JP2002254922A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress generation of fogging of a vehicle window glass when heating is started by a simple means. SOLUTION: An air conditioner comprises heat exchanging means 18 and 24 having the function of cooling and the function of heating supplied air into a cabin. When the foot defroster mode of supplying air from both a defroster blow-off port 26 and a foot blow-off port 28 is selected when starting the heating mode of supplying the air heated by the heat exchanging means 18 and 24 into the cabin, air supply from the defroster outlet 26 is shut off by changing the supply mode to the foot mode during the predetermined time t0 from the starting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner which can improve the anti-fog properties of a vehicle window glass.

[0002]

2. Description of the Related Art Conventionally, in a vehicle air conditioner, warm water (engine cooling water) is circulated through a heating heat exchanger during heating in winter,
The heating heat exchanger heats the conditioned air using hot water as a heat source. In this case, when the temperature of the hot water is low, the temperature of the air blown into the vehicle interior may decrease, and the necessary heating capacity may not be obtained.

[0003] Japanese Patent Laid-Open Publication No. 2000-219034 proposes a refrigeration cycle apparatus capable of exerting a heating function by a hot gas heater cycle. In this conventional device, when the hot water temperature is lower than a predetermined temperature, such as when starting the engine, the compressor discharge gas refrigerant (hot gas) is directly introduced into the evaporator bypassing the condenser,
By radiating heat from gas refrigerant to conditioned air in the evaporator,
It has a heating function.

That is, in the above-described conventional apparatus, the same indoor heat exchanger, the evaporator, installed in the air-conditioning case is switched between the cooler in the cooling mode and the radiator in the heating mode.

[0005] By the way, in an air conditioner for a vehicle, an inside air mode is sometimes set in order to prevent the introduction of polluted outside air during heating in winter. In this case, in order to prevent the fogging of the window glass, it is necessary to exert the cooling and dehumidifying effects of the evaporator. is there.

[0006]

By the way, the condensed water generated once in the evaporator by the cooling mode operation is hard to evaporate at a low outside air temperature in winter and tends to remain for a long time. For this reason, when the heating mode is started by the hot gas heater cycle at the time of the next engine start due to lack of heating capacity, the evaporator acts as a hot gas radiator this time,
Since the temperature of the evaporator rises rapidly, the condensed water remaining on the evaporator surface is re-evaporated, and high-humidity air is blown into the vehicle interior, causing clouding of the vehicle window glass.

[0007] Therefore, Japanese Patent Laid-Open No. 2000-219034 is disclosed.
In the publication, when it is determined that the vehicle window glass is fogged, a blowing mode other than the defroster mode, specifically, a foot mode in which only the foot outlet is opened and the defroster outlet is closed is selected. It has been proposed to prevent blowing of high-humidity air into a vehicle window glass to prevent fogging of the vehicle window glass.

[0008] However, in order to accurately determine the fogging state of the vehicle window glass, information on the window glass temperature and the humidity of the inner surface of the window glass is required. In addition, a circuit for determining the sensor detection signal is required, which increases the cost.

[0009] The present invention has been made in view of the above points,
An object of the present invention is to be able to suppress the occurrence of fogging of a vehicle window glass at the time of starting heating by simple means.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a heat exchange means (18, 24) having a function of cooling and a function of heating air blown into a vehicle cabin. A defroster outlet (26) for blowing air toward the vehicle window glass, and a foot outlet (28) for blowing air toward the passenger's feet,
When the heating mode in which the air heated by the heat exchanging means (18, 24) is blown into the vehicle compartment is started, if the blowing mode allowing the air blowing from the defroster outlet (26) is selected, from the start. During the predetermined time (t0), the amount of air blown out from the defroster outlet (26) is made smaller than after the predetermined time (t0) has elapsed.

Thus, during a predetermined time (t0) after the heating mode is started, the amount of air blown out from the defroster outlet (26) is reduced, so that the fogging of the vehicle window glass during the heating start can be suppressed. Moreover, the fogging of the window glass can be suppressed by a simple means including a timer means for defining a predetermined time (t0) after the heating mode is started. For this reason, it is not necessary to specifically provide sensors for anti-fog control of the window glass and a circuit for determining a sensor detection signal, so that the cost can be reduced, which is extremely advantageous in practical use.

According to a second aspect of the present invention, in the first aspect, the defroster outlet (26) and the foot outlet (2) are provided.
8) and a foot mode in which air is blown out from the foot outlet (28) and air is blown out from the defroster outlet (26) can be switched between a foot defroster mode in which air is blown out from both sides. Exit (2
The blowing mode that allows the air blowing from 6) is the foot defroster mode. During a predetermined time (t0) from the start of the heating mode, the blowing mode is changed to the foot mode and the air is blown from the defroster outlet (26). It is characterized by shutting off air blowing.

