Exhaust purifying apparatus for an internal combustion engine and a failure prevention method therefor
First Claim
1. An exhaust purifying apparatus of an internal combustion engine, comprising:
- an exhaust throttle valve provided in an exhaust passage of the internal combustion engine, so as to be able to be closed to close the exhaust passage;
a relief passage provided communicating with the exhaust passage and bypassing said exhaust throttle valve;
a relief valve provided in said relief passage so as to be able to be closed to close said relief passage, and arranged to be opened to open said relief passage when receiving an increased pressure in the exhaust passage that is closed with closure of said exhaust throttle valve;
fuel cut determining means for determining whether the internal combustion engine is during fuel cut-off; and
a relief-valve forcibly operating means for closing said exhaust throttle valve to open said relief valve when it is determined by said fuel cut determining means that the internal combustion engine is during fuel cut-off.
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Accused Products
Abstract
An exhaust purifying apparatus includes an exhaust throttle valve provided in an exhaust passage of the internal combustion engine for closing the exhaust passage to increase a pressure therein; a relief passage provided bypassing the exhaust throttle valve; a relief valve provided to be able to close the relief passage and to be open when receiving an increased pressure in the exhaust passage with closure of the exhaust throttle valve; fuel cut determining means for determining whether the engine is during fuel cut-off; and a relief-valve forcibly operating means for closing the exhaust throttle valve when the fuel cut determining means determines that the engine is during fuel cut-off, thereby removing condensed water accumulated in the relief passage to avoid faulty operations of the relief valve, and suppressing deteriorated fuel consumption upon operation of the relief valve.
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Citations
12 Claims
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1. An exhaust purifying apparatus of an internal combustion engine, comprising:
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an exhaust throttle valve provided in an exhaust passage of the internal combustion engine, so as to be able to be closed to close the exhaust passage;
a relief passage provided communicating with the exhaust passage and bypassing said exhaust throttle valve;
a relief valve provided in said relief passage so as to be able to be closed to close said relief passage, and arranged to be opened to open said relief passage when receiving an increased pressure in the exhaust passage that is closed with closure of said exhaust throttle valve;
fuel cut determining means for determining whether the internal combustion engine is during fuel cut-off; and
a relief-valve forcibly operating means for closing said exhaust throttle valve to open said relief valve when it is determined by said fuel cut determining means that the internal combustion engine is during fuel cut-off. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An exhaust purifying apparatus of an internal combustion engine, comprising:
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an exhaust throttle valve provided in an exhaust passage of the internal combustion engine, so as to be able to be closed to close the exhaust passage;
a relief passage provided communicating with the exhaust passage and bypassing said exhaust throttle valve;
a relief valve provided in said relief passage so as to be able to be closed to close said relief passage, and arranged to be open to open said relief passage when receiving an increased pressure in the exhaust passage that is closed with closure of said exhaust throttle valve;
deceleration determining means for determining whether the internal combustion engine is during deceleration; and
a relief-valve forcibly operating means for closing said exhaust throttle valve to open said relief valve when it is determined by said deceleration determining means that the internal combustion engine is during deceleration.
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12. A failure prevention method for an exhaust purifying apparatus of an internal combustion engine, comprising the steps of:
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(a) determining whether or not the internal combustion engine is during fuel cut-off or deceleration; and
(b) closing an exhaust throttle valve so as to cause a relief valve to open when it is determined at said step (a) that the internal combustion engine is during fuel cutoff or deceleration, the exhaust throttle valve being provided in an exhaust passage of the internal combustion engine for closing the exhaust passage to increase a pressure in the exhaust passage, and the relief valve being provided to be able to close a relief passage that is provided communicating with the exhaust passage and bypassing the exhaust throttle valve.
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Specification