JP3750277B2 - Air conditioner for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle air conditioner, and more particularly to temperature control in a passenger compartment.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a vehicle air conditioner that automatically controls a vehicle interior temperature to be a set temperature (for example, 18 ° C. to 32 ° C.) set by a passenger is well known. In this conventional apparatus, when the passenger wants to continuously obtain a large heating capacity, for example, the set temperature is set to the maximum, but when the temperature in the passenger compartment approaches the set temperature, the air conditioner automatically heats up. Since the capacity is reduced, the passengers may not be satisfied.
[0003]
Therefore, conventionally, in addition to the above-described automatic control, a vehicle air conditioner capable of setting a maximum heating mode in which an air conditioning operation is fixed to a heating operation state by an occupant's operation is well known. The maximum heating mode in this case is, for example, if the temperature control method is of the air mix type, the air mix door is made to flow all the conditioned air to the heater core and the air conditioning fan is operated at the maximum capacity. I am doing so.
[0004]
In this conventional apparatus, for example, when waiting for a passenger at an airport or the like in winter, an example of using the vehicle unattended and sufficiently warming the passenger compartment in advance in the maximum heating mode can be considered.
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional device, there is a problem that, for example, the instrument panel of a resinous vehicle is thermally deformed or the life of an electric device (such as an LED or a radio) provided in the passenger compartment is shortened. .
[0006]
[Means for Solving the Problems]
As a result of studying the above-described conventional apparatus, the present inventor has found the following. In the conventional apparatus, when the vehicle air conditioner continues the maximum heating operation, the temperature in the passenger compartment becomes, for example, 40 ° C. or higher. And since the vehicle air conditioner is normally set in the instrument panel of a vehicle, the vicinity of an instrument panel may become 90 degreeC or more by the radiant heat from a vehicle air conditioner in this case. Thereby, the instrument panel may be thermally deformed.
[0007]
In addition, when the vehicle interior is in a high temperature state and the vehicle electrical equipment is used in this way, the life of the electrical equipment may be shortened or the resin parts of the electrical equipment may be thermally deformed.
As a result of finding such a problem, in the inventions of claims 1 and 2, when the maximum heating mode is set and the temperature (Tr) in the passenger compartment becomes equal to or higher than the predetermined temperature (T1), the conditioned air The vehicle interior temperature (Tr) is lowered by lowering the temperature of the vehicle interior, and the vehicle interior temperature is automatically controlled so as to become the predetermined set temperature (T2).
[0008]
As a result, when the temperature in the passenger compartment exceeds the predetermined temperature, the temperature in the passenger compartment is lowered by lowering the temperature of the conditioned air, so that the instrument panel can be prevented from becoming hot due to radiant heat from the vehicle air conditioner. It is possible to prevent the instrument panel from being thermally deformed. In addition to this, it is possible to shorten the life of the electric device and prevent the resin component of the electric device from being thermally deformed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to FIGS. First, the overall configuration of the present embodiment will be described with reference to FIG.
The vehicle air conditioner 1 is installed in a resinous instrument panel (not shown). The vehicle air conditioner 1 includes an air conditioning case 2 in which conditioned air is introduced into the vehicle interior, a blower 3 that introduces air into the case 2 and blows the air into the vehicle interior, a refrigeration cycle 4 that constitutes cooling means, and heating. A hot water circuit 5 constituting the means and an air conditioner control device 6 are provided.
[0010]
Branch cases 2 a to 2 c are connected to the air downstream side portion of the case 2. The tip of the branch case 2a is connected to a defroster outlet 7 for blowing air toward the inner surface of the windshield 10 of the vehicle, and the tip of the branch case 2b is used for blowing air toward the upper body of the occupant. Connected to the face outlet 8, the tip of the branch case 2c is connected to a foot outlet 9 for blowing air toward the feet of the passenger.
[0011]
Each air outlet 7-9 is selectively opened and closed by the air outlet switching doors 11 and 12 provided in the upstream opening part of branch case 2a-2c. The outlet switching doors 11 and 12 are driven by driving means 13 (see FIG. 2) such as a servomotor through a link mechanism (not shown).
The blower 3 includes a blower case 3a, a centrifugal fan 3b, and a blower motor 3c as a driving unit thereof, and the amount of blown air is determined according to the voltage applied to the blower motor 3c (blower voltage).