[0013] Thus, during a predetermined time (t0) from the start of heating, by selecting the foot mode, air blowing from the defroster outlet (26) can be avoided, and the suppression of fogging of the window glass can be reliably achieved.

According to the third aspect of the present invention, the predetermined time (t0) is corrected in accordance with a physical quantity (for example, an outside temperature) related to the occurrence of fogging of the vehicle window glass. Therefore, a more appropriate predetermined time (t0) can be set, and the effect of suppressing fogging of the window glass can be improved.

According to the fourth aspect of the invention, the heat exchange means acts as an evaporator for evaporating the low-pressure refrigerant of the refrigeration cycle in the cooling mode, and directly introduces the compressor discharge gas refrigerant of the refrigeration cycle in the heating mode. And an indoor heat exchanger (18) for a hot gas heater cycle that acts as a radiator for the gas refrigerant.

As described above, in the heating mode in which the indoor heat exchanger (18) of the hot gas heater cycle functions as a radiator of the gas refrigerant discharged from the compressor, re-evaporation of condensed water occurs in the indoor heat exchanger (18). However, the defroster outlet (2
By reducing or avoiding the air blowing from 6), the fogging of the vehicle window glass can be suppressed.

According to the fifth aspect of the present invention, the heat exchange means functions as an evaporator for evaporating the low-pressure refrigerant of the refrigeration cycle in the cooling mode, and as a radiator for radiating the high-pressure refrigerant of the refrigeration cycle in the heating mode. The present invention is characterized in that it has an indoor heat exchanger (18) of a heat pump device.

Thus, in the heating mode in which the indoor heat exchanger (18) of the heat pump device operates as a condenser,
Even if re-evaporation of condensed water occurs in the indoor heat exchanger (18),
By reducing or avoiding the air blowing from the defroster outlet (26), it is possible to suppress the fogging of the vehicle window glass.

According to a sixth aspect of the present invention, in the fourth or fifth aspect, a hot water type heat exchanger for heating blast air using hot water as a heat source is provided downstream of the indoor heat exchanger (18) in the air flow. (24).

According to this, before the temperature of the hot water rises sufficiently, the auxiliary heat effect is exerted by the hot gas heater cycle of claim 4 or the indoor heat exchanger (18) of the heat pump device of claim 5 so that the vehicle interior is improved. It is possible to provide a vehicle air conditioner that can promote the start-up of the heating effect and can suppress the occurrence of fogging of the vehicle window glass due to the operation of the hot gas heater cycle or the heat pump device.

According to a seventh aspect of the present invention, in the sixth aspect, when the hot water rises to a predetermined temperature (Tw1) or more in the heating mode, the warm-up control for starting the blower (23) for blowing the blowing air is performed. The predetermined time (t0) is set to a time required for the hot water to rise to another predetermined temperature (Tw3) higher than the predetermined temperature (Tw1) after the heating mode is started.

Thus, even in the case of executing the warm-up control for preventing the blowing of the cool air into the passenger compartment when the heating mode is started, the blower (23) always starts from the defroster outlet (26) during the initial period of starting. Can be reduced or avoided, and fogging of the vehicle window glass can be suppressed.

The reference numerals in parentheses of the above means indicate the correspondence with specific means described in the embodiments described later.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 to 3 show a first embodiment. The first embodiment relates to an air conditioner for a vehicle having a refrigeration cycle device capable of exhibiting a heating function by a hot gas heater cycle. The example which applied the present invention is shown. In FIG. 1, a compressor 10 is driven by a water-cooled vehicle engine 12 via an electromagnetic clutch 11.

The discharge side of the compressor 10 is connected to a condenser (outdoor heat exchanger) 14 through a cooling electromagnetic valve 13, and the outlet side of the condenser 14 separates the gas-liquid of the refrigerant and supplies the liquid refrigerant. It is connected to the receiver 15 for storing. The condenser 14 is an outdoor heat exchanger that is disposed in the vehicle engine room together with the compressor 10 and the like and exchanges heat with the outside air (cooling air) blown by the electric cooling fan 14a.

The outlet side of the receiver 15 is connected to a temperature type expansion valve (first pressure reducing device) 16. The outlet side of the thermal expansion valve 16 is connected to an evaporator (indoor heat exchanger) 18 via a check valve 17. The outlet side of the evaporator 18 is connected to the suction side of the compressor 10 via an accumulator 19.

From the discharge side of the compressor 10, the cooling solenoid valve 13 → condenser 14 → liquid receiver 15 → temperature type expansion valve 16
A normal cooling refrigeration cycle C is constituted by a closed circuit which returns to the suction side of the compressor 10 via the check valve 17 → the evaporator 18 → the accumulator 19 →.

As is well known, the temperature expansion valve 16 adjusts the valve opening (refrigerant flow rate) so that the superheat degree of the refrigerant at the outlet of the evaporator 18 is maintained at a predetermined value during normal refrigeration cycle operation (cooling mode). Is what you do. The accumulator 19 separates the gas-liquid of the refrigerant, stores the liquid refrigerant, and causes the gas refrigerant and a small amount of liquid refrigerant and oil near the bottom to be sucked into the compressor 10 side.

