Air conditioning unit for a motor vehicle

Abstract

Air conditioning unit (1) for air conditioning of at least two zones, wherein: - both zones have a warm air path (5,51) that passes through a heat exchanger (2), - both zones have a cold air path (4,41) that is routed past the heat exchanger (2), - an air stratification flap (142) is arranged downstream of the heat exchanger (2) in the direction of airflow, wherein a first air guide device (21) is provided downstream of the heat exchanger (2) in the direction of airflow, which directs warm air exiting the heat exchanger (2) towards the air stratification flap (142), wherein a MaxDefrost flap (17) is arranged downstream of the heat exchanger (2) in the direction of airflow, which divides the air exiting the heat exchanger (2) into two zones, wherein the MaxDefrost flap (17) has a second air guide device (171) which is arranged between the first air guide device (21) and the air stratification flap (142), characterized in that the second air guide device (171) is arranged at a distance from the MaxDefrost flap (17) and is connected to the MaxDefrost flap (17) by lateral webs. MaxDefrost flap (17) is connected.

Description

[0001] The invention relates to an air conditioning unit for a motor vehicle for air conditioning at least two zones.

[0002] Air conditioning systems for vehicles increasingly feature multiple zones to allow as many occupants as possible to individually adjust the temperature of their seats. A fan located within the air conditioning unit moves a mass airflow into and through the unit. As the airflow passes over the heat transfer surface of an evaporator in a refrigerant circuit, it is dehumidified and / or cooled. The airflow can then be split into a cold air path and a warm air path. The portion of the airflow routed through the warm air path is then passed over the heat transfer surface of a heat exchanger, which, in conventional air conditioning systems for vehicles with internal combustion engines, is typically a heat exchanger connected to the engine's coolant circuit.In vehicles with electric drive, the coolant can be heated electrically, or the heat exchanger can be designed as an electric heater. The warm air flow from the heat exchanger and the cold air flow from the evaporator, which is routed through the cold air path, are combined in a mixing chamber at a specific, adjustable mixing ratio, thus setting the temperature of the intake air for the passenger compartment.

[0003] Air conditioning units have multiple air outlets, for example, for the footwell and for vents in the dashboard. Having the same temperature at the footwell vents and the dashboard vents is often perceived as unpleasant, especially in warm weather; while cool air is desirable from the dashboard, it is often perceived as too cold in the footwell.

[0004] Therefore, the possibility of temperature stratification between the airflow directed towards the footwell and the air for the vents in the dashboard is desirable. For this purpose, an air stratification damper is provided in the warm air path of the air conditioning unit. This damper allows warm air from the heat exchanger to flow directly to the foot vents, thus enabling temperature stratification. However, if the temperature control is set to almost full cold, very little air flows through the heat exchanger. Of this small airflow, only a very small portion reaches the air stratification damper, so that even with the damper fully open, temperature stratification is hardly achieved.

[0005] From US patent 6,311,763 B1, a vehicle air conditioning system is known in which a first air passage, through which outside air flows, and a second air passage, through which inside air flows, are designed to be separate from one another such that outside air in the first air passage is conveyed from a front air outlet toward the front seat side of a passenger compartment after passing through a first part of a heat exchanger. The inside air in the second air passage is conveyed from a rear air outlet toward the rear seat side of the passenger compartment after passing through a second part of the heat exchanger. In this way, the temperature of the air drawn in through an inside air inlet in the second air passage can be adjusted to the temperature of the inside air in the passenger compartment, while the air pressure loss due to inside air suction is reduced.As a result, the air conditioning capacity for the rear seat side of the vehicle's air conditioning system is improved.

[0006] An air conditioning system with independent temperature control, in which the temperatures of the conditioned air are controlled independently of each other, is known from US 5 016 704 A.

[0007] WO 2016 / 194 674 A1 reveals a vehicle air conditioning system which, by means of specifically dimensioned communication openings and an integrated multi-purpose flap, delivers more air to the defroster in defroster mode despite separate rear airflow, while simultaneously minimizing temperature mixing and reducing the number of components in face / foot operation.

