JP2006219043A - Air conditioning device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly blow off cold wind even in the state of using heating in a full reheat-type air conditioning device. <P>SOLUTION: The cooling water is prevented from flowing in the heater core 5 by closing an opening/closing valve 12 provided in a cooling water circuit 14 of the cooling water flowing in the heater core 5. A pump 11, a catch tank 20, and a short-cut cooling water channel 13 forcibly evacuates the cooling water retained inside the heater core 5 to the outside of the heater core 5 and there is no heated cooling water inside of the heater core 5. The thermal capacity of the heater core 5 becomes the thermal capacity of only the heater core 5 itself, and the thermal capacity is largely reduced compared to the state where the cooling water is full in the inside. The cooling air A2 cooled by passing through the evaporator 3 can quickly cool the heater core 5, and quickly lower the temperature of the heated air A3 blowing off from a blowing off port 9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an air conditioner for a vehicle, and more particularly to an improvement of a so-called full reheat type air conditioner that does not include an air mix door.

  Conventionally, for example, an air conditioner 10 shown in FIG. 6 is known as an air conditioner (hereinafter, abbreviated as an air conditioner) mounted on an automobile.

  The air conditioner 10 is an evaporator provided on the downstream side of the blower fan 2 with the air A1 selected from outside or inside the vehicle compartment by the inside / outside air switching door 8 and introduced into the duct 1 by the blower fan 2. The air mix door 4 is provided on the downstream side of the evaporator 3 to allow the amount of the cooling air A2 to pass through according to the degree of opening thereof. A heater core 5 that warms the cooling air A2 that has passed through the air mix door 4 is provided on the downstream side of the door 4, and the cooling air A2 that has passed through the evaporator 3 and the heater core 5 (the cooling water of the engine 6 circulates through the cooling water circuit 7). The hot air A3 that has been warmed after passing through is mixed with each air outlet (defroster, vent, foot, etc.) 9 of the duct 1 Indoors, the mixed air (mixed air) blows A4, is a so-called air-mix method.

  Here, in the air mix type air conditioner, the air mix door 4 occupies a certain wide area for the opening and closing operation, and there is a problem in miniaturizing the air conditioner 10.

  Therefore, a so-called full reheat type air conditioner 10 that does not use the air mix door 4 has been proposed.

  FIG. 7 shows the full reheat type air conditioner 10, and all of the cooling air A <b> 2 cooled by passing through the evaporator 3 passes through the heater core 5, so that the cooling air A <b> 2 is provided downstream of the heater core 5. The hot air A3 that has been heated is blown into the vehicle compartment from the blowout port 9 as blown air.

  The full reheat type air conditioner 10 adjusts the temperature of the hot air A3 by adjusting the flow rate of the engine cooling water flowing inside the heater core 5 or adjusting the temperature of the engine cooling water flowing inside the heater core 5. FIG. 7 shows a cooling water circuit 14 that connects the heater core 5 and the engine 6 with a flow rate control pump 11 and an on-off valve 12, and the on-off valve 12 is closed. In order to prevent the cooling water from flowing into the heater core 5, a bypass shortcut cooling water channel 13 is provided in the cooling water circuit 14.

According to the full reheat type air conditioner 10, the air conditioner 10 itself can be reduced in size, and the increase in the size of the heater core 5 increases the ventilation area through which the cooling air A2 passes through the heater core 5. Resistance can also be reduced (Patent Document 1).
JP-A-9-207553

  However, the technology of the full reheat method disclosed in Patent Document 1 described above has a structure in which all of the cooling air that has passed through the evaporator is passed through the heater core, so a heater core that is larger in size than the heater core used in the mixed door method is used. In other words, the heater core having a large size has a larger heat capacity than the heater core used in the mixed door system because the amount of the cooling water passed through the heater core increases.

  Therefore, from the state where the hot air A3 is blown out by heating, even if it is desired to blow out cold air for the purpose of eliminating the fogging of the windshield or the excessive warming state of the passenger compartment, Since the heat capacity of the heater core is large, the cooling of the heater core by the cooling air that has passed through the evaporator progresses only gradually, and there is a problem that the cool air cannot be blown out quickly.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the air reconditioning apparatus for vehicles of a full reheat system which can blow off cool air quickly from the state in use of heating.

