System and method for cleaning a clogged HVAC drain duct

Abstract

The present disclosure relates to systems and methods for cleaning a clogged HVAC exhaust duct. A vehicle system is provided. The vehicle system may include a duct configured to provide an outlet for condensed water collected in an air chamber that connects a cabin duct to a ventilation manifold device. The vehicle system may also include a cleaning duct that bypasses the air chamber and connects the duct to the ventilation manifold device, and a controller configured to block a passage between the air chamber and the cabin duct and activate a blower of the ventilation manifold device to build pressure in the air chamber and the cleaning duct to clean the duct.

Description

Technical Field

[0001] The present disclosure relates to heating, ventilation, air conditioning, and circulation (HVAC) systems for motor vehicles and methods of operating the same. Background Art

[0002] Most vehicles are equipped with a cabin HVAC unit designed to transfer heat from the refrigerant and heated coolant to the air and blow the air to the vehicle cabin. The HVAC unit may include a heater core, an evaporator core, an air chamber, an air chamber blower, and other components. The air chamber may include a deflecting door and ducts that transfer air to various vents set in the vehicle cabin. When the door in the air chamber is rotated open or adjusted, the air flowing through the air chamber is distributed from one ventilation system to another ventilation system. When the heated air travels through the heater core and the evaporator core, the water vapor in the air around these cores can condense and collect in the bottom of the air chamber. The air chamber may include a drain pipe for discharging the condensed liquid. At this time, the drain pipe may be blocked and cause the condensed liquid to be unable to be discharged from the air chamber. Summary of the invention

[0003] According to one embodiment of the present disclosure, a method for cleaning a pipe is provided, the pipe being configured to provide an outlet for condensed water collected in an air chamber of a vehicle. The method is implemented by a controller and may include: blocking a passage between the air chamber and a cabin duct; activating a blower of a ventilation device to build up pressure in the air chamber and a cleaning duct bypassing the air chamber and connecting the pipe and the ventilation device, thereby cleaning an air chamber discharge duct connected to the air chamber.

[0004] The method may be initiated in response to a predetermined number of engine starts.

[0005] The blocking may include closing a defrost door disposed between the air chamber and the cabin duct.

[0006] The method may further include opening a fresh air circulation door connected to the ventilation manifold device to introduce air outside the vehicle into the air chamber and clean the duct before activating the blower of the ventilation device.

[0007] The method may further include closing a fresh air circulation door after activating the blower of the ventilation device to block a passage between the ventilation manifold device and the air inlet duct, thereby building up pressure in the clean duct and the air chamber.

[0008] The method may further include closing a mode door disposed between the air chamber and the cabin duct to prevent air from escaping from the air chamber, thereby building up pressure within the air chamber.

[0009] The method may further include, after the cleaning step, closing a cleaning duct door disposed in the cleaning duct to block air from passing through the cleaning duct and the tube.

[0010] According to one embodiment of the present disclosure, a vehicle HVAC device is provided. The device may include a tube, a cleaning duct, and a blower. The tube may be configured to provide an outlet for condensed water collected in an air chamber that connects a cabin duct to a ventilation manifold device. The cleaning duct may bypass the air chamber and connect the tube to the ventilation manifold device. The blower of the ventilation manifold device may be configured to build up pressure in the air chamber and the cleaning duct to clean the tube.

[0011] The device may also include a defrost door. The defrost door may be connected between the air chamber and the carriage duct. The defrost door can move between an open position and a closed position to facilitate the accumulation of pressure in the air chamber and the cleaning duct, thereby cleaning the duct.

[0012] The device may include a mode door. The mode door may be connected between the air chamber and the carriage duct. The mode door may be movable between an open position and a closed position. When the mode door is closed, the accumulation of pressure in the air chamber and the cleaning duct may be facilitated to clean the duct.

[0013] The device may include a fresh air door connectable to the ventilation manifold device. The fresh air door may be opened to facilitate air flow from the ventilation manifold device to the air chamber and the cleaning duct.

[0014] The device may include a fresh air circulation door. After the blower is activated, the fresh air circulation door may be closed to block the passage between the ventilation manifold device and the air inlet duct, thereby building up pressure in the clean duct and the air chamber.

[0015] According to another embodiment of the present disclosure, a vehicle system is provided. The vehicle system may include a pipe configured to provide an outlet for condensed water collected in an air chamber, the air chamber connecting a cabin duct to a ventilation manifold device. The vehicle system may also include a cleaning duct and a controller, the cleaning duct bypassing the air chamber and connecting the pipe and the ventilation manifold device, and the controller may be configured to: block the passage between the air chamber and the cabin duct, and activate a blower of the ventilation manifold device to build up pressure in the air chamber and the cleaning duct, thereby cleaning the pipe.

