Thermal cutting machine and dust collecting method thereof

A thermal cutting machine for thermally cutting a workpiece placed on a table from above by means of a torch movable in substantially a horizontal direction, comprising:

• a plurality of exhaust chambers which are separated by at least one partition plate provided in substantially parallel with one side of said table, and are placed side by side inside said table;
• an exhaust port provided at one end side in an exhaust direction of each of said exhaust chambers;
• exhaust means, which is provided at each of said exhaust ports, communicates with said each exhaust port via an exhaust duct shared by each of said exhaust ports or an individual exhaust passage, and performs exhaust of said each exhaust chamber;
• opening and closing drive means for opening and closing each of said exhaust ports;
• an air blow port provided at a side of the other end of each of said exhaust chambers and at a position substantially opposing each of said exhaust ports;
• an air blow device which communicates with an inlet side of each of said air blow ports via an individual air blow duct provided thereto and blows air into said each air blow port;
• air blow opening and closing means which is provided at each of said air blow duct, and performs and stops air blow;
• and
• control means for controlling each of said opening and closing drive means and each of said air blow opening and closing drive means provided at both end sides of each of said exhaust chambers in synchronism with each other, or controlling them individually, correspondingly to a horizontal position of said torch which is under cutting operation.

A dust collecting method of a thermal cutting machine for collecting a flue gas occurring when thermally cutting a workpiece placed on a table from above by means of a torch movable in substantially a horizontal direction, comprising the steps of:

• detecting a horizontal position of said torch while performing cutting operation;
• performing air blow and exhaust for an exhaust chamber corresponding to said horizontal position of the torch out of a plurality of exhaust chambers which are separated in substantially parallel with one side of said table and are placed side by side inside said table;
• and
• after said torch passes the exhaust chamber corresponding to said horizontal position of the torch, continuing air blow and exhaust for the exhaust chamber corresponding to said horizontal position of the torch for a predetermined period of time to perform exhaust of a flue gas inside said table.