JPH08496B2 - Vehicle air conditioning controller - Google Patents

Description

The present invention relates to a vehicle air conditioning control device, and more particularly to humidity control thereof.

[Conventional technology]

In a conventional vehicle air conditioner, the air that has passed through the evaporator supplied with refrigerant from the refrigeration cycle is cooled to around the freezing prevention temperature of the evaporator, and this cooled air is reheated to the required blowout temperature. The temperature inside the vehicle was controlled to the target temperature.

In this method, the blown air is cooled to around the freeze prevention temperature of the evaporator, so that dew condensation occurs on the evaporator surface and the absolute humidity is lowered, and then heated to produce dehumidified air.

[Problems to be solved by the invention]

However, in the air conditioner according to the above-mentioned conventional technique, the blown air is once cooled to around the freeze prevention temperature and reheated, so that blown air with extremely low humidity is produced. For this reason, the humidity of the air in the passenger compartment gradually decreases, and due to the low humidity, the mucous membrane of the eyes and throat of the occupant may be dried, and the occupant may feel discomfort.

The present invention has been made in view of the above problems, and in order to prevent the above-described occupant's discomfort due to excessive dehumidification, air having substantially desired humidity (absolute humidity) is directed to the passenger compartment. It is an object of the present invention to provide an air conditioning control device for a vehicle that blows out as air.

[Means for solving problems]

In order to achieve the above object, the present invention provides a cooler for cooling the air blown toward a passenger compartment, an adjusting means for adjusting the cooling power of the cooler, and the blowout as shown in FIG. Humidity setting means for setting the absolute humidity that is the target humidity of the air, calculating means for obtaining the dew point temperature of the absolute humidity set by this humidity setting means, and the temperature of the air passing through the cooler is obtained by the calculating means. The technical means is provided, which comprises a control means for driving the adjusting means so that the dew point temperature is controlled.

[Action]

 The operation of the configuration shown in FIG. 1 of the present invention will be described below.

The cooler M1 cools the air blown toward the passenger compartment.
For example, it corresponds to an evaporator (evaporator) of a refrigeration cycle.

The humidity setting means M3 sets the target humidity in the vehicle compartment, and this humidity is absolute humidity. This humidity setting means
M3 may be one that sets the absolute humidity as it is, or one that sets the absolute humidity from the relative humidity and the temperature.

The calculating means M4 calculates the dew point temperature at which the relative humidity is 100%, with the absolute humidity set by the humidity setting means M3.

The adjusting means M2 adjusts the cooling power of the passing air by the cooler. For example, if the cooler M1 is an evaporator, this is performed by adjusting the amount and pressure of the refrigerant supplied to the evaporator, changing the effective heat exchange area of the evaporator, or the like.

The control means M5 drives the adjusting means M2 to control the temperature of the air passing through the cooler M1 to the dew point temperature calculated by the calculating means M4.

The absolute humidity of the air that has passed through the cooler M1 is calculated by the humidity setting means.
It is almost equal to the absolute humidity set by M3.

As a result, even if the air that has passed through the cooler M1 is heated, the absolute humidity does not change, so that the air having the absolute humidity set by the humidity setting means can be supplied toward the passenger compartment.

〔The invention's effect〕

According to the present invention, as described in the above operation, the air having the absolute humidity set by the humidity setting means can be supplied toward the vehicle compartment.

Therefore, the air supplied into the vehicle compartment is excessively dehumidified, and the passenger does not feel uncomfortable.

If the absolute humidity set by the humidity setting means is set to a desired humidity for the occupant, the air supplied to the vehicle compartment can be air that is adjusted to the desired humidity.

〔Example〕

A vehicle air conditioning control device to which the present invention is applied will be described below with reference to the drawings.

This example, together with the humidity control which is the gist of the present invention,
It also controls the humidity.

First, the structure of this embodiment will be described with reference to FIGS. 2 to 7.

FIG. 2 shows the configuration of the vehicle air conditioning control device. A vehicle air conditioner (hereinafter referred to as an air conditioner) 2 that performs air conditioning of a vehicle interior 1 has the following configuration.

