JP2015143037A - Air-conditioning control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air-conditioning control device which does not impair comfort of a user even when a temperature of an engine coolant is low.SOLUTION: An air-conditioning control device includes: an evaporator core 31 which cools air blown to a vehicle cabin; a compressor 35 which compresses a refrigerant introduced into the evaporator core 31; a heater core 33 which conducts heat exchange between the air cooled by the evaporator core 31 and a coolant of the engine 2; an air mix door 32 which adjusts an amount of the air used for the heat exchange in the heater core 33; a water temperature sensor 51 which detects a temperature of the coolant of the engine 2; and a cooling heat exchanger temperature adjustment part 60 which increases a target temperature of the evaporator core 31 when a temperature of the coolant of the engine 2 is lower than a predetermined temperature and the air for conducting the heat exchange in the heater core 33 exists.

Description

  The present invention relates to an air conditioning control device, and more particularly to an air conditioning control device that controls an air conditioning device mounted on a vehicle.

  HVAC (Heating, Ventilating, and Air Conditioning), one of the air conditioners mounted on vehicles, cools the inhaled air with a cooling heat exchanger (evaporator core) and then heats the heat exchanger (heater core) It is a mechanism to warm up by. In this HVAC, the amount of air that passes through (heats) the heater core with respect to the air that has passed through the evaporator core is controlled by an air mix (A / M) door to change the ratio of cold air to hot air, thereby The air blown out to the temperature reaches the temperature required by the user.

  During heating, the temperature of the hot air produced by the heater core is low until the temperature of the engine cooling water rises to a certain value. Therefore, by moving the A / M door to the HOT side from the normal time, A technique for achieving the desired heating even when the water temperature is low is widely known.

  The evaporator core generally cools air passing through the evaporator core using a refrigerant compressed by a compressor. As described in Japanese Patent Application Laid-Open No. H10-228707, there is known one that controls a compressor core to be turned on and off according to the temperature of the evaporator core so that the evaporator core can be maintained at a predetermined temperature.

Japanese Patent No. 312509

  Not only during the above-mentioned heating, but also in spring and autumn cooling where strong cooling is not required (that is, when the temperature is adjusted by mixing cold and warm air using an A / M door) When the coolant temperature is low, the heater core temperature is low, and the passing air cannot be sufficiently warmed. For this reason, wind colder than the target blowing temperature requested by the user blows out, which may be uncomfortable for the user.

  Therefore, an object of the present invention is to provide an air conditioning control device that does not impair user comfort even when engine cooling water has a low water temperature.

  According to a first aspect of the present invention, there is provided a heat exchanger for cooling that cools air to be blown into a passenger compartment, and heat exchange for heating that performs heat exchange between the air cooled by the heat exchanger for cooling and a heat source for heating. And an air-conditioning control device that controls an air-conditioning device that adjusts the amount of air to be heat-exchanged by the heat exchanger for heating, and for cooling that adjusts the temperature of the cooling heat exchanger A heat exchanger temperature adjusting unit, the cooling heat exchanger temperature adjusting unit has a temperature of the heating heat source lower than a preset temperature, and there is air that performs heat exchange with the heating heat exchanger As a condition, the target temperature of the cooling heat exchanger is raised.

  As a second aspect of the present invention, a dehumidification necessity determination unit that determines whether or not dehumidification is required in the vehicle interior is provided, and the cooling heat exchanger temperature adjustment unit determines that dehumidification in the vehicle interior is necessary. As a condition, it is preferable not to raise the target temperature of the cooling heat exchanger.

  As a third aspect of the present invention, it is preferable that the dehumidification necessity determining unit determines that dehumidification is necessary when it is detected that the air conditioner blows air toward the window of the passenger compartment.

  As a fourth aspect of the present invention, it is preferable that the dehumidification necessity determining unit determines whether or not dehumidification is necessary based on the humidity in the passenger compartment.

  As described above, according to the first aspect, when the temperature of the heating heat source is low and the temperature of the air cannot be increased by the heating heat exchanger, the target temperature of the cooling heat exchanger is increased. Therefore, it is possible to suppress air blowing that is cooler than the target blowing temperature requested by the user, and to perform air-conditioning control that does not impair user comfort.

