JP3265611B2 - Vehicle air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for a vehicle in which air sucked in by a blower is blown to a heater core in which a cooling fluid of an engine is circulated, and an airflow at a predetermined temperature is obtained by heat exchange in the heater core. . More specifically, the present invention relates to a device for controlling the temperature of an air-conditioned space by adjusting the temperature or flow rate of a cooling fluid flowing through a heater core.

[0002]

2. Description of the Related Art Conventionally, as an air conditioner for a vehicle, an apparatus using an air mix system and a reheat system has been known.
In the air mixing method, as shown in FIG. 10, a mixture of cold air cooled by a cooling device and warm air obtained by heating a part of the cold air with a heater core is used to form an airflow at a predetermined temperature. It is a way to get. The temperature of the airflow is controlled to a desired temperature by changing the mixing ratio of the cold air and the hot air according to the opening of the air mix damper 101. FIG. 11 is an explanatory diagram showing a temporal change in the blown air temperature with respect to a change in the opening degree of the air mix damper in the air conditioner for a vehicle of the air mix type described above. For example, the time constant τ when the air mix damper 101 changes in the direction of the arrow in FIG. 10 and the outlet air temperature changes from 15 ° C. (MAX COOL) to 35 ° C. (MAX HOT) is 10 (sec).

On the other hand, the reheat method is a method in which all the cool air cooled by a cooling device is passed through a heater core and reheated to obtain a desired air flow. This method has the advantage that the mounting space of the air conditioner can be reduced as compared with the air-mixing method described above, and the size of the heater core can be increased when the mounting space is limited, so that the ventilation resistance can be reduced. The temperature of the airflow is controlled to a desired temperature by controlling the temperature of the heater core.
In controlling the temperature of the heater core, the flow rate of the cooling fluid from the cooling system flow path for cooling the engine may be controlled, or the temperature itself of the cooling fluid may be increased or decreased. Therefore, as a temperature control method, a hot water flow control method and a hot water temperature control method are known.

[0004]

Here, there is a case where it is desired to rapidly change the temperature of the blown air in order to quickly remove the fogging of the front window. In this case, in the reheat type vehicle air conditioner, there is a problem that the temperature of the blown air cannot be changed suddenly because the heat capacity of the cooling system flow path including the heater core is large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a reheat-type vehicle air conditioner having improved responsiveness to changes in blown air temperature. It is to be.

[0006]

According to an aspect of the present invention, a cooling fluid from a cooling system flow path for cooling an engine is introduced into a heater core, and wind exchanged with the heater core is introduced into a vehicle interior. A heater system flow path configured by a forward path for guiding the cooling fluid from the cooling system flow path to the heater core for blowing out, and a return path for returning the cooling fluid discharged from the heater core to the cooling system flow path; A pump provided in series with the heater core in the system flow path, and a pump for flowing the cooling fluid through the heater core; and a pump provided in series with the heater system flow path in series with the heater core to pass the flow of the cooling fluid. A valve means for controlling between a shut-off state and a vehicle air conditioner for controlling the blow-out air temperature based on a target blow-out temperature calculated by signals from various sensors and a temperature setting device. I, when the difference of the target air temperature between the present and preceding in the control timing exceeds a predetermined value, the temperature or flow rate of the cooling fluid supplied to the heater core based on the current target air temperature From the value
The difference from the value based on the target blowing temperature of
And then gradually based on the current target outlet temperature.
Control means for applying a signal to the valve means to control the value so as to approach the value is provided.

