差动压实过程原理如图1所示,砂箱经定量加砂后首先进行预压(类似于普通的上压法),预压后的砂型上部紧实度高而下部紧实度低接着进行差动压实(类似于下压法),模样从分型面处压入砂箱内部,对紧实度比较低的砂型下部进行补充压实。最后再进行一次压实(仍类似于普通的上压法),我们称之为终压,终压使模样和模板的分型面退回到砂箱的下平面。 The principle of differential compaction process is shown in Figure 1. The sand box is firstly pre-pressed (similar to the normal pressing method) after the sand is quantitatively added. The pre-pressed sand mold has high compaction at the upper part and low compaction at the lower part. Differential compaction (similar to the pressure method), the sample from the sub-surface pressure into the sandbox, sand compacts lower compaction lower compaction. Finally, a compaction (still similar to the normal pressure method), which we call the final pressure, the final pressure so that the model and the template parting surface back to the flask under the plane.