U.S. patent application number 11/649917 was filed with the patent office on 2007-07-05 for method and device for detecting the state of an air filter of an air conditioning system.
This patent application is currently assigned to Hella KGaA Hueck & Co.. Invention is credited to Carsten Heilenkotter, Thomas Niemann.
Application Number | 20070151263 11/649917 |
Document ID | / |
Family ID | 37852346 |
Filed Date | 2007-07-05 |
United States Patent
Application |
20070151263 |
Kind Code |
A1 |
Niemann; Thomas ; et
al. |
July 5, 2007 |
Method and device for detecting the state of an air filter of an
air conditioning system
Abstract
A method and a device detects the state of an air filter in an
air conditioning system for the interior of a motor vehicle.
Condensed water created at the evaporator is discharged and fed to
a sensor, which determines a parameter of the condensed water, and
which, from a change or a certain value of the measured parameter,
draws a conclusion regarding a change of the state of the air
filter.
Inventors: |
Niemann; Thomas;
(Delmenhorst, DE) ; Heilenkotter; Carsten; (Weyhe,
DE) |
Correspondence
Address: |
WILLIAM COLLARD;COLLARD & ROE, P.C.
1077 NORTHERN BOULEVARD
ROSLYN
NY
11576
US
|
Assignee: |
Hella KGaA Hueck & Co.
|
Family ID: |
37852346 |
Appl. No.: |
11/649917 |
Filed: |
January 4, 2007 |
Current U.S.
Class: |
62/126 ;
62/317 |
Current CPC
Class: |
B60H 3/0616 20130101;
B60H 2003/0683 20130101; B60H 1/32331 20190501; B60H 1/3233
20130101 |
Class at
Publication: |
062/126 ;
062/317 |
International
Class: |
F25B 49/00 20060101
F25B049/00; F25D 17/04 20060101 F25D017/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 5, 2006 |
DE |
10 2006 000842.1 |
Claims
1. A method for detecting the state of an air filter in an air
conditioning system for the interior of a motor vehicle, comprising
the following steps: feeding condensed water created at an
evaporator of the air conditioning system to a sensor; detecting
with the sensor at least one physical characteristic of the water
represented by a value; and deriving a statement regarding the
state of the air filter from the value detected by the sensor.
2. The method according to claim 1, wherein the sensor detects a
change of an electric field.
3. The method according to claim 1, wherein the sensor detects a
changing oscillating behavior of a tuning fork.
4. The method according to claim 1, wherein the detected values are
checked regarding a temporal change of the detected value.
5. The method according to claim 1, wherein the detected value is
compared with a reference value.
6. A device for detecting the state of an air filter in an air
conditioning system for the interior of a motor vehicle,
comprising: a condensed water discharge; and a sensor disposed in
the condensed water discharge.
7. The device according to claim 6, wherein the sensor detects
physical characteristics of the water.
8. The sensor according to claim 6, wherein the sensor has a
capacity.
9. The device according to claim 6, wherein the sensor has an
interdigital resistor.
10. The device according to claim 6, wherein the sensor has a
tuning fork.
11. The device according to claim 6, wherein the sensor is disposed
in a container that is connected to the condensed water
discharge.
12. The device according to claim 11, wherein the sensor is a level
sensor.
13. An air conditioning system for a motor vehicle comprising: an
evaporator; a condensed water discharge disposed in an area of the
evaporator; and a sensor disposed in the condensed water
discharge.
14. A motor vehicle with an air conditioning system comprising: an
evaporator; an air filter; a condensed water discharge disposed in
the area of the evaporator; and a sensor disposed in the condensed
water discharge.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention pertains to a method for detecting the state
of an air filter in an air conditioning system for the interior of
a motor vehicle. Furthermore, the invention pertains to a
corresponding device for carrying out the method for detecting the
state of an air filter of an air conditioning system for the
interior of a motor vehicle and to an air conditioning system for a
motor vehicle.
[0003] 2. The Prior Art
[0004] Air filters, such as pollen filters or, in particular,
activated carbon filters, for example, are integrated in such air
conditioning systems. The problem with active carbon filters is
that even though the filters are superbly suitable for absorbing
pollutants, they only have a limited absorption capability. If an
active carbon filter reaches the limit of its absorption
capability, it begins to release pollutants, which it had already
absorbed. It is thus necessary to replace the filter before this
occurs. The filtering capability of other filters also decreases
after an extended operating time or the air resistance increases,
and the efficiency of the air conditioning system is impacted. It
is known from European Patent No. EP 0908341 B1 to detect a
parameter of the air, which passes through the filter, and to
compare this value with a reference value, and to determine
therefrom, whether or not the filter must be replaced.
SUMMARY OF THE INVENTION
[0005] It is therefore an object of the invention to provide a
method and a device of the above-mentioned type, with which a
particularly simple and reliable inspection is possible.
