Apparatus for controlling power supplied to an electrically heated catalyst attached to an exhaust gas passage of an internal combustion engine
First Claim
1. An apparatus for controlling power supplied to an electrically heated catalyst attached to an exhaust gas passage of an internal combustion engine from a power source through a power supply circuit which includes a circuit opening/closing means that is opened and closed by a control circuit of the internal combustion engine, comprising:
- a fault detecting means for detecting the occurrence of such a fault that the supply of power to the electrically heated catalyst cannot be interrupted by said circuit opening/closing means;
a forcible circuit shut-off means provided in the path of the power supply circuit from said power source to said electrically heated catalyst and forcibly shuts off the power supply circuit when it is actuated; and
a shut-off operation instruction means for causing said forcible circuit shut-off means to effect the shut-off operation when a fault is detected by said fault detecting means.
1 Assignment
0 Petitions
Accused Products
Abstract
When an apparatus for supplying power to an EHC becomes faulty, the supply of power to the EHC is shut off by a means which is separate from a control relay to prevent the catalyst from being overheated. The control relay that is opened and closed by an ECU is provided in a circuit that supplies electric power from a power source to the EHC attached to an exhaust gas passage of an internal combustion engine, and power supplied to the EHC is controlled by the control relay. When the control relay is short-circuited, this short-circuiting fault is detected by some means, and the power supply circuit is forcibly shut off so that power will not be continuously supplied to the EHC from the power source in this state. Means for forcibly shutting off the power supply circuit may be a relay, a breaker or a fuse when the power source is a battery, and may be to suppress the amount of power generated by an alternator when the power source is the alternator.
35 Citations
17 Claims
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1. An apparatus for controlling power supplied to an electrically heated catalyst attached to an exhaust gas passage of an internal combustion engine from a power source through a power supply circuit which includes a circuit opening/closing means that is opened and closed by a control circuit of the internal combustion engine, comprising:
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a fault detecting means for detecting the occurrence of such a fault that the supply of power to the electrically heated catalyst cannot be interrupted by said circuit opening/closing means; a forcible circuit shut-off means provided in the path of the power supply circuit from said power source to said electrically heated catalyst and forcibly shuts off the power supply circuit when it is actuated; and a shut-off operation instruction means for causing said forcible circuit shut-off means to effect the shut-off operation when a fault is detected by said fault detecting means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification