Inside-outside air switching unit

An inside-outside air switching unit includes a switching member in an inside-outside air case and a drive unit that is configured to operate the switching member. The switching member is configured to open and close an outside-air inlet and an inside-air inlet. The switching member includes a first switching door and the second switching door. The first switching door is configured to be positioned by the drive unit to open the outside-air inlet in the inside-outside air intake mode. The second switching door is configured to be positioned by the drive unit to open the inside-air inlet in the inside-outside air intake mode. The drive unit is configured to move the first switching door to close an inside-outside communication passage, which is defined in the inside-outside case between the outside-air inlet and the inside-air inlet, in the inside-outside air intake mode.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase Application under 35 U.S.C. 371 of International Application No. PCT/JP2016/084095 filed on Nov. 17, 2016 and published in Japanese as WO/2017/149855 A1 on Sep. 8, 2017. This application is based on and claims the benefit of priority from Japanese Patent Application No. 2016-037901 filed on Feb. 29, 2016. The entire disclosures of all of the above applications are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to an inside-outside air switching unit that is configured to set an inside-outside air intake mode taking in both of outside air and inside air.

BACKGROUND ART

Inside-outside air switching units are known to take in inside air, which has a higher temperature than outside air, in addition to the outside air in order to reduce a heating load in an outside-air drawing mode (for example, refer to Patent Literature 1). Patent Document 1 discloses an air conditioner for a vehicle that includes an intake door being configured to open and close an outside-air inlet and an inside-air inlet and being provided with a ventilation hole. The air conditioner is configured to take in the inside air by opening the ventilation hole in the outside-air drawing mode.

PRIOR ART DOCUMENT

Patent Document

SUMMARY OF INVENTION

However, the inside-outside air switching unit disclosed in Patent Document 1 is configured to allow the outside-air inlet and the inside-air inlet to come in communication with each other through an interior space of the inside-outside air switching unit in the outside-air drawing mode. In this configuration, noise may transmit from an outside of a vehicle compartment to an inside of a vehicle compartment through the inside-air inlet in the outside-air drawing mode.

It is an objective of the present disclosure to produce an inside-outside air switching unit that is configured to take in both outside air and inside air in an inside-outside air intake mode while preventing noise from transmitting from an outside of a vehicle compartment to an inside of the vehicle compartment.

In an aspect of the present disclosure, an inside-outside air switching unit is configured to set, as an air intake mode, an inside-outside air intake mode taking in both of outside air and inside air.

The inside-outside air switching unit includes an inside-outside air case, a switching member in the inside-outside air case, and a drive unit. The inside-outside air case includes an outside-air inlet configured to take in the outside air and an inside-air inlet configured to take in the inside air. The switching member is configured to open and close the outside-air inlet and the inside-air inlet. The drive unit is configured to operate the switching member.

The switching member includes a first switching door and a second switching door. The first switching door is configured to be positioned by the drive unit to open the outside-air inlet in the inside-outside air intake mode. The second switching door is configured to be positioned by the drive unit to open the inside-air inlet in the inside-outside air intake mode.

The drive unit is configured to position the first switching door to close an inside-outside communication passage in the inside-outside air intake mode. The inside-outside communication passage is defined in the inside-outside air case and connects the outside-air inlet and the inside-air inlet to each other.

That is, in the inside-outside air intake mode, one, i.e., the first switching door, of the first and second switching doors closes the inside-outside communication passage connecting the outside-air inlet and the inside-air inlet to each other. As such, noise from the outside of the vehicle compartment can be prevented from transmitting to the inside of the vehicle compartment through the inside-outside communication passage.

More specifically, in the inside-outside air intake mode, the first switching door, which is configured to open and close the outside-air inlet, closes the inside-outside communication passage. Accordingly, the first switching door changes an open area of the inside-air inlet and thereby adjusting a volume of the inside air to take in.

Therefore, the present disclosure can produce the inside-outside air switching unit that is configured to take in both outside air and inside air in an inside-outside air intake mode while preventing noise from transmitting from an outside of a vehicle compartment to an inside of the vehicle compartment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, parts, which are the same as or equivalent to those described in the preceding embodiment(s), will be indicated by the same reference signs, and the description thereof may be omitted. Also, in the following embodiments, when only some of the constituent elements are described, corresponding constituent elements of a previously described one or more of the embodiments may be applied to the rest of the constituent elements. The following embodiments may be partially combined with each other even if such a combination is not explicitly described as long as there is no disadvantage with respect to such a combination.

First Embodiment

The present embodiment will be described with reference toFIGS. 1 to 8.FIG. 1is a cross-sectional view schematically showing a side of a vehicle mounting an air conditioner1for a vehicle including an inside-outside air switching unit2of the present disclosure. Orientation indicators showing an up-down direction and a front-rear direction in the drawings indicate an up-down direction and a front-rear direction with the air conditioner1mounted to the vehicle.

The air conditioner1for a vehicle shown inFIG. 1is a device that is configured to adjust a temperature in the vehicle compartment by supplying air, of which temperature is adjusted to be a required temperature, into the vehicle compartment. As shown inFIG. 1, the air conditioner1is arranged inside an instrument panel11positioned in a front area in the vehicle compartment inside the vehicle.

As shown inFIG. 2, the air conditioner1is roughly divided into three units, i.e., the inside-outside air switching unit2, a blower unit5, and an air conditioning unit (not shown).

The inside-outside air switching unit2is located above the blower unit5. The inside-outside air switching unit2and the blower unit5in the instrument panel11are assembled to be one unit and face a passenger seat.

The blower unit5serves as a blower that is configured to supply air into the vehicle compartment. The blower unit5includes a blower case51made of resin. The blower case51may be formed by a scroll case that defines a scroll passage therein. The blower case51includes a suction port511in an upper surface thereof and draws air from the suction port511.

The blower case51houses a fan52that is configured to case an air flow to be supplied to the vehicle compartment. In the present embodiment, the fan52is a centrifugal sirocco fan that draws air along a rotational axial direction of a rotary shaft50and discharges the air radial outward. It should be noted that the fan52may be a turbo fan, a radial fan, or the like.

The fan52is rotationally driven by an electric motor53attached to the blower case51. The electric motor53is attached to a portion of the blower case51on a side of the blower case51away from the suction port511.

The air conditioning unit (not shown) is connected to a downstream end of the blower unit5in an airflow direction of the air. The air conditioning unit includes an air conditioning case that defines an air passage therein. The air conditioning case houses a cooling heat exchanger and a heating heat exchanger that are configured to adjust a temperature of the air to be supplied into the vehicle compartment. The blower case51discharges the air when the fan52rotates. The air is supplied into the vehicle compartment after a temperature of which is adjusted to be a required temperature in the air conditioning unit.

The inside-outside air switching unit2is configured to take in inside air (i.e., air inside the vehicle compartment) and outside air (i.e., air outside the vehicle compartment) selectively. The inside-outside air switching unit2includes an inside-outside air case20forming an outer shell thereof. The inside-outside air case20is formed of resin (e.g., polypropylene) having a certain degree of elasticity and an excellent strength.

The inside-outside air case20includes an outside-air inlet201that is configured to take in the outside air and an inside-air inlet202that is configured to take in the inside air. The outside-air inlet201and the inside-air inlet202are formed in a most upstream portion of the inside-outside air case20in the airflow direction. The outside-air inlet201is connected to an outside-air suction port (not shown) defined in a vehicle body.

An air filter21and a switching member22are arranged in the inside-outside air case20. The switching member22is positioned upstream of the air filter21in the airflow direction and is configured to open and close the outside-air inlet201and the inside-air inlet202. The inside-outside air case20defines an inside-outside communication passage20atherein. The inside-outside communication passage20ais defined between the outside-air inlet201and the inside-air inlet202and allows the outside-air inlet201and inside-air inlet202to be in communication with each other therethrough. The inside-outside communication passage20ais an interior space defined in the inside-outside air case20by an upper wall of the inside-outside air case20and the air filter21.

