JPH0732856A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To enable excellent temperature control even in a bi-level mode out of relation to an air-conditioning unit structure base on a vehicle structure. CONSTITUTION:An air conditioner for a vehicle has an evaporator sensor to detect an outlet temperature of an evaporator 31, a compressor control means to turn on a compressor when a detecting temperature by the evaporator sensor becomes a prescribed value or more and an air mix damper control means to control opening of an air mix damper 12 when the detecting temperature becomes the prescribed value or more, and has an air mix damper correcting means to set a temperature to turn on the compressore or a temperature to turn off the compressor is set higher than that in a mode except a bi-level mode in the bi-level mode to open both an upper blowoff port and a lower blowoff port as well as to correct the opening of the air mix damper 12 to the cool side when the temperature becomes a high set temperature or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and more particularly to a vehicle air conditioner in which both upper and lower air outlets are opened and the air conditioning control is properly performed in a so-called bi-level mode. is there.

[0002]

2. Description of the Related Art In recent years, many vehicles are equipped with a vehicle air conditioner for adjusting the interior temperature of the vehicle to an optimum temperature.
In such a vehicle air conditioner, cool air is blown from the upper outlet (face outlet) and warm air is emitted from the lower outlet (foot outlet) in order to aim for head heat that feels comfortable to humans. Is configured.

[0003]

However, in the case of an air conditioning unit having a structure in which the structure of the air conditioning unit is limited by the structure of the vehicle and the temperature rising rate of the upper outlet and the temperature rising rate of the lower outlet are different, the upper outlet is When the so-called bi-level mode in which both the bottom outlet and the bottom outlet are opened, as shown by the dotted line in FIG.
The upper half of the body becomes cold, and the lower half of the body becomes hot, which makes it rather uncomfortable and causes a problem that good temperature control cannot be performed.

Therefore, the present invention has been made in view of the above problems, and provides a vehicle air conditioner capable of excellent temperature control even in the bi-level mode regardless of the structure of the air conditioning unit based on the structure of the vehicle. The purpose is to do.

[0005]

The structural features of the present invention include an air duct for introducing air into a passenger compartment, an inside air introduction port and an outside air introduction port arranged on the inlet side of the air duct, and the air duct. An upper outlet that blows air toward the upper half of the occupant, a lower outlet that blows toward the lower half of the occupant, and outlet opening and closing means that opens and closes the upper outlet and the lower outlet. A blower that blows the air sucked from the inlet side to the outlet side, an evaporator that cools the air sent from the blower, a heater core that heats the cool air sent from the evaporator, and a set opening In a vehicle air conditioner including an air mix damper that distributes the cool air sent from the evaporator to the heater core according to the temperature, An evaporator sensor that detects the outlet temperature of the evaporator, when the temperature detected by the evaporator sensor reaches a predetermined value or higher, a compressor control unit that turns on a compressor that supplies compressed refrigerant to the evaporator, and the detected temperature. In accordance with the air mix damper control means for controlling the opening of the air mix damper, and the outlet mode control means for controlling the outlet opening and closing means according to the outlet mode, the outlet mode control means First value setting means for setting the predetermined value to a first value when the outlet opening / closing means is controlled to open only one of the upper outlet and the lower outlet The outlet mode control means opens both the upper outlet and the lower outlet. While controlling the outlet closing means so that, in that a second value setting means for setting the predetermined value to a second value greater than the first value. Further, an air mix damper correction means for correcting the opening degree of the air mix damper to a cool side when the predetermined value is set to a second value larger than the first value by the second value setting means. Be prepared.

