JP2008296323A5

JP2008296323A5 -

Info

Publication number: JP2008296323A5
Application number: JP2007144689A
Authority: JP
Filing date: 2007-05-31
Publication date: 2010-06-24

Claims

An electric motor mounted in the housing part, a tip tool provided in the housing part that is rotationally driven by the electric motor, a trigger switch part provided in the housing part, and a trigger pushing amount of the trigger switch part In the electric tool having a control circuit unit for controlling the rotation speed of the electric motor from the rotation start to the full speed rotation speed,
The control circuit unit transmits the rotational force of the electric motor to the load of the tip tool in a first pressing range in which the trigger pressing amount of the trigger switch unit is equal to or less than the first pressing amount. In the first rotation speed range between the lower limit rotation speed of the first rotation speed and the upper limit rotation speed defined by the operability of the tip tool lower than the full speed rotation speed. Or in response to the trigger pressing amount so as to be a constant rotational speed, and
In the second pushing range in which the trigger pushing amount of the trigger switch unit exceeds the first pushing amount and reaches the maximum pushing amount, the rotation speed of the electric motor is set to the upper limit rotation speed and the full speed rotation speed. In response to the trigger push-in amount so as to increase at a second rotation speed increase rate higher than the first rotation speed increase rate in the first push-in range. An electric tool characterized by controlling.

The rotational speed of the electric motor is controlled to be a constant rotational speed in the first pushing range, and is controlled to be increased from the constant rotational speed to the full speed rotational speed in the second pushing range. The electric tool according to claim 1.

The trigger push amount of the trigger switch unit is converted into a voltage level by a potentiometer, and the applied voltage of the electric motor is subjected to pulse width modulation by using the converted voltage as a control signal to control the rotation speed of the electric motor. The power tool according to claim 1 or 2, wherein the power tool is provided.

A brushless DC motor having a rotor with a permanent magnet and a stator with a multi-phase armature winding, and a plurality of bridge-connected switching elements, and switching each DC voltage by switching DC voltage An inverter for supplying power to the armature winding, an inverter drive unit for driving the plurality of switching elements with a pulse width modulation signal, and a trigger for controlling the rotation speed of the brushless DC motor by a trigger pushing amount of a trigger operation A switch, a control circuit unit for controlling the rotation speed of the brushless DC motor from the rotation start to the full speed rotation speed based on a trigger pushing amount of the trigger switch unit, and a rotation transmission mechanism unit by the brushless DC motor. In an electric tool comprising a tip tool that is rotationally driven,
The control circuit unit transmits the rotational force of the electric motor to the load of the tip tool in a first pressing range in which the trigger pressing amount of the trigger switch unit is equal to or less than the first pressing amount. In the first rotation speed range between the lower limit rotation speed of the first rotation speed and the upper limit rotation speed defined by the operability of the tip tool lower than the full speed rotation speed. Or to control the duty ratio of the pulse width modulation signal that drives the plurality of switching elements in response to the trigger pressing amount so as to be a constant rotational speed, and
In the second pressing range in which the trigger pressing amount of the trigger switch unit exceeds the first pressing amount and reaches the maximum pressing amount, the rotation speed of the brushless DC motor is set to the upper limit rotation speed and the full speed rotation. In response to the trigger push-in amount so as to increase at a second rotation speed increase rate higher than the first rotation speed increase rate in the first push-in range within a second rotation speed range between And controlling a duty ratio of the pulse width modulation signal for driving the plurality of switching elements.

The control circuit unit includes an applied voltage setting unit that presets a change in the duty ratio of the pulse width modulation signal with respect to the trigger pressing amount of the trigger switch unit, and a drive signal forming unit is configured by an output of the application setting unit. 5. The electric tool according to claim 4, wherein the duty ratio of the pulse width modulation signal is varied by controlling.

A brushless DC motor,
A housing that houses the brushless DC motor;
A trigger switch provided in the housing;
A trigger operation unit movable with respect to the trigger switch;
A tip tool holder driven by the brushless DC motor;
An inverter driving unit for energizing the brushless motor,
When the amount of movement of the trigger operation unit is less than or equal to the first value, the motor speed is controlled to be substantially constant,
A control unit is provided for controlling the rotation speed of the motor to increase at a constant rate according to the movement amount of the trigger operation unit when the movement amount of the trigger operation unit is larger than the first value. A featured electric tool.

A brushless DC motor,
A housing that houses the brushless DC motor;
A trigger switch provided in the housing;
A trigger operation unit movable with respect to the trigger switch;
A tip tool holder driven by the brushless DC motor;
An inverter driving unit for energizing the brushless motor,
When the amount of movement of the trigger operation unit is equal to or less than the first value, the number of rotations of the motor is controlled to increase at a first rate according to the amount of movement of the trigger operation unit, and the amount of movement of the trigger operation is A control unit is provided for controlling the motor speed to increase at a second rate greater than the first rate in accordance with the amount of movement of the trigger operation unit when greater than the first value. An electric tool characterized by