This paper will introduce the design method of cutting machine for large economic CNC machine tools.
1. Design requirements design includes: mechanical part, numerical control part, cutting device and other parts.
2. Application direction: it is required to be widely applicable, which can be used in the blanking workshop of large enterprises for batch cutting of large parts; It can also be used in small machinery factories for small batch production of small parts.
3. Technical level: its comprehensive technical level is required to exceed that of domestic products and close to the world advanced level.
4. Production cost: the comprehensive cost is lower than that of similar domestic cutting machines.
5. Machining accuracy: the machining accuracy exceeds the current relevant national standards.
6. Applicable materials: carbon steel, stainless steel, non-ferrous metals.
In order to meet the above requirements and facilitate processing, control, installation and commissioning, it is decided to adopt the gantry structure as a whole, that is, a cross beam is supported by the walking car on the left and right longitudinal guide rails, and 1 to 6 horizontally movable cutting torch trolleys are installed on the cross beam, and the two walking cars on the longitudinal guide rails drive the cross beam to move longitudinally. At the same time, the cutting torch trolley on the beam drives the cutting torch to move laterally along the beam.
In this way, for the cutting torch, its motion is a combination of longitudinal and transverse motion, so it can complete the motion of any plane curve in the horizontal plane. In order to complete the cutting torch movement, it is necessary to change the rotary movement of the servo motor into the linear movement of the walking car and the cutting torch car on the beam. The optional schemes include the lead screw thread mother motion pair, toothed belt, gear rack motion pair, roller, linear motor, etc.
The numerical control part is used for automatic ignition, automatic drilling, differential compensation operation of cutting torch movement, ignition and extinction of plasma arc, echo of working state, man-machine dialogue, etc. This part is the core of the whole cutting machine, and its performance has a decisive impact on the success or failure of the final design.
This part of the cutting device is used to realize the cutting of the final plate, which will determine the material type, thickness, processing quality and other key indicators that can be processed by the cutting machine. There are many cutting methods that can complete the cutting and meet the design requirements, mainly including oxyacetylene flame, high current plasma arc, oxypropane flame, high-power laser, ultrasonic beam, high-pressure water, etc. Considering the factors such as equipment investment, equipment operation cost and production habits of the enterprise, it is decided to use oxyacetylene flame as the cutting method of medium and thick carbon steel plates.