[0008] Further vehicle air conditioning equipment is described in JP 2015-182 733 A, US 2010 / 0 263 828 A1 and JP 2008 - 179 175 A. The object of the invention is therefore to propose an air conditioning device that creates a temperature stratification even when set to almost completely cold.

[0009] The problem is solved by an object having the features according to one of claims 1, 2 and 3. Further developments are specified in the dependent claims.

[0010] For the purposes of this patent application, the terms "subordinate" and "similar" are to be understood in terms of the airflow direction. The designations "above," "below," and "side by side" refer to the installed state of the air conditioning unit, with an xy-coordinate system arranged such that "above" lies in the positive y-direction and "side by side" in the x-direction.

[0011] The air conditioning unit according to the invention is suitable for air conditioning at least two zones. Most air conditioning units have an evaporator on the air inlet side, which cools and dehumidifies the incoming air. Downstream of this is a heat exchanger. This air is then divided into a warm air path and a cold air path for each zone to be air-conditioned.

[0012] Each warm air path passes through the heat exchanger. The cold air paths are routed around the heat exchanger. At least one cold air path passes over the heat exchanger, and at least one cold air path passes under it. The two warm air paths divide the heat exchanger into an upper and a lower section. The warm air path passing through the upper section of the heat exchanger then mixes with the cold air flow passing over the heat exchanger, and the warm air flow passing through the lower section of the heat exchanger mixes with the cold air flow passing under it.

[0013] The airflow through the lower section is usually assigned to a rear zone of the passenger compartment, i.e., one or more rear seats in a car, while the upper airflow serves at least one front seat. This division into an upper airflow (warm air path through the upper section of the heat exchanger and cold air path above the heat exchanger) and a lower airflow (warm air path through the lower section of the heat exchanger and cold air path below the heat exchanger) can also occur multiple times side by side. For example, two zones with an upper / lower division next to each other create a four-zone climate control system. This system has two front zones (warm air paths through the heat exchanger at the top left and top right, with the cold air paths above each), and two rear zones (warm air paths through the heat exchanger at the bottom left and bottom right, with the cold air paths below each).

[0014] The air conditioner has a damper for air stratification. This damper is located in the immediate vicinity of the heat exchanger to allow warm air from the heat exchanger to flow in. According to the invention, the air conditioner has a first air guide device located downstream of the heat exchanger and in the immediate vicinity of the heat exchanger. This first air guide device directs the airflow from the heat exchanger towards the damper for air stratification. Advantageously, by directing the warm airflow towards the air stratification damper, it can be ensured that even a very small warm airflow reaches the damper, thus enabling temperature stratification.

[0015] According to the invention, the air conditioning unit has a MaxDefrost flap downstream of the heat exchanger in the direction of airflow. The MaxDefrost flap forms the partition between the upper and lower warm air paths as the air exits the heat exchanger. For a defrost function, in which all available warm air is directed to the windshield to remove condensation or defrost it, the MaxDefrost flap can be opened. This allows warm air from the lower sections of the heat exchanger to also reach the windshield. According to the invention, a second air guide is provided on the MaxDefrost flap. This second air guide is arranged between the first air guide and the air stratification flap.Advantageously, the warm airflow is guided over a longer distance, allowing an even greater proportion of the warm airflow to reach the air stratification flap and enabling even greater temperature stratification. Positioning the second air guide on the MaxDefrost flap ensures that it does not obstruct the warm airflow during defrost operation, as the second air guide is removed from the warm airflow path when the MaxDefrost flap opens.

[0016] According to the invention, the second air guide is arranged at a distance from the MaxDefrost flap and connected to the MaxDefrost flap by lateral struts. Thus, the MaxDefrost flap and the second air guide form a channel that advantageously directs the air more effectively.

[0017] In a still preferred embodiment, the warm air path has a flap in the direction of airflow upstream of the heat exchanger.