[0006]

According to the present invention constructed as described above, in the bi-level mode in which both the upper outlet and the lower outlet are opened, when the temperature detected by the evaporator sensor exceeds a predetermined value, the compressor The temperature is controlled so that the temperature to turn on is higher than that in the outlet mode other than the bi-level mode, so the temperature of the wind passing through the evaporator becomes higher, and the upper outlet and the lower outlet also increase. The temperature of the blown air becomes high. Further, the structure of the air conditioning unit is limited by the structure of the vehicle, and the air conditioning unit has a structure in which the temperature rising rate of the upper outlet is different from the temperature rising rate of the lower outlet, that is, the temperature rising rate of the upper outlet is small and the lower outlet is Even in an air conditioning unit having a structure in which the temperature rise rate of the mouth is high, the temperature difference between the air blown from the upper air outlet and the air blown from the lower air outlet can be reduced. Furthermore, since the air mix damper opening is corrected to the cool side, the hot air from the lower outlet is relaxed and the difference in the outlet temperature from the upper outlet and the lower outlet is further reduced, so the upper body becomes cold, The discomfort that the lower half of the body becomes hot is eliminated, and a comfortable cabin space is created, which not only improves the environmental friendliness of the cabin but also has an effect on safety.

[0007]

1 is a functional block diagram of an embodiment of a vehicle air conditioner of the present invention. In FIG. 1, an air duct 10 is arranged in the front portion of a vehicle compartment (not shown). Two air inlets, an inside air inlet 16 and an outside air inlet 17, are provided on the inlet side of the air duct 10, and a defrost outlet 18 and an upper outlet ( Three air outlets, a face outlet 19 and a lower outlet (foot outlet) 20, are provided. An inside / outside air switching damper 11 is rotatably provided at the two air intake ports with respect to the air duct 10. The inside / outside air switching damper 11 is switched by driving the servomotor 11a, and the inside / outside air switching damper 11 is switched. To the outside air introduction port 17 side, the air in the passenger compartment is changed to the inside air introduction port 16 side.
The air outside the passenger compartment is introduced from the outside air introduction port 17 by switching the inside / outside air switching damper 11 to the inside air introduction port 16 side.

The defrost outlet 18, the face outlet 19, and the foot outlet 20, which are the three air outlets, respectively correspond to the outlets, and are respectively a defrost outlet damper 13 and a face outlet damper 14. And the foot outlet damper 15 are provided, and the outlet dampers 13, 14 and 1 are provided.
5 is driven by servomotors 13a, 14a and 15a, respectively. Here, the face outlet damper 14 and the servomotor 14a, and the foot outlet damper 15 and the servomotor 15a can be referred to as outlet opening / closing means.

However, the defrost outlet 18 is arranged toward the surface of the window glass 22 on the inner side of the vehicle compartment, and when the defrost mode to be described later is set, the servo motor 1
The defrost blowout port damper 13 is opened by 3a, and it is possible to blow air to the window glass 22. Further, the face outlet 19 is arranged toward the upper body of the occupant, and when the face mode described later is set, the servo motor 14a opens the face outlet damper 14 so that air can be blown toward the upper body of the occupant. Become. Also,
The foot outlet 20 is arranged toward the lower body of the occupant, and when the foot mode described later is set, the foot outlet damper 15 is opened by the servomotor 15a so that air can be blown toward the lower body of the occupant.

Further, inside the air duct 10, an evaporator 31, a blower 41, a heater core 50 and an air mix damper 12 are arranged. The blower 41 is rotationally driven by a blower motor 42, and sucks air from the set side of the inside air introduction port 16 or the outside air introduction port 17 and blows the air to the downstream side. An evaporator 31 is disposed on the downstream side of the blower 41. The evaporator 31 cools the air sent from the blower 41 and sends the air to the downstream side, which is one of the elements that constitute the refrigeration cycle 30 described later. Is one. An air mix damper 12 driven by a servomotor 12a is rotatably provided on the downstream side of the evaporator 31.

Further, a heater core 50 is arranged downstream of the air mix damper 12. The heater core 50 heats air using engine cooling water (not shown) as a heat source, and heats cold air sent from the evaporator 31, and the air mix damper 1
Reference numeral 2 denotes the heater core 5 that cools the cool air sent from the evaporator 31 according to the opening degree set by the servo motor 12a.
0 and the bypass passage 21.