[0012]
In the air inlet of the blower case 3 a, an inside air introduction port 14 for introducing the vehicle interior air (inside air) into the air conditioning case 2 and an outside air introduction for introducing the vehicle compartment outside air (outside air) into the air conditioning case 2. An inside / outside air switching box 50 formed with a mouth 15 is connected. The inside / outside switching box 50 is provided with an inside / outside air switching door 16 driven by a driving means 17 (see FIG. 2) such as a servo motor. The inside / outside air switching door 16 air-conditions the inside / outside air switching door 16. The inside air introduction air volume introduced into the case 2 and the outside air introduction air quantity introduced into the air conditioning case 2 from the outside air introduction port 15 are controlled.
[0013]
The refrigeration cycle 4 is a well-known one that constitutes a cooling means for cooling the passenger compartment and also a dehumidifying means that removes fogging of the vehicle windshield 10. Specifically, the refrigerant compressor 18 and the refrigerant condenser 19 are provided. , A receiver 20, a decompression device 21, and a refrigerant evaporator 22, and are connected by a refrigerant pipe 24.
Among these, the refrigerant compressor 18 is driven by the vehicle traveling engine 26 via the electromagnetic clutch 25, compresses the gas refrigerant from the refrigerant evaporator 22 side to form a high-temperature high-pressure refrigerant, and the high-temperature high-pressure refrigerant is used as a refrigerant condenser. 19 side is discharged.
[0014]
The refrigerant condenser 19 receives air from the cooling fan 27 and condenses and liquefies the high-temperature and high-pressure refrigerant discharged from the refrigerant compressor 18. The receiver 20 gas-liquid separates the refrigerant from the refrigerant condenser 19 and stores excess refrigerant in the refrigeration cycle 4.
The decompression device 21 decompresses and expands the liquid refrigerant from the receiver 20 to form a low-temperature and low-pressure refrigerant. Specifically, the decompression device 21 itself so that the degree of superheat of the refrigerant flowing through the outlet pipe of the refrigerant evaporator 22 is constant. It is composed of a temperature-actuated expansion valve that adjusts the flow rate of refrigerant passing through.
[0015]
The refrigerant evaporator 22 is disposed in the case 2 and evaporates the low-temperature and low-pressure refrigerant by heat exchange with the air from the blower 3.
The hot water circuit 5 constitutes a heating means for heating the passenger compartment. Specifically, the hot water circuit 5 is disposed on the downstream side of the refrigerant evaporator 22 in the case 2 and uses the engine cooling water as a heat source for the case 2. It consists of a heater core 28 as a heater for heating the air inside, and a hot water pipe 29 connected to the heater core 28.
[0016]
Among these, the heater core 28 is disposed in the case 2 so that the cold air from the refrigerant evaporator 22 forms a bypass passage 30 that bypasses the heater core 28. Of the cold air, the ratio of the amount of air passing through the heater core 28 and the amount of air passing through the bypass passage 30 is adjusted by the position of the air mix door 31 provided on the air upstream side of the heater core 28. The air mix door 31 is driven by a driving means 32 (see FIG. 2) such as a servo motor through a link mechanism (not shown).
[0017]
The air conditioner control device 6 incorporates a ROM, RAM, I / O port, A / D converter, etc. (all not shown) in addition to a microcomputer storing control programs and various arithmetic expressions related to air conditioning control. As shown in FIG. 2, the servo motors 13, 17, 32, and the blower motor are operated based on an operation signal output from the air conditioner operation panel 33 and detection signals from various sensors to be described later. Control signals are output to a motor drive circuit 34 for driving 3c and a clutch drive circuit 35 for driving the electromagnetic clutch 25.
[0018]
The various sensors include an internal air temperature sensor 36 that detects the temperature inside the vehicle interior (hereinafter referred to as the internal air temperature), an external air temperature sensor 37 that detects the temperature outside the vehicle interior, and solar radiation that detects the amount of solar radiation that is radiated into the vehicle interior. A sensor 38, a post-evaporator sensor 39 that detects the air temperature immediately after passing through the refrigerant evaporator 22, and a water temperature sensor 40 that is attached to the outer surface of the heater core 28 and detects the engine cooling water temperature are used.
[0019]
The air-conditioner operation panel 33 is provided on an instrument panel (not shown) in the passenger compartment, and switches a known blow-out mode by operating a temperature setter 33a for setting a preset temperature in the passenger compartment or an occupant as shown in FIG. A blow mode setting switch (not shown) is provided.
The temperature setter 33a in this example can set a range of 17 ° C. to 31 ° C. by 1 ° C., and further, the Lo mode for fixing the air conditioner to the operation mode of the maximum cooling state, and the air conditioner in the maximum heating state. The Hi mode to be fixed to the operation mode can be set.
[0020]
In the Lo mode, the position of the air mix door 31 is fixed to an opening degree (a in FIG. 1) where all the air that has passed through the refrigerant evaporator 22 bypasses the heater core 28, and the blower 3 is fixed to the maximum blowing state. Is.