[0007]

The valve means is controlled between a state where the cooling fluid passes and a state where the cooling fluid is shut off. A cooling system flow path for cooling the engine with respect to the valve means, a forward path for guiding the cooling fluid from the cooling system flow path to the heater core, and a return path for returning the cooling fluid discharged from the heater core to the cooling system flow path. And a heater system flow path composed of: Then, the blow-out air temperature is controlled based on the target blow-out temperature calculated based on signals from various sensors and a temperature setting device. If the difference between the current and previous target blow-out temperatures at the control timing by the control means exceeds a predetermined value, the temperature or flow rate of the cooling fluid supplied to the heater core is set to the current target blow-out temperature. A signal is applied to the valve means and controlled so that the value is temporarily changed from the base value and gradually approaches the value. As described above, in the vehicle air conditioner of the present invention, when the difference between the target outlet temperature before and after the change is large, corrective control is performed so that the target outlet temperature is quickly reached.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to specific embodiments. 1. Overall Configuration FIG. 2 is a diagram showing the overall configuration of the vehicle air conditioner according to the present embodiment. In the air duct 30 of the air conditioner, a switching door 33, a blower 11, an evaporator 12, a heater core 21, and switching doors 70 and 72 are arranged.
The switching door 33 manually introduces outside air into the air duct 30 from outside the vehicle when the introduction port 31 of the air duct 30 is opened, and removes air in the vehicle compartment 34 when the recirculation port 32 of the air duct 30 is opened. Reflux into. The blower 11 sucks air from the inlet 31 or the recirculation port 32 and sends the air to the evaporator 12 as an airflow having an airflow W according to the rotation speed. The evaporator 12 cools the airflow from the blower 11 in cooperation with a cooling system including the electromagnetic clutch 74 and the compressor 75, and sends the cooled airflow to the heater core 21. The electromagnetic clutch 74 is driven under the control of the control device 90, and selectively connects the compressor 75 to the engine 22.

The heater core 21 receives cooling water (cooling fluid) from a cooling device of the engine 22 to be described later and warms a cooling air flow sent from the evaporator 12. The heated air is sent to the switching door 70. The switching door 70 is operatively connected to a servomotor 71,
When 1 is at the home position, the mixed airflow flowing through the air duct 30 while being maintained at the original position (indicated by a solid line in FIG. 2) is passed through the HEAT outlet 14 of the air duct 30 to the passenger compartment 34.
Blow out inside. This means that the switching door 70 is in a foot mode (hereinafter, also referred to as a heat mode) in which warm air is blown from the feet. Switching door 7
0 cooperates with the switching door 72 to supply the mixed airflow to the air duct 3.
The VENT outlet 15 and the HEAT outlet 14 of the air duct 30 function to blow air into the vehicle interior 34 or the DEF outlet 16 of the air duct 30 to blow air into the vehicle interior 34. This means that the switching door 7
0, 72 means to be in vent mode, bi-level mode or defroster mode. The switching door 70 is moved up or down by rotation of the servomotor 71 in accordance with a command from the control device 90 to be in the vent mode, bi-level mode or defroster mode. The servomotor 73 is moved upward or downward by the rotation of the servomotor 73 to be in the vent mode, bilevel or defroster mode.

The control unit 90 includes various sensors 91a, 91
b, 92a, 92b, 93a, and 94
A D converter 98, a microcomputer 99 connected to a temperature setting device 95, a mode setting device 96, and a control switch mechanism 97 are provided. The internal temperature sensor 91a is disposed in the vehicle interior 34, detects the actual temperature _Tr in the vehicle interior 34, and generates an analog signal having a level corresponding to the internal temperature _Tr . The outside air temperature sensor 91b is arranged near the front grill of the radiator of the vehicle, detects the actual temperature Tam of the air outside the vehicle, and generates an analog signal having a level corresponding to the outside air temperature Tam. A water temperature sensor 92a is disposed close to the inlet of the heater core 21, and detects the actual temperature T _W of the cooling water from the cooling device,
It generates an analog signal having a level corresponding to the detected water temperature T _W. Air temperature sensor 92b is disposed in proximity to the outlet of the evaporator 12, detects the temperature T _E of the actual air flow from the evaporator 12, the detected air temperature T _E
Generates an analog signal having a level corresponding to. Opening sensor 93a is operatively connected to the rod to move up and down by a servo motor 71, in relation to the displacement of the rod to detect the actual opening position A _P of the switching door 70, the detection result Generates an analog signal having a level corresponding to. The solar radiation sensor 94 is arranged near the window of the vehicle interior 34, detects the actual amount of solar radiation T _S , and generates an analog signal having a level corresponding thereto.