  According to said 2nd aspect, when it is judged that the dehumidification of a vehicle interior is required, since change of the target temperature of the heat exchanger for cooling is not performed, it can prevent impairing dehumidification performance.

  According to said 3rd aspect, since it determines that dehumidification is required when the air conditioner is blowing air on the window of a vehicle interior, and does not change the target temperature of a heat exchanger for cooling, dehumidification It can prevent impairing performance.

  According to said 4th aspect, in order to judge the necessity of dehumidification based on the humidity in a vehicle interior, without changing the target temperature of the heat exchanger for cooling according to the humidity in a vehicle interior, It can prevent impairing the dehumidifying performance.

FIG. 1 is a conceptual block diagram showing an air conditioning control device according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of the standard target evaporator temperature map. FIG. 3 is a diagram illustrating an example of the lowest odor prevention minimum evaporator temperature map. FIG. 4 is a flowchart for explaining the processing.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1-4 is a figure which shows the air-conditioning control apparatus which concerns on one Embodiment of this invention.

  In FIG. 1, an air conditioner 4 is an HVAC (Heating, Ventilating, and Air Conditioning) device that performs air conditioning such as heating, cooling, dehumidification, and ventilation of a vehicle 1 using an engine (internal combustion engine) 2 as a travel drive source. It is.

  The air conditioner 4 has an outside air introduction port 20a that communicates the inside of the air conditioner 4 to the outside of the vehicle compartment, and an inside air introduction port 20b that communicates the inside of the air conditioner 4 to the vehicle interior as the introduction ports of the air blown into the vehicle interior. Is formed.

  The outside air introduction port 20 a is an introduction port that introduces air outside the vehicle compartment into the air conditioner 4. The inside air introduction port 20b is an introduction port for introducing air in the vehicle interior into the air conditioner 4, that is, an introduction port for introducing air to be circulated in the vehicle interior.

  In the air conditioner 4, there is provided an introduction port switching door 21 for switching the introduction port of the air blown into the vehicle interior between the outside air introduction port 20a and the inside air introduction port 20b. The introduction port switching door 21 moves between a position where the outside air introduction port 20a is completely closed and the inside air introduction port 20b is completely opened, and a position where the inside air introduction port 20b is completely closed and the outside air introduction port 20a is completely opened. The air conditioner 4 is rotatably mounted so as to be able to do so.

  The introduction port switching door 21 is provided with an actuator 22 for driving the introduction port switching door 21. The actuator 22 controls the position of the introduction port switching door 21 according to control by the ECU 3.

  Further, the air conditioner 4 includes a defroster discharge port 24a that communicates with a defroster blowout port that opens toward the vehicle interior side of the front window glass, and a driver's seat and a passenger seat. The vent outlet 24b communicated with the vent outlet opened toward the vehicle and the foot outlet 24c communicated with the leg outlet opened toward the feet of the passenger seated in the driver's seat and the passenger seat are formed. Has been.

  In the air conditioner 4, an outlet switching door 25a for opening and closing the defroster outlet 24a and an outlet switching door 25b for selectively opening and closing the vent outlet 24b and the foot outlet 24c are provided.

  The outlet switching door 25a is rotatably mounted in the air conditioner 4 so as to be movable between a position where the defroster discharge port 24a is completely closed and a position where the defroster discharge port 24a is fully opened.

  The blower outlet switching door 25a is provided with an actuator 26a for driving the blower outlet switching door 25a. The actuator 26a controls the position of the outlet switching door 25a according to control by the ECU 3.

  The outlet switching door 25b moves between a position where the vent outlet 24b is completely closed and the foot outlet 24c is fully opened, and a position where the foot outlet 24c is completely closed and the vent outlet 24b is fully opened. The air conditioner 4 is rotatably mounted so as to be able to do so.

  The blower outlet switching door 25b is provided with an actuator 26b for driving the blower outlet switching door 25b. The actuator 26b controls the position of the outlet switching door 25b in accordance with control by the ECU 3.

  In the air conditioner 4, a blower fan 30, an evaporator core 31, an air mix door 32, and a heater core 33 are provided in order from the air inlet to the outlet.