Reference numeral 3 denotes a ventilation duct of an air conditioner for a vehicle, 4 denotes an inside air inlet that is inserted into the vehicle compartment 1, and 5 denotes an outside air inlet that communicates with the outside of the vehicle compartment. Reference numeral 6 denotes an inside / outside air switching damper for selecting either the inside air intake 4 or the outside air intake 5, which is in the inside air mode at the position shown and in the outside air mode at the position shown by the broken line. Reference numeral 7 denotes a blower that sucks the outside air or the inside air into the duct 3 and blows the air toward the passenger compartment 1. The blower motor 7a and the blower fan 7 are provided.
It consists of 7b. 8 is a refrigeration cycle, 8a is an evaporator, 8b is a variable capacity compressor, 8c is a condenser, 8d
Is a receiver, 8e is an expansion valve, and 8f is a magnetic clutch. The refrigerant circulates in the refrigeration cycle 8 to exchange heat. The high-temperature and high-pressure refrigerant gas compressed by the variable capacity compressor 8b is cooled and liquefied by the condenser 8c, gas-liquid separated by the receiver 8d, atomized by the expansion valve 8e, vaporized by the evaporator 8a, and heat of the evaporator 8a. Take away. The gaseous refrigerant vaporized in the evaporator 8a is sucked into the lid variable capacity compressor 8b,
The surface of the evaporator 8a removes heat from the air, and the condenser 8c
Repeat the refrigeration cycle of dissipating heat to the surface air.
A heating device 9 is composed of a heater core 9a, a hot water source 9b, and a water valve 9c, and is heated by hot water supplied from the hot water source 9b.
The air passing through the heater core 9a is heated. This hot water source 9b
Is an engine that serves as a power source of the vehicle, and uses its cooling water as hot water. Reference numeral 10 denotes an air mix damper which adjusts the amount of air passing through the heater core 9a among the air cooled by the evaporator 8a to adjust the heater core.
It regulates the temperature of the air blown downstream from 9a, that is, in the passenger compartment.

Reference numeral 11 denotes a control device composed of a microcomputer, which includes a CPU, ROM, RAM, I / O ports, which are generally more conventional than before, and a bus for electrically connecting these. The control device 11 receives signals from various sensors and input devices described below and outputs drive signals to various actuators. 12 is an outside air temperature sensor provided outside the vehicle compartment, 13 is an after-evaporation sensor that detects the air temperature behind the evaporator, 14 is an inside air temperature sensor provided in the vehicle compartment, 15 is a solar radiation sensor provided in the vehicle compartment, and 16 is a hot water source. Is a water temperature sensor. 17 is a temperature setter for setting a target temperature in the vehicle interior, 18
Is a humidity setter that sets the target humidity in the passenger compartment as relative humidity,
Reference numeral 19 is various switches for designating modes such as operation and stop of the air conditioner 2, air volume, and inside / outside air. Reference numeral 20 is an inside / outside air switching servomotor for driving the inside / outside air switching damper 6, and 21 is a speed control circuit for adjusting the rotation speed of the blower motor 7a of the blower 7. Reference numeral 22 is a variable displacement actuator which operates the variable displacement mechanism of the variable displacement compressor 8b, 23 is an air mix servomotor which drives the air mix damper 10, and 24 is a water valve servomotor which operates the water valve 9.

In the present embodiment, the variable displacement mechanism of the variable displacement compressor 8b is provided in the cooling amount adjusting means, so the configuration thereof will be described below. Various types of variable displacement compressors have been devised, and the present invention can be applied to all types of variable displacement compressors. For example, as a swash plate type compressor, a compressor as disclosed in JP-A-59-150988 and a vane compressor as disclosed in JP-A-58-128487 are known.

3 and 4 show the variable capacity compressor 8b of this embodiment.
5 and 6 are sectional views for explaining the operation of the variable displacement compressor 8b.

In FIG. 3 and FIG. 4, 100 is a compressor body, and the compressor body 100 is a liner 11 having a cylindrical inner wall 111.
0, and the front and rear open ends of the liner 110 have two side plates.
Covered by 120 and 130 respectively. A cylindrical rotor 200 is rotatably provided in the liner 110 in an eccentric state, and a rotary shaft 210 integrally formed with the rotor 200 is rotatably supported by side plates 120 and 130 via bearings 220 and 230.

