Patent Description:
Heating, ventilation and/or air conditioning units are designed to generate one or more temperature-controlled air streams. In cars, such units are used for the aeration and air conditioning of a car interior. Here, it is commonly possible for variable air streams, which may each have a different temperature, to be fed to different regions of the car interior. In order to adjust whether and how much air is fed to a region, the air streams to different regions of the car interior can be selectively blocked or allowed.

In a heating, ventilation and/or air conditioning unit, a cold air stream is generally available downstream of an evaporator, a proportion of which cold air stream is branched off and warmed by means of a heat exchanger. In this way, a cold air stream and a warm air stream which is separate from said cold air stream are obtained. In order for an air stream for the air conditioning of the car interior to be brought to a desired temperature, the two air streams can be mixed in a predefined mixing ratio.

In order to improve comfort for one or more car occupants, it is desirable for a car occupant to be able to set the temperature for different regions of the car interior to a desired temperature in a particularly exact manner. Document <CIT> discloses a heating, ventilation and/or air conditioning unit according to the preamble of claim <NUM>.

It is therefore an object of the invention to provide a heating, ventilation and/or air conditioning unit with which the temperature and the aeration in different regions of the car interior can be individually adjusted.

Said object is achieved according to the invention by means of a heating, ventilation and/or air conditioning unit for a car according to claim <NUM>. In particular, The heating, ventilation and/or air conditioning unit has a first air guide for guiding a first, cold air stream and having a second air guide for guiding a second, warm air stream which is separate from the first air stream, wherein a heating device for warming the second air stream is arranged in the second air guide. The heating, ventilation and/or air conditioning unit furthermore has a first mixing chamber, wherein the first air guide and the second air guide open into the first mixing chamber, and a second mixing chamber, wherein the first mixing chamber and the second air guide each have at least one inlet opening to the second mixing chamber. In the the second air guide, there is arranged a flap which is movable between a closed position, in which a flow path of the second air stream to the first mixing chamber is closed, and an open position, in which the second air stream can flow into the first mixing chamber, wherein the flap is arranged downstream of the heating device and at an inlet opening of the second air guide into the first mixing chamber. At the inlet opening of the first mixing chamber to the second mixing chamber and at the inlet opening of the second air guide to the second mixing chamber, there is arranged in each case one flap which is mounted so as to be movable between an open position and a closed position and which serves for selectively opening or closing the inlet openings, said flaps being kinematically coupled to one another such that said flaps can close the inlet openings to the second mixing chamber simultaneously.

By means of the heating, ventilation and/or air conditioning unit according to the invention, the cold air stream and the warm air stream can be mixed in the first mixing chamber in order to generate a mixed air stream. The mixed air stream and at least a proportion of the warm air stream can in turn be mixed with one another in the second mixing chamber. In this way, it is possible to generate two differently temperature-controlled air streams. By virtue of the flap being arranged downstream of the heating device and at the inlet opening of the second air guide into the first mixing chamber, it is possible for warm air from the second air guide to be fed to the second mixing chamber, whereas a warm air stream into the first mixing chamber is blocked. If the flap is in the closed position, only cold air from the first air guide is fed to the first mixing chamber. By means of the arrangement according to the invention of the flap in the second air guide, it is thus possible for the temperature of the mixed air that has been mixed in the two mixing chambers to be set in a particularly flexible manner.

The flap, in its closed position, preferably completely closes the inlet opening to the first mixing chamber, such that no warm air can flow into the first mixing chamber aside from small leakage streams.

The heating device is for example a heat exchanger. By means of a heat exchanger, the waste heat of an engine can be utilized to warm the air stream, such that the heating, ventilation and/or air conditioning unit is particularly energy-efficient. Alternatively or in addition, it is also possible for an electric heating element to be provided in order to heat the warm air stream particularly quickly. It is thus possible for a warm air stream to be immediately generated even directly after a cold start.

In the first air guide, there is preferably arranged a further flap which is movable between a closed position, in which a flow path of the first air stream to the first mixing chamber is closed, in particular completely closed, and an open position, in which the first air stream can flow into the first mixing chamber. In this way, a flow volume of the cold air stream into the first mixing chamber can also be adjusted. In this way, the temperature of the mixed air that has been mixed in the first mixing chamber can be set in a particularly flexible manner, in particular through corresponding control of the flap position.

The flap in the first air guide is also referred to as cold-air flap, and the flap in the second air guide is also referred to as warm-air flap.

Through corresponding positioning of the flaps at the inlet openings, it is thus possible for the mixing ratio of warm air and mixed air in the second mixing chamber to be set in a particularly manner. Both flaps may be closed if the second mixing chamber is not required. In the closed state of the flaps, the inlet openings may be completely closed, such that, aside from a small leakage stream, no air can flow through the inlet opening.