  The blower fan 30 blows air that is blown into the passenger compartment. The blower fan 30 is provided with a blower fan motor 34 that rotates the blower fan 30. The blower fan 30 is rotated by a blower fan motor 34 to blow air introduced from the inlet toward the outlet. The rotational force of the blower fan motor 34 is changed in accordance with control by the ECU 3 to change the amount of air blown by the blower fan 30.

  The evaporator core 31 cools the air passing through the evaporator core 31 by causing heat exchange between the air that passes so as to contact the surface of the evaporator core 31 and the refrigerant that expands and vaporizes in the evaporator core 31. And dehumidifying. The evaporator core 31 is provided with a compressor 35 for compressing the refrigerant, and the air conditioner 4 constitutes a known cooling device by controlling the on / off of the compressor 35. That is, the evaporator core 31 constitutes a cooling heat exchanger.

  The air mix door 32 adjusts the flow rate of air passing through the heater core 33. Specifically, the air mix door 32 can move between a position where the air passing through the evaporator core 31 passes through the heater core 33 and a position where the air passing through the evaporator core 31 does not pass through the heater core 33. The air conditioner 4 is rotatably mounted.

  The air mix door 32 is provided with an actuator 36 for driving the air mix door 32. The actuator 36 controls the position of the air mix door 32 (hereinafter also referred to as “air mix door opening”) in accordance with control by the ECU 3.

  The heater core 33 constitutes a heating heat exchanger that exchanges heat between the air cooled by the evaporator core 31 and the cooling water of the engine 2. Cooling water of the engine 2 is circulated through a circulation path 41 by a water pump 40 driven by the engine 2. The circulation path 41 is formed so that the cooling water circulates in the water jacket formed in the engine 2, the radiator 42, and the heater core 33. That is, the cooling water of the engine 2 constitutes a heat source for heating.

  Therefore, the air conditioner 4 constitutes a heating device by controlling the position of the air mix door 32 so that the blower fan 30 is rotated and the air blown into the passenger compartment passes through the heater core 33.

  The ECU 3 includes a CPU (Central Processing Unit), a memory, and the like, and executes air-conditioning control based on various input setting information and various detection information such as sensors in accordance with various control programs stored in the memory in advance.

  In the present embodiment, the input port of the ECU 3 includes an evaporator temperature sensor 50 that detects the temperature of the evaporator core 31, a water temperature sensor 51 that detects the temperature of the cooling water of the engine 2, and a humidity that detects the humidity in the passenger compartment. Various sensors including a sensor 52, a vehicle interior temperature sensor 53 that detects the temperature in the vehicle interior, and an outside air temperature sensor 54 that detects the temperature of the outside air, and a control panel 55 are connected.

  The control panel 55 includes an air introduction mode selection switch in which an air inlet to be blown into the vehicle interior is selected between the outside air inlet 20a and the inside air inlet 20b, a defroster outlet, a vent outlet, and a foot outlet. A blower outlet mode selection switch for selecting a combination of ratios of the amount of air blown out from the air, an air volume adjustment switch for setting the flow rate of air blown out from these blowout openings (hereinafter also simply referred to as “blowout amount”), and setting Various controllers including a temperature setting switch for setting the temperature are provided. On the other hand, various control objects such as the actuators 22, 26 a, 26 b and 36, and the blower fan motor 34 are connected to the output port of the ECU 3.

  For the air outlet mode selection switch, for example, one air conditioning mode is selected from a vent mode, a foot mode, a differential mode, a B / L (bi-level) mode, and a D / F (def / foot) mode. Yes.

  The vent mode is a mode in which conditioned air is blown from the vent outlet. The foot mode is a mode in which conditioned air is blown from the foot outlet. The differential mode is a mode in which conditioned air is blown out from the defroster outlet. The B / L mode is a mode in which conditioned air is blown from the vent outlet and the foot outlet. The D / F mode is a mode in which conditioned air is blown out from the defroster outlet and the foot outlet.

  For example, the ECU 3 detects the vehicle interior temperature detected by the vehicle interior temperature sensor 53 and the temperature set by the temperature setting switch of the control panel 55 when the air conditioner 4 is turned on by the air conditioning switch of the control panel 55. The actuator 36 and the compressor 35 are appropriately controlled so that.