The refrigeration cycle 30 is driven by an engine (not shown) to compress an internal refrigerant, a condenser 33 for condensing the high-pressure refrigerant compressed by the compressor 32, and a condenser 33 for condensing the refrigerant. The receiver 34 that separates the gas component and the liquid component of the formed refrigerant and discharges only the gas refrigerant among them, the expansion valve 35 that decompresses and expands the gas refrigerant from this receiver 34, and the expansion valve 35 It is a well-known one that includes an evaporator 31 that evaporates a refrigerant by removing heat from the surrounding air.

The control unit 60 includes a CPU, ROM, RA
It is composed of a microcomputer including M, a timer, and I / O, and stores an automatic air conditioning control program for air conditioning control in advance. The output terminals A to E of the control device 60 are respectively connected to the servo motors 11a, 12a,
The output terminal F is connected to the blower motor 42 via the drive circuit 43. The servomotor 12a includes an air mix damper opening sensor 12b for detecting the opening θ of the air mix damper 12.
The air mix damper opening degree sensor 12b is connected to the input terminal G of the control device 60.

The output terminal H of the control device 60 is connected to an electromagnetic clutch (not shown) of the compressor 32 via a drive circuit 36. By energizing the coil of this electromagnetic clutch, the rotational force of the engine is increased. Is transmitted to drive the compressor 32. The drive circuit 36 has a function of detecting a current flowing through the coil of the electromagnetic clutch, and the detection signal is connected to the input terminal I of the control device 60. Further, the input terminals J and K of the control device 60 are respectively connected to an inside / outside air switching switch 71 and a temperature setting switch 72 arranged on an operation panel (not shown), and the input terminals M to Q are all connected. Inside air sensor 8
1, outside air sensor 82, water temperature sensor 83, solar radiation sensor 84
And an evaporator sensor 85.

The inside air sensor 81 detects a room temperature Tr by assembling a thermistor whose resistance value changes with a temperature change, for example, in a resin case and sucking the air in the passenger compartment into the case. The outside air sensor 82 has a thermistor similar to the inside air sensor 81 enclosed in a resin case and is attached to the engine room at a place where it is unlikely to be affected by the hot air, and detects the temperature Tam outside the vehicle. The water temperature sensor 83 is a sensor using, for example, a thermistor, and is attached to the heater core 50 to detect the cooling water temperature Tw of the engine. The solar radiation sensor 84 uses, for example, a photodiode in which a current flows in proportion to the amount of received light, and detects the amount of solar radiation Ts that enters the vehicle interior. The evaporator sensor 85 is a sensor using, for example, a thermistor, and is attached to the evaporator 31 to detect the outlet temperature Te of the evaporator 31.

Next, the operation of this embodiment will be described with reference to the flow chart shown in FIG. 2 and the graph shown in FIG. 3. When the control device 60 is powered on and starts the air conditioning control program, it follows the flow chart shown in FIG. Start control. First, in step 102, the control device 60 performs initialization processing, initializes various counters and flags, and proceeds to the next step 104. Step 10
4, the control device 60 reads the set temperature Tset from the temperature setting switch 72, and in order to detect the vehicle environmental condition, the inside air temperature (vehicle interior temperature) Tr from the inside air sensor 81 and the outside air temperature (outside the vehicle interior) from the outside air sensor 82. temperature)
Tam, water temperature sensor 83 to engine cooling water temperature Tw, solar radiation sensor 84 to solar radiation amount Ts, evaporator sensor 85.
The outlet temperature Te of the evaporator 31 is read from each.

Next, in step 106, the control device 60 calculates the required blow-out temperature TAO based on the read-out various data by a previously stored arithmetic expression.

In this case, the set temperature Tse is used as data.
Using t, the inside air temperature Tr, the outside air temperature Tam, and the amount of solar radiation Ts, the required blowing temperature TA is substituted into the arithmetic expression shown in the following equation (1).
Ask for O.

[0019]

## EQU00001 ## TAO = A.times.Tset + B.times.Tr + C.times.Tam + D.times.Ts + E (where A to E are arbitrary constants for setting the gain) Then, the process proceeds to step 108, and the control device 60 performs a previously stored calculation. The target opening θ0 of the air mix damper 12 is calculated from the equation. In this case, as data,
Using the required blowing temperature TAO, the cooling water temperature Tw, and the outlet temperature Te of the evaporator 31, the target opening θ0 of the air mix damper 12 is obtained by substituting it into the arithmetic expression shown in the following equation (2).

[0020]

## EQU00002 ## .theta.0 = [(TAO-Te) / (Tw-Te)]. Times.100% Next, in step 110, the controller 60 sets the blower voltage VB based on the required blowout temperature TAO. The blower voltage VB is a voltage applied to the blower motor 42 via the drive circuit 43 in order to set the amount of air blown by the blower 41. Further, the control device 60 is set so that either the face outlet 19 or the foot outlet 20 or both of them are opened based on the required outlet temperature TAO. Here, the face mode is set to open the face outlet 19, and the foot mode is set to open the foot outlet 20, and the face outlet 19 and the foot outlet 20 are set. It is the bi-level mode that both are set to be opened.

In the face mode in which the face outlet 19 is set to open and in the foot mode in which the foot outlet 20 is set to open, the compressor 32 prevents the evaporator 31 from frosting. The evaporator sensor 85 detects the outlet temperature Te of the evaporator 31, and it is controlled to turn on when it reaches or exceeds a predetermined value Te0. Here, the predetermined value Te0 becomes the first value. Further, the control device 60 is
The air duct 10 based on the required blowing temperature TAO
It is decided whether to introduce inside air or outside air. In this case, the introduction of inside air and outside air is controlled by driving the inside / outside air switching damper 11 by the servomotor 11a,
Either the inside air inlet 16 or the outside air inlet 17 is set to open.

Next, in step 112, the control device 60 determines in step 112 whether the outlet mode is the bi-level mode. This step 1
If the mode is a mode other than the bi-level mode in 12, the process proceeds to step 118, and steps 108 and 1
The control signal determined in 10 is output. When it is determined in step 112 that the bilevel mode is set,
In step 114, the compressor on condition is corrected. Normally, the compressor 32 is the evaporator 31.
In order to prevent the frost of the evaporator 31, the evaporator sensor 85 detects the outlet temperature Te of the evaporator 31, and the predetermined value Te0
Although it is controlled to turn on when the above is reached, in this step 114, as shown in FIG. 3, the predetermined value Te0 'is selected so that the compressor on condition becomes a temperature higher than the predetermined value Te0. However, the outlet temperature of the evaporator 31 is kept so as not to be too low. Here, this predetermined value Te0 'becomes the second value.

Next, in step 116, the controller 60 corrects the air mix damper opening. Here, with respect to the air mix damper target opening of the above-mentioned equation 2,
The air mix damper opening is corrected based on the following equation (3), and the air mix damper opening is corrected to the cool side by this correction.

[0024]

[Mathematical formula-see original document] θ0 '= [(TAO-Te0') / (Tw-Te0 ')] × 100% Then, the process proceeds to step 118, in which the control device 60 executes the steps 108, 110, 112 and 114. Determined air mix damper opening θ
0 ', the blower voltage VB, the outlet mode (bi-level mode), and the inside / outside air mode are output as control signals, and this flow ends in step 120.

The effect of the above embodiment will be described. In the bi-level mode in which both the upper outlet and the lower outlet are opened, the temperature at which the compressor is turned on when the temperature detected by the evaporator sensor exceeds a predetermined value. Since the temperature is controlled to be higher than in other than bi-level mode, the temperature of the wind passing through the evaporator becomes higher, and the temperature of the wind blown out from the upper and lower outlets increases accordingly. The structure of the air conditioning unit is limited by the structure of the vehicle, and the temperature rise rate of the upper outlet is different from that of the lower outlet, that is, the temperature rise rate of the upper outlet is small and that of the lower outlet is small. Even in an air conditioning unit with a high temperature rise rate, it is too cold from the upper outlet Can be prevented, and the air mix damper opening is corrected to the cool side, so the hot air from the lower outlet is also moderated and the difference in the outlet temperature from the upper outlet and the lower outlet is reduced. Since it becomes smaller, the upper half of the body becomes colder, and the lower half of the body becomes hot, eliminating the discomfort and providing a comfortable cabin space, which not only improves the environmental friendliness of the cabin but also has an effect on safety.

