)

Claims (3)

A compressor (32) for compressing the refrigerant;
An evaporator (16) for cooling the air by evaporating the refrigerant;
An evaporator temperature detecting means (43) for detecting the temperature (TE) of the evaporator (16);
Wet bulb temperature detection means (44) for detecting the wet bulb temperature (Twet) of the evaporator (16);
Control means (36) having a fuel saving mode for controlling the operation of the compressor (32) and performing intermittent operation while switching the operation of the compressor (32) between on and off during cooling operation;
The fuel saving mode is set to a plurality of levels with different conditions for executing the intermittent operation, and includes a fuel saving mode selection means (45) operated by a passenger to select the fuel saving mode at a predetermined level. ,
The control means (36)
In the comfort index (IR) indicating the comfort level of the occupant, the first threshold (Y1) indicating the upper limit of the comfort range and the second threshold (Y2) set to a value equal to or higher than the first threshold (Y1), A value corresponding to the fuel saving mode selected by the fuel saving mode selection means (45) is set;
The temperature (TE) of the evaporator (16) is equal to or lower than a first predetermined temperature (Twet-A) set to be equal to or lower than the wet bulb temperature (Twet) of the evaporator (16), and the comfort index (IR) is determined to be less than or equal to the first threshold (Y1), and then the compressor (32) is turned off, and the temperature (TE) of the evaporator (16) is changed to the evaporator (16). When the temperature becomes higher than the second predetermined temperature (Twet-B) set lower than the wet bulb temperature (Twet) of the vehicle, or when the comfort index (IR) becomes equal to or higher than the second threshold (Y2). Turns on the compressor (32), the vehicle air conditioner.   The vehicle comfort vehicle according to claim 1, wherein the comfort index (IR) is a skin temperature (IR) of the occupant, and includes a skin temperature detecting means (42) for detecting the skin temperature (IR). Air conditioner.   The control means (36) has a higher value of the first threshold value (Y1) in the fuel saving mode at a high level, which is a level for achieving further fuel saving, than the first threshold value (Y1) in the fuel saving mode at a low level. The vehicle air conditioner according to claim 1 or 2, wherein the vehicle air conditioner is set.

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