On the other hand, a hot gas bypass passage 20 for bypassing the condenser 14 and the like is provided between the discharge side of the compressor 10 and the inlet side of the evaporator 18.
0 is a heating solenoid valve 21 and a throttle (second pressure reducing device) 2
1a are provided in series. The diaphragm 21a can be constituted by a fixed diaphragm such as an orifice or a capillary tube. A hot gas heater cycle H for heating is constituted by a closed circuit that returns from the discharge side of the compressor 10 to the heating electromagnetic valve 21 → throttling (second pressure reducing device) 21 a → evaporator 18 → accumulator 19 and returns to the suction side of the compressor 10. Is done.

The air conditioner case 22 of the vehicle air conditioner forms an air passage through which air flows toward the vehicle interior. The interior of the air conditioner case 22 is air-driven (vehicle air or outside air) by an electric air-conditioning blower 23. Is blown. Evaporator 1
Reference numeral 8 denotes an indoor heat exchanger installed in the air-conditioning case 22, and a low-pressure refrigerant flows into and evaporates from the refrigeration cycle C in the cooling mode. At this time, the blown air of the air-conditioning blower 23 is cooled by the heat absorption of the refrigerant evaporation latent heat.

In the heating mode, the evaporator 18 functions as a radiator because the high-temperature refrigerant gas (hot gas) flows from the hot gas bypass passage 20 and radiates heat to the blown air.

In the air conditioning case 22, a hot water type heating heat exchanger 24 for heating the blast air using hot water (engine cooling water) from the vehicle engine 12 as a heat source is installed downstream of the evaporator 18 in the air. I have. A bypass passage 24a is provided on the side of the heating heat exchanger 24 so as to bypass the blown air. The bypass passage 24a flows through the bypass passage 24a by the air mix door 25 serving as a temperature control unit. Air volume passing through the heating heat exchanger 24 (hot air volume)
The temperature of the air blown into the vehicle cabin is adjusted by adjusting the ratio of the air flow.

Downstream of the heating heat exchanger 24, a plurality of outlets 26 to 28 for blowing conditioned air into the vehicle interior are provided. The defroster outlet 26 blows out conditioned air toward the inner surface of the vehicle window glass G, the face outlet 27 blows out conditioned air toward the occupant's face, and the foot outlet 28 The conditioned air is blown out toward the feet of the occupant. The air outlets 26 to 28 are blow mode switching doors 29 to 31, respectively.
It is opened and closed by. The hot water circuit to the heating heat exchanger 24 is provided with a hot water valve 32 for controlling the flow of hot water.

In this embodiment, the air mix door 25, the blow-out mode switching doors 29 to 31, and the hot water valve 32 are respectively actuators 45, 46, and 47 formed by servo motors.
Driven by

Electronic control unit for air conditioning (hereinafter referred to as ECU)
Reference numeral 33 is composed of a microcomputer and its peripheral circuits, and performs arithmetic processing on input signals according to a preset program to control the operation of the air conditioner. That is, the opening and closing of the solenoid valves 13 and 21 and the electromagnetic clutch 11
, The cooling fan 14 a of the condenser 14, the air blower 23, the drive actuator 45 of the air mix door 25, the drive actuator 46 of the blowout mode switching doors 29 to 31, and the drive actuator 47 of the hot water valve 32.
The operations such as the above are controlled by the ECU 33. In FIG. 1, electrical connections between the ECU 33 and an air conditioner other than the electromagnetic valves 13 and 21 and the electromagnetic clutch 11 are omitted for simplification of the drawing.

The ECU 33 includes a water temperature sensor 34 for the vehicle engine 12, an evaporator outlet temperature sensor 35 for detecting the temperature of the evaporator 18, a compressor discharge pressure sensor 36,
And a detection signal from the sensor group 37. As is well known, the sensor group 37 includes an outside air temperature sensor, an inside air temperature sensor, a solar radiation sensor, and the like.

An operation signal is input from a group of operation switches on an air-conditioning operation panel 38 installed near the instrument panel in the vehicle compartment. As the operation switch group, specifically, an air conditioner switch 39 for instructing start or stop of the compressor 10 of the refrigeration cycle, a heating switch 40 for setting a heating mode by a hot gas heater cycle, and a temperature for setting a desired temperature in a vehicle compartment A setting switch 41, a blowing mode switching switch 42 for switching the blowing mode, an air volume switching switch 43 for switching the air volume, and the like are provided. The air conditioner switch 39 plays a role of a cooling switch for setting a cooling mode.