[0018] Preferably, a third air guide is arranged between this flap of the warm air path and the heat exchanger. This directs the airflow even as it is supplied to the heat exchanger, further improving the possibility of temperature stratification. Particularly preferably, the third air guide is oriented such that the air is "transferred" through the heat exchanger to the first air guide downstream. In other words, the third air guide is oriented so that the first air guide is flush behind it, with the heat exchanger in between.

[0019] In a further preferred embodiment, the warm air flow flap has a central axis of rotation located in the horizontal x-direction. This orientation of the axis of rotation results in an upper and a lower opening when the flap is opened. A fourth air guide is arranged and shaped such that, at small opening angles of the warm air path flap, no air can flow above the axis of rotation, i.e., through the upper opening of the flap. This is achieved by shaping a portion of the air guide in a circular arc, so that when the warm air path flap opens, only a very small gap remains between the fourth air guide and the flap's edge. Advantageously, this results in a more directed (and minimal) warm air flow.Particularly preferred is the third air guide device also arranged in the lower area, so that the air entering through the lower opening of the flap is "taken over" by the third air guide device and led to the heat exchanger.

[0020] The fourth air guidance device is preferably designed such that up to an opening angle of approximately 15° of the flap of the warm air path or approximately 30% of the maximum opening angle of the flap of the warm air path, an inflow of air above the axis of rotation of the flap is prevented.

[0021] Furthermore, it is particularly advantageous that the first and third air guides extend horizontally across the entire width of the heat exchangers. This prevents airflow around the air guides.

[0022] In another preferred embodiment, the MaxDefrost damper and the air stratification damper are driven by a common kinematic mechanism. Compared to the known coupling between the MaxDefrost damper and a temperature damper, where the coupling mechanism always has to be routed around the heat exchanger in a complex manner, the coupling of the MaxDefrost damper with the air stratification damper is advantageously simple to implement, since both dampers are located close to each other.

[0023] The MaxDefrost flap and the air stratification flap are particularly well-suited to be coupled in such a way that the air stratification flap closes before the MaxDefrost flap opens. This advantageously ensures that no warm air is lost through the air stratification flap during defrost operation. Furthermore, it also prevents potential collisions between adjacent flaps, for example, due to malfunctions.

[0024] Furthermore, the coupling is preferably designed in such a way that the air stratification flap can only be reopened after the MaxDefrost flap has been closed.

[0025] Further details, features, and advantages of embodiments of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. These show: Fig. 1: A sectional view of an air conditioning unit according to the invention in normal operation, Fig. 2: An enlarged view of the warm air path during normal operation, Fig. 3: a 3D representation of the warm air path during normal operation, Fig. 4: a sectional view of an air conditioning unit according to the invention in defrost mode, Fig. 5: an enlarged view of the warm air path during defrost operation, and Fig. 6: a 3D representation of the warm air path in defrost mode.

[0026] Fig. Figure 1 shows a sectional view of an air conditioning unit 1 according to the invention. The air conditioning unit 1 is a four-zone air conditioning unit with two climate zones for the front seats of a passenger car and two climate zones for the rear seats. The sectional view in Fig. Figure 1 shows a section where the section plane is vertical, with the x-axis as the normal vector. The air conditioner 1 first passes the incoming air over an evaporator 3, which cools and dehumidifies the air. After the evaporator 3, the airflow splits into a cold air path 4 for the front zones of the air conditioner 1, a warm air path 5 for the front zones, and an air path for the rear zones, which is regulated by a temperature damper 15 and further divided into a warm air path 51 (rear zone) and a cold air path 41 (rear zone).