In the Hi mode, the position of the air mix door 31 is fixed to an opening degree (b in FIG. 1) through which all the air that has passed through the refrigerant evaporator 22 passes through the heater core 28, and the blower 3 is fixed to the maximum blowing state. Is.
[0021]
The Hi mode is set when the set temperature of the temperature setter 33a is operated to raise the temperature further than 31 ° C. The Lo mode is set when the set temperature of the temperature setter 33a is operated to lower the temperature further than 17 ° C.
Next, the contents of control performed by the air conditioner control device 6 will be described based on the flowchart of FIG.
[0022]
When the ignition switch of the vehicle is turned on and power is supplied to the air conditioner control device 6, first, in step S10, various counters, flags, etc. are initialized and constants are set.
Next, in step S20, as various information reading, the set temperature signal (Tset) of the temperature setter 33a and the values (Tr, Tam, Ts, Te, Tw) obtained by A / D converting the detected values of the sensors 36-40. ) And other switch states of the air conditioner operation panel 33 are read.
[0023]
Subsequently, in step S30, it is determined whether or not the setting state of the temperature setting device 33a read in step S20 is set to the Hi mode. And when the determination result in this step S30 is YES, it progresses to step S40 and performs Hi mode control. This Hi mode control will be described in detail later.
[0024]
On the other hand, if the Hi mode is not set in step S30 and the set temperature is set to any one of 17 ° C. to 31 ° C., the process proceeds to step S50. In step S50, a target blowing temperature (hereinafter referred to as TAO), which is a target temperature of the conditioned air blown into the passenger compartment, is calculated based on Equation 1 below.
[0025]
[Expression 1]
TAO = Kset * Tset-Kr * Tr-Kam * Tam-Ks * Ts + C
Here, Kset, Kr, Kam, and Ks are gains, and C is a correction constant.
Next, in step S60, the target opening degree SW of the air mix door 31 is determined based on the following formula 2 so that the temperature of the air blown into the vehicle interior becomes the TAO.
[0026]
[Expression 2]
SW = {(TAO−Te) / (Tw−Te)} × 100 (%)
As described above, in the calculation processing in steps S50 and S60, the temperature in the passenger compartment is automatically controlled so as to be the set temperature set by the temperature setter 33a (hereinafter, this is the normal temperature control). .
[0027]
Next, in step S70, the blower voltage applied to the blower motor 3c is determined from the characteristic diagram shown in FIG. 4, and in the next step S80, the inlet mode is determined based on the TAO. As shown in FIG. 4, the suction port mode is set to either the outside air introduction mode or the inside air circulation mode according to the TAO. Here, the outside air introduction mode is a mode in which the inside air introduction port 14 is closed by the inside / outside air switching door 16, the outside air introduction port 15 is opened, and outside air is introduced into the air conditioning case 2. The inside air circulation mode is a mode in which the inside air introduction port 14 is opened at the inside / outside air switching door 16, the outside air introduction port 15 is closed, and the inside air is introduced into the air conditioning case 2.
[0028]
Next, in step S90, the air outlet mode is determined based on the TAO from the characteristic diagram shown in FIG. For example, as the TAO increases, the blowing mode is determined in the order of the following face mode, bi-level mode, and foot mode.
The FACE (face) mode is a mode in which conditioned air is blown out from the face air outlet 8, and the B / L (bilevel) mode is in which conditioned air is blown out from both the face air outlet 8 and the foot air outlet 9. The FOOT (foot) mode is a mode in which conditioned air is blown out from the foot outlet 9.
[0029]
Subsequently, in step S100, the operation of the refrigerant compressor 18 is determined. In this operation determination, if the temperature detected by the post-evaporator sensor 39 is 3 degrees or less, the refrigerant compressor 18 is stopped so that frost is not generated in the evaporator 22, and if the temperature is higher than 4 degrees, the refrigerant compressor 18 is stopped. Is activated.
Next, in step S110, control signals are output to the servo motors 13, 17, 32, the motor drive circuit 34, and the clutch drive circuit 35 so that the control target values are obtained. Thereafter, in step S101, it is determined whether or not a predetermined control cycle τ has elapsed. If it has elapsed, the process returns to step S2, and if it has not elapsed, the control in step S110 is repeated until τ has elapsed.
[0030]
Next, the contents of the Hi mode control in step S40 will be described.
First, in step S41, it is determined whether or not the internal air temperature detected by the internal air temperature sensor 36 is higher than a predetermined temperature T1 (for example, 40 ° C.). If the determination result in step S41 is NO, the process proceeds to step S45. , Hi mode control is performed.
