PARTICULATE MATTER DETECTION SENSOR AND CONTROL DEVICE OF CONTROLLING THE SAME
First Claim
1. A control device of controlling a particulate matter detection sensor placed in an exhaust gas pipe of an internal combustion engine through which exhaust gas emitted from the internal combustion engine flows and discharged to the outside, the particulate matter detection sensor having a particulate matter sensor element comprised of an insulation substrate, a detection part composed of a pair of detection electrodes formed on a surface of the insulation substrate, and a heater part of generating heat energy when receiving electric power in order to heat the detection part at a predetermined temperature,the control device comprising a control part which detects an electrical resistance value between the pair of the detection electrodes in the detection part, the electrical resistance value between the pair of the detection electrodes in the detection part changing in accordance with a change of quantity of particulate matter accumulated in the detection part, and the control part adjusting electric power supply to the heater part,the control part comprising:
- combustion control means which executes combustion control when the internal combustion engine is started to operate, and in the combustion control, the combustion control means supplies electric power to the heater part in order to maintain the detection part of the particulate matter detection sensor at a predetermined temperature T1 for a predetermined period S1 of time in order to burn the accumulated particulate matter in order to eliminate the accumulated particulate matter from the detection part of the particulate matter detection sensor; and
usual control means which executes usual control after completion of the combustion control which is executed when the internal combustion engine is started to operate, wherein in the usual control, the usual control means supplies electric power to the heater part in order to maintain the detection part of the particulate matter sensor element at a temperature T2 which is less than the predetermined temperature T1 in order to detect particulate matter accumulated in the detection part.
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Accused Products
Abstract
A particulate matter (PM) detection sensor is placed in an exhaust gas pipe of a diesel engine. The PM sensor element has a detection part composed of a pair of detection electrodes and a heater part. The detection electrodes and the heater part are stacked in the PM sensor element. A control circuit instructs a heater power supply to supply electric power to the heater part when the diesel engine is started to operate. The heater part heats the detection part at a predetermined temperature T1 within a range of 600° C. to 900° C. for a predetermined period S1 of time, for example, 650° C. for 20 seconds, in order to burn and completely eliminate particulate matter accumulated in the detection part. This control process avoids incorrect detection of the PM detection sensor. After this process, the control circuit executes usual control of the PM detection sensor.
44 Citations
7 Claims
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1. A control device of controlling a particulate matter detection sensor placed in an exhaust gas pipe of an internal combustion engine through which exhaust gas emitted from the internal combustion engine flows and discharged to the outside, the particulate matter detection sensor having a particulate matter sensor element comprised of an insulation substrate, a detection part composed of a pair of detection electrodes formed on a surface of the insulation substrate, and a heater part of generating heat energy when receiving electric power in order to heat the detection part at a predetermined temperature,
the control device comprising a control part which detects an electrical resistance value between the pair of the detection electrodes in the detection part, the electrical resistance value between the pair of the detection electrodes in the detection part changing in accordance with a change of quantity of particulate matter accumulated in the detection part, and the control part adjusting electric power supply to the heater part, the control part comprising: -
combustion control means which executes combustion control when the internal combustion engine is started to operate, and in the combustion control, the combustion control means supplies electric power to the heater part in order to maintain the detection part of the particulate matter detection sensor at a predetermined temperature T1 for a predetermined period S1 of time in order to burn the accumulated particulate matter in order to eliminate the accumulated particulate matter from the detection part of the particulate matter detection sensor; and usual control means which executes usual control after completion of the combustion control which is executed when the internal combustion engine is started to operate, wherein in the usual control, the usual control means supplies electric power to the heater part in order to maintain the detection part of the particulate matter sensor element at a temperature T2 which is less than the predetermined temperature T1 in order to detect particulate matter accumulated in the detection part. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification