Effective measures for cutting heat deformation of cutting machines

--By CNC CUTTER LIMITED

The use of cnc cutting machine cutting speed of the appropriate choice can make the cutting surface of the hanging slag is very small, or even no hanging slag phenomenon, slag is convenient and easy. Cutting speed can be judged by sound and observation of the flow of the slag. The proper cutting speed slag flows with a regular wild ripple sound, and the slag outlet is basically in a straight line with the mouth cutting.


Cutting too fast and too slow are not conducive to ensuring the quality of the cut, cutting too fast may cause the phenomenon of not cutting, cutting too slow not only cause waste but also will make the top of the cut melt together phenomenon, need to carry out secondary cutting. Cut the mouth model can be selected according to the thickness of the plate, the larger the number of cut number, the thickness of the steel plate may be cut thicker. Cut the mouth distance to the flame flame heart and steel plate in the same plane is appropriate, cut the mouth distance from the steel plate too close to make the cut mouth blocked, too far will make the steel plate preheating area increased, deformation increased, and make the cutting speed reduced.

1. Correct selection of flame cutter gas pressure, cutting speed and cut mouth model. Selecting the appropriate gas pressure, cutting speed and cut-mouth model according to the thickness of the plate makes the cut show smooth, the cut wave marks are small, the top and bottom edges are square, and the cut scales are easy to remove. The cutting oxygen pressure is too high, not only to waste, but also close to the top of the cut parts will produce a regular groove. Cutting oxygen pressure is too low, cutting surface has a thicker scale skin into, difficult to remove. The high pressure of acetylene will form an overheating, near the top of the cutting surface to form a larger groove, acetylene pressure is too low to ensure the smooth progress of cutting.

2. Cutting gas.  High-quality oxygen and acetylene are the fundamental guarantee of increasing efficiency and obtaining high-quality cutting surfaces, and the purity of oxygen should be greater than or equal to 99%. If the purity is not enough, then the cutting surface is rough, hanging slag is serious, increasing the time of slag, resulting in waste of working hours. Liquid oxygen cutting can be used if conditions permit to further improve the quality of the cutting surface. Bottled acetylene should be used as far as possible, its high purity, stable pressure, not only can improve the quality of cutting surface, but also energy-saving effect is obvious.

3. Factors and measures affecting the quality of CNC flame cutters. High precision, good performance of cutting equipment can improve the quality of cutting surface and dimensional accuracy, but cutting gas, cutting parameters, reasonable cutting procedures also directly affect the quality.

4. Control of the cutting quality of various thickness plates. Different plate thickness should use different cutting speed, cutting gas pressure and different cutting type, plate thickness 6-12mm sheet due to heat and easy deformation, in the beginning of cutting parts can not be cut from the edge of the steel plate, and the use of perforation method to make the edge of the steel plate closed state, and the edge of the plate cutting and steel plate edge has a certain distance, This can limit the size deviation of parts caused by deformation, for 20-100 thick plate, because cutting is not easy to deform and perforated operation of the slag is easy to block the mouth, can be used from the edge of the steel plate cut in, thick plate in the CNC automatic gas cutting machine when there is often a lack of vertical cutting surface quality problems, therefore, Before making a thick plate cut, two crosscuts should be cut horizontally and vertically, and the verticality of the two directions of the torch should be adjusted with a right-angle ruler, so that the cutting surface is perpendicular to the surface of the steel plate.

5. Control of cutting quality of perforated parts.  The inner hole of the part should be cut out before the inner hole of the part is cut, which is beneficial to the dimensional accuracy of the inner hole and its surroundings. If properly perforated can greatly reduce the time to clean the mouth, improve work efficiency, in addition to the diameter of the hole can be further reduced, and the thickness of the plate can be appropriately increased. When perforating, in order to reduce the preheating time should appropriately increase the preheating oxygen (medium thick plate should be so), select a reasonable perforation point, observe the change of the preheating of the steel plate, when the cutting temperature (i.e. ignition point), open the cutting oxygen control valve, the speed will be appropriately increased until all open the cutting oxygen control valve, you can complete the perforation action. In the perforation process, pay attention to adjust the speed and oxygen control valve, so that the slag roughly with the cut mouth into a 40-degree direction fly out. When the diameter of the inner hole is less than the thickness of the plate, it is not appropriate to perforate cutting, the aperture should be machined, when the thickness of the plate is more than 120mm also should not be perforated cutting, such as the inner hole diameter is larger, can be in the corresponding position using mechanical processing method drilling 20mm cutting hole, and then the inner hole cutting.

6. Control of the quality of long piece slayings. For slender pieces (i.e. larger parts of length and width) in accordance with the conventional method of cutting, due to the thermal deformation of the steel plate will often appear on the arch and warping, the operation of a little attention will encounter the cut mouth, affecting the smooth progress of the cutting. Easy to cause stalls or bending, breaking torches and other accidents. Therefore, local water spray can be used to cool, bridge cutting, that is, artificial lying edge left a few sections of 15-30mm bridge does not cut, so that it is connected with the mother plate through the bridge to contain the cold shrink and upper arch;

7. Reasonable cutting procedures. Cnc cutting machine is taken by the computer to take real-time control to complete automatic cutting, which recognizes the program, so the programming method of parts on the steel plate plays a decisive role in the processing quality of cutting parts.

8. Effects of cutting order. The cutting order refers to the order in which several sets of arranged parts nested in size on a steel plate are cut in turn. Generally should follow the principle of field first inside and back, first small and then large, that is, cut the inner contour of the cut part or nested parts in the inner contour, then cut the outer outline, first cut the small area of the part, and then cut large-size parts, Otherwise, cutting the inner contours or other small parts on a steel plate that has been detached from the motherboard and is not self-weighted enough to maintain reliable positioning will cause further deformation and thus scrap.

9. Impact of the direction of cutting. The correct cutting direction should ensure that the last cutting edge and the mother board mostly separated, if prematurely with the mother board mostly separated, then the surrounding corner frame is not enough to resist the thermal deformation stress in the cutting process, resulting in the cutting part in the cutting process shift, the size of the difference.

10. The choice of fire point. In general, the fire point of the cutting part is ideal in the middle of the cut part cut outside the edge of the steel plate. Distance from the General Assembly to make the steel plate perforated, iron chip splash, easy to block the mouth caused by tempering, affecting the quality of the cut, reduce the cut life and production efficiency, distance too small, will hurt the cut parts appear waste.

11. Choice of lead cutting mode. The ideal introduction is the introduction of a circular arc, which gradually approaches along the cutting edge of the cut line, to achieve a smooth transition of the cut cross-section. The introduction of the straight line is along the cutting edge of the french direction, in the introduction of the position will appear arc pit affect the appearance of the cut, serious will cause waste.


CNC CUTTER cnc plasma and flame cutting effections