[0027] A heat exchanger 2 is located downstream of the evaporator 3. The warm air path 5 is routed through the heat exchanger 2. The warm air path 5 has a damper 162 upstream of the heat exchanger 2. The cold air path 4, which is routed over the heat exchanger 2, also has a damper 161. The air path for the rear zone is split by the temperature damper 15 into a warm air path 51, which is routed through the lower part of the heat exchanger 2, and a cold air path 41, which is routed under and around the heat exchanger 2. After exiting the heat exchanger 2, the warm air path 51 is routed under it, mixed there with the cold air path 41, and then exits through an air outlet 18 for the rear zone.A MaxDefrost flap 17 downstream of the heat exchanger 2 divides the warm air path 5 coming through the heat exchanger 2 according to the subdivision into warm air path front 5 and warm air path 51 rear in front of the entrance to the heat exchanger 2.

[0028] All illustrations shown are sectional views, so that only two zones, a front and a rear, are visible underneath.

[0029] In the area downstream of the heat exchanger 2, there is a mixing chamber 6 for the front zone, where the warm air flow 5 and the cold air path 4 meet and mix. From the mixing chamber 6, the air is distributed to the outlets of the air conditioning unit 1, namely to: - a defrost outlet 11 with associated defrost flap 111, which directs the air to the windshield, - an indirect outlet to the dashboard 12 with associated flap 121, - an outlet to the dashboard 13 with associated flap 131, and - a front footwell outlet 14 with associated flap 141 and additional air stratification flap 142.

[0030] Upstream of the footwell outlet 14 is a mixing area 143, in which the air from the air stratification flap 142 and the flap 141 for the front footwell outlet 14 mixes.

[0031] An air guide device 171 is arranged on the MaxDefrost flap 17. An air guide device 21 is also arranged at the outlet of the heat exchanger 2. The air guide devices 171 and 21 are arranged such that an airflow coming from the heat exchanger 2 is directed to the air stratification flap 142.

[0032] The warm air flap 162 at the front has a centrally located pivot axis 165, so that when opened, part of the airflow passes through the flap 162 above the pivot axis 165 and part below it. The flap 162 has an air guide 163 which, at a small opening angle of the warm air flap 162 at the front, prevents air from entering through the opening above the pivot axis 165. A further air guide 164 is arranged to direct the air flowing in below the pivot axis 165 of the warm air flap 162 directly to the heat exchanger 2. After passing through the heat exchanger 2, this airflow is then directed by the air guides 21 and 171 to the air stratification flap 142.

[0033] By directing the warm air to the air stratification flap 142, even with a low proportion of warm air and the associated small opening angle of the flap 162 for the warm air path at the front, a warm air flow can be directed to the air stratification flap 142, thus achieving a relevant temperature stratification between the front footwell outlet 14 and the outlets to the dashboard 12, 13.

[0034] Fig. Figure 2 shows a closer view of the warm air path 5. The opening position of the front warm air flap 162 is still so small that the air guide 163 almost completely prevents airflow over the front warm air flap 162, and the warm air path flows entirely into the lower part of the front warm air flap 162. There, it is directed by the air guide 164 directly to the heat exchanger 2 and from there by the air guides 21 and 171 to the air stratification flap 142. The portion of the warm air that does not flow into the air stratification flap 142 flows into the mixing chamber 6 and is available there for mixing the air for the outlets to the dashboard 13 and 12 and also for the flap 141 for the front footwell outlet 14.

[0035] Fig. 3 shows the representation from Fig. 1. Three-dimensional. The air guide devices 164, 163, 21, and 171 are clearly visible. The air guide device 171 has an air guide surface aligned largely parallel to the MaxDefrost flap 17, which is connected to the MaxDefrost flap 17 by lateral struts. The air guide devices 164 and 21 are flat, plate-shaped structures that extend across the entire width of the chamber, preventing air from flowing past them laterally.