[0016] According to one embodiment of the present disclosure, the controller is further configured to: close a defrost door disposed between the air chamber and the cabin duct to prevent air from escaping from the air chamber, thereby further building up pressure in the air chamber.

[0017] According to an embodiment of the present disclosure, the controller is further configured to open a fresh air circulation door connected to the ventilation manifold device, wherein the opened fresh air circulation door is configured to facilitate the introduction of air outside the vehicle into the air chamber and the cleaning of the duct.

[0018] According to an embodiment of the present disclosure, the controller is further configured to: after activating the blower, close the fresh air circulation door to block the passage between the ventilation manifold device and the air inlet duct, thereby further building up pressure in the clean duct and the air chamber.

[0019] According to one embodiment of the present disclosure, the controller is further configured to: close a mode door disposed between the air chamber and the cabin duct to prevent air from escaping from the air chamber, thereby further building up pressure in the air chamber.

[0020] According to one embodiment of the present disclosure, the blocking and the enabling are responsive to a number of engine start events. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic illustration of a motor vehicle HVAC system in accordance with at least one embodiment of the present disclosure.

[0022] Figure 2 is a schematic illustration of a control system for a motor vehicle HVAC system.

[0023] Figure 3 is a flow chart for an apparatus illustrating a method of operating a motor vehicle HVAC system. DETAILED DESCRIPTION

[0024] As required, specific embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of the present invention, which may be implemented in various alternative forms. The drawings are not necessarily drawn to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to utilize the present invention in various forms.

[0025] Reference Figure 1, a schematic diagram of a vehicle HVAC system is shown. The HVAC system 10 may include a plenum 12, which may include or house a heater core or air conditioning evaporator core 14, and / or the plenum 12 may receive heated coolant from an engine or an auxiliary heat source (including but not limited to, refrigerant, electricity, etc.). An air mixing door 16 may be disposed between the heater core 14 and the evaporator core 18, and may be operated to change the position of one or more vents to control the amount of hot air and cold air in the plenum, thereby achieving a desired temperature in the vehicle cabin. A defrost door or defog door 20 and a mode door 22 are operably connected to the plenum. The defrost door or defog door 20 is disposed between the plenum 12 and a defrost nozzle 42. The panel mode door 22 is disposed between the plenum 12 and a plurality of outlet vents 40. More specifically, the defrost door or defog door is operably connected between the plenum and a vent 40 disposed in a vehicle dashboard near a vehicle windshield. When the defrost or defog door 20 is open, the defrost or defog door 20 allows heated or cooled air to flow from the air chamber to the vents 40. The mode door 22 is operable to open or close the passage for various heating or cooling settings. For example, when the occupant wishes to defrost the windshield, the defrost setting may be selected and the defrost or defog door 20 may be enabled to allow heated air to flow from the air chamber 12 to the vents 40 through the defrost or defog door 20.

[0026] As the heated air travels through the heater and air conditioning core 14, water vapor in the air around these cores can condense and collect in the bottom of the air chamber 12. When the vehicle is moving, the collected fluid can sway and shake within the air chamber 12. The movement of the fluid can upset the occupants of the vehicle compartment or cause annoying noises. In addition, if the fluid is kept in the air chamber 12 for an extended period of time, a moldy, stale or damp odor may be generated in the vehicle compartment, causing another customer annoyance. The air chamber 12 may include a drain 46 for draining the condensed liquid and preventing the noise and odor associated with the water collected in the air chamber 12. Sometimes, debris (including but not limited to blades, spider webs, screws or other parts within the HVAC unit 10) may accumulate in the drain 46, causing a blockage or obstruction.

[0027] The ventilation manifold 24 connects the plenum 12 to a ventilation device or blower assembly 31, which includes a blower volute 30, a fan 28, and a fan motor 26. The fan 28 can be driven by the fan motor 26. The fan motor 26 can be controlled from a controller 50 ( Figure 2) receives an electrical signal for opening and closing. In addition, the speed of fan 28 can be set at various rates between a minimum set value and a maximum set value. Fan 28 can be operably connected to air inlet duct 36. Blower volute 30 and filter 32 can be arranged between air inlet duct 36 and fan 28. However, the filter can be arranged in other positions other than the described position in the ventilation device or blower assembly. The blower volute can increase the energy of the air in the HVAC unit. Fresh air inlet door 34 can be arranged in air inlet duct 36. Fresh air inlet door 34 can be positioned in open position, closed position and any adjustable position between open position and closed position. When fresh air inlet door 34 is opened, fresh air inlet door 34 allows air to flow through air inlet duct 36 from fresh air opening 38 through fan 28.