Next, the operation of the present embodiment in the above configuration will be described. First, the operation of the refrigeration cycle will be described. In the cooling mode, the ECU 33 opens the solenoid valve 13 for cooling and the solenoid valve 21 for heating closes. Therefore, when the electromagnetic clutch 11 is connected and the compressor 10 is driven by the vehicle engine 12,
The refrigerant gas discharged from the compressor 10 is a cooling solenoid valve 13 in an open state.
And flows into the condenser 14.

In the condenser 14, the refrigerant is cooled and condensed by the outside air blown by the cooling fan 14a. Then, the refrigerant after passing through the condenser 14 is gas-liquid separated by the liquid receiver 15, and only the liquid refrigerant is depressurized by the temperature type expansion valve 16 to be in a low-temperature low-pressure gas-liquid two-phase state.

Next, the low-pressure refrigerant passes through the check valve 17 and flows into the evaporator 18 to absorb heat from the conditioned air blown by the blower 23 and evaporate. The conditioned air cooled by the evaporator 18 mainly blows out from the face outlet 27 into the room to cool the vehicle interior. The gas refrigerant evaporated in the evaporator 18 is sucked into the compressor 10 via the accumulator 19,
Compressed. In addition, the broken line part of FIG. 2 shows the normal refrigerating cycle C for cooling.

In the heating mode in winter, the heating switch 4
When 0 is input, the ECU 33 controls the cooling electromagnetic valve 13.
Is closed, the heating electromagnetic valve 21 is opened, and the hot gas bypass passage 20 is opened. Therefore, the heating solenoid valve 21 with the high-temperature discharge gas refrigerant of the compressor 10 in the open state is opened.
After the pressure is reduced by the restrictor 21a through the passage, it flows directly into the evaporator 18.

At this time, the check valve 17 prevents the gas refrigerant from the hot gas bypass passage 20 from flowing to the temperature type expansion valve 16 side. Therefore, the refrigeration cycle is controlled by the compressor 10
Discharge side → heating solenoid valve 21 → throttle 21a → evaporator 18
The operation is performed in a closed circuit (hot gas heater cycle H) that returns from the accumulator 19 to the suction side of the compressor 10.
2 indicates this hot gas heater cycle H.

Then, the superheated gas refrigerant which has been decompressed by the throttle 21a radiates heat to the blown air in the evaporator 18 to heat the blown air. Here, the amount of heat released from the gas refrigerant in the evaporator 18 is due to the compression work of the compressor 10. Further, since the driving load of the compressor 10 is applied to the vehicle engine 12 by the operation of the hot gas heater cycle H,
This has the effect of promoting warm-up of the vehicle engine 12 and hastening the rise of the hot water temperature.

The hot water (cooling water) of the engine 12
By flowing hot water through the hot water type heating heat exchanger 24 via the hot water valve 32, the blown air can be further heated in the heat exchanger 24, and the hot air can be blown into the vehicle interior. The gas refrigerant radiated by the evaporator 18 is sucked into the compressor 10 via the accumulator 19 and again
Compressed.

Next, FIG. 3 shows a specific control example according to the first embodiment. The control routine of FIG. 3 is an ignition switch (not shown) of the vehicle engine 12 or an operation switch (not shown) of the air conditioning operation panel 38. auto switch,
Start by turning on a blower switch or the like), first, in step S100, detection signals from the sensors 34 to 37,
Operation signals and the like from operation switches 39 to 41 of the air conditioning operation panel 38 are read.

Subsequently, in step S110, a target blowing temperature TAO of the conditioned air blown into the vehicle compartment is calculated.
The target outlet temperature TAO is set in the vehicle interior by a temperature setting switch 4.
This is a blowing temperature required to maintain the set temperature Tset of 1 and is a basic target value of the air conditioning control. Target outlet temperature T
As is well known, AO can be calculated based on the set temperature Tset, the internal temperature Tr, the external temperature Tam, and the amount of solar radiation Ts related to the air conditioning heat load.

Next, in step S120, various air conditioning control target values are determined based on the target outlet temperature TAO. Specifically, the target opening SW of the air mix door 25
Is determined based on the target outlet temperature TAO, the evaporator outlet temperature Te, and the engine hot water temperature Tw. The target air flow BLW of the air blown by the blower fan 23 is calculated based on the TAO. The basic control of the target airflow BLW is performed by the above TA as shown in the map of FIG.
High temperature side (maximum heating side) and low temperature side (maximum cooling side) of O
To increase the target air flow, and decrease the target air flow in the TAO intermediate temperature range.

However, at the time of winter heating activation, warm-up control shown in the map of FIG. 4B is performed in order to prevent blowing of cool air into the vehicle interior. That is, the engine hot water temperature T
When w is lower than the first predetermined temperature Tw1 (for example, 30 ° C.), the power supply to the fan drive motor 23a of the air-conditioning blower 23 is cut off to stop the blower 23, thereby blowing the cool air into the vehicle compartment. To prevent. Then, when the heater core hot water temperature Tw exceeds the first predetermined temperature Tw1, the blower 23 is started with the minimum air flow Lo.

The warming-up of the vehicle engine 12 proceeds, and the hot water temperature Tw further increases from the first predetermined temperature Tw1 to the second predetermined temperature TW.
When the temperature rises toward w2 (for example, 60 ° C.), the voltage applied to the fan drive motor 23a of the blower 23 is increased in conjunction therewith, thereby increasing the airflow of the blower 23 from the minimum airflow Lo to the maximum airflow Hi. And raise it. When the water temperature Tw becomes higher than the second predetermined temperature Tw2, the warm-up control ends, and a transition is made to a steady state in which the target air volume is determined based on the map of FIG.

In step S120, the blowing mode is determined according to the TAO. As shown in the map of FIG. 5, this blowing mode is switched and set as the face (FACE) mode → bi-level (B / L) mode → foot (FOOT) mode as the TAO rises from the low temperature side to the high temperature side.

It should be noted that the face mode and the bi-level are final decisions, whereas the foot mode is a tentative decision.
In a high-temperature region (when heating is required) in which the temperature is equal to or higher than the predetermined temperature B4, when the window glass G is in a condition easily fogged (for example, at low outside air temperature, low solar radiation, high vehicle speed, etc.), the foot mode is set. Instead, the foot defroster mode is selected.

On the other hand, in a high temperature range where TAO is equal to or higher than the predetermined temperature B4 (when heating is required), when the window glass G is not in a condition that is easily clouded, the foot mode is selected as shown in the map of FIG.

In the first embodiment, the foot defroster mode is a blowout mode in which air is blown from both the defroster outlet 26 and the foot outlet 28 at the same time. It is about the same. On the contrary, the foot mode is the defroster outlet 26
The air blowing from the air outlet is stopped, and air is blown out only from the foot outlet 28 or both the foot outlet 28 and a side face outlet (not shown).

The face mode and the bi-level mode in FIG. 5 are conventional blowing modes.
The mode switching temperatures B1 and B2 are, for example, about 25 to 29 ° C., and the mode switching temperatures B3 and B4 are, for example, 4
The temperature is around 0 ° C.

Each of the above blowing modes (face, bi-level, foot, and foot defroster modes)
In addition to the automatic switching by TAO, the air conditioning operation panel 38
Can also be set by the manual operation of the blowout mode changeover switch 42. When the above blowout modes are manually set, the manually set blowout mode is determined in step S120.

The defroster mode in which the face outlet 27 and the foot outlet 28 are fully closed by the face door 30 and the foot door 31 and the defroster outlet 26 is fully opened by the defroster door 29 is an air conditioning operation panel 38.
The defroster mode is determined in step S120 when the blowout mode changeover switch 42 is manually operated to the defroster position only when the blowout mode changeover switch 42 is manually operated to the defroster position. In the defroster mode, the defroster outlet 2
Air may be blown out from both the side face 6 and the side face outlet (not shown).

In step S120, the cooling mode and the heating mode are determined, and the intermittent operation (ON-OFF) of the compressor is determined. The cooling mode is determined by turning on the air conditioner switch 39, and the heating mode by the hot gas heater cycle H is determined by turning on the heating switch 40. Here, the cooling mode and the heating mode may be determined by automatic control based on TAO. For example, the cooling mode may be determined when TAO is in a low-temperature region equal to or lower than a predetermined temperature, and the heating mode may be determined when TAO is in a high-temperature region equal to or higher than a predetermined temperature.

The intermittent operation of the compressor in the cooling mode depends on the TAO, the outside temperature Tam, etc.
O, the compressor 10 is stopped when the actual evaporator outlet temperature Te falls below the target evaporator outlet temperature TEO (OF).
When the evaporator outlet temperature Te rises above the target evaporator outlet temperature TEO, the compressor 10 is operated (O).
N) state.

In the heating mode using the hot gas heater cycle, if the compressor discharge pressure detected by the pressure sensor 36 exceeds the upper limit of the target range, the compressor 10 is stopped (OFF), and conversely, the compressor discharge pressure Is below the lower limit of the target range, the compressor 10 is turned on (ON).

Next, in step S130, it is determined whether or not the elapsed time t after starting the heating mode has exceeded a predetermined time t0 shown in FIG. Here, the activation of the heating mode in the first embodiment refers to a point in time when an operation command of the heating mode by the hot gas heater cycle H is issued by operating the heating switch 40 of the air conditioning operation panel 38. Therefore, at the time of the warm-up control described above, even when the blower 23 is in the stopped state, the air conditioner heating mode is activated when the operation command of the heating mode by the hot gas heater cycle H is issued and the compressor 10 is activated. .

A predetermined time t0 after starting the heating mode
Means that after the vehicle engine 12 is started in a cold winter, the hot water temperature Tw becomes equal to the first predetermined temperature T of the warm-up control described above.
w1 (for example, 30 ° C.), specifically, a first predetermined temperature Tw1 and a second predetermined temperature Tw2 (for example, 60 ° C.).
(° C.) and an intermediate temperature Tw3 (for example, about 40 ° C.).

