Fastening tool

A fastening tool that is configured to fasten workpieces via a fastener having a pin and a cylindrical part, comprising:

• a motor having a motor shaft;
• a housing that houses the motor;
• a pin gripping part that is configured to grip the pin;
• a driving mechanism that is connected to the pin gripping part, and configured to perform rearward movement of moving rearward from an initial position along a driving axis that defines a front-rear direction of the fastening tool, by normal rotation of the motor shaft, and perform forward movement of moving forward to the initial position along the driving axis by reverse rotation of the motor shaft;
• a position obtaining part that is configured to obtain a relative position of the driving mechanism in the front-rear direction relative to the housing;
• and
• a motor controlling part that is configured to execute drive control of the motor to change a moving direction and a moving speed of the driving mechanism;
• wherein:
• the motor controlling part:
• starts the forward movement of the driving mechanism such that the moving speed reaches a first speed;
• reduces the moving speed to a second speed lower than the first speed by constant-speed rotation control for adjusting a driving voltage of the motor such that a number of revolutions per unit time of the motor shaft reaches a predetermined target number of revolutions, when the obtained relative position reaches a deceleration position rearward of the initial position in the forward movement;
• and
• stops driving of the motor when the obtained relative position reaches a predetermined braking position forward of the deceleration position and rearward of the initial position.

A fastening tool that is configured to fasten workpieces via a fastener having a pin and a cylindrical part, comprising:

• a motor having a motor shaft;
• a housing that houses the motor;
• a pin gripping part that is configured to grip the pin;
• a driving mechanism that is connected to the pin gripping part, and configured to perform rearward movement of moving rearward from an initial position along a driving axis that defines a front-rear direction of the fastening tool, by normal rotation of the motor shaft, and perform forward movement of moving forward to the initial position along the driving axis by reverse rotation of the motor shaft;
• a position obtaining part that is configured to obtain a relative position of the driving mechanism in the front-rear direction relative to the housing;
• and
• a motor controlling part that is configured to execute drive control of the motor to change a moving direction and a moving speed of the driving mechanism;
• wherein:
• the motor controlling part:
• starts the forward movement of the driving mechanism such that the moving speed reaches a first speed;
• determines a negative acceleration such that the moving speed is reduced to a second speed lower than the first speed in a braking position located at a predetermined distance rearward from the initial position, and reduces the moving speed at the determined (negative) acceleration, when the moving speed reaches the first speed in the forward movement;
• and
• stops driving of the motor when the obtained relative position reaches the braking position.