Method and device for monitoring the service life of a filter

• US 6,894,620 B2
• Filed: 08/09/2002
• Issued: 05/17/2005
• Est. Priority Date: 08/17/2001
• Status: Expired due to Fees

• Current Assignee: Carl Freudenberg KG
• Original Assignee: Carl Freudenberg KG
• Inventors: Malig, Christoph, Borris, Richard, Reinhardt, Heinz
• Primary Examiner(s): PHAM, TOAN NGOC
• Application Number:
  US10/215,587
• Publication Number:
  US 20030052791A1
• Time in Patent Office: 1,012 Days
• Field of Search: 340/607, 340/606, 340/608, 340/611, 552/15, 552/74, 553/091, 553/853, 964/17, 964/18, 964/19, 95/23, 95/25
• US Class Current: 340/607
• CPC Class Codes: B01D 46/0086 Filter condition indicators
• CPC Class Codes: B01D 46/444 by flow measuring
• CPC Class Codes: B60H 2003/0683 the quality of the filter or the air being checked
• CPC Class Codes: B60H 3/0616 with provisions for replacing the filter element

Abstract

A method of monitoring the service life of a filter (1) in a filter system equipped with a fan, in particular a filter (1) in an air conditioning system of a motor vehicle, the instantaneous air speed (21) preferably being measured on each startup of the system using a sensor (2, 20) downstream from the filter (1), compared to the reference air speed (R) from the unloaded filter (1), and transmitted to a service computer and/or indicated on a display, and the need to replace the filter being signaled when this value falls below a predetermined threshold or threshold range of the instantaneous air flow rate (21).

Claims

1. A method of monitoring the service life of a filter (1) in a filter system equipped with a fan, comprising:

measuring the instantaneous air speed (21) using a sensor (2, 20) downstream from the filter (1), comparing it to the reference air speed (R) from the unloaded filter (1) and transmitting it to a service computer or indicating it on a display, wherein the need to replace the filter is signaled when this value drops below a predetermined threshold or threshold range of the instantaneous air speed (21), wherein the reference air speed for the filter system is determined during every new filter installation, the reference air speed calculated from a volumetric flow of air in the system.

2. The method according to claim 1, wherein the instantaneous air speed is measured on each startup of the system.

3. The system according to claim 2, wherein the reference air speed (R) is measured at a predetermined electrical voltage across the fan for the filter system.

4. The method according to claim 1, wherein the reference air speed (R) is measured at a predetermined electrical voltage across the fan for the filter system.

5. The method according to claim 1, wherein the sensor (2, 20) is connected to a warning light.

6. The method according to claim 1, wherein the sensor (2, 20) is connected to an acoustic warning signal.

7. The method according to claim 1, wherein it is possible to connect the sensor (2, 20) to the service computer of the motor vehicle or to the diagnostic system of a motor vehicle repair facility.

8. The method according to claim 1, wherein the sensor (2, 20) generates signals as a function of the electrical voltage across the sensor (2, 20).

9. A method of monitoring the service life of a filter (1) in a filter system equipped with a fan, comprising:

measuring the difference in the instantaneous air speed (21) using a sensor (2, 20) downstream from the filter (1), comparing this difference to a reference air speed from the unloaded filter (1), and transmitting it to a service computer or indicating it on a display, wherein the need to replace the filter is signaled when this value drops below a predetermined difference from a threshold or threshold range, wherein the reference air speed for the filter system is determined during every new filter installation, the reference air speed calculated from a volumetric flow of air in the system.

10. The method according to claim 9, wherein the difference in the reference air speed (R) is measured for two predetermined electrical voltages across the fan for the filter system.

11. The method according to claim 9, wherein the sensor (2, 20) is connected to a warning light.

12. The method according to claim 9, wherein the sensor (2, 20) is connected to an acoustic warning signal.

13. The method according to claim 9, wherein it is possible to connect the sensor (2, 20) to the service computer or the motor vehicle or to the diagnostic system of a motor vehicle repair facility.

14. The method according to claim 9, wherein the sensor (2, 20) generates signals as a function of the electrical voltage across the sensor (2, 20).

15. A device for monitoring the service life of a filter (1), comprising a sensor (2, 20) situated downstream from the filter (1), which measures the air speed of the air flow led through the filter (1), and transmits a drop in the air speed to a service computer or to a display as a function of the load state of the filter (1), wherein the device is configured to determine a reference air speed for the filter system during every new filter installation, the reference air speed calculated from a volumetric flow of air in the system.

16. The device according to claim 15, wherein the sensor (2) is attached to the filter (1).

17. The device according to claim 15, wherein the sensor (2, 20) is attached to a housing (9) which accommodates the replaceable filter (1).