DPF failure detection method and DPF failure detection device

摘要

The present invention provides a DPF failure detection method and a DPF failure detection device, which can be realized with a simple configuration and detect a failure at low cost. The theoretical deposited amount of PM on a DPF 4 is calculated from the operating state of an internal combustion engine 2. The actual deposited amount of the PM on the DPF 4 is measured based on the electrical capacitance of an electrical capacitance type PM sensor 6. When the divergence of the actual deposited amount from the theoretical deposited amount exceeds an allowable limit, it is determined that the DPF 4 has a failure.

主权项

1. A diesel particulate filter (referred to as “DPF” hereinafter) failure detection method for detecting a failure in a DPF that is arranged in an exhaust pipe guiding exhaust gas from an internal combustion engine to the atmosphere,
the DPF failure detection method comprising: calculating a deposited amount (referred to as “theoretical deposited amount” hereinafter) of a particulate matter (referred to as “PM” hereinafter) deposited on the DPF from an operating state of the internal combustion engine; measuring a deposited amount (referred to as “actual deposited amount” hereinafter) of the PM on the DPF based on an electrical capacitance of an electrical capacitance type PM sensor configured by two electrodes disposed in the DPF; and determining that the DPF has a failure, when a divergence of the actual deposited amount from the theoretical deposited amount exceeds an allowable limit.