ELECTRIC POWER TOOL
First Claim
1. An electric power tool comprising:
- an electric motor configured to reciprocate a tip tool within a range of a predetermined angle; and
a control part configured to detect a load of the tip tool, and to control a rotating speed of the electric motor on the basis of the detection result of the load.
2 Assignments
0 Petitions
Accused Products
Abstract
An object of the present invention is to provide an electric power tool capable of automatically changing the rotating speed of an electric motor in accordance with operation conditions. The electric power tool 11 which carries out an operation of polishing, peel-off, cutting, or the like by swinging a tip tool 13 attached to a tool retaining part 31 within the range of predetermined angles by the drive power of the electric motor 12, wherein the electric power tool has a control device configured to indirectly detect the load of the tip tool from a current value, and to control the rotating speed of the electric motor 12 to a maximum rotating speed and a minimum rotating speed on the basis of the load of the tip tool 13.
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Citations
24 Claims
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1. An electric power tool comprising:
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an electric motor configured to reciprocate a tip tool within a range of a predetermined angle; and a control part configured to detect a load of the tip tool, and to control a rotating speed of the electric motor on the basis of the detection result of the load. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An electric power tool comprising:
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an electric motor configured to drive a tip tool selected from among various tip tools and attached to a tool attaching part, the tip tool being detachable from the tool attaching part; a switching element configured to control a voltage applied to the electric motor on the basis of a control signal; a rotating speed detecting part configured to detect a rotating speed of the electric motor; and a control part configured to generate the control signal so that the rotating speed of the electric motor becomes equal to a first rotating speed when a control value as the control signal is larger than a load judge reference value, and configured to generate the control signal so that the rotating speed of the electric motor becomes equal to a second rotating speed lower than the first rotating speed when the control value is smaller than a no-load judge reference value. - View Dependent Claims (9)
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10. An electric power tool comprising:
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a switching element configured to control an alternating-current voltage applied to an electric motor by a conduction angle on the basis of a control signal; a rotating speed detecting part configured to detect a rotating speed of the electric motor; and a control part configured to generate the control signal on the basis of the rotating speed of the electric motor detected by the rotating speed detecting part, and to output the control signal to the switching element, wherein when the conduction angle of the switching element is larger than a load judge reference value, the control part judges that the electric motor is in a load state, and generates the control signal so that the rotating speed of the electric motor becomes equal to a first rotating speed set by a setting signal; and when the conduction angle of the switching element becomes smaller than a no-load judge reference value, the control part judges that the electric motor is in a no-load state, and generates the control signal so that the rotating speed of the electric motor becomes equal to a second rotating speed lower than the first rotating speed set by the setting signal. - View Dependent Claims (11, 12, 13)
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14. An electric power tool comprising:
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an electric motor configured to drive a tip tool selected from among various tip tools and attached to a tool attaching part, the tip tool being detachable from the tool attaching part; a switching element configured to control a voltage applied to the electric motor on the basis of a control signal; a control part configured to generate and output the control signal to the switching element; and a current detecting part configured to detect a current flowing to the electric motor, and to output a current value indicative of the detected current to the control part;
whereinwhen the current value indicative of the current flowing to the electric motor is larger than a current load judge reference value, the control part judges that the electric motor is in a load state, and generates the control signal so that the rotating speed of the electric motor becomes equal to a first rotating speed set by a setting signal; and when the current flowing to the electric motor becomes smaller than a current no-load judge reference value, the control part judges that the electric motor is in a no-load state, and generates the control signal so that the rotating speed of the electric motor becomes equal to a second rotating speed lower than the first rotating speed set by the setting signal. - View Dependent Claims (15, 16, 17)
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18. An electric power tool comprising:
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a switching element configured to control a voltage applied to an electric motor by a conduction angle on the basis of a control signal; a rotating speed detecting part configured to detect a rotating speed of the electric motor; and a control part configured to generate the control signal on the basis of the rotating speed of the electric motor detected by the rotating speed detecting part, and to output the control signal to the switching element;
whereinthe control part detects an initial conduction angle of the switching element, judges that the electric motor is in a load state when the conduction angle of the switching element is increased from the initial conduction angle, and sets the rotating speed of the electric motor on the basis of the initial conduction angle and the increased conduction angle. - View Dependent Claims (19, 20, 21, 22, 23)
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24. An electric power tool comprising:
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a switching element configured to control a voltage applied to an electric motor on the basis of a control signal; a rotating speed detecting part configured to detect a rotating speed of the electric motor; a current detecting part configured to detect a current flowing to the electric motor; and a control part configured to generate the control signal on the basis of the rotating speed of the electric motor detected by the rotating speed detecting part, and to output the control signal to the switching element;
whereinthe control part detects an initial current flowing to the electric motor, judges that the electric motor is in a load state when the current flowing to the electric motor is increased from the initial current value, and sets the rotating speed of the electric motor on the basis of the initial current value and the increased current value.
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Specification