Fastening tool

1. A fastening tool configured to fasten a workpiece via a fastener, the fastener having a pin and a cylindrical part, the fastening tool comprising:

a housing extending in a front-rear direction of the fastening tool along a driving axis;

a fastener-abutment part held by a front end portion of the housing so as to be capable of abutting the cylindrical part;

a pin-gripping part movable in the front-rear direction along the driving axis relative to the fastener-abutment part and configured to grip a portion of the pin;

a motor housed in the housing and including a motor body and a motor shaft, the motor body including a stator and a rotor, the motor shaft extending from the rotor;

a driving mechanism at least partially housed in the housing and configured to be driven by power of the motor and to move the pin-gripping part rearward along the driving axis relative to the fastener-abutment part to pull the pin gripped by the pin-gripping part and deform the cylindrical part abutting on the fastener-abutment part, thereby fastening the workpiece via the fastener; and

a handle protruding downward from the housing in an up-down direction orthogonal to the front-rear direction, the handle having a trigger in an upper end portion of the handle and configured to be depressed by a user, wherein:

the driving mechanism includes:

a rotary member supported by a rotary member holding part of the housing so as to be rotatable around the driving axis while movement of the rotary member in the front-rear direction is restricted, the rotary member being configured to be rotationally driven by the power of the motor; and

a movable member connected to the pin-gripping part and configured to be engaged with the rotary member so as to be movable in the front-rear direction along the driving axis while rotation of the movable member around the driving axis is restricted, and to linearly move in the front-rear direction when the rotary member is rotationally driven;

a rotation axis of the motor shaft is parallel to the driving axis and on a lower side of the driving axis;

a virtual plane including the driving axis and the rotation axis includes a center of the handle in a left-right direction orthogonal to the front-rear direction and the up-down direction;

the trigger is between the rotary member and the motor body in the front-rear direction;

the fastening tool further comprises:

an intervening member that is (1) a separate member from the rotary member and (2) between the rotary member and the rotary member holding part at a rear end of the rotary member in the front-rear direction; and

an elastic member directly between and in contact with the rotary member holding part and the intervening member;

there is a distance between the intervening members and the rotary member holding part when the fastening tool is at rest; and

the distance defines a maximum amount of compression of the elastic member when the fastening tool is in use.

2. The fastening tool as defined in claim 1 , wherein the rotary member and the motor body are spaced apart from each other in the front-rear direction.

3. The fastening tool as defined in claim 2 , wherein the rotary member and the motor partially overlap when viewed from the rear.

4. The fastening tool as defined in claim 1 , wherein:

the rotary member has a driven gear on its outer periphery,

the driving mechanism includes an intermediate shaft configured to be rotationally driven with rotation of the motor shaft and having a driving gear engaged with the driven gear, and

the intermediate shaft is coaxial with the motor shaft.

5. The fastening tool as defined in claim 1 , wherein:

the driving mechanism is configured to fasten the workpiece via the fastener and break the pin at a small-diameter part for breakage, and

the fastening tool further comprises:

a pintail passage extending in the front-rear direction along the driving axis and configured to allow passage of a pintail separated by breakage of the pin; and

a collection container for the pintail removably attached to a rear end portion of the housing and having an internal space communicating with a rear end of the pintail passage.

6. The fastening tool as defined in claim 5 , wherein the collection container is configured such that the driving axis and the rotation axis of the motor shaft are located within a region occupied by the collection container when viewed from the rear.

7. The fastening tool as defined in claim 5 , wherein:

the movable member is a hollow member having the pintail passage,

the fastening tool further comprises a dustproof member held by the rear end portion of the housing and in contact with an outer peripheral surface of a rear end portion of the movable member, and

the dustproof member is disposed configured such that the movable member moves in the front-rear direction with the outer peripheral surface in sliding contact with the dustproof member.

8. The fastening tool as defined in claim 1 , further comprising:

an illumination device in a lower end portion of the housing and configured to irradiate light to a peripheral region of a front end portion of the fastener-abutment part; and

a trigger-protection part extending from the lower end portion of the housing to a front end portion of the handle and configured to provide a space for a user's finger in front of the trigger,

wherein the trigger-protection part has a passage for wiring for the illumination device.

9. The fastening tool as defined in claim 1 , further comprising a position-detecting mechanism configured to detect that the pin-gripping part is in a reference position, wherein

the driving mechanism is configured to move the pin-gripping part forward along the driving axis relative to the fastener-abutment part to an initial position based on a detection result of the detection device after the workpiece is fastened, and

the intervening member is configured to abut an abutment part of the movable member when the pin-gripping part is moved forward beyond the initial position.