[0028] A blockage cleaning duct or cleaning duct 44 may be disposed between the ventilation manifold 24 and the discharge duct 46. In the event that the discharge duct 46 is blocked or obstructed, the cleaning duct 44 may allow air generated by a fan to flow from the air inlet duct to the discharge duct 46 to clear the obstruction. A cleaning duct door 45 may be disposed within the cleaning duct 44. When air travels from the air inlet duct 36 to the air chamber 12, the door 45 may remain closed to prevent air from escaping through the duct 44. In the event that the discharge duct 46 is blocked or at specific time intervals, the door 45 may be opened to clean the blocked or obstructed discharge duct 46. The cleaning duct door 45 may be opened once a blockage is detected, or the cleaning duct door 45 may be opened at predetermined time intervals.

[0029] The ventilation manifold 24, the vents 40, the ducts and defrost nozzles 42, the plug cleaning duct or cleaning duct 44, the exhaust pipe 46 and the air inlet duct 36 can be made of various materials, including but not limited to ABS resin, polypropylene and SMA resin. These components can be produced by various processes such as blow molding or injection molding to form components with complex shapes and designs. These components can also be produced by other rapid manufacturing processes such as three-dimensional printing or other additive manufacturing technologies.

[0030] Reference Figure 2, a vehicle HVAC control system is shown. The control system may include a controller 50 electrically connected to various components of the HVAC system. The controller 50 may be a plurality of controllers communicating via a serial bus (e.g., a controller area network (CAN), FlexRay, Ethernet, etc.) or via a dedicated electrical conduit. The controller typically includes any number of microprocessors, microcontrollers, ASICs, ICs, volatile memory (e.g., RAM, DRAM, SRAM, etc.) and non-volatile memory (e.g., FLASH, ROM, EPROM, EEPROM, MRAM, etc.) and software code that cooperate with each other to perform a series of operations. The controller may also include predetermined data or "lookup tables" based on calculations and test data and stored in the memory. The controller may communicate with other vehicle systems and controllers via one or more wired or wireless vehicle connections using a universal bus protocol (e.g., CAN, LIN, Ethernet, etc.). The "controller" referred to herein refers to one or more controllers.

[0031] The controller 50 includes a data input 54 for receiving data regarding the status of the ignition system of the motor vehicle. The data input 54 may receive data indicating the speed of the engine (driving the vehicle) measured in revolutions per minute. The data input 54 may receive occupant status (including, but not limited to, the status of vehicle door locks, seat belt sensors, seat occupant sensors, or other suitable sensors capable of monitoring the presence of a motor vehicle occupant). In addition to the vehicle occupant status, the vehicle occupant may select a particular heating or cooling setting, including, but not limited to, defrost, defog, air conditioning, and heating. The dashboard vents 40, floor outlet vents, and rear outlets 48 ( Figure 1 ) can be opened to provide air to the cabin for various heating and cooling settings. The data input sensor 54 can also receive heating or cooling settings. The controller 50 can also receive multiple ignition switch on or ignition switch off events from the keyless entry device 52. The controller can calculate or determine the number of ignition switch on or ignition switch off events performed and compare the number to a predetermined value indicating a blocked exhaust pipe. In addition, the number of engine starts and stops can be compared to a predetermined value indicating that the exhaust is blocked. Finally, the data input 54 can receive data from the automotive technician for unblocking or cleaning the blocked exhaust pipe 46.

[0032] like Figure 2As further shown in FIG. 1 , the controller 50 is operably connected to the air mix door 16, the defroster door 20, the mode door 22, the fresh air inlet door 34 and their associated actuators (not shown). The actuators may include a small motor and one or more gear sets operably connected to the various doors mentioned above. The controller 50 is configured to shift the air mix door 16, the defroster door 20, the mode door 22 and the fresh air inlet door 34 between an open position and a closed position.