The air filter21is a filter that removes a foreign material such as dust from air flowing into the blower unit5. The air filter21is formed of a material having air permeability. The material forming the air filter21may be a non-woven fabric with resin fiber such as PET or PP.

The switching member22includes an outside-air door23, an inside-air door24, and a drive mechanism30that is configured to rotate the outside-air door23and the inside-air door24. The outside-air door23is configured to open and close the outside-air inlet201. The inside-air door24is configured to open and close the inside-air inlet202.

The outside-air door23and the inside-air door24are rotatably housed in the inside-outside air case20. In the present embodiment, the outside-air door23and the inside-air door24each is configured by a rotary door. In the present embodiment, the outside-air door23and the inside-air door24are configured by rotary doors having the same shape in order to share parts.

Configurations of the outside-air door23and the inside-air door24in the present embodiment will be described hereafter in detail referring toFIG. 3. As described above, in the present embodiment, the outside-air door23and the inside-air door24are configured by rotary doors having the same shape. As such,FIG. 3shows one of the outside-air door23and the inside-air door24.

As shown inFIG. 3, the outside-air door23and the inside-air door24rotate about a longitudinal axis CL of a door shaft25in the present embodiment. Each of the outside-air door23and the inside-air door24includes the door shaft25, an outer wall26, and side plates27. The outer wall26has an arc shape extending along a rotational direction R of the door shaft25in cross section. The side plates27are positioned at both ends of the outer wall26in an axial direction of the door shaft25. The door shaft25, the outer wall26, and the side plate27are made of resin (e.g., polypropylene) and are molded integrally to be one piece.

The door shaft25is positioned at a portion serving as a linchpin of the side plates27that each has a fan shape. The door shaft25is supported rotatably relative to the inside-outside air case20. The door shaft25is connected to the drive mechanism30shown inFIG. 2.

The outer wall26and the side plates27are configured to close the outside-air inlet201and the inside-air inlet202defined in the inside-outside air case20. In the present embodiment, the outer wall26and the side plates27each has a dimension to be able to close the outside-air inlet201and the inside-air inlet202defined in the inside-outside air case20. Specifically, the outer wall26has a dimension required to close the inside-outside communication passage20adefined in the inside-outside air case20.

As shown inFIG. 2, the outside-air door23and the inside-air door24in the present embodiment includes gaskets28,29respectively in order to suppress a leak of air when opening and closing the outside-air inlet201and the inside-air inlet202. The gaskets28,29are fixed to peripheral edges of the outer wall26and the side plates27respectively by a method such as adhesion. The gaskets28,29are formed of a porous material such as urethane foam preferably.

The drive mechanism30serves as a device that is configured to rotate the outside-air door23and the inside-air door24. In the present embodiment, the drive mechanism30includes a first drive part31, which is configured to operate the outside-air door23, and a second drive part32, which is configured to operate the inside-air door24, so that the outside-air door23and the inside-air door24are operated independently.

The first drive part31and the second drive part32are independent from each other. The first drive part31and the second drive part32each includes a servo motor (not shown) connected to the door shaft25and a drive circuit (not shown) operating the servo motor. Operations of the first drive part31and the second drive part32are controlled separately based on controls signals from a controller10for the air conditioner1for a vehicle. For explanation purpose, the first drive part31and the second drive part32are circled by a dashed line showing the drive mechanism30inFIG. 2. However, it should be understood that the first drive part31and the second drive part32may be proximate to each other or may be positioned separately. In addition, although the drive mechanism30is illustrated above the inside-outside air switching unit2, the drive mechanism30may not be positioned above the inside-outside air switching unit2.

Here, the controller10of the air conditioner1for a vehicle is configured by a microcomputer, which includes a memory such as CPU, ROM, or RAM, and a peripheral circuit of the microcomputer. The controller10performs various calculations and processes based on control programs stored in the memory, and controls actuations of the various devices connected to the output side thereof. The memory of the controller10is configured by a non-transitional physical storage medium.