The two flaps can be moved by means of a single drive, in particular from the open position into the closed position and vice versa.

A position of the flaps can be controlled particularly easily by means of such a kinematic coupling.

More specifically, the two flaps may be kinematically coupled to one another such that the flaps are movable with one another oppositely in linear fashion or are movable with one another oppositely in non-linear fashion. This is possible by means of a corresponding design of an interposed mechanism, for example of the cam track of the cam mechanism. Such a coupling has the advantage that the setting of the flap positions relative to one another can be performed within certain specifications. This means that the setting possibilities for the two flaps relative to one another can be restricted, specifically such that only setting possibilities which are expedient from an energy aspect are allowed.

In one embodiment, the first mixing chamber has at least one outlet opening which leads to a car interior. In this way, the temperature-controlled mixed air can be fed to the car interior for the ventilation and temperature control thereof. For example, at least in each case one outlet opening to a windscreen, to a front seat, in particular to a driver's seat and a front passenger seat and/or to a rear seat bench may be provided.

At the at least one outlet opening, there is preferably likewise arranged a flap which is mounted so as to be movable between an open position and a closed position and which can close the associated outlet opening as required if no air stream is required in a car region associated with the outlet opening.

More specifically, the first mixing chamber may have separate channels to different interior regions, which channels are each closable by means of a dedicated flap.

Furthermore, the heating, ventilation and/or air conditioning unit may have an evaporator, wherein the first and the second air guide are arranged downstream of the evaporator. By means of the evaporator, the air can firstly be cooled before it enters the air guides. In particular, at the evaporator, an overall air stream is cooled to the temperature of the cold air stream. Said overall air stream can then be divided into the first and the second air guide.

The first air guide, the second air guide, the first mixing chamber and/or the second mixing chamber may be formed in a common housing. In this way, the heating, ventilation and/or air conditioning unit is of particularly compact form. Furthermore, in this way, the outlay for the assembly of the unit can be kept low. The housing is formed for example by multiple shells which are connected to one another.

The first air guide and the second air guide may in this case have a common partition at least in certain sections. This likewise contributes to a compact design of the unit.

The heating device and/or the evaporator are preferably accommodated in the common housing. This likewise contributes to a compact design of the heating, ventilation and/or air conditioning unit.

In order to set the position of all of the abovementioned flaps, the heating, ventilation and/or air conditioning unit may have an electronic control device which is designed to control the position of the movably mounted flaps. It is thus possible for a temperature profile desired by a car occupant to be set in the car interior.

Further advantages and features of the invention will emerge from the following description and from the appended drawings, to which reference is made. In the drawings:.

<FIG> shows a heating, ventilation and/or air conditioning unit <NUM> according to the invention for a car in a schematic sectional illustration. The heating, ventilation and/or air conditioning unit <NUM> serves for the aeration and air conditioning of a car interior.

The heating, ventilation and/or air conditioning unit <NUM> has a housing <NUM>, which is preferably manufactured from plastic.

The housing <NUM> has an inlet opening <NUM> and multiple outlet openings <NUM>, <NUM>, <NUM>, which lead to various air diffusers distributed in the interior.

An evaporator <NUM> is arranged in the region of the inlet opening <NUM>. More specifically, the evaporator <NUM> is arranged in the housing <NUM>.

Downstream of the inlet opening <NUM> and downstream of the evaporator <NUM>, the air guide channel <NUM> divides into a first air guide <NUM> for guiding a first, cold air stream and a second air guide <NUM> for guiding a second, warm air stream in the housing <NUM> formed. The first air guide <NUM> may also be referred to as cold-air guide, and the second air guide <NUM> may be referred to as warm-air guide.

The air guides <NUM>, <NUM> are formed at least in certain sections as channels and/or are formed at least in certain sections by walls of the housing <NUM>, along which the cold air stream and/or warm air stream can flow.

A heating device <NUM>, more specifically a heat exchanger, is arranged in the second air guide <NUM>. The heating device <NUM> is likewise arranged in the housing <NUM>.

Instead of a heat exchanger or in addition to this, the heating device <NUM> may also comprise an electric heating element.

The heating device <NUM> is dimensioned so as to completely fill a flow cross section of the second air guide <NUM> at the position at which the heating device <NUM> is arranged, aside from manufacturing-induced gaps in the peripheral region. This means that the entirety of the second, warm air stream must flow through the heating device.

The heating, ventilation and/or air conditioning unit <NUM> furthermore comprises a first mixing chamber <NUM> and a second mixing chamber <NUM>. The two mixing chambers <NUM>, <NUM> are likewise formed in the housing <NUM> but are separate from one another.

Here, the first air guide <NUM> is led past the heating device <NUM> and opens directly into the first mixing chamber <NUM> downstream of the heating device <NUM>.