In this case, the TAO is calculated using Equation 1 in step S43, and the process proceeds to step S44. In step S44, the blower voltage is set to the maximum of the characteristics shown in FIG. And it progresses to step S45 and the target opening degree SW of the said air mix door 31 is fixed so that it may be in a maximum heating state. That is, in the Hi mode control, TAO is calculated in step S43, but the blower voltage and the target opening degree SW are not determined by the characteristic diagram of FIG. In the Hi mode control, the inlet mode and the outlet mode are set in the characteristic diagrams of FIGS. 6 and 7 based on the TAO calculated in step S43.
[0031]
On the other hand, if the determination result in step S41 is YES, the process proceeds to step S43. Here, when it is determined as YES in step S41 and the inside air temperature is 40 ° C. or higher, there is no passenger in the normal passenger compartment, and the passenger compartment is unmanned and the passenger compartment is heated in the Hi mode for, for example, 1-2 hours. is there. For example, as described above, when waiting for a passenger at an airport or the like in winter, the vehicle is unmanned and the vehicle interior is sufficiently warmed in advance by the Hi mode control.
[0032]
In this case, the process proceeds to step S46, Tset is set to a predetermined set temperature (31 ° C.) as the set temperature, and the process proceeds to step S50. That is, when the inside air temperature becomes 40 ° C. or higher, the Hi mode control is stopped and the normal temperature control is resumed. Therefore, when the Hi mode is set and the internal air temperature is 40 ° C or higher, which is higher than the maximum set temperature (31 ° C in this case) among the set temperatures, the internal air temperature is lowered by reducing the temperature of the conditioned air. The internal air temperature is automatically controlled to be a predetermined set temperature (31 ° C.).
[0033]
As a result, the internal temperature is controlled so as to drop from 40 ° C. to 31 ° C. by the normal temperature control, and the instrument panel can be prevented from becoming hot due to the radiant heat from the air conditioning case 2. It is possible to prevent thermal deformation. In addition to this, it is possible to shorten the life of light-emitting diodes and the like, which are electrical components used in in-vehicle radios, and to prevent the resin components of in-vehicle radios from being thermally deformed.
[0034]
(Other embodiments)
In the above embodiment, the temperature control method of the vehicle air conditioner was an airmic type in which hot air is mixed with cold air. However, the present invention adjusts the flow rate of hot water flowing through the heater core to adjust the temperature of the air conditioning air. A so-called reheat type of adjustment is also applicable.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration diagram of a vehicle air conditioner according to an embodiment of the present invention.
FIG. 2 is a diagram showing a control system of a vehicle air conditioner in the embodiment.
FIG. 3 is a flowchart showing control details in the embodiment.
FIG. 4 is a diagram showing a relationship between TAO and a blower voltage in the embodiment.
FIG. 5 is a diagram showing a relationship between TAO and a suction port mode in the embodiment.
FIG. 6 is a diagram illustrating a relationship between TAO and the outlet mode in the embodiment.
FIG. 7 is a flowchart showing the contents of Hi mode control in the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Vehicle air conditioner, 6 ... Air conditioner control apparatus, 33a ... Temperature setting device.

Claims (2)

The vehicle interior temperature (Tr) can be controlled automatically so that it becomes the set temperature (Tset), and the maximum heating mode that forcibly fixes the air-conditioning operation to the maximum heating state by the passenger can be set A vehicle air conditioner,
When the maximum heating mode is set and the temperature (Tr) in the vehicle interior is equal to or higher than a predetermined temperature (T1), the temperature (Tr) in the vehicle interior is decreased by reducing the temperature of the conditioned air, A vehicle air conditioner that is automatically controlled so that the temperature in the passenger compartment becomes a predetermined set temperature (T2). Target blowing temperature calculating means (S50) for calculating a target blowing temperature (TAO) of the conditioned air blown into the vehicle interior based on at least the set temperature (Tset) and the vehicle interior temperature (Tr);
By adjusting the temperature of the conditioned air in accordance with the target air temperature (TAO) calculated by the target air temperature calculating means (S50), the temperature (Tr) in the passenger compartment becomes the set temperature (Tset). And a temperature control means (S50, 60) for performing normal temperature control,
When the maximum operation mode is set and the temperature (Tr) in the vehicle compartment is equal to or higher than the predetermined temperature (T1), the set temperature (Tset) is set to the predetermined set temperature (T2), The vehicle air conditioner according to claim 1, wherein the normal temperature control is performed by the temperature control means (S50, S60) so that the temperature (Tr) in the vehicle interior becomes the predetermined set temperature (T2).

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