JPH10226221A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the warm air from blowing against passenger's will when a reheating type air conditioner is switched on and its cooling mode is selected. SOLUTION: The valve system which controls the supply of warm water to a heater core 8, is open when the electricity is turned off. Further, a microcomputer controls a cold air bypass door 10 to open a cold air bypass 9 under the condition which allows warm air to blow off against passenger's will when an air conditioner is turned on. This allows the mixed air of warm air passed the heater core 8 and cold air passed the cold air bypass 9 to blow into a passenger compartment, therefore the temperature of the air blowing into the passenger compartment can be lowered, and the occupants are freed from experiencing an uncomfortable feeling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the temperature of a heating heat exchanger by opening and closing a valve for controlling the supply of hot water into the heating heat exchanger. The present invention relates to an air conditioner for a vehicle that controls a vehicle.

[0002]

2. Description of the Related Art Conventionally, the supply of hot water to a heat exchanger for heating is controlled by opening and closing a valve means provided in a hot water circuit, whereby the temperature of the heat exchanger for heating is adjusted and blown out into a vehicle interior. 2. Description of the Related Art A vehicle air conditioner (a so-called reheat air conditioner) that controls a wind temperature to a predetermined temperature is well known.

In such a reheat type air conditioner, the valve means is closed when energized and opened when non-energized so that even if the power supply fails due to disconnection of a harness or the like, the heating capacity can be secured for the time being. It is configured to be.

[0004]

Therefore, while the vehicle is not in use (that is, while the ignition switch is turned off), the valve means is de-energized and is opened. Flows into the heating heat exchanger, and the heating heat exchanger is in a high temperature state until the water temperature decreases due to natural heat radiation.

Accordingly, when the ignition switch is turned on and air conditioning is started in this state, even if the cooling mode is selected and the valve means is controlled to be closed, the heat storage until the heat storage amount of the heating heat exchanger is reduced. Unexpectedly, the warm air is blown out, and the occupant's feeling deteriorates. Then, this invention aims at solving the said problem.

[0006]

Means for Solving the Problems To achieve the above object, the invention according to claim 1 comprises a water temperature detecting means for detecting a water temperature in a heat exchanger for heating, and an air sucked from an inlet.
A cool air bypass passage for bypassing the heating heat exchanger and directly leading to the outlet, and a cool air bypass opening / closing means for opening / closing the cool air bypass passage are provided.After starting air conditioning, the water temperature detected by the water temperature detecting means is equal to or higher than a predetermined temperature. During the interval, the cool air bypass opening / closing means is controlled so as to open the cool air bypass passage.

According to this, when air conditioning is started and the cooling mode is selected, even if the heat storage amount of the heating heat exchanger is high and the water temperature detected by the water temperature detecting means is equal to or higher than the predetermined temperature, At this time, since the cool air bypass opening / closing means is controlled so as to open the cool air bypass passage, a mixed air of the warm air passing through the heating heat exchanger and the cool air passing through the bypass passage is blown into the vehicle interior. Therefore, the temperature of the air blown into the vehicle interior can be reduced, and the feeling of the occupant can be prevented from being deteriorated.

Further, the invention according to claim 2 is provided with a water temperature detecting means for detecting a water temperature in the heating heat exchanger. After the start of air-conditioning, while the water temperature detected by the water temperature detecting means is equal to or higher than a predetermined temperature, air is blown. It is characterized in that the means is stopped. According to this, when the air conditioning is started and the cooling mode is selected, even if the heat storage amount of the heating heat exchanger is high and the water temperature detected by the water temperature detecting means is equal to or higher than the predetermined temperature, the air is blown at this time. Since the means is stopped, no warm air is blown into the vehicle interior. Therefore, it is possible to prevent the occupant's feeling from being deteriorated due to the blowing of warm air.

Further, the invention according to claim 3 is provided with a water temperature detecting means for detecting a water temperature in the heating heat exchanger, and after the start of air conditioning, while the water temperature detected by the water temperature detecting means is higher than a predetermined temperature, The air outlet opening / closing means is controlled so as to be in a defroster mode in which air is blown out only from the defroster air outlet among the air outlets.

According to this, when air conditioning is started and the cooling mode is selected, even if the heat storage amount of the heating heat exchanger is high and the water temperature detected by the water temperature detecting means is higher than the predetermined temperature, At this time, since the defroster mode is set, warm air is not blown out to the passenger in the vehicle compartment. Therefore, it is possible to prevent the occupant's feeling from being deteriorated due to the blowing of warm air.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Next, a first embodiment in which the present invention is used as a vehicle air conditioner will be described with reference to FIGS. In the present embodiment, each air-conditioning unit in an air-conditioning unit for air-conditioning a vehicle interior space is configured to be controlled by an air-conditioning control device (hereinafter, referred to as an ECU).

