Isuzu Motors Limited

Isuzu Motors Limi Ted

Isuzo Motors Limited

Tadashi Uchiyama

Satoshi Hanawa

Naoto Murasawa

Hidekazu Fujie

Mitsuhiro Aso

Masafumi Noda

Suzuhiro Saiki

Tomoaki Kakihara

Hideki Nemoto

Futoshi Nakano

Kenji Fujii

Teruo Nakada

Kazuo Oosumi

Takayuki Furukawa

Kazuo Ohsumi

Keisuke Nakamura

This particulate matter (PM) sensor is provided with a porous body that has a partition disposed in a passage for exhaust gas including particulate matter, at least a pair of electrodes that oppose each other in a prescribed direction so as to sandwich the porous body, and a deposition part that includes the surface of the partition on the upstream side of the passage, has the particulate matter deposited thereon, and has, formed therein, pores having an average pore diameter smaller than the average pore diameter of the portion of the partition other than the deposition part.

Particulate matter (PM) sensor for detecting quantity of PM in exhaust gas from e.g. diesel engine

There is provided a first PM sensor provided upstream of a filter and including a first sensor filter having a plurality of first cells collecting PM in the exhaust gas to be introduced into the filter, and a first pair of electrodes arranged to face each other with the first cell interposed therebetween, a second PM sensor provided downstream of the filter and including a second sensor filter having a plurality of second cells collecting PM in the exhaust gas discharged from the filter, and a second pair of electrodes arranged to face each other with the second cell interposed therebetween, and a filter state determination unit for acquiring an efficiency of collecting the PM in the filter, based on a first electrostatic capacitance between the first pair of electrodes and a second electrostatic capacitance between the second pair of electrodes.

Exhaust purification device

There is provided the diagnostic device for a sensor which is arranged in an exhaust passage of an internal combustion engine and detects a particulate matter amount in exhaust, the diagnostic device including a time-rate-of-change calculation unit which calculates a time rate of change of the particulate matter amount detected by the sensor during a period in which a fuel injection amount of the internal combustion engine is equal to or less than a predetermined injection amount threshold, and an abnormality determination unit which determines an abnormality of the sensor based on the time rate of change of the particulate matter amount calculated by the time-rate-of-change calculation unit.

Diagnostic device and sensor

The sensor includes: a collection partL,M,S in which a plurality of filter members for collecting particulate matter in exhaust gas are arranged in descending order of porosity from an exhaust upstream side to an exhaust downstream side of the exhaust gas; a pair of electrodeswhich is arranged to each of the plurality of filter membersL,M,S and facing each other with the plurality of filter members interposed therebetween; and estimation meanstofor estimating a particulate matter amount collected on each of the plurality of filter members having different porosities based on a capacitance change amount between the pair of electrodes

Sensor for detecting an emission amount of particulate matter

The PM sensor includes: a filter member having a plurality of measuring cells which are defined by a porous partition wall and configured to trap particulate matter in exhaust gas; at least a pair of electrode members which are disposed to face each other with the measuring cell sandwiched therebetween to form a condenser; a heater member which heats the measuring cell to burn and remove particulate matter accumulated in the measuring cell; and an estimation unit which estimates an amount of the particulate matter contained in the exhaust gas based on an electrostatic capacity between the pair of electrode members.

Sensor

The sensor includes a filter member including cells that trap PM in exhaust gas, electrode members arranged to face each other with the cell interposed and forming a capacitor, an electric heater that executes, when an amount of PM has accumulated in the cells, filter regeneration for combusting and removing the PM, a temperature sensor that acquires the temperature of the filter member, a storage unit that stores therein a reference temperature, which is the temperature of the filter member where the filter regeneration has been executed in a state in which PM is not flowing into the filter member, and estimation units that estimate a PM amount included in the exhaust gas based on (a) an electrostatic capacitance change amount between the electrode members during a regeneration interval and (b) a difference between the temperature acquired by the temperature sensor and the reference temperature during a filter regeneration interval.

Particulate matter (PM) sensor

The sensor includes a filter member including cells that trap PM in exhaust gas; electrode members arranged to face each other with the cell interposed and forming a capacitor, an electric heater that executes, when an amount of PM has accumulated in the cells, filter regeneration of heating the cells to combust and remove the PM, a storage unit that stores a reference reduction amount, which is an electrostatic capacitance reduction amount between the electrode members in a case where the filter regeneration is executed in a state where the PM is not flowing into the filter member, and estimation units that estimate a PM amount based on (a) an actual electrostatic capacitance change amount between the electrode members during a regeneration interval period, and (b) a difference between an actual electrostatic capacitance reduction amount between the electrode members and the reference reduction amount during a filter regeneration period.

An exhaust purification system includes: a diesel oxidation catalyst (DOC) provided on an exhaust path of an engine; an upstream diesel particulate filter (DPF) and a downstream DPF that are provided on the exhaust path at positions downstream of the DOC to collect particulate matter contained in exhaust gas; electrodes that detect a capacitance of the upstream DPF; a particulate matter accumulation estimating unit that estimates at least an amount of particulate matter accumulated in the downstream DPF on the basis of the capacitance received from the electrodes; and a forced regeneration control unit that injects fuels into the DOC and performs forced regeneration that burns and removes at least the particulate matter accumulated in the downstream DPF when the estimated amount of particulate matter from the particulate matter accumulation estimating unit surpasses a predetermined amount.

