Impact Plate Design

Impact Plate Design

According to the collision theory of theoretical mechanics, when the raw materials impact the impact plate perpendicularly, we can get ideal crushing efficiency. But the blow bar makes rotatory movement, if we want all the raw materials in crushing cavity be shot on impact plate perpendicularly, the curve of impact plate should be an involute. The feature of involute is, at each contact point of impact plate, raw materials impact perpendicularly, in other words, the incidence angle d=0. At this time, the crushing efficiency is ideally. But it’s very difficult to produce involute impact plate, and also because of the mutual interference of raw materials in crushing cavity, their moving track is irregular. So in actual production, we generally adopt fold line impact plate to replace involute impact plate.

Design Of Fold Line Impact Plate

The projection angle directly affects the moving space range and moving curves of raw materials, thus affect the shape of impact plate. For impact crusher with two-stage impact plate, we can set the first impact plate according to the incidence angel d=0 and the size of feed opening. Turn the blow bar about 25° from the unloading point, and then considering the incidence angel as 0 and the minimum size of discharge opening and the corresponding angle, we can determine the position of the second-stage impact plate.

In the actual production process of impact crusher, the raw materials are different from sizes and shapes. For impact crusher with three-stage impact plate, we can set the first impact plate according to the incidence angel d=0 and the feed opening size. Turn the blow bar about 20°, 40°, then make the incidence angel as 0, we can determine the position of second and third impact plate.