Here, four slits 201 are formed in the rotor 200 in a substantially radial shape, and a vane 240 is inserted in each slit 210 so as to be movable back and forth. The space between the liner 110 and the rotor 200 is divided into four working chambers 140 by four vanes 240, and each working chamber 140 moves with the rotation of the rotor 200 and changes its volume. ing.

The side plate 120 is formed with an intake port 121 that opens toward the working chamber 140 in the volume increasing stage.
A discharge port 111 that opens toward the working chamber 140 that has reached the minimum volume stage is formed.

A housing 150 is closely arranged on the outer surface of the side plate 120, and the housing 150, the side plates 120 and 130, and the liner 110 are integrally fixed by a bolt (not shown). housing
A suction pressure chamber 151 is formed between 150 and the side plate 120,
The suction pressure chamber 151 is a working chamber in the volume increasing stage through the suction port 121.
It is designed to communicate with 140. A suction port 152 is formed in the housing 150 so as to communicate with the suction pressure chamber 151. One end of a rotary shaft 210 of the rotor 200 penetrates the housing 150 and extends to the outside, and receives the driving force of an automobile running engine via an electromagnetic clutch (not shown). A seal member 153 is disposed between the rotary shaft 210 and the housing 150 to prevent the fluid to be compressed and the lubricating oil from flowing out along the rotary shaft 210.

A housing 160 is attached to the liner 110, and a discharge pressure chamber 161 is formed in the housing 160. The discharge pressure chamber 161 is adapted to communicate with the working chamber 140, which has reached the minimum volume stage, via the discharge port 111.
A discharge valve 162 and a stopper 163 that regulates the opening stroke of the discharge valve are provided inside. A discharge port 164 that communicates with the discharge pressure chamber 161 is formed in the housing 160.

The side plate 120 is provided with three bypass holes 122, 123, 124 in parallel with each other for connecting the working chamber 140 and the suction pressure chamber 151 that have entered the volume reduction stage, and the side plate 120 intersects with these bypass holes 122, 123, 124. A cylinder hole 170 is provided.

A spool 180 is slidably provided in the cylinder hole 170, and when the spool 180 moves in the cylinder hole 170, the bypass holes 122, 123, 124 are opened and closed sequentially. Here, bypass holes 122,123,124
Of the hole diameter or the cross-sectional area of the working chamber 140 are sequentially increased in the rotating direction of the rotor 200, whereby the effective compression volume of the working chamber 140 is decreased by approximately the same amount when the bypass holes 122, 123, and 124 are sequentially opened and closed by the spool 180. It is like this.

The open end of the cylinder hole 170 is closed by a blind plug 175, and the inside of the cylinder hole 170 is partitioned by a spool 180 into a suction pressure introducing chamber 176 and a discharge pressure introducing chamber 177. A compression spring 178 for urging the spool 180 in the direction of opening the bypass holes 122 to 124 is provided therein. Between the outer periphery of the spool 180 and the cylinder hole 170, there is a gap that allows the compressed fluid to leak from the discharge pressure introducing chamber 177 to the suction pressure introducing chamber 176.

The discharge port 111 and the discharge introduction chamber 177 are communicated with each other via a pressure guiding passage 179, and a solenoid valve 300 as the variable capacity actuator 22 is provided in the middle of the pressure guiding passage 179.

In this embodiment, when the solenoid valve 300 is operated to open the pressure guiding passage 179, the discharge pressure is introduced into the discharge pressure introducing chamber 177, and the spool 180 moves against the spring 178, whereby the bypass hole 124 Close the order of ~ 122. On the other hand, when the pressure guiding passage 179 is closed by the solenoid valve 300, the discharge pressure introducing chamber
The pressure inside 177 leaks to the suction pressure introducing chamber 176 side through the gap between the spool 180 and the cylinder hole 170, and approaches the suction pressure. Therefore, the spool 180 is pushed and moved by the spring 178 to sequentially open the bypass holes 122 to 124. Next, FIGS. 5 (A) to (D)
The operation of the rotary compressor having the above configuration will be described with reference to FIG. In addition, in FIGS. 5A to 5D, the rotor 200 is assumed to rotate in the clockwise direction (arrow direction).