  An air conditioner for a vehicle according to the present invention includes an on-off valve that selectively prevents coolant from flowing into a heater core into a flow path of engine coolant that flows into a heater core disposed downstream of an evaporator, and a heater core Cooling water draining means for forcibly removing the cooling water accumulated in the interior of the heater, when cooling air is blown out rapidly, the on-off valve is closed to stop the flow of cooling water into the heater core, and the cooling water draining means Thus, by extracting the warm cooling water accumulated in the heater core, the heat capacity of the heater core can be rapidly reduced, and the cooling air can be rapidly cooled by the cooling air passing through the heater core, and the blown-out air can be rapidly cooled. .

  That is, in the vehicle air conditioner according to the present invention, the heater core connected to the engine cooling water system is provided downstream of the evaporator in the ventilation path and substantially over the entire cross section of the ventilation path. In the vehicle air conditioner that adjusts the temperature of the air that has been guided to the ventilation path and passed through the heater core by controlling the flow rate or the water temperature of the engine cooling water that circulates the engine cooling water, the engine cooling water that flows into the heater core An on-off valve for selectively preventing the engine coolant from flowing into the heater core, and at least the engine coolant accumulated in the heater core in a state where the on-off valve is closed, Cooling water drainage means forcibly withdrawn from the outside of the heater core is provided.

  Here, the air conditioner in which the heater core is provided on substantially the entire cross section of the ventilation path generally means a full reheat type air conditioner.

  That is, in a full reheat type air conditioner that does not use an air mix door, substantially all of the cooling air that has been cooled by passing through the evaporator passes through the heater core. The full reheat type air conditioner is blown downstream from the heater core by adjusting the flow rate of the engine cooling water flowing inside the heater core or adjusting the temperature of the engine cooling water flowing inside the heater core. Adjust the air temperature.

  As the cooling water draining means, for example, a cooling water draining pump and a catch tank additionally provided as necessary can be applied.

  The drainage pump may also be a pump (such as a pump for controlling the flow rate) provided in advance for circulating the engine cooling water in the engine cooling water system.

  According to the vehicle air conditioner of the present invention, the on-off valve provided in the flow path of the engine cooling water flowing into the heater core is closed to prevent the engine cooling water from flowing into the heater core, and the cooling water The drainage means forcibly extracts the engine cooling water accumulated inside the heater core to the outside of the heater core, whereby the heat capacity of the heater core can be reduced.

  Thereby, the cooling air cooled by passing through the evaporator can rapidly cool the heater core, and the temperature of the blown-out air can be drastically lowered.

  On the other hand, by opening the on-off valve, the engine cooling water warmed by the engine circulates in the engine cooling water system, flows into the heater core, and warms the cooled cooling air through the evaporator. Can do. At this time, since this air conditioner is a full reheat type, it does not have an air mix door unlike an air mix type air conditioner, and therefore it can be an air conditioner having a small size.

  According to the vehicle air conditioner of the present invention, the on-off valve provided in the flow path of the engine cooling water flowing into the heater core is closed, and the engine cooling water accumulated inside the heater core is forced to the heater core. By extracting to the outside, the heat capacity of the heater core is reduced, the cooling air cooled by passing through the evaporator can cool the heater core rapidly, and the temperature of the blown-out air can be drastically lowered.

  On the other hand, by setting the open / close valve in the open state, the full reheat type air conditioner can be made smaller in size than the air mix type air conditioner.

  Hereinafter, the best embodiment of the air harmony device for vehicles concerning the present invention is described using a drawing.

  FIG. 1 is a schematic diagram illustrating an air conditioner 10 according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating details of a catch tank 20 in the air conditioner 10 of FIG.

  The illustrated air conditioner 10 omits the cooling system portion other than the evaporator 3, extends from the outside of the passenger compartment to the passenger compartment, and the end on the inner side of the passenger compartment serves as an outlet (defroster, vent, foot) into the passenger compartment. The open ventilation duct 1 (ventilation path), the inside / outside air switching door 8 for selectively switching the air outside the vehicle interior or the air inside the vehicle interior as the air to be introduced into the ventilation duct 1, and the inside of the duct 1. A blower fan 2 that is disposed downstream of the inside / outside air switching door 8 and sucks air (outside air or inside air) A1 on the side selected by the inside / outside air switching door 8 into the duct 1, and a part of the cooling system. The evaporator 3 for cooling the air A1 sucked by the blower fan 2 and the most of the cooling air A2 cooled by the evaporator 3 pass therethrough. And a heater core 5 provided over substantially the entire surface of the cross section of the duct 1 in the flow side.