The A / D converter 98 converts analog signals from the sensors 91a to 94 into digital signals based on a request from the microcomputer 99, and converts these digital signals into the internal temperature _Tr and the opening position. A _P , outside temperature Tam,
The values are given to the microcomputer 99 as representing the water temperature T _W , the air temperature T _E, and the solar radiation T _S. The temperature setter 95 is provided in the passenger compartment 34, selects a desired set temperature Tset by manual operation of an occupant, and generates this as a temperature set signal. The mode setting device 96 is constituted by a plurality of manual switches, and by operating any of these switches, an auto air conditioner mode, a heat mode,
A command signal representing a bi-level mode, a vent mode, or a defroster mode is generated. The control switch mechanism 97 includes first to fourth self-returning operation switches, and the first operation switch operates the blower 11
Generates a first command signal necessary for automatic control.
The second, third and fourth operating switches necessary to set the air volume W of the air flow generated from the blower 11 by the operation each predetermined high airflow value H _1, the intermediate air volume value M _e and Teikazeryouchi L _O The second, third and fourth command signals are generated.

The microcomputer 99 is composed of a single-chip LSI, and receives a constant voltage from a constant voltage circuit (not shown) to be ready for operation. The microcomputer 99 includes a CPU 80, a ROM 81, and a RAM.
82, an input / output interface 83 (hereinafter referred to as I / O) and a clock circuit. RAM 82 is I /
Through O83, digital signals from the A / D converter 98, temperature setting signals from the temperature setting device 95, and command signals from the mode setting device 96 and the control switch mechanism 97 are received and temporarily stored. A signal is selectively applied to the CPU 80. In this embodiment, the RAM 8
Numeral 2 is constantly supplied with power from the DC power supply B and has a memory holding function. FIG. 12 shows a predetermined control program and a relationship between the duty ratio and the target blowing temperature in the ROM 81.
Are stored in the data map. CPU8
Reference numeral 0 designates a control signal for driving valve devices 25a and 25b, which will be described later, in accordance with a control program which will be described later.
4 is output. Further, the CPU 80 controls the servo motor 7
1 and 73 to control the opening of the switching door 70 and the switching door 72 in accordance with the determined blowing mode.

2. Configuration of Heater System As shown in the equivalent circuit of FIG. 3, the cooling system for the engine includes a cooling system flow path 42, an engine 22, a pump 40, and a radiator 41. Also, the heater system flow path 43
Supplies the high-temperature cooling water from the cooling system flow path 42 to the heater core 21.
And a return path 45 for returning the low-temperature cooling water cooled by the heater core 21 to the cooling system flow path 42. The first valve 25a and the pump 26 are provided on the outward path 44 of the heater system flow path 43. And
In order to recirculate the low-temperature cooling water output from the heater core 21 to the heater core 21, the first return path 45 and the first
A recirculation passage 46 connecting the valve 25a and the pump 26 is formed. Further, the cooling system flow path 4 is connected to the first valve 25a.
In the second heater system flow path 43, a forward path 45 and a return path 44
And a bypass passage 47 is formed to communicate with the above. By this bypass path 47, regardless of the engine speed,
The pressure of the high-temperature cooling water diverted to the heater system flow path 43 becomes substantially constant, and the occurrence of water hammer when the first valve 25a and the second valve 25b open and close can be suppressed. This prevents the impact pressure due to the cooling water from being applied to the heater core 21.

3. Configuration of Valve The first valve 25a, the second valve 25b, and the recirculation path 46 are incorporated in the same housing as shown in FIG. In this embodiment, the first valve 25a and the second valve 25b operate in conjunction with each other,
When the first valve 25a is in the passing state (ON state) / blocking state (OFF state), the second valve 25b is in the blocking state (OFF state) / passing state (ON state) opposite to the first valve 25a. It is configured to take.

