Method and apparatus for detecting degree of clogging in particle trapping member of internal combustion engine

Claim 3

A method according to claim 1, wherein the degree of clogging of said particle-trapping-member is detected from the value of a selected one of ΔP1/P2 and P1/P2, where ΔP1 is the difference of pressures before and after said particle-trapping-member, P1 is the pressure on the inlet side of said particle-trapping-member, and P2 is the pressure on the inlet side of said muffler.

Claim 4

In an exhaust gas purifying-system for an internal combustion engine provided with a particle-trapping-member disposed in an exhaust gas flow path, an apparatus for detecting the degree of clogging of the particle-trapping-member of said internal combustion engine, comprising a muffler whose outlet is open to the atmosphere and making up a flow resistor disposed in said exhaust gas flow path at the downstream side of said particle-trapping-member, exhaust gas pressure lead pipes disposed at the inlet and outlet sides of said particle-trapping-member respectively, pressure converters connected to said exhaust gas pressure lead pipes respectively for converting pressure into electrical signals, and a computer supplied with the electrical signals from said pressure converters for comparing a selected one of the difference ΔP1 of pressures before and after said particle-trapping-member and the pressure P1 at the inlet side of said particle-trapping-member with an exhaust gas flow rate signal, thereby detecting the degree of clogging of said particle-trapping-member caused by capturing particles.

Claim 5

In an exhaust gas purifying-system for an internal combustion engine provided with a particle-trapping-member disposed in an exhaust gas flow path, an apparatus for detecting the degree of clogging of the particle-trapping-member of said internal combustion engine, comprising a muffler whose outlet is open to the atmosphere and making up a flow resistor disposed in said exhaust gas flow path at the downstream side of said particle-trapping-member, exhaust gas pressure lead pipes disposed at the inlet and outlet sides of said particle-trapping-member respectively, pressure converters connected to said exhaust gas pressure lead pipes respectively for converting pressure into electrical signals, and a computer supplied with the electrical signals from said pressure converters for comparing a selected one of the difference ΔP1 of pressures before and after said particle-trapping-member and the pressure P1 at the inlet side of said particle-trapping-member with an exhaust gas flow rate signal, thereby detecting the degree of clogging of said particle-trapping-member caused by capturing particles.

Claim 6

An apparatus according to claim 3, further comprising a display unit for informing the vehicle driver of the degree of clogging of said particle-trapping-member in response to an output from said computer, an intake manifold for supplying intake air to said internal combustion engine, and an intake throttle valve disposed in said intake manifold for controlling the rise in temperature of the exhaust gas by reducing the volume of the intake air by the rotation.

Claim 7

In an exhaust gas purifying-system for an internal combustion engine provided with a particle-trapping-member disposed in an exhaust gas flow path, an apparatus for detecting the degree of clogging of the particle-trapping-member of said internal combustion engine, comprising a muffler making up a flow resistor disposed in said exhaust gas flow path, exhaust gas pressure lead pipes disposed at the inlet and outlet sides of said particle-trapping-member respectively, pressure converters connected to said exhaust gas pressure lead pipes respectively for converting pressure into electrical signals, and a computer supplied with the electrical signals from said pressure converters for comparing a selected one of the difference ΔP1 of pressures before and after said particle-trapping-member and the pressure P1 at the inlet side of said particle-trapping-member with an exhaust gas flow rate signal, thereby detecting the degree of clogging of said particle-trapping-member caused by capturing particles, wherein said computer includes means for zero-setting said pressure converters when said internal combustion engine is stopped, low-pass filters for removing the ripples of output signals from said zero-setting means, amplifiers for amplifying the pressure signals free of the ripples to a required voltage level, and a comparison-decision circuit for comparing the output signals from said amplifiers with each other and producing a regeneration command signal for said particle-trapping-member.

Claim 8

In an exhaust gas purifying-system for an internal combustion engine provided with a particle-trapping-member disposed in an exhaust gas flow path, an apparatus for detecting the degree of clogging of the particle-trapping-member of said internal combustion engine, comprising a muffler making up a flow resistor disposed in said exhaust gas flow path, exhaust gas pressure lead pipes disposed at the inlet and outlet sides of said particle-trapping-member respectively, pressure converters connected to said exhaust gas pressure lead pipes respectively for converting pressure into electrical signals, and a computer supplied with the electrical signals from said pressure converters for comparing a selected one of the difference ΔP1 of pressures before and after said particle-trapping-member and the pressure P1 at the inlet side of said particle-trapping-member with an exhaust gas flow rate signal, thereby detecting the degree of clogging of said particle-trapping-member caused by capturing particles, wherein said computer includes means for zero-setting said pressure converters when said internal combustion engine is stopped, low-pass filters for removing the ripples of output signals from said zero-setting means, amplifiers for amplifying the pressure signals free of the ripples to a required voltage level, and a comparison-decision circuit for comparing the output signals from said amplifiers with each other and producing a regeneration command signal for said particle-trapping-member.

Claim 11

An apparatus according to claim 3, further comprising a display unit for informing the vehicle driver of the degree of clogging of said particle-trapping-member in response to an output from said computer, and an electric heater provided in close proximity to the upstream side of said particle-trapping-member.