The rise in the hot water temperature Tw is correlated with the elapsed time after the start of the vehicle engine 12, and the hot gas heater cycle H is simultaneously with or immediately after the start of the vehicle engine 12 in order to promote warming of the engine. Since the activation is usually performed, the elapsed time t may be the elapsed time after the activation of the vehicle engine 12.

If the elapsed time t after starting the heating mode is within the predetermined time t0, the process proceeds to the next step S140, and it is determined whether or not the blowing mode determined in step S120 is the foot defroster (F / D) mode. If the determination is YES, the blowing mode is changed to the foot (FOOT) mode in the next step S150.

The next step S160 is a step S12.
0 and the various air conditioning control target values determined in step S150,
1, electromagnetic valves 13 and 21, condenser cooling fan 14a, motor 23a of blower 23, actuator 45 of air mix door 25, actuator 46 of blow mode doors 29, 30, 31 and actuator 47 of hot water valve 32
) To execute the air conditioning control.

In the foot defroster mode, as shown in FIG. 5, the TAO is set to a high temperature range higher than a predetermined mode switching temperature B4 (for example, about 40 ° C.) as in the foot mode. In such high temperature range,
In order to quickly start the heating effect in the vehicle interior, a heating mode using the hot gas heater cycle H is executed.

However, if condensed water adheres to the surface of the evaporator (indoor heat exchanger) 18, when the evaporator 18 radiates the superheated gas refrigerant by the hot gas heater cycle H, the condensed water on the evaporator surface is condensed. The water re-evaporates to form a high humidity atmosphere around the evaporator. Then, immediately after the blower 23 is started by the warm-up control, the hot water temperature Tw is low (Tw = Tw1), so that the heating capacity of the heat exchanger 24 for hot water heating is small. As a result, the rate of temperature rise of the high humidity air around the evaporator is small, so that the air after passing through the heat exchanger 24 blows out into the vehicle compartment with a high relative humidity.

Therefore, in this state, if the state of air blowing from the defroster outlet 26 to the inner surface of the vehicle window glass G (for example, the foot defroster mode) is selected,
The blowing of the high humidity air induces fogging of the vehicle window glass G.

Therefore, in the first embodiment, when the heating mode by the hot gas heater cycle H is executed, even if the foot defroster mode is selected for a predetermined time t0 after the heating is started, this is not performed. Forcibly change to foot mode. In this foot mode, the defroster outlet 26 and the face outlet 27 are connected to the defroster door 2.
9. Completely closed by the face door 30 and the foot outlet 28
Is fully opened by the foot door 31, air can be prevented from blowing from the defroster outlet 26 to the inner surface of the vehicle window glass G. For this reason, even if the condensed water on the evaporator surface re-evaporates due to the heat radiation in the evaporator 18, the fogging of the vehicle window glass G can be prevented.

In the defroster mode in which the face outlet 27 and the foot outlet 28 are fully closed by the face door 30 and the foot door 31 and the defroster outlet 26 is fully opened by the defroster door 29, the blow mode switch 42 is set to the defroster position. Since the setting is made only when the manual operation is performed, the first embodiment does not forcibly change to the foot mode when the defroster mode is set from the idea of respecting the occupant's operation intention.
Even when the defroster mode is set, fogging of the vehicle window glass G due to the re-evaporation of the condensed water in the evaporator 18 occurs. Therefore, the forced change from the defroster mode to the foot mode may be performed.

(Second Embodiment) In the first embodiment, the control of the present invention is applied to a vehicular air conditioner which executes a heating mode by a hot gas heater cycle H to promote the rise of a heating effect at the time of starting heating. However, in the second embodiment, the control of the present invention is applied to a vehicle air conditioner in which an air conditioning refrigeration cycle is configured as a heat pump cycle capable of switching between a cooling function and a heating function.

FIG. 7 is an overall configuration diagram of the second embodiment.
The same or equivalent parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Only different points from the first embodiment will be described.

For switching the refrigerant flow path between the cooling mode and the heating mode of the heat pump cycle, two solenoid valves 13 and 2 are provided.
1 is a three-way valve type, and when the cooling mode is set by turning on the air conditioner (cooling) switch 39,
The two solenoid valves 13 and 21 close the switching passages 50 and 51 side. Therefore, the discharge side of the compressor 10 → the first solenoid valve 13
The refrigerant circulates in a closed circuit of an outdoor heat exchanger (condenser) 14, a pressure reducing device 16, an indoor heat exchanger (evaporator) 18, a second solenoid valve 21, an accumulator 19, and a suction side of the compressor 10. Thereby, the indoor heat exchanger 18 acts as an evaporator (cooler) and exerts a cooling function.

