At present, there exist a variety of cutting machines for cutting metal members, among which the gantry-type numerical control cutting machine is widely used. This machine comprises a cross beam, a driving trolley, and a driven trolley, wherein the driving trolley and the driven trolley are symmetrically and rigidly connected to the bottom surface of the welded cross beam at two ends thereof, at two ends thereof, said rigid connection being in such a way that a connecting plate is connected to the bottom surface of the cross beam, and the connecting plate is connected to the driving trolley and the driven trolley. Such a machine has the following shortcomings and deficiencies:
1. The cross beam is individually welded. The manufacturing is difficult, costly, and it is not easy to ensure manufacturing precision. Meanwhile, the manufactured beam is big, heavy, and has an unpleasant appearance.
2. As the two ends of the cross beam are rigidly connected to the driving trolley and the driven trolley, stress and deformation may be incurred due to certain reasons during the operation of the cutting machine. This affects the stable operation of the cutting machine, and in serious circumstances machine parts may be damaged.