Industrial robot

1. An industrial robot, comprising:

a tool mounting portion to which a tool is to be mounted;

a tool mounting rotation arm for rotatably supporting the tool mounting portion;

a swing arm for swingably supporting the tool mounting rotation arm via a swing shaft;

a shoulder for rotatably supporting the swing arm via a swing arm rotating shaft;

a lower arm for rotatably supporting the shoulder via an upper arm rotating shaft;

a rotation frame for rotatably supporting the lower arm via a lower arm rotating shaft;

a tube arranged along the lower arm from the rotation frame to the shoulder; and

a robot base for rotatably supporting the rotation frame via a rotation frame rotating shaft;

wherein the tool mounting rotation arm includes a tool mounting rotating portion in a cylindrical shape, the tool mounting portion being rotatably engaged with a inner periphery of the tool mounting rotating portion,

wherein a flow path for supplying driving gas to the tool mounting portion is arranged from the robot base to the tool mounting portion through the interiors of the rotation frame, the tube, the shoulder, the swing arm and the tool mounting rotation arm,

wherein the flow path includes a rotational flow path formed along a sliding surface of the tool mounting portion against the tool mounting rotating portion when the tool mounting portion is rotated, and

wherein the rotational flow path is formed by a tool mounting rotating portion side groove portion formed over the entire circumference of the inner periphery of the tool mounting rotating portion and a tool mounting portion side groove portion formed over the entire circumference of an outer periphery of the tool mounting portion and facing the tool mounting rotating portion side groove portion at the sliding surface.

2. An industrial robot according to claim 1 , wherein the flow path includes:

a tool mounting rotation arm inner inflow path formed in the tool mounting rotation arm, communicating with the rotational flow path in the tool mounting rotation arm and adapted to supply inflow gas to the rotational flow path, and

a connection path formed in the tool mounting portion, communicating with the rotational flow path in the tool mounting portion and connected to a locking mechanism of the tool.

3. An industrial robot according to claim 2 , further comprising:

an intermediate power transmission shaft provided at an inner peripheral side of the swing shaft via an intermediate power transmission shaft bearing portion and adapted to transmit a rotational drive force from the swing arm to the tool mounting rotation arm; and

an inner shaft pipe mounted as a part of the flow path at an inner peripheral side of the intermediate power transmission shaft via an inner shaft pipe bearing portion.

4. An industrial robot according to claim 3 , wherein:

the swing arm includes a swing arm main body which is open at a side toward one end of the swing shaft and a swing arm cover for covering an opening of the swing shaft main body;

the tool mounting rotation arm includes a tool mounting rotation arm main body which is open at a side toward the other end of the swing shaft and a tool mounting rotation arm cover for covering an opening of the tool mounting rotation arm main body at the side toward the other end of the swing shaft;

the swing arm cover includes a swing arm cover bearing portion and a swing arm cover flow path provided at a side of the swing arm cover toward the one end of the swing shaft;

one end of the swing arm cover flow path communicates with an introduction pipe extending from the robot base to the swing arm and the other end thereof communicates with the swing arm cover bearing portion;

the tool mounting rotation arm cover includes a tool mounting rotation arm cover bearing portion and a tool mounting rotation arm cover flow path provided at a side toward the other end of the swing shaft;

one end of the tool mounting rotation arm cover flow path communicates with the tool mounting rotation arm cover bearing portion and the other end thereof communicates with a tool mounting rotation arm inner pipe; and

one end of the inner shaft pipe is inserted into the swing arm cover bearing portion and the other end thereof is inserted into the tool mounting rotation arm cover bearing portion.