The second air guide <NUM> furthermore has an inlet opening <NUM> to the second mixing chamber <NUM>. In other words, the second air guide <NUM> has a branch to the second mixing chamber <NUM>. Here, the inlet opening <NUM> is formed in a common wall <NUM> of the second air guide <NUM> and of the second mixing chamber <NUM>.

Furthermore, the first mixing chamber <NUM> has an inlet opening <NUM> to the second mixing chamber <NUM>.

Of the outlet openings <NUM>, <NUM>, <NUM>, two outlet openings <NUM>, <NUM> are formed in the first mixing chamber <NUM> and one outlet opening <NUM> is formed in the second mixing chamber <NUM>.

The two outlet openings <NUM>, <NUM> lead for example to different front regions in a car interior, such as a windscreen and a front seat, and conduct mixed air to said regions from the first mixing chamber <NUM>. In particular, the first mixing chamber <NUM> has separate channels <NUM>, <NUM> to different interior regions.

For example, the outlet opening <NUM> leads to a footwell and conducts mixed air to said footwell from the second mixing chamber <NUM>.

The second mixing chamber <NUM> has a smaller volume than the first mixing chamber <NUM>, because a smaller volume flow is required for air conditioning in a footwell of the car than in the other regions of the car interior.

It is optionally possible for yet further outlet openings to be provided if a yet further subdivision of the mixed air streams is desired.

In order to adjust the distribution of all air streams in the housing <NUM> and the feed of the mixed air streams to the car interior, multiple movably mounted flaps <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> are provided in the housing.

At the two inlet openings <NUM>, <NUM> to the second mixing chamber <NUM>, there is arranged in each case one flap <NUM>, <NUM> which is mounted so as to be movable between an open position and a closed position in order to selectively open or close the inlet openings <NUM>, <NUM>.

When the flap <NUM> is closed, the two mixing chambers <NUM>, <NUM> are separated from one another in terms of flow.

The two flaps <NUM>, <NUM> are kinematically coupled to one another, for example by means of a mechanism such as a cam mechanism <NUM>. Accordingly, both flaps <NUM>, <NUM> can be moved simultaneously through the actuation of a camshaft <NUM>. The cam mechanism <NUM> is illustrated purely schematically in <FIG>.

The two flaps <NUM>, <NUM> are kinematically coupled to one another such that the two flaps can close the inlet openings <NUM>, <NUM> to the second mixing chamber <NUM> simultaneously.

Here, the flaps <NUM>, <NUM> may be movable with one another oppositely in linear fashion or movable with one another oppositely in non-linear fashion. This is possible through corresponding design of the cam track of the cam mechanism <NUM> or generally of the mechanism.

Furthermore, a flap <NUM>, also referred to as cold-air flap, is arranged in the first air guide <NUM>. As viewed in a flow direction, the flap <NUM> is situated to the side of the heating device <NUM> and defines the opening to the first mixing chamber <NUM>.

Furthermore, a flap <NUM>, also referred to as warm-air flap, is arranged in the second air guide <NUM>. The flap <NUM> is arranged downstream of the heating device <NUM> and at an inlet opening <NUM> of the second air guide <NUM> into the first mixing chamber <NUM>.

Both the cold-air flap <NUM> and the warm-air flap <NUM> are movable from an open position into a closed position in order to adjust the air stream through the associated air guide <NUM>, <NUM>. In the closed position of the flap <NUM>, <NUM>, an air stream through the associated air guide <NUM>, <NUM> is preferably blocked completely, aside from small leakage streams.

Depending on the positioning of the flaps <NUM>, <NUM>, the temperature of the mixed air thus lies between the temperature of the cold air and the temperature of the warm air.

The flaps <NUM>, <NUM> are arranged at the outlet openings <NUM>, <NUM> and can be moved from an open position into a closed position in order to adjust or completely block an air stream through the outlet openings <NUM>, <NUM> to the car interior. In particular, the channels <NUM>, <NUM> to the various interior regions are each closable by means of the flaps <NUM>, <NUM>.

A further flap at the outlet opening <NUM> can be omitted, because an air stream through the outlet opening <NUM> can already be blocked by means of the flaps <NUM>, <NUM>.

The flaps <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> illustrated in <FIG> are exclusively so-called two-wing flaps, that is to say the flaps <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> have wings which intersect at the center of rotation and which extend to both sides beyond the center of rotation by a similar or equal length. Such a form of the flaps <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> has the advantage that a torque acting on the flaps <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> as a result of an air flow is considerably lower than that in the case of a single-wing flap. In particular, the resultant torque may be approximately zero. It is however also conceivable for one or more flaps to be designed as single-wing flaps.

In <FIG>, the flaps <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> are illustrated in each case in a closed position. For illustrative purposes, an open position of the flaps <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is additionally illustrated by dashed lines.