First, the configuration of the air conditioning unit will be described with reference to FIG. At the air upstream side of the air conditioning case 1 in the air conditioning unit, an inside air inlet 2 for sucking inside air, an outside air suction port 3 for sucking outside air, and inside / outside air switching for opening and closing these suction ports 2, 3. A door 4 is provided. The inside / outside air switching door 4 is driven by a servo motor 5 (see FIG. 3) as its driving means.

At the downstream side of the inside / outside air switching door 4,
A blower 6 as a blower is provided. And
An evaporator 7 as a cooling heat exchanger is provided downstream of the blower 6. The evaporator 7 constitutes a well-known refrigeration cycle together with a condenser (not shown) and a decompression device (not shown), in addition to a compressor (not shown) driven by an engine of an automobile.

A heater core 8 as a heat exchanger for heating is disposed at a downstream side of the evaporator 7 on the air side. In the heater core 8, engine cooling water flows therein, and the cooling water is used as a heat source to reheat air passing through the heater core 8. Further, in the air conditioning case 1, a cool air bypass passage 9 through which cool air from the evaporator 7 bypasses the heater core 8 is formed, and a cool air bypass door 10 that opens and closes the cool air bypass passage 9 is provided. In addition,
The cool air bypass door 10 is driven by a servomotor 11 (see FIG. 3) as a driving means thereof.

A defroster outlet 12 for blowing air toward the inner surface of the vehicle windshield, a face outlet 13 for blowing air toward the upper body of the passenger in the passenger compartment, and a passenger compartment on the downstream side of the air conditioning case 1. A foot outlet 14 for blowing air toward the feet of the occupant is formed, and further, outlet mode opening / closing doors 15 and 16 for opening and closing the respective outlets 12 to 14 are provided. These doors 1
5 and 16 are driven by servo motors 17 and 18 (see FIG. 3) as respective driving means.

Next, the configuration of the hot water circuit 19 of this embodiment will be described with reference to FIG. Hot water circuit 1 in the present embodiment
9 mainly includes a heater core 8, an engine 20, and a valve device 2.
1, the electric pump 22 and the mechanical pump 23, and depending on the open / close state of the valve device 21, a circulation mode indicated by a solid arrow in the drawing and a circulation mode indicated by a broken arrow in the drawing are formed.
In the circulation mode shown by the dashed arrow in the figure, the hot water flows by the action of the electric pump 22.

Here, the valve device 21 is specifically constituted by an electromagnetic valve, and the energization is controlled by an ECU as shown in FIG. Further, this valve device 21 is opened when the ECU is de-energized, and the hot water circuit 19
The warm water in the inside can flow in the form shown by the solid line in the figure by natural convection. The reason why the valve device 21 is opened when the power is not supplied to the valve device 21 is to ensure the heating capacity for the time being even when the power supply of the valve device 21 fails due to a disconnection of the harness or the like. is there.

The power supply of the electric pump 22 is also controlled by the ECU. The mechanical pump 23 is a pump directly connected to the engine 20. Next, the configuration of the control system of the present embodiment will be described with reference to FIG. The ECU 24 includes a well-known microcomputer including a CPU, a ROM, a RAM, and the like (not shown), a drive circuit that controls a blower voltage applied to the blower 6, an A / D conversion circuit, and the like. The ignition switch 25 of the engine 20 is closed. At this time, power is supplied from the battery 26.

The input terminals of the ECU 24 include a temperature setting device 27 for setting a target temperature in the vehicle interior, an inside air temperature sensor 28 for detecting the inside air temperature, and an outside air temperature sensor 2 for detecting the outside air temperature.
9. Solar radiation sensor 3 for detecting the amount of solar radiation applied to the vehicle interior
Signals from an evaporator temperature sensor 31 for detecting the air temperature immediately after passing through the evaporator 7 and a water temperature sensor 32 for detecting the temperature of the engine cooling water flowing into the heater core 8 are input. The water temperature sensor 32 is provided near the hot water outlet in the heater core 8.