In FIG. 1, the valve device 25 has a housing 50, and the housing 50 has a first inlet 51 for introducing high-temperature cooling water from a cooling system channel 42, and the high-temperature cooling water is supplied to the first inlet 51. A first outlet 52 for discharging to the heater core 21 side, a second inlet 53 for introducing low-temperature cooling water discharged from the heater core 21, and a second outlet 53 for discharging the low-temperature cooling water to the cooling system flow path 42 side. An outlet 54 is formed. First inlet 51
And the first discharge port 52 are connected to the outward path 44 of the heater system flow path 43. The second inlet 53 and the second outlet 54 are connected to the return path 45 of the heater system flow path 43.

In the housing 50, a first introduction port 51 is provided.
A first valve body 55 and a first valve seat 56 constituting the first valve 25a are formed in a flow path connecting the first valve 25a and the first discharge port 52. In addition, a return path 46 connected to the first outlet 52 is formed inside the housing 50. The second inlet 53 and the second outlet 54 communicate with each other, and the second valve 2 is provided in a flow path connecting the second inlet 53, the second outlet 54, and the return path 46.
A second valve body 57 and a second valve seat 58 that constitute 5b are formed. The first valve body 55 and the second valve body 57 are fixed to the plunger 59. The plunger 59 is connected to a slider 62, and a coil sprink 61 is interposed between the slider 62 and the stator 63.
When the solenoid 60 provided on the upper part of the housing 50 is not energized, the slider 62 is moved in a direction to increase the distance between the slider 62 and the stator 63 by the urging force of the coil sprink 61. As a result, the plunger 59 is urged in a direction to open the first valve 25a and close the second valve 25b. On the other hand, when the solenoid 60 is energized, the slider 62 moves in the direction of the stator 63 and the plunger 59 moves.
Are driven in a direction in which the first valve 25a is closed and the second valve 25b is opened.

4. Operation of the Air Conditioner As shown in FIG. 2, the air conditioner has a blower motor 11a.
The air is blown by a fan 11b driven by the heater, and the air is cooled by heat exchange in the evaporator 12 and heated by heat exchange in the heater core 21.
Then, it is a device that blows out from the VENT outlet 15, HEAT outlet 14, and DEF outlet 16 into the vehicle interior.

VENT outlet 15, HEAT outlet 16, D
The outlet mode from which of the EF outlets 14 air is blown into the vehicle interior is set by adjusting the opening of the switching doors 70 and 72.

FIG. 4 is a circuit diagram corresponding to the equivalent circuit of FIG. As shown in FIG. 4, the heater core 21 is disposed in the heater system flow path 43 of the cooling water. That is, the engine 22
The cooling water heated in the above-described embodiment normally circulates through the heater system flow path 43 in the order of A → B → pump 26 → heater core 21 → C → D → engine 22 →. Thus,
High-temperature cooling water is supplied to the tapor 21, and the air blown by the blower 11 is supplied to the heater core 2 as described above.
Heated by 1.

The cooling water heater system channel 43 is
Is disposed at a position as shown in FIG. That is, when the energization of the valve device 25 is stopped and deenergized,
The first valve body 55 (FIG. 1) of the first valve 25a is displaced upward as shown in FIG. 5 (a). Thereby, A → B → Pump 2
Cooling water circulates in the circuit of 6 → heater core 21 → C → D. In this case, since the cooling water heated by the engine 22 is directly supplied to the heater core 21, the heating core 2
The temperature of 1 is high. Hereinafter, when the first valve 25a is in the fully opened state, the valve device 25 is said to be in the on state.

