Electric hoisting machine and control device and control method therefor

A control device that controls an electric hoisting machine that winds and/or unwinds a traction member on or from a rotating body by rotating a rotating body forward and backward by way of the forward and backward rotation drive of an electric motor, comprising:

• a tension detection part that detects a tension of the traction member;
• an input part that inputs a mode switching signal to switch between a winding mode to rotate the rotating body forward to wind the traction member on the rotating body and a unwinding mode to rotate the rotating body backward to unwind the traction member from the rotating body;
• and
• a control unit that receives a detection signal from the tension detection part and a mode switching signal from the input part and controls the operation of the electric motor in response to the mode switching signal,
• wherein the control unit controls the electric motor in response to a detection signal from the tension detection part so that when set to the unwinding mode by the mode switching signal, the rotating body is rotated backward where a tension of the traction member is equal to or greater than a predetermined threshold value, and the rotating body is prevented from being rotated backward where a tension of the traction member falls below a predetermined threshold value.

A control method that controls an electric hoisting machine that winds and/or unwinds a traction member on a rotating body by rotating a rotating body forward and backward by way of the forward and backward rotation drive of an electric motor, comprising:

• a tension detection step of detecting a tension of the traction member;
• an input step of inputting a mode switching signal to switch between a winding mode to rotate the rotating body forward to wind the traction member on the rotating body and an unwinding mode to rotate the rotating body backward to unwind the traction member from the rotating body;
• and
• an control step of controlling e operation of the electric motor in response to a mode switching signal obtained from the input step,
• wherein when set to the unwinding mode by the mode switching signal, the control method controls the electric motor in response to a detection signal obtained from the tension detection step, so that the rotating body is rotated backward when a tension of the traction member is equal to or greater than a predetermined threshold value and the rotating body is prevented from being rotated backward when a tension of the traction member falls below a predetermined threshold value.

An electric hoisting machine that winds and/or unwinds a traction member on a rotating body by rotating a rotating body forward and backward by way of the forward and backward rotation drive of an electric motor, comprising:

• a tension detection part that detects a tension of the traction member;
• an input part that inputs a mode switching signal to switch between a winding mode to rotate the rotating body forward to wind the traction member on the rotating body and an unwinding mode to rotate the rotating body backward to unwind the traction member from the rotating body;
• and
• a control unit that receives a detection signal from the tension detection part and a mode switching signal from the input part and controls the operation of the electric motor in response to the mode switching signal,
• wherein the control unit controls the electric motor so that when set to the unwinding mode by the mode switching signal in response to a detection signal from the tension detection part, the rotating body is rotated backward where a tension of the traction member is equal to or greater than a predetermined threshold value, and the rotating body is prevented from being rotated backward where a tension of the traction member falls below a predetermined threshold value.