The electric motor53operating the fan52of the blower unit5, the drive mechanism30operating the switching member22of the inside-outside air switching unit2, and the various devices mounted to the air conditioning unit (not shown) are connected to the output side of the controller10.

A sensor group including an inside-air sensor101, an outside-air sensor102, an insolation sensor103, and a humidity sensor104is connected to an input side of the controller10. The inside-air sensor101is configured to detect an inside-air temperature Tr. The outside-air sensor102is configured to detect an outside-air temperature Tam. The insolation sensor103is configured to detect a solar insolation amount Ts in the vehicle compartment. The humidity sensor104is configured to detect a relative humidity Rh in the vehicle compartment.

An operation panel105near the instrument panel11is also connected to the input side of the controller10. The operation panel105is provided with various operation switches such as an air-conditioning operation switch and a temperature setting switch. The temperature setting switch may be configured to set a target temperature in the vehicle compartment. The air-conditioning operation switch may be a switch that is configured to output a request signal to the controller10so that the electric motor53of the fan52is operated to adjust a temperature of air supplied to the vehicle compartment from the air conditioning unit.

The controller10is configured integrally with control units that are configured to control various devices connected to its output side. The controller10serves as a control unit including hardware and/or software that is/are configured to control operations of the various devices.

For example, in the present embodiment, the controller10sets air intake modes by controlling the outside-air door23and the inside-air door24using the drive mechanism30. Thus, in the present embodiment, hardware and/or software of the controller10configured to set the air intake modes by controlling the drive mechanism30may serve as a mode controller10a. In the present embodiment, the drive mechanism30and the mode controller10aserve as a drive unit that is configured to operate the switching member22.

Next, operations of the inside-outside air switching unit2in the present embodiment will be described hereafter. In the present embodiment, the inside-outside air switching unit2is configured to set, as the air intake modes, an outside-air intake mode, an inside-air intake mode, and an inside-outside air intake mode selectively based on a control signal from the controller10. For example, the controller10may set, as the air intake modes, the outside-air intake mode, the inside-air intake mode, and the inside-outside air intake mode selectively based on a heat load in air conditioning for the vehicle compartment or an operation signal from the operation panel. The heat load may be determined based on a target supply temperature, the outside-air temperature, and/or the relative humidity in the vehicle compartment.

In the outside-air intake mode, the inside-outside air case20takes in the outside air. In the outside-air intake mode, the drive mechanism30moves the inside-air door24to close the inside-air inlet202and moves the outside-air door23to open the outside-air inlet201as shown inFIG. 4.

Specifically, in the present embodiment, the drive mechanism30moves the outside-air door23to open the outside-air inlet201and to open the inside-outside communication passage20ain the outside-air intake mode so that a certain volume of the outside air is taken in.

In the inside-air intake mode, the inside-outside air case20takes in the inside air. In the inside-air intake mode, the drive mechanism30moves the outside-air door23to close the outside-air inlet201and moves the inside-air door24to open the inside-air inlet202as shown inFIG. 5.

In the inside-outside air intake mode, the inside-outside air case20takes in both of the outside air and the inside air. In the inside-outside air intake mode, when the outside-air inlet201and the inside-air inlet202are in communication with each other through the inside-outside communication passage20a, noise may easily transmit into the vehicle compartment from outside of the vehicle compartment via the inside-outside communication passage20a. This is undesirable because it may cause a discomfort to an occupant.

Then, in the inside-air intake mode, the drive mechanism30moves the outside-air door23to open the outside-air inlet201and to close the inside-outside communication passage20aand moves the inside-air door24to open the inside-air inlet202as shown inFIG. 6.

In the present embodiment, the outside-air door23serves as a first switching door that is configured to be positioned by the drive mechanism30to open the outside-air inlet201in the inside-outside air intake mode. In addition, in the present embodiment, the inside-air door24serves as a second switching door that is configured to be positioned by the drive mechanism30to open the inside-air inlet202in the inside-outside air intake mode.