A control signal is output from an output terminal of the ECU 24 to the servo motors 5, 11, 17, 18 and the valve device 21. Next, a control process performed by the microcomputer will be described with reference to a flowchart of FIG. When the ignition switch 25 is turned on and power is supplied to the ECU 24, the routine of FIG. 4 is started, and initialization processing is performed in step S10.
In the next step S20, the set temperature set by the temperature setter 27 and the detected values of the sensors 28 to 32 are read.

Then, in the next step S30, R
Based on the following equation 1 stored in the OM, the required blow-out temperature TAO, which is the target temperature of the blow-out temperature into the vehicle compartment, is calculated.

[0022]

TAO = Kset × Tset−Kr × Tr−Kam × Tam−Ks × Ts + C (° C.) where Tset is the temperature set by the temperature setting device 27, Tr is the temperature detected by the inside air temperature sensor 28, and Tam is the outside temperature The temperature detected by the air temperature sensor 29 and Ts is a value detected by the solar radiation sensor 30. Also, Kset, Kr, Kam, and Ks are
Each is a correction gain, and C is a correction constant.

Then, in the next step S40, the valve device 2
Close 1. That is, in FIG. 2, the hot water in the hot water circuit 19 is set in a state where it can flow in a form shown by a broken line in the figure. Next, in step S50, the temperature detected by the evaporator temperature sensor 31 and the temperature detected by the water temperature sensor 32 are substituted into a predetermined arithmetic expression to estimate the actual temperature of the air blown into the vehicle interior.

Next, in step S60, the required blowing temperature (TAO) is compared with the estimated blowing temperature, and when the estimated blowing temperature is higher, that is, hot air is blown out against the occupant's will. If the condition is satisfied, step S70
Then, the opening of the cool air bypass door 10 is calculated in accordance with the difference between the required blowing temperature and the estimated blowing temperature, and the next step S8
At 0, the servo motor 11 (FIG. 3) of the cool air bypass door 10 is controlled so as to achieve the opening.

If the result of the comparison in step S60 shows that the estimated blowing temperature is lower, the normal control is performed, that is, the valve device 21 is opened and closed to obtain the required blowing temperature. According to the present embodiment described above, while the ignition switch 25 is turned off and the valve device 21 is in a non-energized state (at this time, the valve device 21 is open),
The temperature of the heater core 8 increases due to natural convection, and as a result, even when the estimated blowing temperature is higher than the required blowing at the start of air conditioning and hot air is blown out against the occupant's will, the cool air Since the bypass door 10 is opened at an appropriate opening, a mixed air of warm air passing through the heater core 8 and cool air passing through the cool air bypass passage 9 is blown into the vehicle interior. Therefore, the temperature of the air blown into the vehicle interior can be reduced, and the feeling of the occupant can be prevented from being deteriorated.

(Second Embodiment) Next, the second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. FIG. 5 is a flowchart showing a control process performed by the microcomputer. Parts having the same functions as those in FIG. 4 are denoted by the same reference numerals, and a description thereof will be omitted.

In the present embodiment, if the result of the comparison in step S60 indicates that the estimated blowing temperature is higher,
In step S100, the blower 6 is stopped. Therefore,
Warm air is not blown into the vehicle interior, which can prevent the occupant's feeling from being deteriorated due to the blown warm air. (Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. 6 only for parts different from the first and second embodiments.

FIG. 6 is a flow chart showing the control processing performed by the microcomputer. Parts having the same functions as those shown in FIGS. 4 and 5 are denoted by the same reference numerals, and a description thereof will be omitted. In the present embodiment, step S60
As a result of the comparison in step S110, if the estimated blowout temperature is higher, in step S110, the blowout mode opening / closing door 15 is set to the position indicated by the two-dot chain line in FIG. As
Servo motors 17 and 1 for the opening and closing doors 15 and 16
8 (FIG. 3). Also in this case, the warm air is not blown into the vehicle interior, and it is possible to prevent the occupant's feeling from being deteriorated due to the blown warm air.

(Modification) In the above embodiment, the water temperature in the heater core 8 is controlled by controlling the valve device 21 in FIG. 2 and repeating the circulation mode indicated by the solid line and the circulation mode indicated by the broken line in FIG. Has been described, but the present invention is also applicable to a type in which the flow rate of hot water from the engine 20 to the heater core 8 is adjusted.

In the second and third embodiments, the case where the cool air bypass passage 9 is provided has been described. However, the cool air bypass passage 9 may not be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of an air conditioning unit of each embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a configuration of a hot water circuit 19 according to each of the embodiments.

FIG. 3 is a block diagram of a control system of each embodiment.

FIG. 4 is a flowchart showing control processing by the microcomputer according to the first embodiment of the present invention.