Exhaust purification system

A diagnosis device includes: a diesel particulate filter (DPF) collecting particulate matter (PM) in exhaust gas; a resistive type PM sensor provided downstream of the DPF, detecting an amount of PM from current flowing through PM deposited between electrodes. An actual regeneration interval calculator calculating an actual interval from completion of regeneration of the sensor to a start of the next regeneration; a PM slippage amount calculator estimating an amount of PM slippage in exhaust gas that slips through the DPF, assuming the DPF is normal; an estimated regeneration interval calculator calculating, on the basis of the PM slippage amount, an estimated interval from completion of the regeneration of the sensor to the start of the next regeneration; and a DPF failure-normal determination device determining whether the DPF has failed or is normal by comparing the actual interval to the estimated interval.

Diagnosis device

An exhaust gas purification device, including a diesel particulate filter ('DPF') for collecting particulate matter contained in an exhaust gas, a forced regeneration unit or performing forced regeneration, a capacitance detection unit for detecting a capacitance of the DPF, a total accumulated amount estimation unit for estimating a total amount of accumulated particulate matter and ash collected in the DPF on the basis of the detected capacitance, and an ash accumulated amount calculation unit for calculating an amount of accumulated ash by using, as the amount of accumulated ash, the total amount of accumulation which is estimated when the forced regeneration finishes.

A particulate matter measuring device includes: a diesel particulate filter (DPF) in which upstream side and downstream side openings of multiple cells partitioned by porous partition walls are alternately plugged; a pair of first electrodes received in a pair of first electrode cells arranged diagonally with a central cell therebetween; a pair of second electrodes received in a pair of second electrode cells arranged diagonally with the central cell therebetween; a first connecting member for connecting the first electrodes to each other; a second connecting member for connecting the second electrodes to each other; and a unit that calculates an amount of particulate matter trapped in the DPF on the basis of capacitance between the electrodes. The four cells which are adjacent to each other around the partition walls of the central cell and sandwiched between the first electrode cells and the second electrode cells are used as measurement cells.

Particulate matter measurement device

A diagnostic device includes: a diesel oxidation catalyst (DOC) for oxidizing hydrocarbon (HC) and nitrogen monoxide in an exhaust gas; a selective catalytic reduction (SCR) catalyst for reducing and purifying NOx contained in the exhaust gas; a NOx purification rate calculation unit which calculates, based on NOx values at upstream and downstream sides of the SCR catalyst, a low temperature NOx purification rate and a high temperature NOx purification rate; a HC heat generation rate calculation unit which calculates an HC purification rate based on at least the difference between the exhaust gas heat quantities at upstream and downstream sides of the DOC; and a deterioration determination unit which determines the deterioration in the NOproducing capability of the DOC based on the calculated low temperature NOx purification rate, the calculated high temperature NOx purification rate, and the calculated HC purification rate.

Diagnostic device for an oxidation catalyst

A diagnosis device diagnoses a cooler adapted to cool a fluid flowing through intake and exhaust systems of an engine, and includes: a downstream temperature sensor for detecting a fluid temperature downstream of the cooler; a fluid temperature calculation unit for calculating a fluid temperature upstream of the cooler based on a fluid state quantity; a sensor output value calculation unit for assuming an upstream temperature sensor configured to detect a fluid temperature upstream of the cooler, reflecting a sensor response delay in the calculated fluid temperature, and calculating an estimated sensor output value of the upstream temperature sensor; and a cooler diagnosis unit for diagnosing the cooling efficiency of the cooler based on an actual sensor input value entered from the downstream temperature sensor and the calculated estimated sensor output value.

An exhaust purification system includes: a diesel oxidation catalyst (DOC) provided on an exhaust passage of an engine; a diesel particulate filter (DPF) provided on the exhaust passage at a position downstream of the DOC to collect particulate matter contained in exhaust gas; electrodes that detect a capacitance of the DOC; a particulate matter accumulation estimating unit that estimates an amount of particulate matter accumulated in the DPF on the basis of the detected capacitance; and a forced regeneration control unit that injects fuel into the DOC and performs forced regeneration that burns and removes at least the particulate matter accumulated in the DPF when the estimated accumulated particulate matter amount surpasses a predetermined amount.

An exhaust gas purification device includes a diesel particulate filter (DPF) for capturing particulate matter (PM) in an exhaust gas, a selective catalytic reduction (SCR) device for reducing NOx in the exhaust gas, detecting units for detecting the DPF electrostatic capacity, an estimating unit for estimating the inside temperature of the DPF based on the electrostatic capacity, and a controlling unit for executing forced DPF regeneration. A lower limit temperature is defined as a temperature to trigger PM combustion, and an upper limit temperature is defined as a temperature to avoid filter erosion. The controlling unit executes the forced regeneration with an amount of fuel supplied for causing the inside temperature to reach the lower limit temperature, when the inside temperature is at or above the SCR activation temperature, and executes the forced regeneration with another amount of fuel supplied for causing the inside temperature to reach the upper limit temperature, when the inside temperature is below the SCR activation temperature.

Growing community of inventors

Kamakura, Japan

Tadashi Uchiyama