  Further, in the memory of the ECU 3, a standard target evaporator temperature map in which the standard target evaporator temperature Tnet is associated with the air conditioning mode and the target outlet temperature Bt as shown in FIG. 2 is stored in advance.

  The target blowing temperature Bt is the temperature of the air that is blown into the vehicle compartment necessary to bring the temperature in the vehicle compartment to the temperature set by the temperature setting switch of the control panel 55. This target blowing temperature Bt is calculated based on the difference between the temperature set by the temperature setting switch and the temperature in the passenger compartment, the outside air temperature, and the like.

  The value of the standard target evaporator temperature map is, for example, the evaporator core 31 required to blow out the air at the target blowing temperature Bt based on the temperature of the heater core 33 during normal running, the temperature of the air introduced into the air conditioner 4, and the like. The temperature is obtained and set by experiments or the like.

  The ECU 3 sets the target of the evaporator core 31 from the standard target evaporator temperature map based on the air conditioning mode selected by the blower outlet mode selection switch and the target blowout temperature Bt calculated based on the temperature set by the temperature setting switch. The temperature is set.

  In FIG. 1, when the temperature of the evaporator core 31 detected by the evaporator temperature sensor 50 (hereinafter simply referred to as “detected temperature”) and the target temperature set by the standard target evaporator temperature map are different, On / off control of the compressor 35 is performed so that the detected temperature becomes the target temperature.

  When the air conditioner 4 is turned on and the water temperature detected by the water temperature sensor 51 is lower than a predetermined value, the ECU 3 is configured such that the air mix door opening is an opening at which air is introduced into the heater core 33. As described above, the target temperature of the evaporator core 31 is set high.

  Specifically, the ECU 3 determines whether or not the water temperature Wt detected by the water temperature sensor 51 is lower than a preset threshold water temperature Cwt. Here, the threshold water temperature Cwt is a lower limit value of the water temperature of the engine coolant that can increase the temperature of the air passing through the heater core 33. This threshold water temperature Cwt is obtained by experiments or the like and stored in the memory of the ECU 3. The threshold water temperature Cwt may be calculated from the temperature of the air that has passed through the evaporator core 31, the target blowing temperature Bt, or the like.

  Further, the ECU 3 determines whether or not the air conditioning mode selected on the control panel 55 is other than the D / F mode or the differential mode. When the air-conditioning mode is the D / F mode or the differential mode, the target temperature of the evaporator core 31 is not changed because there is a possibility that the occupant is required to remove / prevent fogging of the window glass. The air-conditioning mode may be selected by the ECU 3 in accordance with the target temperature, the outside air temperature, the vehicle interior humidity, or the like, in addition to the selection by operating the occupant's control panel 55.

  Further, the ECU 3 determines whether or not the air mix door opening degree (MAXCOOL state) is such that air does not pass through the heater core 33 according to the control state of the actuator 36 of the air mix door 32. When the air mix door opening is MAXCOOL, the air to be blown into the passenger compartment does not pass through the heater core 33, so the low coolant temperature of the engine coolant does not affect. For this reason, the ECU 3 does not change the target temperature of the evaporator core 31. Note that the air mix door opening becomes MAXCOOL when the ECU 3 requests maximum cooling based on the target temperature, the passenger compartment temperature, or the like.

  Further, the ECU 3 determines whether or not the wind glass is likely to be fogged depending on whether or not the humidity in the vehicle compartment detected by the humidity sensor 52 is higher than a preset threshold humidity. Here, the threshold humidity is an upper limit value of humidity in a state in which the window glass is not fogged, and is obtained by an experiment or the like and stored in the memory of the ECU 3.

  When the wind glass is easily fogged, the dehumidifying ability is required to prevent fogging, so the ECU 3 does not change the target temperature of the evaporator core 31. Note that whether or not the windshield is easily fogged depends on the wiper driving condition (when the wiper is driven, it tends to fog), the number of passengers detected by the seat belt switch, etc. You may judge. That is, the ECU 3 constitutes a dehumidification necessity determination unit 61.