On the other hand, when the valve device 25 is energized and energized, the first valve body 55 of the first valve 25a and the second valve 57 of the second valve 25b move downward as shown in FIG. 5 (b). Displace. As a result, the section between A and B is shut off, and the warm water in the heater core returns to the engine 22 as shown by the heater core 21 → C → E → B → pump 26 → heater core 21 →. It is returned to the heater core 21 again without being heated. For this reason, the temperature of the heater core 21 decreases.
Hereinafter, when the first valve 25a is in the fully closed state, the valve device 25 is said to be in the off state.

Therefore, by turning on and off the valve device 25 at a certain duty ratio, the temperature of the heater core 21 can be set near a desired value. In this device, the temperature fluctuation is suppressed within an allowable range by changing the cycle of the duty ratio control according to the duty ratio, the voltage applied to the blower motor, and the blow mode, and the valve device is controlled. 25 has improved durability.

5. Air-Conditioning Control Next, a description will be given with reference to a timing chart of FIG. 7 based on a flowchart of FIG. 6 showing a processing procedure of the air-conditioning control of the CPU 80 used in the present embodiment apparatus. The program is repeatedly executed by interruption at predetermined time intervals. In step 100, after initialization, TAOFLAG = 0 and DutyFLAG = 0, which will be described later, various sensors, that is, a water temperature sensor 92a and an internal temperature sensor 9 are set.
1a, output values (Tw, _Tr, Tam, Ts) of the outside temperature sensor 91b, the solar radiation sensor 94, etc., the output value (Tset) of the temperature setting device 95, the output value of the mode setting device 96, and the state of the control switch mechanism. Output value is input. Next, at step 102, the target outlet temperature TAO at the current interrupt timing is calculated from those values.
_NEW is calculated by the following equation. TAO _NEW = K _s・ Tset-K _r・ T _r -Kam ・ Tam-K _S・ T _S + C where K _s is the temperature setting gain, K _r is the inside air temperature gain, and Kam
Is the outside air temperature gain, K _S is the solar radiation gain, and C is the correction constant. Next, the process proceeds to step 104, where the target outlet temperature at the current interrupt timing calculated in step 102 is set.
Target outlet temperature TA at TAO _NEW and previous interrupt timing
From O _OLD, it is determined whether the inequality represented by the following equation is satisfied. | TAO _NEW −TAO _OLD |> 5 If the inequality in step 104 is satisfied, that is, if the difference between the target outlet temperatures before and after the interrupt timing exceeds 5 ° C.,
Move to step 106. In step 106, TAO
After FLAG = 1, the process proceeds to step 108. If the inequality is not satisfied in the above step 104, TAOFLAG =
The process proceeds to step 108 with the value being 0. In step 108, the duty ratio DTS ₀ corresponding to the target outlet temperature TAO _NEW is obtained from the characteristic diagram of FIG.

Next, the routine proceeds to step 110, where TAOFLAG
It is determined whether or not = 1. At step 110, T
If AOFLAG = 1, the process shifts to step 112 and DutyFLAG
After setting = 1, the process proceeds to step 114. Step 1
At 14, it is determined whether or not DutyFLAG = 1. Here, if DutyFLAG = 1 and it is the first time to change the duty ratio, the flow shifts to step 116, where the _first duty ratio DTS ₁ is calculated by the following equation. DTS ₁ = DTS ₀ + 4 (DTS ₀ -DTS) where DTS is the target outlet temperature at the previous interrupt timing
This is the duty ratio corresponding to TAO _OLD . Then step 1
In 18 the first duty ratio DTS ₁ calculated in step 116 is output. Then, after the DutyFLAG = 0 in step 120, the process proceeds to step 122 to update the previous duty ratio as DTS = DTS _1. Next, the routine proceeds to step 124, where n =
The process returns to step 114 described above.