Below, the functioning of the heating, ventilation and/or air conditioning unit <NUM> will be discussed on the basis of <FIG>. Here, the various air streams are illustrated by arrows for the purposes of improved understanding.

When the heating, ventilation and/or air conditioning unit <NUM> is in operation, air flows through the inlet opening <NUM> into the housing <NUM>. Here, the air stream flows through the evaporator <NUM>, such that a cold overall air stream is generated.

This overall air stream can, in a manner dependent on the position of the flap <NUM>, be divided into the first, cold air stream and the second, warm air stream. In order to generate a cold air stream in the first air guide <NUM>, the flap <NUM> must be at least partially opened, such that air can flow into the first air guide <NUM>.

Here, the temperature of the cold air stream corresponds to the temperature of the overall air stream.

The warm air stream is generated by virtue of that part of the overall air stream which flows into the second air guide <NUM> flowing through the heating device <NUM> and, in the process, absorbing heat.

Subsequently, the cold air stream and optionally at least a proportion of the warm air stream can flow into the first mixing chamber <NUM>, wherein, in the mixing chamber <NUM>, the two air streams that have entered are merged again and thoroughly mixed. The volume of the warm air stream fed to the first mixing chamber <NUM> is in this case dependent on the position of the flap <NUM>. The temperature of the mixing air in the first mixing chamber can in this case be set to a desired temperature through corresponding adjustment of the respective volume of the warm air stream and of the cold air stream.

The temperature-controlled mixed air from the mixing chamber <NUM> can subsequently be fed via the outlet openings <NUM>, <NUM> to the car interior, if the flaps <NUM>, <NUM> are at least partially open, for the purposes of air conditioning of the associated regions of the car interior.

Additionally, mixed air can be generated in the second mixing chamber <NUM> by virtue of mixed air on the first mixing chamber <NUM> being fed to the second mixing chamber <NUM> via the inlet opening <NUM> and, additionally, warm air being branched off from the second air guide <NUM> and fed to the second mixing chamber <NUM> via the inlet opening <NUM>. It is thus possible, in the second mixing chamber <NUM>, for mixed air to be generated which has a temperature which differs from the temperature generated in the first mixing chamber <NUM>, wherein, in particular, the mixed air generated in the second mixing chamber <NUM> may be warmer than the mixed air generated in the first mixing chamber <NUM>.

Warm air from the second air guide can be fed to the second mixing chamber <NUM> even when the warm-air flap <NUM> is closed, because the flap <NUM> is arranged at the inlet opening of the second air guide <NUM> to the first mixing chamber <NUM>, and the inlet opening <NUM> of the second air guide <NUM> to the second mixing chamber thus lies within the second air guide <NUM>.

The mixed air from the second mixing chamber <NUM> can be fed via the outlet opening <NUM> to a further region of the car interior, in particular the footwell.

The two flaps <NUM>, <NUM> can both be completely closed. In this case, only the first mixing chamber <NUM> is used, and in this case the second mixing chamber <NUM> is inactive.

Claim 1:
A heating, ventilation and/or air conditioning unit (<NUM>) for a car, having a first air guide (<NUM>) for guiding a first, cold air stream and having a second air guide (<NUM>) for guiding a second, warm air stream which is separate from the first air stream, wherein a heating device (<NUM>) for warming the second air stream is arranged in the second air guide (<NUM>),
having a first mixing chamber (<NUM>), wherein the first air guide (<NUM>) and the second air guide (<NUM>) open into the first mixing chamber (<NUM>), and
having a second mixing chamber (<NUM>), wherein the first mixing chamber (<NUM>) and the second air guide (<NUM>) each have at least one inlet opening (<NUM>, <NUM>) to the second mixing chamber (<NUM>), and
wherein, in the second air guide (<NUM>), there is arranged a flap (<NUM>) which is movable between a closed position, in which a flow path of the second air stream to the first mixing chamber (<NUM>) is closed, and an open position, in which the second air stream can flow into the first mixing chamber (<NUM>), wherein the flap (<NUM>) is arranged downstream of the heating device (<NUM>) and at an inlet opening (<NUM>) of the second air guide (<NUM>) into the first mixing chamber (<NUM>),
wherein at the inlet opening (<NUM>) of the first mixing chamber (<NUM>) to the second mixing chamber (<NUM>) and at the inlet opening (<NUM>) of the second air guide (<NUM>) to the second mixing chamber (<NUM>), there is arranged in each case one flap (<NUM>, <NUM>) which is mounted so as to be movable between an open position and a closed position and which serves for selectively opening or closing the inlet openings (<NUM>, <NUM>), both flaps (<NUM>, <NUM>) being kinematically coupled to one another such that said flaps (<NUM>, <NUM>) can close the inlet openings to the second mixing chamber simultaneously.