[0036] In the Fig. 1, Fig. 2 to Fig. 3 is the air conditioning unit 1 in normal operation. This means that the defrost flap 111 is closed or only slightly open, the flaps 121, 131 for the dashboard vents are partially open, the air stratification flap 142 is open, allowing air at a higher temperature than the dashboard vents 13, 12 to be supplied to the front footwell vent 14. The flap 162 for the front warm air is slightly open, allowing only an airflow under the flap 162 to enter and be directed by the air guide 164 directly to the heat exchanger 2. After the heat exchanger 2, the now heated air is fed through the air guide device 21, which forms a channel towards the air stratification flap 142 with the MaxDefrost flap 17, and subsequently through the air guide device 171, which also forms a channel towards the air stratification flap 142 with the MaxDefrost flap 17, to the air stratification flap 142.The remaining warm air rises upwards in the y-direction into the mixing chamber 6. The temperature flap 15 for the rear zones is rotated so that the desired temperature is mixed and exits through the air outlet for the rear zone 18.

[0037] Fig. 4 shows the representation according to Fig. 1 in defrost mode. For this, the MaxDefrost flap 17 is folded downwards so that all the air flowing through the heat exchanger 2 flows upwards towards the mixing chamber 6. The warm air flap 162 at the front is fully open, allowing air to flow to the heat exchanger 2 both above and below the flap 162. The cold air flap at the front is fully closed. Similarly, the temperature flap for the rear zones is also positioned so that the warm air path 51 is fully open and the cold air path 41 is fully closed. The air guide 171, located on the MaxDefrost flap 17, has been moved downwards with the MaxDefrost flap 17 so that it does not obstruct the upward airflow in the y-direction. The cold air flap 161 at the front is fully closed.Likewise, flaps 121 and 131 for the dashboard outlets, as well as flap 141 for the front footwell outlet 14 and the air stratification flap 142, are completely closed. This ensures that the entire airflow from the evaporator 3 passes through the heat exchanger 2 and then to the defrost outlet 11, thus making all the warm air available from the air conditioning unit 1 available to a fogged or frozen windshield.

[0038] Fig. 5 and Fig. 6 show analogous representations to the Fig. 2 and Fig. 3 in defrost mode. Reference symbol list 1 air conditioner 2 heat exchangers 21 Air guidance system 3 evaporators 4 Cold air path 1st and 2nd zone 41 Cold air path 3rd and 4th zone 5 Warm air path 1st and 2nd zone 51 Warm air path 3rd and 4th zone 6 Mixing chamber 1st and 2nd zone 11 Defrost outlet 111 Defrost flap 12 Indirect dashboard outlet 121 Flap Outlet Dashboard Indirect 13 Dashboard outlet 131 Flap Outlet Dashboard 14 Front footwell outlet 141 Front footwell outlet flap 142 Air stratification flap 143 Mixing area front foot outlet 15 Rear temperature flap 161 Cold air flap front 162 Front warm air flap 163 Air guide device Warm air path 164 Air guide device flap warm air path 165° rotary axis flap warm air path 17 MaxDefrost flap 171 Air guide device MaxDefrost flap 18 air outlets for the rear zone

