Anomalous condition detecting apparatus for cooling motor fan
First Claim
1. An apparatus for detecting an anomalous condition of a cooling motor fan to be mounted on a vehicle, comprising:
- a detector for detecting a rotational electromotive force generated according to a rotation of a motor during a driving of said motor fan; and
a decision circuit for deciding whether an anomalous condition exists or not based on said detected rotational electromotive force,whereinsaid motor fan operates by receiving a drive signal,said decision circuit makes a decision that the anomalous condition exists when the voltage between a pair of motor terminals is smaller than a first predetermined value in a state that said drive signal is being output, andsaid predetermined value is a value obtained by subtracting a variation value in the rotational electromotive force from a value of the rotational electromotive force during a normal rotation of said motor.
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Accused Products
Abstract
The present invention relates to an apparatus for detecting an anomalous condition of a cooling motor fan to be mounted on a vehicle. The anomalous condition detecting apparatus includes a detector for detecting a pair of positive and negative terminals of a motor of the motor fan and a decision circuit for deciding whether an anomalous condition exists or not based on a voltage detected between the terminals. For example, an external resistor is provided between the positive terminal of the motor and the power source, the negative terminal of the motor is earthed, a voltage between the terminals of the motor is detected as a potential of the positive terminal, and the decision circuit decides that an anomalous condition exists when the potential of the positive terminal is smaller than a predetermined value in a state that a drive signal of the motor fan is being output. Accordingly, it is possible to detect an anomalous condition of the motor fan at low cost.
22 Citations
13 Claims
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1. An apparatus for detecting an anomalous condition of a cooling motor fan to be mounted on a vehicle, comprising:
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a detector for detecting a rotational electromotive force generated according to a rotation of a motor during a driving of said motor fan; and a decision circuit for deciding whether an anomalous condition exists or not based on said detected rotational electromotive force, wherein said motor fan operates by receiving a drive signal, said decision circuit makes a decision that the anomalous condition exists when the voltage between a pair of motor terminals is smaller than a first predetermined value in a state that said drive signal is being output, and said predetermined value is a value obtained by subtracting a variation value in the rotational electromotive force from a value of the rotational electromotive force during a normal rotation of said motor.
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2. An apparatus for detecting an anomalous condition of a cooling motor fan to be mounted on a vehicle, comprising:
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a detector for detecting a rotational electromotive force generated according to a rotation of a motor during a driving of said motor fan; and a decision circuit for deciding whether an anomalous condition exists or not based on said detected rotational electromotive force, wherein said motor has a plurality of pairs of positive and negative terminals, and said rotational electromotive force is a value detected as a potential difference between the positive and negative terminals other than the terminals being used for driving said motor. - View Dependent Claims (3, 4)
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5. An apparatus for detecting an anomalous condition of a cooling motor fan to be mounted on a vehicle, comprising:
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a detector for detecting a voltage between a pair of positive and negative terminals of a motor of said motor fan; a decision circuit for deciding whether an anomalous condition exists or not based on the voltage detected between said terminals; and an external resistor provided between said positive terminal of said motor and a power source, wherein said motor fan operates by receiving a drive signal, said decision circuit makes a decision that the anomalous condition exists when the voltage between said terminals is smaller than a first predetermined value in a state that said drive signal is being output, and said decision circuit makes a decision that the anomalous condition exists when the voltage between said terminals is larger than a second predetermined value smaller than said first predetermined value in a state that said drive signal is not being output.
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6. An apparatus for detecting an anomalous condition of a cooling motor fan to be mounted on a vehicle, comprising:
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a detector for detecting a voltage between a pair of positive and negative terminals of a motor of said motor fan; a decision circuit for deciding whether an anomalous condition exists or not based on the voltage detected between said terminals; and an external resistor provided between said positive terminal of said motor and a power source, wherein said motor fan operates by receiving a drive signal, said decision circuit makes a decision that the anomalous condition exists when the voltage between said terminals is smaller than a first predetermined value in a state that said drive signal is being output, said motor has an internal resistor, and said first predetermined value is a value based on a reference value to be determined by a resistance ratio between resistance values of said external resistor and said internal resistor and a voltage of said power source during a normal rotation of said motor. - View Dependent Claims (7)
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8. An apparatus for detecting an anomalous condition of first and second cooling motor fans connected in series to be mounted on a vehicle, comprising:
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a detector for detecting a potential between motors of said first and second cooling motor fans, and a decision circuit for deciding whether an anomalous condition exists or not based on said potential detected between motors. - View Dependent Claims (9, 10)
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11. An apparatus for detecting an anomalous condition of a cooling motor fan to be mounted on a vehicle, comprising:
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a detector for detecting a rotational electromotive force generated according to a rotation of a motor during a driving of said motor fan; and a decision circuit for deciding whether an anomalous condition exists or not based on said detected rotational electromotive force, wherein said motor further includes a commutator having a plurality of conductive blocks mutually insulated, a pair of conductive brushes for contacting with said commutator, and a plurality of coils connected in series through said plurality of conductive blocks, said detector has a detecting brush for being brought into contact with said commutator between said pair of conductive brushes, and said rotational electromotive force is obtained by being detected as a potential between said coils generated in said detecting brush. - View Dependent Claims (12, 13)
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Specification