小径木星形纵向锯解后重组刨切单板的数学理论描述

Description of Small-Diameter Wood Sliced Veneer after Star-Sawing in Longitudinal Direction and Recombining by Mathematical Method

【目的】提出将小径木纵向锯解为多块扇形木材后重组为近似板材再刨切为弦切单板的工艺,以提高原木出材率。【方法】首先对理想原木进行数学建模,并分别对短径方向、长径方向的弦切单板建立数学模型;然后以建立的原木及弦切单板数学模型为基础,绘制最优星形下锯图及最优弦切单板刨切图;最后分别对星形下锯与直接刨切2种不同工艺进行出材率计算,以比较原木出材率的高低。【结果】通过对模型的比较,短径方向弦切单板宽度大于长径方向弦切单板宽度,要求弦切单板宽度时,应以短径方向弦切单板为模型基础进行最优下刀;要求弦切单板数量时,应以长径方向弦切单板为模型基础进行最优下刀。计算出材率结果显示,相对于直接刨切,采用星形下锯工艺可以提高原木出材率。【结论】采用星形纵向锯解后重组刨切单板的工艺可提高原木出材率,同时可为实际选材提供理论支持,选择原木尺寸规格越大,出材率越高。

【Objective】The current study proposed a measure which sliced the reconstituted sector board after starsawing in longitudinal direction in order to improve the volume ratio of log. 【Method 】This study firstly conducted a mathematical model on the ideal log model. Then,established face cut board mathematical model from the short trail direction and the long trail direction. On the basis of the established mathematical model of log and face cut board,the optimal star-sawing pattern and sliced face cut board diagram could be established. Finally,this paper calculated volume ratio of log which sliced under two different processes consisting of star-sawing and sliced directly.【Result】The analysis pointed out that the width of slicing face cut board,which perpendicular to the short trail direction,was greater than that perpendicular to the long trail direction. It was reasonable to slice face cut board perpendicular to short trail direction if the veneer＇s width was required. However,if the veneer＇s quality was an important factor,it should be cut perpendicular to the long trail direction. The calculated results showed that the volume ratio of log could be improved by new star-sawing sliced technology. 【Conclusion】This study demonstrated the theory that star-sawing method can improve the volume ratio of log provided the theoretical support for the actual selection,the volume ratio of log could be improved to a certain degree by choosing larger size log when slicing veneer.