  Here, the heater core 5 is connected to a cooling water circuit 14 through which engine cooling water for cooling the engine 6 of the vehicle on which the air conditioner 10 is mounted, and the cooling water heated by the engine 6 is cooled water. The heater core 5 is warmed by flowing into the heater core 5 via the circuit 14 (engine cooling water system), and the cooling air A2 passing through the outer surface of the heater core 5 is warmed to be blown out from each outlet 9 as hot air A3. It is configured.

  More specifically, the cooling water circuit 14 includes an on-off valve 12 that selectively blocks engine coolant from flowing into the heater core 5 and a downstream portion of the on-off valve 12 when the on-off valve 12 is closed. Cooling water draining means for forcibly extracting the engine cooling water accumulated inside (including the heater core 5) to the outside of the heater core 5 is provided.

  Here, as a cooling water drainage means, a heater water pump 11 (drainage pump) provided in the cooling water circuit 14 and engine cooling water provided downstream from the pump 11 and extracted from the heater core 5 by the pump 11. The short-circuiting cooling water channel 13 (bypass) that connects the catch tank 20 that temporarily accumulates while preventing the backflow of the coolant, and the upstream side of the on-off valve 12 and the downstream side of the catch tank 20 in the cooling water circuit 14. Channel).

  The water pump 11 is also used as a pump conventionally provided as a pump for controlling the flow rate of the cooling water circuit 14.

  The shortcut cooling water channel 13 is provided so that the cooling water does not flow into the heater core 5 with the on-off valve 12 closed.

  As shown in the figure, the pump 11 is provided in a portion of the cooling water circuit 14 on the downstream side of the heater core 5.

  As shown in FIG. 2, the catch tank 20 is formed with an inlet 21 through which cooling water flows from the cooling water circuit 14 (heater core 5) and an outlet 22 through which the cooling water circuit 14 discharges the cooling water. The cooling water storage portion of the catch tank 20 (main body portion of the tank 20) opens at a position higher than the liquid level height position 24 when the amount of cooling water corresponding to the cooling water capacity in the heater core 5 is stored. The outlet 22 opens at the lowest height position of the storage portion. Note that the air intake port 23 opened to the atmosphere is provided to adjust the pressure due to the temperature change in the tank 20.

  Next, the effect | action of the vehicle air conditioner 10 of this embodiment is demonstrated with reference to FIG.

  Here, FIG. 3 is a schematic diagram in which a portion of the cooling water circuit 14 is extracted from the air conditioner 10 shown in FIG. 1, (a) is a state in which the on-off valve 12 is open, and (b) is an on-off valve 12 in FIG. Each represents a closed state.

  FIG. 4 is a flowchart for explaining a control sequence for the on-off valve 12, the pump 11, and the like by a controller (not shown) in accordance with an instruction for air conditioning mode selection.

  First, as shown in FIG. 3A, when the on-off valve 12 is opened, the cooling water warmed by the engine 6 passes through the cooling water circuit 14 to the on-off valve 12, the heater core 5, the pump 11, and the catch. It returns to the engine 6 through the tank 20 in order, and the cooling water circuit 14 is repeatedly circulated similarly in the following.

  Here, since the heater core 5 is so large as to cover substantially the entire cross section of the duct 1, the amount of cooling water filling the inside is large, and the heat capacity of the heater core 5 including the cooling water is equal to the cross sectional area of the duct 1. Compared to the heat capacity of the heater core used in the air mix type air conditioner when substantially the same, it is very large.

  Therefore, it is possible to sufficiently warm the cooling air A2 that has been cooled by passing through the evaporator 3, and the hot air A3 warmed by the heater core 5 is blown out from the duct outlet 9 into the vehicle interior. The heating effect which warms with warm air A3 can be acquired.

  And since the air conditioner 10 of this embodiment is a full reheat system, it is not equipped with an air mix door like an air mix type air conditioner, and is reduced in size compared with an air mix type heating apparatus. Can do.

  On the other hand, even during the heating described above, that is, in the state where the hot air A3 is blown out from the air outlet 9, for example, the purpose of eliminating fogging of the windshield or the purpose of eliminating excessive warm conditions in the vehicle interior, etc. For this reason, you may want to blow out cold air.

  In this case, when the on-off valve 12 is closed under the control of a controller (not shown), the inside of the portion of the cooling water circuit 14 on the downstream side of the on-off valve 12 (including the heater core 5) is sucked by the pump 11. The cooling water is extracted, and the extracted cooling water is stored in a catch tank 20 (see FIG. 2) provided on the downstream side of the pump 11.

