| 摘要 |
PURPOSE: A method and a device for controlling the magnetic force of the magnet of a hoist are provided to make the magnet the most appropriate to a load and to maintain the hoist in the safe state all the time by controlling the magnetic force of the magnet corresponding to the load. CONSTITUTION: A magnet(12-1) for an electronic magnet hoist generates the magnetic flux by using an electric coil(13). A magnet(12-2) for a permanent magnet hoist is combined with a variable permanent magnet and a fixed permanent magnet generating the magnetic flux by using the electronic coil. A magnetic force detector(14) detects the strength of the magnets. A current detector(15) detects the strength of the currents flowing through the electronic coil. A magnetic force control unit(20) controls the magnetic force of the magnets by flowing currents through the electronic coil. An operating device(30) controls the attachment and removal of the magnets. A central control unit(50) receives the signals of the magnetic force detector and the current detector and generates a control signal for controlling the magnetic force control unit. A display device(40) displays the magnetic force of the magnets. |