Here, when the controller10sets the inside-outside air intake mode, noise may transmit into the vehicle compartment from outside of the vehicle compartment when the inside-air door24opens the inside-air inlet202before the outside-air door23closes the inside-outside communication passage20a

As such, in the present embodiment, the controller10controls the drive mechanism30to operate the outside-air door23and the inside-air door24as shown inFIG. 7when setting the inside-outside air intake mode. That is, as shown inFIG. 7, the controller10moves the outside-air door23to open the outside-air inlet201and to close the inside-outside communication passage20aat step S10. Subsequently, at step S20, the controller10determines whether the outside-air door23closes the inside-outside communication passage20a. For example, the determination at step S20may be executed based on a factor such as a rotational angle of the door shaft25of the outside-air door23.

When the outside-air door23is determined not to close the inside-outside communication passage20aat step S20, the controller10waits for the outside-air door23to close the inside-outside communication passage20acompletely.

On the other hand, when the outside-air door23is determined to close the inside-outside communication passage20aat step S20, the controller10moves the inside-air door24to open the inside-air inlet202at step S30.

Here, in an environment in which the relative humidity Rh in the vehicle compartment is high in the inside-outside air intake mode, a window12of the vehicle may be fogged easier as the volume of the inside air increases. In contrast, in an environment in which the relative humidity Rh in the vehicle compartment is low in the inside-outside air intake mode, efficiency of the air conditioning in the inside-outside air intake mode may not be improved sufficiently.

Then, in the present embodiment, the controller10operates the inside-air door24so that an open area Sin of the inside-air inlet202changes depending on the relative humidity Rh in the vehicle compartment in the inside-outside air intake mode. The relative humidity Rh may be a detection value of the humidity sensor104. That is, in the present embodiment, the controller10operates the inside-air door24so that the open area Sin of the inside-air inlet202decreases as the relative humidity Rh in the vehicle compartment rises in the inside-outside air intake mode. In other words, in the present embodiment, the controller10operates the inside-air door24so that the open area Sin of the inside-air inlet202increases as the relative humidity Rh in the vehicle compartment decreases in the inside-outside air intake mode.

More specifically, in the present embodiment, the controller10operates the inside-air door24so that the open area Sin of the inside-air inlet202decreases in proportion to an increase of the relative humidity Rh in the vehicle compartment as shown inFIG. 8.

The inside-outside air switching unit2of the above-described present embodiment is configured to operate the outside-air door23to close the inside-outside communication passage20adefined in the inside-outside air case20in the inside-outside air intake mode. As such, noise from the outside of the vehicle compartment can be prevented from transmitting to the inside of the vehicle compartment through the inside-outside communication passage20a. Specifically, since the outside-air door23closes the inside-outside communication passage20ain the inside-outside air intake mode, the outside-air door23can change the volume of the inside air to take in by changing the open area Sin of the inside-air inlet202.

Therefore, the present embodiment can produce the inside-outside air switching unit2that is configured to take in both outside air and inside air in an inside-outside air intake mode while preventing noise from transmitting from an outside of a vehicle compartment to an inside of the vehicle compartment.

In addition, in the inside-outside air switching unit2of the present embodiment, the controller10operates the inside-air door24so that the open area Sin of the inside-air inlet202decreases as the relative humidity Rh in the vehicle compartment rises in the inside-outside air intake mode. As such, the volume of the inside air taken in can be reduced when the relative humidity Rh in the vehicle compartment is high. As a result, the window12of the vehicle can be prevented from being fogged due to an inflow of the inside air into the vehicle compartment. Further, the volume of the outside air taken in can be increased when the relative humidity Rh in the vehicle compartment is low. As a result, the air conditioning can be performed with high efficiency.

Moreover, in the inside-outside air switching unit2of the present embodiment, the inside-air door24is positioned to open the inside-air inlet202while the outside-air door23closes the inside-outside communication passage20ain the inside-outside air intake mode. Accordingly, the noise can be prevented from transmitting from outside of the vehicle compartment to inside of the vehicle compartment more efficiently in the inside-outside air intake mode.

