矩形竹片剖分模型在竹筒开片中的应用

Bamboo Tube Lengthwise Cutting by Using Rectangular Strip Splitting Model

以毛竹(Phyllostachys heterocycle)竹筒为研究对象,经测定竹筒直径和壁厚,确定了毛竹壁厚与其直径的关系;建立针对矩形竹片的竹筒剖分数学模型,计算并分析了不同竹筒直径、加工余量、开片数时的矩形竹片截面尺寸、截面积、截面出材率,获得了竹筒开片数的合理取值范围、依据宽度的规格竹片的竹筒最佳开片数,给出了根据竹筒小头直径、加工余量、竹片规格选取竹筒开片数的检索表。结果表明:毛竹壁厚随其直径的增大而线性增大;竹筒开片数增加,竹片厚度增大而宽度减小,开片数较小时变化较明显,开片数较大时变化很小;开片数取8时,可获得最大截面的矩形竹片;竹筒的截面出材率随开片数的增加先增后减,开片数取15时可获得最大截面出材率;竹筒开片数的合理取值范围为8~15,综合考虑各因素开片数取12较为理想;对于宽度22 mm的规格竹片,竹筒小头直径为120、110、100、90 mm时,对应的最佳开片数分别为12、11、10、9;小头直径小于80 mm的竹筒,不适合用来生产规格竹片。

Taking the bamboo tube as the research object,the relationship between the wall thickness and the diameter of the bamboo tube was determined by measuring the diameter and wall thickness of the bamboo tube.By establishing a mathematical model of lengthwise cutting bamboo tube to prepare rectangle strip,the cross-sectional dimensions,cross-sectional area and cross-sectional outturn rate of rectangular strips with different bamboo tube diameters,processing allowances and number of lengthwise cutting were calculated and analyzed.The reasonable value range for the number of lengthwise cutting,and the optimal lengthwise number of cutting based on the specifications of width are obtained.The key for selecting the number of lengthwise cutting according to the small end diameter,the processing allowance and specifications of bamboo sheets was established.The results show that the wall thickness of moso bamboo increases linearly with the increase of its diameter.As the number of lengthwise cutting of the bamboo tube increases,the thickness of the bamboo slices increases while the width decreases.The change is more obvious when the number of lengthwise cutting is small,and the change is small when the number of lengthwise cutting is large.As the number of lengthwise cutting increases,the thickness of the bamboo sheets increases while the width decreases.When the number of lengthwise cutting is 8,the rectangular strips with the largest cross-section can be obtained.The cross-sectional outturn rate first us increased and then decreased with the increase of the number of lengthwise cutting.The maximum cross-sectional outturn rate can be obtained when the number of lengthwise cutting is 15.The reasonable range of the number of lengthwise cutting is 8-15,but the optimal number of lengthwise cutting is 12 when considering various factors.For the size of 22 mm wide specifications bamboo sheets,when the small end diameter is 120,110,100 and 90 mm,the corresponding optimal number of cutting is 12,11,10 and 9.respectively,and the small end diameter is smaller than 80 mm,which is not suitable for the production of specifications slices.