On the other hand, when the heating mode is set by turning on the heating switch 40, the two solenoid valves 13, 21 open the switching passages 50, 51 side. For this reason, the compressor 1
0 discharge side → first solenoid valve 13 → switching passage 50 → indoor heat exchanger (condenser) 18 → pressure reducing device 16 → outdoor heat exchanger (evaporator) 14 → switching passage 51 → second solenoid valve 21 → accumulator 19 → The refrigerant circulates in a closed circuit on the suction side of the compressor 10. Thereby, the indoor heat exchanger 18 acts as a condenser (radiator) and exerts a heating function.

Also in the heat pump cycle, the condensed water generated during the previous cooling mode operation is re-evaporated by the heat radiating action of the indoor heat exchanger 18 to form high humidity air in the air conditioning case 22 at the time of the next heating mode startup. I do. Therefore, when the high humidity air blows out from the defroster outlet 26 to the inner surface of the vehicle window glass G, the vehicle window glass G is fogged.

Therefore, in the second embodiment, the control shown in FIG. 3 according to the first embodiment, that is, when the elapsed time t after starting the heating mode of the heat pump cycle is within the predetermined time t0, the blow mode is set. Even if the foot defroster mode is selected, by performing control for forcibly changing the mode to the foot mode, fogging of the window glass G due to the heat radiation action of the indoor heat exchanger 18 of the heat pump cycle can be reliably prevented. .

Note that the switching between the cooling mode and the heating mode in the second embodiment is not performed by a manual switch operation, but by T
Automatic switching by AO or the like is possible.

Further, in the second embodiment, the heat pump device in which the normal high-pressure refrigerant is used as the refrigerant and the high-pressure side refrigerant is condensed in the high-pressure side heat exchanger has been described, but CO ₂ (carbon dioxide) is used as the refrigerant. A heat pump device consisting of a supercritical cycle in which the pressure on the high pressure side of the cycle is set to be equal to or higher than the critical pressure of the refrigerant and the gas discharged from the compressor is released in a gas (gas phase) state by the heat exchanger on the high pressure side. Of course, the invention can be applied. In any of the heat pump devices, the indoor heat exchanger 18 is in the heating mode.
Acts as a radiator for high-pressure refrigerant.

(Third Embodiment) In the first embodiment, the control of the present invention is applied to a vehicle air conditioner capable of setting a heating mode by a hot gas heater cycle H. In the second embodiment, heating by a heat pump cycle is performed. The control of the present invention is applied to an air conditioner for a vehicle in which a mode can be set. In the third embodiment, a hot water heating system is provided downstream of an air flow of an evaporator 18 in a normal cooling refrigeration cycle. Exchanger 2
The control according to the present invention is applied to a general vehicle air conditioner in which the control unit 4 is disposed.

Even in such a general vehicle air conditioner, when the refrigeration cycle is operated for dehumidifying and heating operation in winter to cause the evaporator 18 to exert a cooling function, the evaporator 1
8 Condensed water adheres to the surface. Therefore, in this condensed water adhesion state, when the vehicle engine 11 is temporarily stopped, the engine warm water temperature Tw is reduced to about the same as the outside temperature, and then the vehicle engine 11 is restarted to start the heating mode, the evaporator 18 Condensed water scatters into the blast air to form high humidity air. Then, while the engine hot water temperature Tw is low (while the heating capacity of the hot-water heating heat exchanger 24 is small), the temperature of the high-humidity air slightly increases even if the heat-passing heat exchanger 24 is passed. Since the relative humidity of the air does not sufficiently decrease, when the high humidity air blows out from the defroster outlet 26 to the inner surface of the vehicle window glass G, the vehicle window glass G is fogged.

Therefore, in the third embodiment, the first,
As in the second embodiment, a predetermined time t after the heating mode is started.
When it is within 0, even if the foot defroster mode is selected as the blowout mode, by performing control to forcibly change the mode to the foot mode, the heat radiation action of the indoor heat exchanger 18 of the heat pump cycle is reduced. The fogging of the window glass G due to this can be reliably prevented.

In the third embodiment, the heating mode refers to, for example, a TAO high temperature region (TAO ≧ B
4) When the foot mode or the foot defroster is selected as the blowing mode, or when the opening of the air mix door 25 forming the temperature control means is in the high opening range near the maximum heating position (solid line position in the drawing). It can be defined depending on when it is operated.

Then, in the heating mode state defined in this way, the time when the operation command of the blower 23 is issued is defined as the heating mode activation time. During warm-up control,
The time when the operation command of the blower 23 is issued before the start of the actual operation of the blower 23 is the start time of the heating mode. Also in the third embodiment, the elapsed time t after starting the heating mode may be set as the elapsed time after starting the vehicle engine.

(Fourth Embodiment) In the first embodiment, the predetermined time t0 is a predetermined fixed time. However, the warming-up time of the vehicle engine 12 becomes longer as the outside air temperature becomes lower. The time required for Tw to rise to a predetermined temperature Tw3 (FIG. 6) becomes longer.

