What Are The Principles Of The Casting Position Of The Machinery Castings?
What are the principles of the casting position of the Machinery Castings?
According to the solidification theory of machine tool casting research and production experience, to determine the pouring position should consider the principle.
1, an important part of the machine tool casting should be placed in the lower part. Machinery Castings The lower metal of the machine tool is solidified under the static pressure of the upper metal and is contracted and compact.
2, important processing surface should be down or stand upright. Experience shows that pores, non-metallic inclusions and other defects appear in the upward surface, and the downward surface or side facade is usually relatively smooth, the possibility of defects are small, the individual processing surface must be upward, should be appropriate to enlarge Processing margin to ensure that after processing does not appear defects. A variety of machine tool bed surface is the key surface, not allowed to have trachoma, pores, Machinery Castings slag holes, cracks and shrinkage and other defects, and requires the organization dense and uniform, to ensure that the hardness value within the specified range.
3, so that the machine plane of the large plane down or tilted. For large flat castings, tilting can be used in order to increase the metal surface of the rising speed, Machinery Castings to prevent sand scar scar defects. Tilt pouring, according to the sand box size, H value is generally controlled in the 200 ~ 400mm range.
4, should ensure that the casting can be filled. For castings with thin-walled parts, the thin-walled parts should be placed in the lower half or placed below the pouring track to avoid defects such as pouring, cold separation and so on.
5, should be beneficial machine tool casting shrinkage. For the shrinkage of the alloy or the thickness of the casting structure is uneven and prone to shrinkage, Machinery Castings shrinkage casting should give priority to the conditions of the order of solidification, to facilitate the placement of risers and play the role of riser.
6, to avoid hanging sand, hanging sand or cantilever sand core, easy under the core, box and test. Experience shows that hanging sand in the box, pouring easy to collapse. Machinery Castings It is inconvenient to place the hanging core on the upper half. Cantilever sand core is not stable, easy to skew under the action of metal buoyancy, it should try to avoid. In addition, to take care of the core, the box, the convenience of inspection.
7, should be the box position, pouring position and machine tool cooling position consistent. Flip the mold is not only large amount of labor, but also easy to cause sand core movement, Machinery Castings out of sand, and even fire and other defects.