Claims

[1] Air conditioning unit (1) for air conditioning of at least two zones, wherein: - both zones have a warm air path (5,51) that passes through a heat exchanger (2), - both zones have a cold air path (4,41) that is routed past the heat exchanger (2), - an air stratification damper (142) is arranged downstream of the heat exchanger (2) in the direction of airflow, wherein a first air guide device (21) is provided downstream of the heat exchanger (2) in the direction of airflow, which directs warm air exiting the heat exchanger (2) towards the air stratification damper (142), wherein a MaxDefrost damper (17) is arranged downstream of the heat exchanger (2) in the direction of airflow, which divides the air exiting the heat exchanger (2) into two zones, wherein the MaxDefrost damper (17) has a second air guide device (171) which is arranged between the first air guide device (21) and the air stratification damper (142), characterized by , that the second air guide device (171) is arranged at a distance from the MaxDefrost flap (17) and is connected to the MaxDefrost flap (17) by lateral struts. [2] Air conditioning unit (1) for air conditioning of at least two zones, wherein: - both zones have a warm air path (5,51) that passes through a heat exchanger (2), - both zones have a cold air path (4,41) that is routed past the heat exchanger (2), - an air stratification damper (142) is arranged downstream of the heat exchanger (2) in the direction of airflow, wherein a first air guide device (21) is provided downstream of the heat exchanger (2) in the immediate vicinity of the heat exchanger (2), which directs warm air exiting the heat exchanger (2) towards the air stratification damper (142), wherein a MaxDefrost damper (17) is arranged downstream of the heat exchanger (2) in the direction of airflow, which divides the air exiting the heat exchanger (2) into two zones, wherein the MaxDefrost damper (17) has a second air guide device (171) which is arranged between the first air guide device (21) and the air stratification damper (142), wherein the warm air path (5) upstream of the heat exchanger (2) in the direction of airflow has a damper (162),wherein a third air guide device (164) is arranged between the flap (162) of the warm air path (5) and the heat exchanger (2), wherein the flap (162) of the warm air path (5) has a central axis of rotation (165) in the horizontal x-direction and a fourth air guide device (163) is arranged and shaped such that at small opening angles of the flap (162) of the warm air path (5) no air can flow into the warm air path (5) above the axis of rotation (165), and the air flowing in below the axis of rotation (165) is directed by the third air guide device (164) to the heat exchanger (2). [3] Air conditioning unit (1) for air conditioning of at least two zones, wherein: - both zones have a warm air path (5,51) that passes through a heat exchanger (2), - both zones have a cold air path (4,41) that is routed past the heat exchanger (2), - an air stratification damper (142) is arranged downstream of the heat exchanger (2) in the direction of airflow, wherein a first air guide device (21) is provided downstream of the heat exchanger (2) in the direction of airflow, which directs warm air exiting the heat exchanger (2) towards the air stratification damper (142), wherein a MaxDefrost damper (17) is arranged downstream of the heat exchanger (2) in the direction of airflow, which divides the air exiting the heat exchanger (2) into two zones, wherein the MaxDefrost damper (17) has a second air guide device (171) which is arranged between the first air guide device (21) and the air stratification damper (142), characterized by , that the MaxDefrost flap (17) and the air stratification flap (142) are driven via a common kinematics. [4] Air conditioning unit (1) according to claim 1, characterized by, that the warm air path (5) has a flap (162) in the direction of airflow in front of the heat exchanger (2), wherein a third air guide device (164) is arranged between the flap (162) of the warm air path (5) and the heat exchanger (2). [5] Air conditioning unit (1) according to claim 4, characterized by , that the flap (162) of the warm air path (5) has a central axis of rotation (165) in the horizontal x-direction and a fourth air guide device (163) is arranged and shaped such that at small opening angles of the flap (162) of the warm air path (5) no air can flow into the warm air path (5) above the axis of rotation (165), and the air flowing in below the axis of rotation (165) is directed by the third air guide device (164) to the heat exchanger (2). [6] Air conditioning unit (1) according to claim 2 or 5, characterized by, that the fourth air guide device (163) prevents air from flowing in over the axis of rotation (165) of the flap (162) of the warm air path (5) up to an opening angle of 15° of the flap (162). [7] Air conditioning unit (1) according to claim 2 or 5, characterized by , that the first air guide device (21) and the third air guide device (164) extend in the horizontal x-direction over the entire width of the heat exchanger (2). [8] Air conditioning unit (1) according to one of claims 2 or 5 to 7, characterized by , that the third air guide device (164) and the first air guide device (21) are arranged at the same height (y-direction) of the heat exchanger (2). [9] Air conditioning unit (1) according to claim 1, 2 or 4 to 8, characterized by , that the MaxDefrost flap (17) and the air stratification flap (142) are driven via a common kinematics. [10] Air conditioning unit (1) according to claim 3, characterized by, that the MaxDefrost flap (17) and the air stratification flap (142) are coupled such that the air stratification flap (142) is closed before the MaxDefrost flap (17) opens. [11] Air conditioning unit (1) according to claim 10, characterized by , that the air stratification flap (142) should only be reopened after the MaxDefrost flap (17) has been closed.

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