Therefore, in the fourth embodiment, as shown in FIG. 9, the predetermined time t0 is made longer as the outside air temperature detected by the outside air temperature sensor in the sensor group 37 becomes lower.
Thereby, "control of forced change to the foot mode" in step S150 can be maintained for an appropriate period of time irrespective of the fluctuation of the outside air temperature, and the anti-fog control of the window glass G can be more appropriately executed. .

(Other Embodiments) In each of the above-described embodiments, if the foot defroster mode is selected as the blowing mode when the heating is started within the predetermined time t0, the defroster blowing is performed. Although the mode is forcibly changed to the foot mode in which the air is not blown out from the outlet 26, the air blowout from the defroster outlet 26 is limited to a small amount without completely reducing the air blowout from the defroster outlet 26. Even in the foot mode, the anti-fog property of the window glass G can be ensured depending on the vehicle type. Therefore, the present invention is not limited to the foot mode in which the air blowing from the defroster outlet 26 is completely zero as the foot mode within the predetermined time t0 after the heating is started.

[Brief description of the drawings]

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

FIG. 2 is an operation explanatory view of a hot gas heater cycle according to the first embodiment.

FIG. 3 is a flowchart illustrating an outline of air conditioning control according to the first embodiment.

FIG. 4 is an explanatory diagram of control of the amount of air blown out of the vehicle interior according to the first embodiment.

FIG. 5 is an explanatory diagram of automatic switching control of a blowing mode according to the first embodiment.

FIG. 6 is an explanatory diagram of a predetermined time t0 according to the first embodiment.

FIG. 7 is an overall configuration diagram showing a second embodiment.

FIG. 8 is an overall configuration diagram showing a third embodiment.

FIG. 9 is an explanatory diagram of a predetermined time t0 according to a fourth embodiment.

[Explanation of symbols]

12: vehicle engine, 18: evaporator (indoor heat exchanger),
24: heat exchanger for hot water heating, 26: defroster outlet, 28: foot outlet, 33: controller.

Continuation of the front page (72) Inventor Mayumi Yoshida 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (Reference) 3L011 CP00

Claims (7)

[Claims] 1. A heat exchange means (18, 24) having a function of cooling and heating a blast air into a vehicle interior; a defroster outlet (26) for blowing the blast air toward a vehicle window glass; A foot outlet (28) for blowing the blast air toward the foot of the occupant; and a defroster outlet for starting the heating mode in which the air heated by the heat exchange means (18, 24) is blown into the vehicle interior. When the blowing mode allowing the air blowing from (26) is selected, a predetermined time (t
0) The air conditioner for a vehicle, wherein the amount of air blown out from the defroster outlet (26) is made smaller than after the lapse of the predetermined time (t0). 2. A foot defroster mode in which air is blown out from both the defroster outlet (26) and the foot outlet (28), and air is blown out from the foot outlet (28) and the defroster outlet (26). And a foot mode for shutting off the air blowing from the air outlet. The blowing mode allowing the air blowing from the defroster outlet (26) is the foot defroster mode. ), The outlet mode is changed to the foot mode and the defroster outlet (2
The air conditioner for a vehicle according to claim 1, wherein air blowing from (6) is shut off. 3. The vehicle air conditioner according to claim 1, wherein the predetermined time (t0) is corrected in accordance with a physical quantity related to occurrence of fogging of the vehicle window glass. 4. The heat exchange means acts as an evaporator for evaporating a low-pressure refrigerant of a refrigeration cycle in a cooling mode,
2. A heating apparatus according to claim 1, further comprising a hot gas heater cycle indoor heat exchanger in which the compressor discharge gas refrigerant of the refrigeration cycle is directly introduced and functions as a gas refrigerant radiator in the heating mode. The air conditioner for a vehicle according to any one of the above-mentioned items. 5. The heat exchange means acts as an evaporator for evaporating a low-pressure refrigerant of a refrigeration cycle in a cooling mode,
4. The air conditioner according to claim 1, further comprising an indoor heat exchanger of the heat pump device that functions as a radiator for radiating the high-pressure refrigerant of the refrigeration cycle in the heating mode. 5. Vehicle air conditioner. 6. A hot water heating heat exchanger (24) for heating the blast air using hot water as a heat source is provided downstream of the indoor heat exchanger (18) in the air flow. The vehicle air conditioner according to 4 or 5. 7. When the hot water rises to a predetermined temperature (Tw1) or more in the heating mode, warm-up control for starting a blower (23) that blows the blown air is performed, and the predetermined time ( 7. The method according to claim 6, wherein t0) is set to a time required for the hot water to rise to another predetermined temperature (Tw3) higher than the predetermined temperature (Tw1) after activation of the heating mode. The vehicle air conditioner according to any one of the preceding claims.