Then, in step 114, DutyFLAG = 0
Therefore, the process proceeds to step 126, where n = 2 by the following equation.
, The second duty ratio DTS ₂ is calculated. The process proceeds to _{DTS n = 0.5DTS n-1 +} 0.5DTS 0 then step 128, the second duty ratio DTS ₂ calculated in step 126 is outputted. Next, the routine proceeds to step 130, where it is determined whether the inequality represented by the following equation is satisfied. | DTS _n −DTS ₀ | <0.01 The inequality in step 130 is not satisfied, that is, the difference between the _second duty ratio DTS ₂ and the duty ratio DTS ₀ corresponding to the target outlet temperature TAO _NEW at the current interrupt timing is less than 0.01. At the time of, the difference is still large, so that the process proceeds to step 132. Then, n = n + 1 is set in step 132, and the above steps 126 to 132 are repeated. When the inequality is satisfied in step 130, the process proceeds to step 134. In step 134, DTS is set to DTS ₀ , and the current DTS ₀ is updated to DTS for the next time, and the process proceeds to step 136. In step 136, the target outlet temperature is updated from the previous value TAO _OLD to the current value TAO _NEW , assuming that TAO _OLD = TAO _NEW . Then, the process proceeds to step 138, where TAOFLAG = 0.
And terminate this program. In addition, the above-mentioned step 11
If TAOFLAG = 0, the difference between the target blow-out temperatures is 5 ° C. or less, and there is no large fluctuation. Then, the process proceeds to step 140, and the conventional duty ratio DTS ₀ without the correction control determined in step 108 is output. After that, the process proceeds to step 136 described above, and the same processing is performed thereafter.

As described above, in the vehicle air conditioner of the present invention, the difference between the target outlet temperatures before and after the interruption timing | TAO _NEW -T
AO _OLD | is required. If the difference | TAO _NEW -TAO _OLD | is larger than a predetermined value , the duty ratio DTS is
After the value DTS ₀ is changed from DTS ₀ based on the target blow temperature TAO _NEW to DTS ₁ , correction control is performed so as to gradually approach the value DTS ₀ . As a result, as shown in FIG.
TAO when the target outlet temperature is changed from TAO _OLD to TAO _NEW
The duty ratio of when it is FLAG = 0 is the DTS → DTS _0. Similarly, when TAOFLAG = 1, the duty ratio is DTS → DTS ₁ → DTS ₂ →... → DTS _n → DTS ₀ .

More specifically, the present invention relates to a change in the blow-out air temperature and the like when the target blow-out temperature is changed from 15 ° C. (TAO _OLD ) to 35 ° C. (TAO _NEW ) by the foot mode and the blower motor 11a voltage of 8V. Were compared with and without the correction control according to the above. As shown in FIG. 9, in the conventional control without the correction control, the response time is slow because the heat capacity of the cooling water system including the heater core 21 is large, and the time constant τ of the blown air temperature is 40 (sec).
Met. On the other hand, as shown in FIG. 8, when the correction control according to the present invention was performed, the response time was fast and the time constant τ of the outlet air temperature was reduced to 6 (sec). The change of the target outlet temperature in the above embodiment is changed from 15 ° C to 35 ° C,
The case where the outlet air temperature is increased has been described. Considering the steady state of a vehicle air conditioner, the cooling water has a high temperature (for example,
80 ° C) and can be used at all times, so the correction control of this device when raising the blown air temperature works effectively. Here, the correction control of the vehicle air conditioner according to the present invention is performed, for example, by changing the target outlet temperature from 35 ° C.
° C, and is also effective in lowering the blown air temperature. However, in the case where the temperature of the blown air is decreased in this way, even if the cooling water is circulated through the recirculation passage 46, the cooling water temperature in the heater core 21 does not drop rapidly, and the cooling capacity is limited. The effect of the correction control of the present apparatus is not remarkable as in the embodiment.

In the above-described embodiment, the temperature of the cooling water flowing through the heater core 21 is determined by changing the duty ratio at which the valve device 25 is turned on and off. The same configuration can be obtained by using a valve device such as a control valve. In this case, when the target outlet temperature is greatly changed and correction control becomes necessary, the valve opening of the valve device is once greatly opened and gradually closed to the opening when there is no correction control. , A similar result can be obtained. Further, in the above-described embodiment, the description has been made of the hot water temperature control method of adjusting the temperature of the cooling water passing through the heater core 21 in the reheat-type vehicle air conditioner, but the flow rate of the cooling water flowing through the heater core 21 is adjusted. Thus, the same result can be obtained even when used in a hot water flow rate control method for controlling the blown air temperature.

