Electric tightening device
First Claim
1. An electric tightening device comprising:
- a power source that passes current to a motor;
a voltage detector that detects a terminal voltage of the power source;
a storing unit in which a threshold value of the terminal voltage of the power source is stored; and
a controller connected to the voltage detector and the storing unit, wherein the controller detects a minimum value of the power source terminal voltage generated upon start of the motor by the voltage detector, compares the voltage minimum value with the threshold value in the storing unit and, when the voltage minimum value is less than the threshold value, notifies of shortage of the power source terminal voltage.
1 Assignment
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Accused Products
Abstract
A controller compares a minimum value of power source voltage which decreases in association with starting current generated upon start of a motor with a threshold value in a storing unit. When the minimum value is less than the threshold value, the controller notifies of shortage of the power source terminal voltage, and stops the motor. The controller also compares a value obtained by integrating the power source voltage which decreases in association with starting current generated upon start of the motor for only predetermined time with the threshold value in the storing unit, when the integral value is less than the threshold value, notifies of shortage of the power source terminal voltage, and stops the motor.
15 Citations
6 Claims
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1. An electric tightening device comprising:
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a power source that passes current to a motor;
a voltage detector that detects a terminal voltage of the power source;
a storing unit in which a threshold value of the terminal voltage of the power source is stored; and
a controller connected to the voltage detector and the storing unit, wherein the controller detects a minimum value of the power source terminal voltage generated upon start of the motor by the voltage detector, compares the voltage minimum value with the threshold value in the storing unit and, when the voltage minimum value is less than the threshold value, notifies of shortage of the power source terminal voltage.
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2. An electric tightening device comprising:
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a power source that passes current to a motor;
a voltage detector that detects a terminal voltage of the power source;
a current detector that detects current flowing in the motor;
a storing unit in which a threshold value of the terminal voltage of the power source is stored; and
a controller connected to the voltage detector, the current detector, and the storing unit, wherein the controller detects starting current generated upon start of the motor by the current detector, detects a minimum value of the power source voltage generated when the starting current is detected by the voltage detector, compares the voltage minimum value with the threshold value in the storing unit and, when the voltage minimum value is less than the threshold value, notifies of shortage of the power source terminal voltage.
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3. An electric tightening device comprising:
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a power source that passes current to a motor;
a current detector that detects current flowing in the motor;
a storing unit in which a threshold value of the starting current is stored; and
a controller connected to the current detector and the storing unit, wherein the controller detects a maximum value of the starting current generated upon start of the motor by the current detector, compares the current maximum value with the threshold value in the storing unit and, when the current maximum value is less than the threshold value, notifies of shortage of the power source terminal voltage.
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4. An electric tightening device comprising:
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a power source that passes current to a motor;
a voltage detector that detects a terminal voltage of the power source;
a current detector that detects current flowing in the motor;
a storing unit in which a threshold value of the starting current is stored; and
a controller connected to the voltage detector, the current detector, and the storing unit, wherein the controller detects a minimum value of the power source terminal voltage generated upon start of the motor by the voltage detector, detects a maximum value of the starting current obtained when the voltage minimum value is detected by the current detector and, when the current maximum value is less than a threshold value, notifies of shortage of the power source terminal voltage.
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5. An electric tightening device comprising:
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a power source that passes current to a motor;
a voltage detector that detects a terminal voltage of the power source;
a storing unit in which a threshold value of a value obtained by integrating the terminal voltage of the power source is stored; and
a controller connected to the voltage detector and the storing unit, wherein the controller integrates the power source terminal voltage which decreases in association with starting current generated upon start of the motor for only predetermined time, compares the integral voltage value with the threshold value in the storing unit and, when the integral value is less than the threshold value, notifies of shortage of the power source terminal voltage.
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6. An electric tightening device comprising:
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a power source that passes current to a motor;
a current detector that detects current flowing in the motor;
a storing unit in which a threshold value of a value obtained by integrating the current flowing in the motor is stored; and
a controller connected to the current detector and the storing unit, wherein the controller integrates the starting current generated upon start of the motor for only predetermined time, compares the integral current value with the threshold value in the storing unit and, when the integral value is less than the threshold value, notifies of shortage of the power source terminal voltage.
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Specification