  Actually, since the outlet 22 for draining the cooling water to the cooling water circuit 14 is opened at the lowest part of the storage part of the catch tank 20, the cooling water flowing into the storage part almost instantaneously It is discharged from the outlet to the cooling water circuit 14.

  As shown in FIG. 3B, after the on-off valve 12 is closed, the cooling water from the engine 6 does not flow to the circuit leading to the heater core 5, and therefore, the upstream side of the on-off valve 12 and the catch tank It flows through the shortcut cooling water passage 13 connecting the downstream side of 20 and returns to the engine 6, and thereafter, the cooling water circuit 14 is circulated in this repetition.

  Thus, the on-off valve 12 is closed to prevent the cooling water from flowing into the heater core 5, and the pump 11, the catch tank 20, and the shortcut cooling water channel 13 as the cooling water draining means are provided inside the heater core 5. By forcibly removing the accumulated cooling water to the outside of the heater core 5, there is no heated cooling water inside the heater core 5, the heat capacity of the heater core 5 becomes only the heat capacity of the heater core 5 itself, and the cooling water is contained inside. Compared to the state where it is satisfied, the heat capacity is significantly reduced.

  Thereby, it becomes possible for the cooling air A2 cooled by passing through the evaporator 3 to cool the heater core 5 rapidly, and the temperature of the hot air A3 blown out from the air outlet 9 can be drastically lowered.

  Therefore, even during heating, the windshield can be quickly removed from fogging, or an excessive warm state in the vehicle compartment can be eliminated.

  Further, according to the full reheat type air conditioner 10, the air conditioner 10 itself can be reduced in size, and the increase in the size of the heater core 5 increases the ventilation area through which the cooling air A2 passes through the heater core 5. Resistance can also be reduced.

  Next, the operation of the air conditioner 10 will be described according to the flowchart shown in FIG.

  Here, when the set temperature of the air conditioner 10 (desired temperature of the air A3 blown from the air outlet 9) is the maximum temperature, it is referred to as F / H, and when it is the minimum temperature, it is referred to as F / C. Setting the F / H mode, setting the minimum temperature F / C to the F / C mode, and setting the temperature between these maximum temperature F / H and minimum temperature F / C to the temperature control mode Let's say.

  In the F / C mode, as in general air conditioning control, for example, the compressor is turned on and the rotational speed is controlled according to the given conditions (set temperature, set air volume, etc.). In this mode, the valve 12 is closed, the pump 11 is stopped, and the cooling air A2 is blown out from each outlet 9.

  On the other hand, in the F / H mode, as in general air conditioning control, for example, the cooling water is set such that the compressor is turned off, the on-off valve 12 is opened, the pump 11 is operated, and the cooling water is passed through the heater core 5. Is circulated through the cooling water circuit 14, and the hot air A3 having the highest temperature F / H is controlled to be blown out from each outlet 9.

  Further, in the temperature adjustment mode, for example, the temperature of the compressor and the amount of cooling water passing through the heater core 5 are adjusted as appropriate, and the hot air A3 automatically adjusted to a temperature corresponding to the set temperature is blown out from the outlet 9. This is the mode to control.

  A controller (not shown) reads the detection values of various sensors such as a solar radiation sensor, a vehicle interior temperature sensor, and an outside air temperature sensor (not shown), and controls the rotation speed of the compressor of the cooling system based on the instructed set temperature and set air volume. The air volume control of the blower fan 2, the flow temperature control to the heater core 5, and the like are performed. Since these operations are the same as the air conditioning control in a general full reheat type vehicle air conditioner, detailed description is omitted.

  Further, the flowchart of FIG. 4 in the present embodiment is control according to the set temperature by the occupant, and therefore the description starts from the process of reading the set temperature instructed by the occupant by button operation or the like.

  First, the current set temperature is read (S1). It is determined whether or not the read set temperature is the lowest temperature F / C. If it is the lowest temperature F / C, the previous set temperature is read (S2).

  When the previous set temperature is the minimum temperature F / C, the occupant determines that the set temperature has been set the previous time (minimum temperature F / C), and sets the air conditioning mode to the F / C mode ( S3) The process is terminated.

  In step 2 (S2), if the previous set temperature is not the lowest temperature F / C, the occupant changes the set temperature from the previous set temperature (F / H mode or temperature control mode) to the lowest temperature F / C (F / C). It is determined that the mode has been switched to (C mode), and the mode is switched to the immediate cooling (rapid cooling) mode in preparation for switching to the F / C mode (S4).

  Thereby, the on-off valve 12 is closed, and warm cooling water is prevented from flowing into the heater core 5. Furthermore, the cooling water recovery mode to the catch tank 20 is started (S5).

  This is because the pump 11 sends warm cooling water accumulated in the cooling water circuit 14 from the on-off valve 12 to the heater core 5 and the pump 11 to the catch tank 20 to empty the inside of the heater core 5 and rapidly increase the heat capacity. The cooling air A2 passing through the heater core 5 is rapidly prevented from being heated by the heater core.

  In the cooling water recovery mode, a predetermined time t [second] is counted. This t [second] is set based on a value obtained by dividing the cooling water amount [liter] accumulated in the path of the on-off valve 12 to the heater core 5 to the pump 11 by the flow rate [liter / second] of the pump 11.

  After the elapse of t [seconds], the pump 11 is stopped, the cooling water recovery mode to the catch tank 20 is terminated (S6), the immediate cooling mode is terminated (S7), and the mode is switched to the F / C mode (S3). The process is terminated.

  In order to determine whether or not the setting temperature instruction has been changed during the t [second] time count in the immediate cooling mode, reading of the set temperature is repeated until this t [second] time has elapsed. The change in the set temperature is monitored (S8), and when the set temperature changes from the minimum temperature F / C, the process returns to Step 5 (S5) (Process A) and starts counting for a fixed time t [second] again. When the set temperature changes during monitoring, other than the minimum temperature F / C, the cooling water recovery mode to the catch tank 20 is forcibly terminated (S9), the immediate cooling mode is terminated, and the occupant instructs to change. The mode is switched to the F / H mode corresponding to the set temperature F / H or the temperature control mode corresponding to the temperature between F / H and F / C (S10), and the process is terminated.

  When it is determined in step 1 (S1) that the current set temperature is not the lowest temperature F / C, it is further determined whether or not the current set temperature is the highest temperature F / H. When it is determined that the temperature is H, the mode is switched to the F / H mode (S11), and the process is terminated. When it is determined that the temperature is not the maximum temperature F / H, the mode is switched to the temperature control mode (S12). finish.

  Thus, according to the air conditioner 10 according to the present embodiment, the on-off valve 12 that selectively blocks the cooling water from flowing into the heater core 5 into the flow path of the cooling water flowing into the heater core 5, and the on-off valve When the cooling water accumulated in the heater core 12 is forcibly extracted to the outside of the heater core 5 in the closed state, the on-off valve 12 is closed and the cooling water is supplied to the heater core. The cooling water draining means forcibly removes the cooling water accumulated inside the heater core 5 to the outside of the heater core 5 to reduce the heat capacity of the heater core 5.

  As a result, the cooling air A2 cooled by passing through the evaporator 3 can rapidly cool the heater core 5, and the temperature of the blown-out air can be drastically reduced.

  On the other hand, when the on-off valve 12 is opened, the cooling water warmed by the engine 6 circulates in the cooling water circuit 14 and flows into the heater core 5 and passes through the evaporator 3 to be cooled. Air A2 can be warmed. At this time, since the air conditioner 10 is a full reheat type, it does not include an air mix door unlike an air mix type air conditioner, and thus can be an air conditioner having a small size.

  Further, in the air conditioner 10 of the present embodiment, the cooling water draining means includes a pump 11 provided in the cooling water circuit 14, and cooling water provided downstream from the pump 11 and extracted from the heater core 5 by the pump 11. By including a catch tank 20 that temporarily accumulates while preventing backflow, and a shortcut cooling water passage 13 that communicates the upstream portion of the cooling water circuit 14 with respect to the on-off valve 12 and the downstream portion of the catch tank 20. The cooling water extracted from the heater core 5 by the pump 11 can be reliably received by the catch tank 20 provided downstream of the pump 11, and the once received cooling water flows back to the heater core 5. Can be prevented, and the heat capacity of the heater core 5 can be reliably reduced.

  In addition, since the pump 11 is also used by a pump provided in advance to circulate the cooling water in the cooling water circuit 14, an increase in manufacturing cost due to the installation of the pump 11 can be suppressed.

  In addition, since the pump 11 is provided downstream of the heater core 5 in the cooling water circuit 14, the cooling water can be reliably extracted from the heater core 5 by the suction operation by the pump 11.

  Further, the catch tank 20 has an inlet 21 and an outlet 22, and the inlet 21 supplies an amount of cooling water corresponding to the cooling water capacity in the heater core 5 to the tank body portion (storage portion) of the catch tank 20. Since the opening is made at a position higher than the liquid level height position 24 at the time of storage, it is possible to prevent the engine coolant stored in the storage portion from flowing backward from the inlet 21 to the heater core 5.

  On the other hand, since the outlet 22 is opened at the lowest height position in the tank body portion, the cooling water can be smoothly and reliably drained from the tank body portion.

  In the air conditioner 10 according to the present embodiment, as shown in FIG. 5, an air intake pipe 30 for introducing outside air (in particular, a portion between the on-off valve 12 and the heater core 5) is provided in the cooling water circuit 14 (particularly the portion between the on-off valve 12 and the heater core 5). An intake pipe) may be installed.

  When the cooling water draining means (pump 11 or the like) draws the cooling water of the heater core 5, the passage through which the cooling water of the heater core 5 passes is supplied from the outside through the air intake pipe 30 provided in the cooling water circuit 14. Since air is introduced, the inside of the cooling water circuit 14 can be prevented from being evacuated, and the cooling water can be easily extracted.

  The air intake pipe 30 only needs to be formed so as to prevent rainwater or the like other than air from entering from the outside. For example, the air intake pipe 30 may be realized by its shape (open downward). Or a valve that selectively allows only air to pass therethrough. Therefore, it is not necessarily limited to the pipe shape shown in the figure.

  Further, it is preferable to provide a check valve so as to allow one-way passage from the outside to the inside so that the cooling water does not leak from the inside to the outside.

It is a mimetic diagram showing the air harmony device concerning one embodiment of the present invention. It is a figure which shows the detail of the catch tank in the air conditioner of FIG. It is the schematic diagram which extracted the part of the cooling water circuit from the air conditioner shown in FIG. 1, (a) represents the state where the on-off valve was opened, and (b) represents the state where the on-off valve was closed, respectively. It is a flowchart for demonstrating the control sequence with respect to the on-off valve, the pump, etc. by the controller which is not illustrated according to the instruction | indication of air-conditioning mode selection. It is a schematic diagram which shows the air conditioning apparatus of embodiment by which the air intake pipe for external air introduction | transduction was provided in the cooling water circuit. It is a schematic diagram which shows the air conditioning apparatus of an air mix system. It is a schematic diagram which shows the conventional air conditioning apparatus of a full reheat system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Duct 2 Blower fan 3 Evaporator 5 Heater core 6 Engine 9 Outlet 10 Air conditioner 11 Pump 12 On-off valve 13 Short cut cooling water channel 14 Cooling water circuit 20 Catch tank A2 Cooling air A3 Hot air

Claims (5)

A heater core connected to the engine cooling water system is provided downstream of the evaporator in the ventilation path and substantially over the entire cross section of the ventilation path, and controls the flow rate or temperature of the engine cooling water circulating inside the heater core. Thus, in the vehicle air conditioner for adjusting the temperature of the air that has been guided to the ventilation path and passed through the heater core,
An on-off valve for selectively preventing the engine cooling water from flowing into the heater core into the flow path of the engine cooling water flowing into the heater core;
A vehicle air conditioner comprising: cooling water drainage means for forcibly extracting at least the engine cooling water accumulated in the heater core to the outside of the heater core in a state where the on-off valve is closed. apparatus.   The cooling water draining means includes a drain pump provided in the engine cooling water system, and a temporary pump while preventing a reverse flow of the engine cooling water provided downstream from the drain pump and extracted from the heater core by the drain pump. The catch tank which accumulates automatically, The bypass flow path which connects the upstream part and the downstream part of the catch tank of the on-off valve of the engine cooling water system was provided. Air conditioner for vehicles.   The vehicle air conditioner according to claim 2, wherein the drain pump is provided downstream of the heater core in the engine coolant system. The catch tank is formed with an inlet through which the engine cooling water flows from the engine cooling water system and an outlet through which the engine cooling water is discharged from the engine cooling water system,
The inlet is opened at a position higher than the liquid level when the engine cooling water in an amount corresponding to the engine cooling water capacity in the heater core is stored in the engine cooling water storage portion of the catch tank. The vehicle air conditioner according to claim 2 or 3, wherein the outlet is opened at a lowest height position in the storage portion. The vehicle air conditioner according to any one of claims 1 to 4, wherein an intake pipe for introducing outside air is provided in a flow path of the heater core through which the engine coolant passes. .

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