  The ECU 3 determines that the water temperature Wt is lower than the threshold water temperature Cwt, the air conditioning mode is other than the D / F mode or the differential mode, the air mix door opening is not MAXCOOL, and the humidity in the vehicle interior is the threshold humidity. The target temperature of the evaporator core 31 is set by a method to be described later on the condition that it is as follows.

  In the memory of the ECU 3, as shown in FIG. 3, a different odor prevention minimum evaporator temperature map in which the different odor prevention minimum evaporator temperature Est is associated with the air conditioning mode and the introduced air temperature Mt is stored in advance.

  Here, the introduction air temperature Mt uses the outside air temperature Ot when the outside air introduction port 20a is selected as the introduction port of the air to be blown into the vehicle interior, and when the inside air introduction port 20b is selected as the introduction port. The inside air temperature Rt is used.

The lowest odor prevention evaporator temperature Est is a target temperature of the evaporator core 31 for preventing the generation of a bad odor due to mold or the like when the temperature of the evaporator core 31 is maintained at a high temperature. The lower odor preventing minimum evaporator temperature Est is set to a smaller value as the introduced air temperature Mt is higher (positive side) (Y ₀₁ > Y ₀₂ >...> Y ₀₆ ).

  When the air conditioning mode is the foot mode, a larger value is set than when the vent mode and the B / L mode are used. This is because the foot mode makes it difficult to feel a strange odor compared to the vent mode and the B / L mode in which the wind is blown toward the vicinity of the occupant's face. The lowest odor prevention evaporator temperature Est may be specified by one constant instead of a map. Further, the lowest odor prevention evaporator temperature Est is set to a value such as a map so that a value higher than the standard target evaporator temperature Tnet is selected.

Then, the ECU 3 calculates and sets a low water temperature target evaporator temperature Tcet, which is the target temperature of the evaporator core 31 when the engine cooling water is at a low temperature, according to the following equation (1).
Low water temperature target evaporator temperature Tcet = MIN (unpleasant odor prevention minimum evaporator temperature Est, target blowing temperature Bt-α) (1)

  Here, MIN (a, b) means that a and b are compared and the smaller value is selected. That is, the ECU 3 selects the smaller value of the lowest odor prevention minimum evaporator temperature Est and (target outlet temperature Bt−α) as the low water temperature target evaporator temperature Tcet.

  Α is a value corresponding to the degree of increase in the temperature of the air blown into the passenger compartment by the heater core 33, and is calculated based on a fixed value or the outside air temperature Ot or the engine coolant water temperature Wt. Since the cooling is desired as the outside air temperature Ot increases, α takes a large value so that the temperature of the evaporator core 31 is lowered. Moreover, you may make it enlarge (alpha), so that the water temperature Wt is high. Note that α is selected so that the value of (target outlet temperature Bt−α) is higher than the standard target evaporator temperature Tnet. That is, the ECU 3 constitutes a cooling heat exchanger temperature adjusting unit 60.

  The target evaporator temperature setting operation by the air conditioning control device according to the embodiment of the present invention configured as described above will be described with reference to FIG. The target evaporator temperature setting operation described below is executed when the air conditioner 4 is turned on.

  First, the ECU 3 calculates the standard target evaporator temperature Tnet from the air conditioning mode and the target outlet temperature Bt using the standard target evaporator temperature map of FIG. 2 (step S11).

  Next, the ECU 3 determines whether or not the water temperature Wt detected by the water temperature sensor 51 is lower than a preset threshold water temperature Cwt (step S12).

  When it is determined that the water temperature Wt is equal to or higher than the threshold water temperature Cwt, the ECU 3 sets the standard target evaporator temperature Tnet as the target evaporator temperature Tet (step S17) and ends the process.

  When it is determined that the water temperature Wt is lower than the threshold water temperature Cwt, the ECU 3 determines whether the air conditioning mode is other than the D / F mode or the differential mode (step S13).

  When it is determined that the air conditioning mode is the D / F mode or the differential mode, the ECU 3 proceeds to step S17, sets the standard target evaporator temperature Tnet as the target evaporator temperature Tet, and ends the process.