[0006] According to the invention, the state of an air filter in an
air conditioning system for the interior of a motor vehicle is
detected by supplying the condensed water created in the air
conditioning system to a sensor, which detects at least one
physical characteristic of the condensed water. From the value
detected by the sensor, there is derived a statement regarding the
state of the air filter. The invention realizes the idea that the
air absorbed from the environment in the air conditioning system or
the HVAC system is initially guided through a filter, for example a
pollen filter or an active carbon filter, and is then guided
through the evaporator of the air conditioning system, which cools
the temperature of the air. In so doing, moisture in the air
condenses at the evaporator and is discharged as condensed water.
This condensed water created downstream from the filter, which is
to be tested, thus contains an amount of pollutants or dirt
particles, which is directly correlated with the state of the
filter. It is thus proposed according to the invention, to test the
condensed water instead of the air, as this can be carried out in a
comparatively simple manner.
[0007] Preferably, the sensor detects a physical variable of the
condensed water or a parameter, which is determined by one or a
plurality of physical variables of the condensed water, such as
leak tightness, permeability, viscosity, and temperature, for
example. Preferably, an electric field is formed, which is
influenced by the condensed water, which is guided through this
electric field, and the sensor detects a change of the electric
field. In another preferred embodiment of the invention, the sensor
detects a changing oscillation behavior of an oscillating element
in the condensed water. A tuning fork, for example, is used for
this purpose. Other measuring methods for detecting parameters or
physical characteristics of the condensed water are also
possible.
[0008] In a preferred embodiment of the invention, the detected
value is tested with reference to a temporal change of the detected
value. In the alternative, the detected value is compared with a
reference value. A statement regarding the state of the filter is
then derived from the change of the detected value or from the
deviation from the reference value.
[0009] In the device for detecting the state of an air filter of an
air conditioning system for the interior of a motor vehicle with a
condensed water discharge, which carries out the above-mentioned
method, it is essential to the invention that a sensor for
determining a parameter of the condensed water is disposed in the
condensed water discharge.
[0010] Preferably, the sensor is disposed in the bottom area of a
container, which is filled with discharging condensed water. The
container, in turn, has a further discharge. Preferably, a level
sensor, which checks the level and thus ensures that the discharge
of the condensate occurs, is integrated in the container.
[0011] Preferably, the sensor detects physical characteristics of
the water, such as, in particular, the leak tightness, the
permeability, the viscosity, and the temperature or of a parameter,
which is influenced by these values, which, in turn, are again
influenced by the contents of the water and, in particular, by the
dirt particles. Preferably, the sensor comprises a capacity. Said
capacity can detect an electric field applied in the container or
its change. In another preferred embodiment, the sensor has an
interdigital resistor, which also detects an electric field applied
in the container or its change. Interdigital resistors essentially
consist of two conductors, which are isolated from one another,
which engage with protrusions offset in a duct-like manner. In
another preferred embodiment, the sensor comprises an oscillating
element, for example a tuning fork, the frequency behavior of which
is a function of the characteristics of the ambient condensed
water.
[0012] Another aspect of the invention is the provision of an air
conditioning system for a motor vehicle, that comprises an air
filter and a condensed water discharge at the evaporator, and a
sensor of the above-mentioned type is disposed in the condensed
water discharge. An additional aspect of the invention is that a
motor vehicle is provided with an air conditioning system that has
an air filter and a condensed water discharge at the evaporator,
and a sensor of the above-mentioned type is disposed in the
condensed water discharge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Other objects and features of the present invention will
become apparent from the following detailed description considered
in connection with the accompanying drawing. It is to be
understood, however, that the drawing is designed as an
illustration only and not as a definition of the limits of the
invention.
[0014] The sole FIGURE of the drawing illustrates a part of an air
conditioning system in a HVAC system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] The sole figure of the drawing illustrates a part of an air
conditioning system 1 in a HVAC system 1 (heating, ventilating, air
conditioning). In the right-hand area of this HVAC system 1, air is
supplied into the system via a supply 3 by means of a ventilator 2.
The system comprises a filter 4, an evaporator 5 of the air
conditioning system and, normally, a heat exchanger 6 for the
possible heating of the air, which is guided through. In the
left-hand area, the air is guided through ducts 11 to the fan
nozzles. In addition to the evaporator, the air conditioning system
itself comprises further, non-illustrated components, i.e. in
essence, a condenser, a pump for driving the cooling means, and a
compressor for condensing the cooling means. Typically, a discharge
7 for condensed water is disposed below evaporator 5 of the air
conditioning system. Said discharge fills a container 8, in which a
sensor 9 is disposed. Preferably, sensor 9 is disposed in the
bottom area. Sensor 9 measures a parameter of the condensed water,
which is influenced by the physical variables, such as leak
tightness, permeability, viscosity, and temperature of the
condensed water, and also by the dust or dirt content of the
condensed water. A predetermined change of the measuring value or a
predetermined deviation from a reference value is detected by a
corresponding electronic circuit and it derives therefrom a
statement regarding the state of the sensor. Preferably, the
electronic circuit is integrated in the housing of the HVAC system
1. Preferably, a level sensor, which ensures that the discharge of
the condensed water actually takes place via line 10, is also
disposed in the container 8.
[0016] Accordingly, while only a few embodiments of the present
invention have been shown and described, it is obvious that many
changes and modifications may be made thereunto without departing
from the spirit and scope of the invention.
* * * * *