When the rotor 200 is rotated by the engine output, etc.,
The compressed fluid is sucked into the working chamber 140 from the suction port 121, while the compressed fluid is discharged from the discharge port 111.

The solenoid valve 300 is turned on and the pressure guiding passage 179 is opened,
The discharge pressure is introduced into the discharge pressure introducing chamber 177. This allows
The spool 180 moves in the direction of compressing the spring 178 to sequentially close the bypass holes 124-122. Therefore, the compressor operates at the maximum discharge capacity.

When the solenoid valve 300 is turned off and the pressure guiding passage 179 is closed, the pressure in the discharge pressure introducing chamber 177 gradually approaches the suction pressure, and the spool 180 is pushed by the spring 178 to move and bypass the bypass holes 122 to 124. Open gradually. Therefore, the discharge capacity of the compressor is reduced.

As shown in FIG. 5 (A), when the spool 180 closes all the bypass holes 122 to 124, the discharge amount of the compressed fluid is the working chamber 14 immediately after the vane 240 has passed through the suction port 121.
The amount of the fluid to be compressed confined within 0 is V ₁ .

On the other hand, as shown in FIG. 5B, when the bypass hole 122 is open and the bypass holes 123 and 124 are closed,
The actual discharge amount of the compressed fluid is the vane 240 with the bypass hole 1
It becomes the amount V _{2 of the} fluid to be compressed that is confined in the working space 140 immediately after passing through 22.

Similarly, in the state of FIG. 5 (C) and FIG. 5 (D), the actual discharge amount of the compressed fluid was confined in the working chamber 140 immediately after the vane 240 passed through the bypass holes 123 and 124, respectively. The amounts of the fluid to be compressed are V ₃ and V ₄ .

As is clear from FIGS. 5A to 5D, as the bypass holes 122 to 124 are sequentially opened, the actual discharge amount of the compressed fluid is sequentially decreased (V ₁ > V ₂ > V ₃ > V _4). ).

In the present embodiment, the positions and the diameters of the bypass holes 122 to 124 can be appropriately determined. For example, as shown in FIG. 6, the discharge amount in the state of FIG. ) When V _{1 is set} to 1, the discharge amount V ₂ in the state of FIG. 5 (B) is 3/4, and the discharge amount V in the state of FIG. 5 (C)
₃ can be halved, and the discharge amount V ₄ in the state of FIG. 5 (D) can be ¼. Therefore, the discharge amount of the fluid to be compressed can be changed substantially continuously and over a large range as the spool 180 moves.

In this embodiment, the solenoid valve 300 is driven by the duty ratio, and the position of the spool 180 can be adjusted arbitrarily.

Next, the outline of the program of the control device 11 provided with the microcomputer will be described with reference to the flowchart of FIG.

The control device 11 is a switch for instructing the operation of the air conditioner 2.
The operation will start with the closing of 19. FIG. 7 is a flowchart of a program relating to temperature control and humidity control in the operation.

In step 401, the signal from the outside air temperature sensor 12 is Tam, the signal from the post-evaporation sensor 13 is TE, and the inside air temperature sensor 1
The signal of 4 is Tr, the signal of the solar radiation sensor 15 is TS,
The signal of the water temperature sensor 16 is input as TW, the target temperature set by the temperature setting unit 17 is input as Test, and the target humidity set by the humidity setting unit 18 is input as Hset. Step 40
In 2, the required outlet temperature TAO for making the temperature of the passenger compartment 1 the target temperature is calculated based on the following equation.

TAO = Kset * Tset-Kr * Tr-Kam * Tam-KS * TS + C (Kset, Kr, Kam, KS, C are predetermined constants.) In step 403, the dew point temperature THO is calculated. In this example, since the target humidity is given as relative humidity, the absolute humidity that is the target humidity at the target temperature, the relative humidity is 100
Calculate the dew point temperature in%. The relationship between temperature, relative humidity and absolute humidity is generally known from the moist air diagram. The dew point temperature is calculated using a polynomial approximation formula.Based on this moist air diagram, a map for determining the dew point temperature from the relative humidity and temperature is created and stored in ROM. May be obtained by linearly interpolating to obtain the dew point temperature.

