PARTICULATE MATTER DETECTION SENSOR

• US 20120085146A1
• Filed: 09/23/2011
• Published: 04/12/2012
• Est. Priority Date: 10/12/2010
• Status: Abandoned Application

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: MAEDA, Eriko, Kimata, Takehito
• Application Number:
  US13/242,210
• Publication Number:
  US 20120085146A1
• Time in Patent Office: Days
• US Class Current: 73/23.31
• CPC Class Codes: F01N 13/008 Mounting or arrangement of exhaust sensors in or on exhaust apparatus sensor arrangements for engine control F02D41/1439
• CPC Class Codes: F01N 2560/05 the means being a particulate sensor
• CPC Class Codes: F01N 2560/20 Sensor having heating means
• CPC Class Codes: G01N 15/0656 using electric, e.g. electrostatic methods or magnetic methods by investigating individual particles G01N15/1031, G01N15/12
• CPC Class Codes: G01N 27/043 of a granular material

Abstract

A PM-sensor having a sensor element is provided to an exhaust pipe. The sensor element has a concaved chamber on a particulate matter detection surface of an insulating substrate body, and a detection electrode formed on a bottom surface of the chamber. An insulating protecting layer covers an upper opening of the concaved chamber. The insulating protecting layer has a plurality of penetrating holes through which only particulate matter to be detected can passes.

Claims

1. A particulate matter detection sensor comprising:

a sensor element having an insulating substrate body on which a detection electrode is provided for detecting a particulate matter contained in a subject measured gas, wherein

the sensor element has a particulate matter detector portion which includes a detection surface on a surface of the insulating substrate body;

a concaved chamber on the detection surface;

the detection electrode provided on a bottom surface of the concaved chamber; and

an insulating protecting layer covering the concaved chamber, and

the insulating protecting layer has a plurality of penetrating holes through which only particulate matter to be detected can pass.

2. A particulate matter detection sensor according to claim 1, wherein

a diameter of the penetrating holes is not greater than 10 μ

m.

3. A particulate matter detection sensor according to claim 1, wherein a diameter of the penetrating holes is not greater than 2.5 μ

m.

4. A particulate matter detection sensor according to claim 1, wherein

a distance between the detection electrodes and the insulating protecting layer is greater than a diameter of the particulate matter which is detected.

5. A particulate matter detection sensor according to claim 1, wherein the insulating protecting layer is a ceramic layer having the penetrating holes or a porous ceramic layer.

6. A particulate matter detection sensor according to claim 1, wherein

the insulating protecting layer is mainly made of oxide ceramics, carbide ceramics, or nitride ceramics.

7. A particulate matter detection sensor according to claim 1, wherein the penetrating holes are comprised of multiple kinds of holes each of which diameter is different from each other, and a pair of electrodes is provided to each kind of holes.

8. A particulate matter detection sensor according to claim 1, wherein

the sensor element is accommodated in a cover having an aperture and is disposed in an exhaust pipe of an internal combustion engine, and

the particulate matter detector portion is disposed in such a manner as to be exposed to an exhaust gas emitted from the engine.

9. A particulate matter detection sensor according to claim 1, wherein

the sensor element has a heater portion including a heater electrode for heating the particulate matter detection portion.