Here, when the switching member22is formed of a single switching door, it may be difficult to adjust a ratio between an intake volume of the outside air and an intake volume of the inside air. For example, in a case where the switching member22is formed of a single switching door, the intake volume of the outside air may be reduced when the intake volume of the inside air is increased to reduce an air-conditioning load. As such, the window12of the vehicle may be fogged.

Then, in the present embodiment, the inside-outside air switching unit2includes the drive mechanism30that is formed of the first drive part31configured to operate the outside-air door23and the second drive part32configured to operate the inside-air door24. As such, the outside-air door23and the inside-air door24can be operated independently. Therefore, the intake volume of the outside air and the intake volume of the inside air can be adjusted separately.

In addition, in the present embodiment, the inside-outside air switching unit2is configured to set, as the air intake modes, the outside-air intake mode, the inside-air intake mode, and the inside-outside air intake mode selectively.

As such, the inside-outside air case20can select which air to take in in response to usage environment.

Second Embodiment

Next, a second embodiment will be described with reference toFIG. 9. The present embodiment is different from the above-described first embodiment in a correspondence relationship between the relative humidity Rh in the vehicle compartment and the inside-air inlet202in the inside-outside air intake mode.

In the present embodiment, the controller10operates the inside-air door24so that the open area Sin of the inside-air inlet202decreases gradually as the relative humidity Rh in the vehicle compartment rises in the inside-outside air intake mode as shown inFIG. 9. In other words, in the present embodiment, the controller10operates the inside-air door24so that the open area Sin of the inside-air inlet202increases gradually as the relative humidity Rh in the vehicle compartment decreases in the inside-outside air intake mode.

The remaining structures are the same as in the first embodiment. With the above-described configuration in the present embodiment, the same operational effects as in the first embodiment can be obtained.

Other Embodiments

The inside-outside air switching unit2of the present disclosure is described above with example embodiments. However, it should be understood that the inside-outside air switching unit2of the present disclosure is not limited to the above-described embodiments and may be modified, e.g., as follows.

As described above, in the above-described embodiments, the inside-outside air switching unit2is configured to change the open area Sin of the inside-air inlet202based on the relative humidity Rh in the vehicle compartment in the inside-outside air intake mode. However, the above-described embodiments are preferable example embodiments, and it should be understood that the present disclosure is not limited to the above-described embodiments. For example, the inside-outside air switching unit2may be configured to operate the inside-air door24so that the open area Sin of the inside-air inlet202is fixed in the inside-outside air intake mode.

As in the above-described embodiments, the inside-outside air switching unit2may be preferably configured to move the inside-air door24to open the inside-air inlet202while the outside-air door23closes the inside-outside communication passage20ain the inside-outside air intake mode. However, the present disclosure is not limited to such example embodiments. For example, the inside-outside air switching unit2may be configured to move the inside-air door24to open the inside-air inlet202before the outside-air door23closes the inside-outside communication passage20acompletely in the inside-outside air intake mode.

The inside-outside air switching unit2includes the first drive part31configured to operate the outside-air door23and the second drive part32configured to operate the inside-air door24preferably as in the above-described embodiments. However, the present disclosure is not limited to such example embodiments. For example, the inside-outside air switching unit2may be configured to operate one of the outside-air door23and the inside-air door24with a drive part and to operate the other of the outside-air door23and the inside-air door24with a link mechanism connected to the drive part.

The inside-outside air switching unit2may be preferably configured to set, as the air intake modes, the outside-air intake mode, the inside-air intake mode, and the inside-outside air intake mode selectively as in the above-described embodiments. However, the present disclosure is not limited to such example embodiments. For example, the inside-outside air switching unit2may be configured to switch between the outside-air intake mode and the inside-outside air intake mode. Alternatively, the inside-outside air switching unit2may be configured to switch between the inside-air intake mode and the inside-outside air intake mode.

