Patent application number | Description | Published |
20110186318 | MOTOR CONTROL DEVICE, ELECTRIC POWER TOOL, AND RECORDING MEDIUM - A motor control device includes a target value setting unit, a measuring unit, a deviation calculating unit, a proportional control unit, an integral control unit, and a disabling unit. The deviation calculating unit calculates a deviation between a target value, set by the target value setting unit, and a measured value for rotational speed, measured by the measuring unit. The disabling unit disables proportional control, performed by the proportional control unit, when the deviation, calculated by the deviation calculating unit, is a value within a predetermined range. | 08-04-2011 |
20110232933 | ELECTRICAL POWER TOOL - In a speed change device of an electrical power tool, a reset arm is provided separately from a switch lever, which arm is operated by a reset motor. Due to tilting motion of the reset arm, a lock ring can be returned to an unlocking position in which a second stage internal gear can be rotated, so that the speed change device can be rest to a high speed low torque mode. | 09-29-2011 |
20110315417 | ROTARY IMPACT TOOL - A rotary impact tool includes: a hammer rotating by receiving a rotational force of a motor; an anvil rotating by receiving a rotational force of the hammer; and an end tool attached to the anvil, the rotary impact tool being constructed such that when a torque of a value not less than a predetermined value is applied to the anvil from the outside, the hammer is disengaged from the anvil to rotate idle and applies an impact to the anvil in a rotational direction after rotating idle by a predetermined angle, the rotary impact tool including an impact detection means detecting impacts and a speed switching means switching the rotational speed of the motor, and when the impact detection means detects an impact during rotation of the anvil in a tightening direction, the speed switching means switches the rotational speed of the motor from a normal speed to a low speed. | 12-29-2011 |
20120152583 | CORDLESS ELECTRIC POWER TOOL - A cordless electric power tool comprises a motor that drives a tool, a battery that supply electric power to the motor and a motor drive circuit that is disposed between the motor and the battery. The motor is a three-phase brushless motor, and the battery has a nominal voltage of 18 volts. An overall electric efficiency of the cordless electric power tool becomes at least 70 percent when a value of current passing through the motor becomes at least 35 amperes but no more than 45 amperes and the cordless electric power tool outputs power of at least 450 watts but no more than 550 watts. | 06-21-2012 |
20130082627 | MOTOR CURRENT DETECTION APPARATUS, MOTOR CONTROLLER, AND ELECTRIC POWER TOOL - A motor current detection apparatus in the present invention includes: a current detection unit, a first filter, and a second filter. The detection unit detects a conduction current flowing from a battery to a brushless motor and outputs a conduction current signal corresponding to the detected conduction current. The first filter extracts a first current signal which is included in the conduction current signal outputted from the detection unit and is a signal component in a frequency band equal to or lower than a predetermined first cutoff frequency. The second filter extracts a second current signal which is included in the conduction current signal outputted from the detection unit and is a signal component in a predetermined frequency band within a frequency band equal to or lower than a predetermined second cutoff frequency higher than the first cutoff frequency and having the second cutoff frequency as a maximum value. | 04-04-2013 |
20130133911 | ROTARY IMPACT TOOL - There is provided a rotary impact tool that includes: a motor; a hammer configured to be rotated by the motor; an anvil configured to be intermittently applied with an impact force in a rotation direction by a rotational force of the hammer; a rotation speed detection device configured to detect a rotation speed of the motor; an extreme value pair detection device configured to detect an extreme value pair, which is a pair of a maximum value and a minimum value of the rotation speed, based on the rotation speed detected by the rotation speed detection device; and an impact detection device configured to detect that the impact force is being applied when an extreme value difference, which is a difference between the maximum value and the minimum value, is equal to or more than a first threshold value. | 05-30-2013 |
20130207590 | ELECTRIC POWER TOOL - An electric power tool according to the present invention is provided with a tool main body, an induction motor, a power supply unit, and an inverter. The power supply unit and the inverter are integrally incorporated in the tool main body together with the induction motor. | 08-15-2013 |
20130307446 | Braking Apparatus for Three-Phase Brushless Motor, and Motor-Driven Appliance Provided with Same - A braking apparatus for a three-phase brushless motor is provided in a motor-driven appliance, and includes a switching circuit having six switching elements and a brake control device. The brake control device executes two-phase short-circuit control in braking control in which a braking force is generated in the motor. In the two-phase short-circuit control, an on/off state of each of the switching elements is set in such a manner that two out of three conduction paths constituting one of a positive electrode side conduction path that connects three terminals of the motor and a positive electrode side of a direct current power source and a negative electrode side conduction path that connects the three terminals and a negative electrode side of the power source are in a conducting state and other of the three conduction paths is in a non-conducting state. | 11-21-2013 |
20130314007 | ELECTRIC POWER TOOL - An electric power tool is provided with a three-phase brushless motor that drives a tool and a motor driver that drives the three-phase brushless motor with square voltage waves. The motor driver is able to set a conduction angle to a value that is equal to or more than 130 degrees but not more than 180 degrees, and especially to change the conduction angle among at least two values that are equal to or more than 130 degrees but not more than 180 degrees. In this configuration, it may be preferable that the conduction angle is set to a larger value as a load applied to the tool becomes smaller. On the other hand, it may be also preferable that the conduction angle is set to a larger value as a load applied to the tool becomes smaller. | 11-28-2013 |
20140096986 | POWER TOOL - A chain saw as a power tool includes a combustion engine and an electric motor. The chain saw has a driving shaft which drives a saw chain, a battery pack which provides electric current to the electric motor, a controller which is connected to the battery pack, and a sensor which detects a driving state of a driving mechanism including the combustion engine and the electric motor. In the chain saw, the saw chain is driven in a hybrid driving mode in which both the combustion engine and the electric motor drive the driving shaft. Further, the controller controls a driving of the combustion engine based on a detection result of the sensor. | 04-10-2014 |
20140165946 | POWER TOOL - To attain further rationalization in a power tool in which a tool bit is driven by an engine. During driving of the saw chain, when the user returns a throttle lever to its initial position by releasing only the throttle lever while keeping pressing a throttle lock lever, or when the user returns the throttle lever to the initial position by releasing the throttle lever and releases the throttle lock lever, driving of an engine is stopped. Thus, further rationalization can be attained in the power tool. | 06-19-2014 |