FIG. 5 is a flowchart showing a control process by a microcomputer according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing control processing by a microcomputer according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air-conditioning case 2 Inside air suction port 3 Outside air suction port 6 Blower (blowing means) 8 Heater core (heating heat exchanger) 9 Cold air bypass passage 10 Cold air bypass door (cool air bypass opening / closing means) 12 Defroster outlet 13 Face outlet 14 Foot Outlet 15, 16 Outlet mode opening / closing door (outlet opening / closing means) 19 Hot water circuit 20 Engine 21 Valve device (Valve means)

Claims (3)

[Claims] An air blowing means (6) for generating an air flow, a suction port (2, 3) for sucking air at one end side, and an air outlet (39) for blowing air into a vehicle cabin at the other end side. 12 ~
14) is formed, and the air sucked from the suction ports (2, 3) by the blowing means (6) is supplied to the air outlets (12 to 12).
Air-conditioning case (1) that blows out toward the passenger compartment from 14)
A heating heat exchanger (8) provided in the air-conditioning case (1) for heating the air blown into the vehicle interior by using hot water as a heat source; and supplying the hot water to the heating heat exchanger (8). The hot water circuit (19) is provided in the hot water circuit
9) for opening and closing the valve means (21) to control the temperature of the heating heat exchanger (8) to control the temperature of the air blown into the vehicle compartment. In the air conditioner, a water temperature detecting means (32) for detecting a water temperature in the heating heat exchanger (8), and an air sucked from the suction ports (2, 3) is supplied to the heating heat exchanger (8). To bypass the outlet (12-1
4) a cool air bypass passage (9) directly leading to 4); and a cool air bypass opening / closing means (10) for opening / closing the cool air bypass passage (9). After the start of air conditioning, the water temperature detected by the water temperature detecting means (32) is predetermined. The air conditioner for a vehicle, wherein the cool air bypass opening / closing means (10) is controlled so as to open the cool air bypass passage (9) while the temperature is equal to or higher than the temperature. 2. An air blowing means (6) for generating an air flow, an air inlet (2, 3) formed on one end side and an air outlet (2) on the other end side for blowing air into a vehicle cabin. 12 ~
14) is formed, and the air sucked from the suction ports (2, 3) by the blowing means (6) is supplied to the air outlets (12 to 12).
Air-conditioning case (1) that blows out toward the passenger compartment from 14)
A heating heat exchanger (8) provided in the air-conditioning case (1) for heating the air blown into the vehicle interior by using hot water as a heat source; and supplying the hot water to the heating heat exchanger (8). The hot water circuit (19) is provided in the hot water circuit
9) for opening and closing the valve means (21) to control the temperature of the heating heat exchanger (8) to control the temperature of the air blown into the vehicle compartment. In the air conditioner, a water temperature detecting means (32) for detecting a water temperature in the heating heat exchanger (8) is provided. After the start of air conditioning, while the water temperature detected by the water temperature detecting means (32) is equal to or higher than a predetermined temperature, An air conditioner for a vehicle, wherein the blowing means (6) is stopped. 3. A blower means (6) for generating an air flow, a suction port (2, 3) formed on one end side for sucking air, and a defroster for blowing air on the inner surface of a vehicle windshield on the other end side. An air outlet (12), a face air outlet (13) for blowing air to the upper body of the vehicle occupant, and a foot air outlet (14) for blowing air at the foot of the vehicle occupant are formed, respectively. The air sucked from the suction ports (2, 3) is supplied to the air outlets (12 to 1).
4) an air-conditioning case (1) that blows out toward the vehicle interior; air outlet opening / closing means (15, 16) that opens and closes each of the air outlets (12 to 14); A heating heat exchanger (8) for heating the air blown into the vehicle interior by using hot water as a heat source; and a hot water circuit (19) for supplying the hot water to the heating heat exchanger (8). This hot water circuit (1
9) for opening and closing the valve means (21) to control the temperature of the heating heat exchanger (8) to control the temperature of the air blown into the vehicle compartment. In the air conditioner, a water temperature detecting means (32) for detecting a water temperature in the heating heat exchanger (8) is provided. After the start of air conditioning, while the water temperature detected by the water temperature detecting means (32) is equal to or higher than a predetermined temperature, The air conditioner for a vehicle, wherein the air outlet opening / closing means (15, 16) is controlled so as to be in a defroster mode in which air is blown out only from the air outlet (12) among the air outlets (12 to 14). apparatus.