In step 404, the outside temperature Tam and the frost prevention temperature Tho
If the outside temperature Tam is lower than the frost prevention temperature, the process proceeds to step 405, the magnet clutch 8f is turned off, and the operation of the variable capacity compressor 8b is prohibited. This is because the outside temperature Tam is low and cooling by the refrigeration cycle 8 is not necessary.

In step 406, the required outlet temperature TAO and the dew point temperature THO
And when TAO <THO, branch to YES, and if TAO≥THO, branch to NO. In step 407, the dew point temperature THO is compared with the frost prevention temperature Tho, and if THO ≦ Tho, YES is set,
If THO> Tho, branch to NO.

If YES is obtained in either step 406 or step 407, the process proceeds to step 408, and the magnet clutch 8f is turned on. In step 409, the drive duty given to the solenoid valve is changed so that the temperature of the air passing through the evaporator 8a becomes the frost prevention temperature Tho. This is feedback-controlled based on the temperature TE indicated by the post-evaporation sensor 13. Step 406 and step 407
And when the required outlet temperature TAO is lower than the dew point temperature THO,
The temperature control is prioritized, and the dew point temperature THO is the frost prevention temperature Th.
When it is lower than o, it indicates that priority is given to frost prevention. Needless to say, even if the required blow-out temperature TAO is lower than the frost prevention temperature, priority is given to the anti-slost.

In step 410, the magnet clutch is turned on.
In step 411, the drive duty applied to the solenoid valve 300 is changed so that the temperature of the air passing through the evaporator 8a becomes the dew point temperature THO. This step 41
1 is the temperature T indicated by the post-evaporation sensor 13 as in step 409.
Feedback control is performed based on E.

In step 412, the opening / closing of the water valve 9c is instructed. The temperature TE indicated by the post-evaporator sensor 13 is the required outlet temperature TAO
If it is lower, the water valve 9c is opened, and if it is higher, it is closed. In step 413, the opening of the air mix damper 10 is calculated based on the output TE of the post-evaporation sensor 13 and the like in order to realize the required blowout temperature TAO, and a command is given to the air mix servo motor 23 to send the air mix. The opening of the damper 10 is adjusted. In step 414, the required outlet temperature TA
The air volume is determined according to O, a command is given to the speed control circuit 21, and the rotation speed of the blower motor 7a is adjusted.

The operation shown in FIG. 7 is repeated in a predetermined cycle to adjust the temperature in the vehicle interior and the humidity of the air blown toward the vehicle interior.

Next, the operation of this embodiment will be described based on FIG. 7 and FIG. 8 which is a part of the moist air diagram.

In this embodiment, the humidity control is performed when step 410 and step 411 in the flowchart of FIG. 7 are executed.

For example, the target temperature set by the temperature setter 17 is 27
(℃), the target humidity set by the humidity setter 18 is relative humidity
It is assumed to be 50 (%). First, it is assumed that the required outlet temperature TAO is calculated in step 402 and is, for example, 20 (° C.). In step 403, the dew point temperature THO is calculated. From the moist air diagram in Fig. 8, relative humidity of 50 (%) at 27 (° C)
The absolute humidity is about 0.011 (kg / kg), and the dew point temperature at that absolute humidity is about 15.5 (° C). Therefore,
After step 410 and step 411, the post-evaporation sensor 13
The driving duty of the solenoid valve is given such that the temperature TE indicated by is the dew point temperature, that is, about 15.5 (° C.). As a result, the discharge capacity of the variable capacity compressor 8b changes, and the cooling amount of the passing air by the evaporator 8a is adjusted. When the temperature of the air passing through the evaporator 8a is set to the dew point temperature, the excess humidity becomes water drops and adheres to the surface of the evaporator 8a, the inner surface of the ventilation duct 3, or the like. When these operations are illustrated in FIG. 8, there is a change from the point P ₁ to the point P ₂ .