The outside-air door23and the inside-air door24, serving as the switching member22, each is formed of a rotary door in the above-described embodiments. However, the outside-air door23and/or the inside-air door24may be formed of another door such as a cantilever door or a butterfly door.

When the outside-air door23and the inside-air door24are the same in shape as in the above-described embodiments, the outside-air door23and the inside-air door24can be used in common. However, the outside-air door23and the inside-air door24may be different from each other in shape.

The constituent element(s) of each of the above embodiments is/are not necessarily essential unless it is specifically stated that the constituent element(s) is/are essential in the above embodiment, or unless the constituent element(s) is/are obviously essential in principle.

Furthermore, in each of the above embodiments, in the case where the number of the constituent element(s), the value, the amount, the range, and/or the like is specified, the present disclosure is not necessarily limited to the number of the constituent element(s), the value, the amount, and/or the like specified in the embodiment unless the number of the constituent element(s), the value, the amount, and/or the like is indicated as indispensable or is obviously indispensable in view of the principle of the present disclosure.

Furthermore, in each of the above embodiments, in the case where the shape of the constituent element(s) and/or the positional relationship of the constituent element(s) are specified, the present disclosure is not necessarily limited to the shape of the constituent element(s) and/or the positional relationship of the constituent element(s) unless the embodiment specifically states that the shape of the constituent element(s) and/or the positional relationship of the constituent element(s) is/are necessary or is/are obviously essential in principle.

CONCLUSION

In a first aspect described in a part of or a whole of the above-described embodiments, the inside-outside air switching unit is configured to move the first switching door, which is one of the first switching door and the second switching door and is positioned between the outside-air inlet and the inside-air inlet, to close the inside-outside communication passage in the inside-outside air intake mode.

In a second aspect, the drive unit is configured to operate the second switching door so that the open area of the inside-air inlet decreases as the relative humidity in the vehicle compartment rises in the inside-outside air intake mode. As such, the intake volume of the inside air can be reduced when the relative humidity in the vehicle compartment is high. As a result, the window of the vehicle can be prevented from being fogged due to an inflow of the inside air into the vehicle compartment. In addition, when the relative humidity in the vehicle compartment is low, the intake volume of the outside air can be increased.

Here, when the controller sets the inside-outside air intake mode, noise may transmit into the vehicle compartment from outside of the vehicle compartment when the inside-air door opens the inside-air inlet before the outside-air door closes the inside-outside communication passage.

In contrast, in a third aspect of the present disclosure, the drive unit is configured to move the second switching door to open the inside-air inlet while the first switching door closes the inside-outside communication passage in the inside-outside air intake mode. Since the second switching door opens the inside-air inlet while the first switching door closes the inside-outside communication passage in the inside-outside air intake mode, noise can be prevented from transmitting from outside of the vehicle compartment to inside of the vehicle compartment in the inside-outside air intake mode more certainly.

Here, when the switching member is formed of a single switching door, it may be difficult to adjust the ratio between the intake volume of the outside air and the intake volume of the inside air. For example, in a case where the switching member is formed of a single switching door, the intake volume of the outside air may be reduced when the intake volume of the inside air is increased to reduce an air-conditioning load. As such, the window of the vehicle may be fogged.

Then, in a fourth aspect, the drive unit includes the first drive part configured to operate the first switching door and the second drive part configured to operate the second switching door. As such, the first switching door and the second switching door can be operated independently. Therefore, the intake volume of the outside air and the intake volume of the inside air can be adjusted separately.

In a fifth aspect, the drive unit is configured to move the first switching door to open the outside-air inlet and to move the second switching door to close the inside-air inlet in the outside-air intake mode in which the outside air is taken in. In the inside-air intake mode in which the inside air is taken in, the drive unit is configured to move the first switching door to close the outside-air inlet and to move the second switching door to open the inside-air inlet. Thus, the inside-outside air switching unit is configured to set, as the air intake modes, the outside-air intake mode, the inside-air intake mode, and the inside-outside air intake mode selectively. As such, the inside-outside air switching unit can select which air to take in in response to usage environment.