  When it is determined that the air conditioning mode is other than the D / F mode or the differential mode, the ECU 3 determines whether or not the air mix door opening is not MAXCOOL (step S14).

  When it is determined that the air mix door opening is MAXCOOL, the ECU 3 proceeds to step S17, sets the standard target evaporator temperature Tnet as the target evaporator temperature Tet, and ends the process.

  When it is determined that the air mix door opening is not MAXCOOL, the ECU 3 determines whether or not the window glass is not easily fogged (step S15).

  If it is determined that the window glass is likely to be fogged, the ECU 3 proceeds to step S17, sets the standard target evaporator temperature Tnet as the target evaporator temperature Tet, and ends the process.

  When it is determined that the window glass is not easily fogged, the ECU 3 sets the target evaporator temperature Tcet at the time of low water temperature as the target evaporator temperature Tet (step S16), and ends the process.

  Therefore, when the air conditioner 4 is turned on and the engine coolant water temperature Wt is lower than the threshold water temperature Cwt, if the air mix door opening is not MAXCOOL, the set temperature of the evaporator core 31 is increased. Therefore, it is possible to suppress the blowing of wind that is colder than the target blowing temperature required by the air conditioning, and it is possible to perform air conditioning control that does not impair the comfort of the user.

  Further, since the set temperature of the evaporator core 31 is increased, the operating rate of the compressor 35 can be lowered, and the fuel efficiency can be improved.

  In addition, when the air conditioning mode is the D / F mode or the differential mode, or when it is determined that the wind glass is likely to be cloudy, since the set temperature of the evaporator core 31 is not changed, the dehumidification performance can be prevented from being impaired. Air conditioning control reflecting the user's intention can be performed.

  Moreover, since the lowest odor prevention evaporator temperature Est is used, the generation of a strange odor due to excessive increase in the target evaporator temperature Tet can be suppressed, and the user's comfort can be improved.

  In this embodiment, the heater core 33 is used as a heat exchanger for heating and the evaporator core 31 is used as a heat exchanger for cooling. However, the present invention is not limited to this. Further, the heat source is not limited to the refrigerant and the engine coolant.

  Further, in the present embodiment, the blowing of the cold air is prevented by changing the target evaporator temperature Tet, but the control for moving the air mix door 32 to the HOT side in which a large amount of air flows through the heater core 33 may be used together. .

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

1 Vehicle 2 Engine 3 ECU
4 Air Conditioner 30 Blower Fan 31 Evaporator Core 32 Air Mix Door 33 Heater Core 34 Blower Fan Motor 35 Compressor 40 Water Pump 41 Circulation Path 42 Radiator 50 Evaporator Temperature Sensor 51 Water Temperature Sensor 52 Humidity Sensor 53 Car Interior Temperature Sensor 54 Outside Air Temperature Sensor 55 Control Panel 60 Cooling heat exchanger temperature adjustment unit 61 Dehumidification necessity determination unit

Claims (4)

A cooling heat exchanger for cooling the air blown into the passenger compartment;
A heat exchanger for heating that performs heat exchange between the air cooled by the heat exchanger for cooling and a heat source for heating;
An air-conditioning control device that controls an air-conditioning device comprising an air mix door that adjusts the amount of air to be heat-exchanged by the heating heat exchanger,
A cooling heat exchanger temperature adjusting unit for adjusting the temperature of the cooling heat exchanger;
The cooling heat exchanger temperature adjustment unit is provided on the condition that the temperature of the heating heat source is lower than a preset temperature and the air that performs heat exchange in the heating heat exchanger is present. An air conditioning control device characterized by raising a target temperature of a heat exchanger for cooling. A dehumidification necessity judgment unit for judging whether or not dehumidification is required in the vehicle interior;
2. The cooling heat exchanger temperature adjusting unit does not increase the target temperature of the cooling heat exchanger on the condition that it is determined that dehumidification in the passenger compartment is necessary. The air conditioning control device described.   The said dehumidification necessity judgment part judges that the said dehumidification is required when it detects that the said air conditioner is blowing air toward the window of the said compartment. Air conditioning control device.   The air conditioning control device according to claim 2, wherein the dehumidification necessity determination unit determines whether the dehumidification is necessary based on humidity in the vehicle interior.

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