[0029]

The present invention is constructed as described above, and when the difference between the current and previous target blowing temperatures at the control timing exceeds a predetermined value, the temperature of the cooling fluid supplied to the heater core or After temporarily changing the flow rate from the value based on the current target outlet temperature, a signal is applied to the valve means so as to gradually approach the value. That is, the temperature or the flow rate of the cooling fluid supplied to the heater core is temporarily changed from the value based on the current target blowing temperature and corrected. For example, the temporary change is such that if the difference between the current and previous target outlet temperatures exceeds a predetermined value and is positive, the temperature or flow rate of the cooling fluid will be greater than the value based on the current target outlet temperature. You. Then, the rising of the outlet air temperature is sharply corrected. Thus, the time constant of the blown air temperature can be made smaller than the time constant when the value based on the current target blowout temperature remains. In other words, the vehicle air conditioner of the present invention has an effect that it is possible to rapidly change the blown air temperature to approach the target blown air temperature.

[Brief description of the drawings]

FIG. 1 is a structural diagram showing a configuration of a vehicle air conditioner according to a specific embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an electric system of the apparatus.

FIG. 3 is a block diagram equivalently showing an air heating system of the apparatus.

FIG. 4 is an explanatory diagram showing a heating system when a valve device according to the device is used.

FIG. 5 is an explanatory diagram showing a flow of cooling water of a valve device according to the device.

FIG. 6 is a flowchart showing a processing procedure of air conditioning control by a CPU of the apparatus.

FIG. 7 is a timing chart based on the processing procedure of the flowchart in FIG. 6;

FIG. 8 is an explanatory diagram showing a result when correction control is performed using the present apparatus.

FIG. 9 is an explanatory diagram showing a result when no correction control is performed in FIG. 8;

FIG. 10 is an explanatory diagram showing an air mix system used in a conventional device.

FIG. 11 is an explanatory diagram showing a change in blown air temperature in the air mix system of FIG. 10;

FIG. 12 is a characteristic diagram showing a relationship between a target outlet temperature and a duty ratio of an on / off signal.

[Explanation of symbols]

11-blower 12-evaporator 21-heater core 22-engine 25-valve device (valve means) 41-
Radiator 42-Cooling system flow path 43-Heater system flow path 44-Forward path 45-Return path 46-Reflux path 47-Bypass path 90-Control device (control means) 99-Microcomputer (control means)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Sho 59-192413 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60H 1/00 101 B60H 1/08 621

Claims (1)

(57) [Claims] 1. A cooling fluid from a cooling system flow path for cooling an engine is introduced into a heater core, and the cooling fluid is guided to the heater core from the cooling system flow path in order to blow out wind exchanged with the heater core into a vehicle interior. An outward path, a heater system flow path composed of a return path for returning the cooling fluid discharged from the heater core to the cooling system flow path, and provided in series with the heater core in the heater system flow path; A pump for flowing the cooling fluid, and valve means interposed in the heater system flow path in series with the heater core to control the flow of the cooling fluid between a passing state and a shutoff state; An air conditioner for a vehicle, which controls an outlet air temperature based on a target outlet temperature calculated by a signal from a sensor or a temperature setting device, wherein the target at a control timing is a current target and a target at a previous time. If the difference between the output temperature exceeds a predetermined value, the temperature or flow rate of the cooling fluid supplied to the heater core, the present target
From the value based on the outlet temperature, based on the previous target outlet temperature
After setting the value so that the difference with the value becomes larger, gradually
An air conditioner for a vehicle , comprising: control means for applying a signal to the valve means to control the value so as to approach a value based on the current target outlet temperature .