In this embodiment, the compressor is turned on in the bi-level mode with the predetermined value Te0 'as the determination condition, but the compressor may be turned off in the bi-level mode. When the outside air is low, the inside air mode is set,
It may be possible to prevent the introduction of cold outside air. Further, in the present embodiment, the evaporator outlet temperature T at which the compressor is turned on is set.
Although eo ′ is set to a predetermined value, as shown in FIG. 5, the outlet temperatures of the evaporator with the compressor turned on are Teo ′ and Teo ″.
Alternatively, the temperature may be varied depending on the required blowing temperature TAO.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment of the present invention.

[Fig. 3] Required outlet temperature T in each outlet mode
It is a 1st characteristic view which shows the evaporator outlet temperature which turns on the compressor with respect to AO.

FIG. 4 is a temperature control characteristic diagram showing the relationship between the required blow-out temperature TAO and the air mix damper opening of the embodiment of the present invention and the conventional example.

FIG. 5: Required outlet temperature T in each outlet mode
It is a 2nd characteristic view which shows the evaporator outlet temperature which turns on the compressor with respect to AO.

[Explanation of symbols]

10 ... Air duct, 12 ... Air mix damper, 12a
... Servo motor, 16 ... Inside air inlet, 17 ... Outside air inlet, 19 ... Upper outlet (face outlet), 2
0 ... Lower outlet (foot outlet), 31 ... Evaporator, 32 ... Compressor, 36 ... Compressor drive circuit, 41 ... Blower, 50 ... Heater core, 60 ... Control device, 85 ... Evaporator sensor.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yuji Ito 1-1, Showa-cho, Kariya city, Aichi Nihon Denso Co., Ltd. (72) Inventor Shinji Ukai 1-1-chome, Showa-cho, Kariya city, Aichi prefecture Co., Ltd. (72) Inventor Kazushi Yamamoto 1-1-1, Showa-cho, Kariya city, Aichi prefecture

Claims (2)

[Claims] 1. An air duct for introducing air into a passenger compartment, an inside air introduction port and an outside air introduction port provided on an inlet side of the air duct, and an upper body of an occupant provided on an outlet side of the air duct. An upper outlet for blowing air toward the lower body, a lower outlet for blowing toward the lower half of the occupant, outlet opening / closing means for opening and closing the upper outlet and the lower outlet, and air sucked from the inlet side to the outlet side. A blower that blows air, an evaporator that cools the air that is sent from the blower, a heater core that heats the cold air that is sent from the evaporator, and a cool air that is sent from the evaporator according to the set opening degree. An air conditioner for a vehicle, comprising: an air mix damper distributed to the heater core; and an air conditioner for detecting an outlet temperature of the evaporator. When the temperature detected by the evaporator sensor is equal to or higher than a predetermined value, a compressor controller that turns on a compressor that supplies compressed refrigerant to the evaporator, and an opening of the air mix damper according to the detected temperature. And an outlet mix mode control means for controlling the outlet opening / closing means in accordance with the outlet mode, the outlet mode control means including the upper outlet and the lower outlet. When controlling the outlet opening / closing means to open only one of the mouths,
First value setting means for setting the predetermined value to a first value, and the outlet mode control means controls the outlet opening / closing means to open both the upper outlet and the lower outlet. And a second value setting means for setting the predetermined value to a second value that is larger than the first value. 2. The air conditioner for a vehicle according to claim 1, wherein when the predetermined value is set to a second value larger than the first value by the second value setting means, the air mix damper. An air conditioner for a vehicle, comprising air mix damper correction means for correcting the opening of the air conditioner to the cool side.