Device for indicating fuel filter clogging in internal combustion engines, particularly diesel engines

• US 7,552,626 B2
• Filed: 03/23/2005
• Issued: 06/30/2009
• Est. Priority Date: 04/09/2004
• Status: Expired due to Fees

• Current Assignee: UFI Filters SpA (Giorgio Girondi)
• Original Assignee: UFI Filters SpA (Giorgio Girondi)
• Inventors: Girondi, Giorgio
• Primary Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US10/594,958
• Publication Number:
  US 20080264153A1
• Time in Patent Office: 1,560 Days
• Field of Search: 731/143.1, 731/143.8, 731/144.1, 731/144.2, 731/144.3
• US Class Current: 73/114.38
• CPC Class Codes: B01D 29/232 with corrugated, folded or wound sheets
• CPC Class Codes: B01D 29/606 by pressure measuring
• CPC Class Codes: B01D 35/143 Filter condition indicators
• CPC Class Codes: F02M 37/40 with means for detection of clogging

Abstract

A device for indicating clogging of the fuel filter (1) of internal combustion engines, in particular diesel engines, the filter having an outer casing (2) closed by a cover (3) of amagnetic material, and a filter element (5) which, together with a disc (30) to which it is connected, defines two chambers (6and 7) for fuel entry and exit respectively; the device further includes a pressure sensor (10) sensing the difference between the entry and exit fuel pressure and housed inside the filter casing, and a sensor (21) for generating a signal proportional to the pressure difference which is located outside the filter casing and is not mechanically connected to the pressure sensor.

Claims

1. A fuel filter comprising a device for indicating clogging of the fuel filter of internal combustion engines, the filter comprising an outer casing closed by a cover of amagnetic material, and a filter element which, together with a disc to which said filter element is connected, defines two chambers for fuel entry and exit respectively, said device comprising a pressure sensor means sensing the difference between the entry and exit fuel pressure and housed inside the filter outer casing, and a means for generating a signal proportional to said pressure difference which is not mechanically connected to the pressure sensor means and is located outside the filter casing, characterised in that the pressure sensor means comprises an elastically deformable element which defines a variable volume inside the fuel entry or exit chamber;

a conduit which connects said volume to the other chamber; and

a magnet which, associated with said elastically deformable element, moves to follow the elongation or contraction of said elastically deformable element, whereby said elastically deformable element is composed of an extendable membrane.

2. An indicator device to be used in connection with the filter as define in claim 1.

3. The filter as claimed in claim 1, characterised in that said pressure sensor means is housed in the fuel entry chamber.

4. An indicator device to be used in connection with the filter as define in claim 3.

5. The filter as claimed in claim 1, characterised in that said elastically deformable element is fixed to the filter element connection disc.

6. An indicator device to be used in connection with the filter as define in claim 5.

7. The filter as claimed in claim 1, characterised in that said conduit is a through hole passing through the thickness of the element connection disc, in correspondence with said elastically deformable element.

8. An indicator device to be used in connection with the filter as define in claim 7.

9. The filter as claimed in claim 1, characterised in that said signal generating means comprise:

a Hall sensor sensitive to the magnetic field of the magnet of the pressure sensor means, and a processor for processing the voltage signal generated by the Hall sensor.

10. An indicator device to be used in connection with the filter as define in claim 9.

11. The filter as claimed in claim 1, characterised in that the signal generating means is positioned on the filter cover.

12. An indicator device to be used in connection with the filter as define in claim 11.