[0033] Reference Figure 3 , a flow chart 100 for a method of operating a vehicle HVAC system 10 is shown. In operation 102, the controller branches to determine whether there is a trigger condition for cleaning a clogged exhaust pipe. If not, the controller branches to operation 112, and the method ends. If yes, the controller branches to operation 104. In operation 104, the air mixing door 16, the defroster door 20, the mode door 22, and the fresh air inlet door 34 can be closed after receiving a signal from the controller 50. After operation 104, the air inlet door 34 is opened in operation 106. When the air inlet door 34 is opened, fresh air can be sucked from the fan 28 once the fan 28 is driven. In operation 108, the air mixing door 16 is set to full cooling mode. In full cooling mode, the fresh air inlet door 34 is closed. Closing the fresh air inlet door 34 can increase the pressure in the air chamber 12. In operation 109, the cleaning duct door 45 can be opened to facilitate air flow through the cleaning duct 44. In operation 110, the fan motor 26 and the fan 28 can be set to maximum speed. When at maximum speed, fan 28 forces air through air inlet duct 36, through purge duct 44, through exhaust duct 46 (eg, Figure 1 46 to clear any blockage within the discharge pipe 46.

[0034] It should be understood that Figure 3 The flowchart in FIG. 1 is for exemplary purposes only, and method 100 should not be construed as being limited to Figure 3 Some steps of method 100 may be rearranged, while other steps may be omitted entirely.

[0035] Although exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the present invention. More specifically, the words used in the specification are descriptive rather than restrictive, and it should be understood that various changes may be made without departing from the spirit and scope of the present invention. In addition, the features of the embodiments of each implementation may be combined to form further embodiments of the present invention.

Claims

1. A method for cleaning a tube configured to provide an outlet for condensed water collected in an air compartment of a vehicle, the method comprising the following steps performed by a controller: blocking the passage between the air chamber and the carriage duct; The blower of the ventilation device is activated to build up pressure in the air chamber and in a cleaning conduit bypassing the air chamber and connected between the tube and the ventilation device, thereby cleaning the tube connected to the air chamber.

2. The method according to claim 1, wherein: The blocking step is initiated in response to a predetermined number of engine starts.

3. The method according to claim 1, wherein: The blocking includes closing a defrost door disposed between the air chamber and the cabin duct.

4. The method according to claim 1, further comprising: Before activating the blower of the ventilation unit, open the fresh air circulation door connected to the ventilation unit to introduce air from outside the vehicle into the air chamber and clean the ducts.

5. The method according to claim 1, further comprising: After the ventilation unit's blower is activated, the fresh air circulation door is closed to block the passage between the ventilation unit and the air inlet duct, thereby further building up pressure in the clean duct and air chamber.

6. The method according to claim 1, further comprising: A mode door disposed between the air chamber and the carriage duct is closed to prevent air from escaping from the air chamber, thereby further building up pressure within the air chamber.

7. The method according to claim 1, further comprising: After the blower of the ventilation device is activated, a clean duct door disposed in the clean duct is closed to block air from passing through the clean duct and the tube.

8. A vehicle HVAC device comprising: a tube configured to provide an outlet for condensed water collected in a plenum connecting the cabin duct to the ventilation manifold assembly; a cleaning duct bypassing the plenum and connected between the tube and the ventilation manifold assembly; The blower of the ventilation manifold device is configured to build up pressure in the air chamber and the cleaning duct to clean the duct.

9. The vehicle HVAC device of claim 8 further comprising a defrost door connected between the plenum and the cabin duct and movable between an open position and a closed position to facilitate the buildup of pressure within the plenum and the duct to clean the duct.

10. The vehicle HVAC device of claim 8, further comprising a mode door connected between the air chamber and the cabin duct and movable between an open position and a closed position to facilitate the buildup of pressure within the air chamber and the cleaning duct to clean the duct.

11. The vehicle HVAC device of claim 8, further comprising a fresh air door connected to the ventilation manifold device, the fresh air door being configured to facilitate air flow from the ventilation manifold device to the plenum and the purge duct when opened.

12. The vehicle HVAC device of claim 11, wherein: The fresh air door is also configured to block a passage between the ventilation manifold assembly and the air inlet duct when closed to further build pressure within the clean duct and the air chamber. 13 . The vehicle HVAC device of claim 8 , further comprising a clean duct door disposed within the clean duct to block air from passing through the clean duct and the tube.

14. A vehicle system comprising: a tube configured to provide an outlet for condensed water collected in a plenum connecting the cabin duct to the ventilation manifold assembly; a clean duct bypassing the plenum and connected between said tube and the ventilation manifold assembly; A controller is configured to block the passage between the air chamber and the cabin duct and activate a blower of the ventilation manifold device to build pressure within the air chamber and the cleaning duct to clean the duct.

15. The vehicle of claim 14, wherein: The controller is further configured to perform the blocking and the enabling in response to a plurality of key-on events occurring.

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