Then, by steps 412 to 414, the evaporator 8a
The temperature of the air passing through is heated up to the required outlet temperature TAO, here 20 (° C.). This is the change from point P _{2 in} FIG. 8 to point P ₃ . That is, the air blown into the passenger compartment is adjusted to the temperature and humidity represented by the point P ₃ . This air is blown into the passenger compartment, and the temperature in the passenger compartment is controlled to the target temperature. Humidity of blown air (relative humidity)
Is a value different from the target humidity (relative humidity), but becomes substantially the target humidity (relative humidity) when the temperature of the blown air rises to the target temperature without being humidified. Therefore, as long as the processing in steps 410 and 411 is executed, the humidity (relative humidity) will not drop below the target humidity even if the temperature inside the vehicle is at or above the target temperature. . That is, in FIG. 8, although the defined humidity of the outlet air to be changed from the point P ₃ to the point P ₄ (absolute humidity), in fact, humidity present in the passenger compartment, the point P ₃ by breathing such as passenger Therefore, the change is like point P ₅ .

As described above, in the present embodiment, by setting the target temperature and the target humidity, it is possible to blow out the air having the humidity that will be the target humidity (relative humidity) at the target temperature. Moreover, since the capacity of the compressor in the refrigeration cycle is changed, the load applied to the engine that drives the compressor can be reduced. In addition, compared to the conventional method of cooling to the frost prevention temperature, not only can humidity control be performed at a selected humidity, but since it only cools to the dew point temperature, the amount of reheating can be reduced, and it can be used for cooling and heating. The lost expenses can be reduced.

Further, in this embodiment, the target humidity is given as the relative humidity and also as the target humidity in the vehicle compartment. Then, the dew point temperature of the absolute humidity that becomes the target humidity (relative humidity) at the target temperature is obtained, and the air is cooled to this dew point temperature to dehumidify. That is, the target humidity of the blown air in the claims is this absolute humidity. Thereby, the blown air having the humidity (relative humidity) such that the target humidity (relative humidity) is reached when the temperature of the blown air reaches the target temperature is provided.

However, the target humidity may be given as the relative humidity and also as the target humidity of the blown air. In this case, since the temperature of the blown air is the required blowout temperature, the dewpoint temperature of the absolute humidity that is the target humidity (relative humidity) is obtained at this required blowout temperature, and the air is cooled to this dewpoint temperature and dehumidified. That is, the target humidity of the blown air in the claims is this absolute humidity. Thereby, blown air having a desired humidity (relative humidity) can be obtained. The target humidity may be given as absolute humidity.

Further, in this embodiment, as the adjusting means M2 which is a means for adjusting the cooling power of the cooler M1 shown in FIG. 1, a variable capacity compressor for supplying a refrigerant to the evaporator 8a shown in FIG.
The amount of refrigerant was changed using 8b and a variable displacement actuator. However, there are various kinds of adjusting means, and it can also be realized by changing the pressure of the refrigerant in the evaporator 8a by adjusting the opening degree of the expansion valve 8e.

Further, in this embodiment, the temperature of the air that has passed through the evaporator 8a is detected by the post-evaporation sensor 13, and feedback control is performed so that the temperature becomes a desired dew point temperature.
However, a refrigerant pressure sensor may be provided at the refrigerant outlet of the evaporator 8a, and feedback control may be performed so that the refrigerant pressure becomes a pressure corresponding to the dew point temperature. You may perform open loop control by the rule.

One embodiment of the present invention described above and another embodiment that is a modification thereof control the air blown toward the vehicle interior to an absolute humidity set by a humidity setting device without providing a humidity sensor. It is possible to

[Brief description of drawings]

FIG. 1 is a block configuration diagram of the present invention, FIG. 2 is a block configuration diagram of a vehicle air conditioning control device according to one embodiment of the present invention, and FIGS. 3 and 4 are variable capacity compressors of one embodiment. 5 and 6 are explanatory views for explaining the operation of the variable displacement compressor of one embodiment, and FIG. 7 is a flowchart showing a part of the operation of the control device of one embodiment. FIG. 8 is a moist air diagram for explaining the operation of the embodiment. M1 …… cooler, M2 …… adjusting means, M3 …… humidity setting means, M4
…… Computing means, M5 …… Control means.

Claims (1)

[Claims] 1. A cooler for cooling air blown toward a passenger compartment, an adjusting means for adjusting a cooling power of the cooler, and a humidity setting means for setting an absolute humidity as a target humidity of the blown air. And a calculating means for obtaining the dew point temperature of the absolute humidity set by the humidity setting means, and the adjusting means for driving the temperature of the air passing through the cooler to the dew point temperature obtained by the calculating means. An air conditioning control device for a vehicle, comprising: