可转位浅孔钻的径向力分析和试验研究

发布时间：2019-05-23 22:09

【摘要】：随着工程材料和涂层工艺的不断发展，可转位浅孔钻在实际生产中得到了广泛的应用。然而，在其钻孔质量方面与国外成熟产品相比存在一些差距，其中可转位浅孔钻的径向力问题是影响其钻孔质量的最主要的因素。与麻花钻相比，可转位浅孔钻具有较好的钻孔质量、较低的轴向力、更高的切削速度和进给速度。但由于可转位浅孔钻刀片的非对称布局，容易导致其在钻孔过程中受到未平衡的径向力，过大的径向力会引起钻头振动使钻孔质量降低。因此，如何最大限度地减小可转位浅孔钻在钻孔过程中受到的径向力，就成为设计和优化可转位浅孔钻的关键。本文基于不等分剪切区模型来计算剪切面上的剪切应力。结合等效平面法将直角切削理论应用到单刃斜角切削的建模中，并根据直角切削和单刃斜角切削之间的切削力变换关系对单刃斜角切削的切削力进行分析。为分析可转位浅孔钻在钻孔过程中受到的径向力，本文将可转位浅孔钻的切削刃离散为一系列无限小的斜角切削单元。在分析了可转位浅孔钻几何角度的基础上，以单刃斜角切削为基础模型，根据斜角切削和钻削之间的切削力变换关系对可转位浅孔钻的钻削力进行分析，建立计算可转位浅孔钻径向力的数学模型。最后，对铝合金Al7050-T7451进行多组不同切削参数的钻削试验，通过数值计算和钻削试验结果的比较，对本文所建立的数学模型的有效性进行验证。本文的主要内容有： 1．以安装有两个WCMX型刀片的可转位浅孔钻为本文的研究对象，建立了分析可转位浅孔钻几何角度(法前角、刃倾角和主偏角等)的数学模型，对可转位浅孔钻的几何角度沿钻头径向上的变化情况进行了分析，并与向量法分析可转位浅孔钻的几何角度进行了比较。 2．采用不等分剪切区模型计算剪切面上的剪切应力。在剪切区内，材料的本构关系采用Johnson-Cook方程表示，结合切削层材料在剪切区内速度、应变、应力和温度的控制方程，通过数值方法求解剪切面上的剪切应力。随后采用等效平面法将不等分剪切区模型的理论应用到单刃斜角切削的建模中，将单刃斜角切削等效为一系列与等效平面平行的直角切削薄片，并根据这些与等效平面平行的直角切削薄片和单刃斜角切削之间的切削力变换关系对单刃斜角切削的切削力进行了分析。 3．分析了将可转位浅孔钻的切削刃离散为一系列无限小的单刃斜角切削单元的离散过程。在分析可转位浅孔钻几何角度的基础上，，以单刃斜角切削为基础模型，根据单刃斜角切削单元和可转位浅孔钻之间的切削力变换关系对可转位浅孔钻钻孔的钻削力进行分析，对微元钻削力进行数值积分求和得到可转位浅孔钻钻孔的钻削力，最终建立了可转位浅孔钻的径向力计算模型。 4．对铝合金Al7050-T7451进行了多组不同切削参数的钻削试验，通过数值计算和试验结果的比较验证了所建立的计算可转位浅孔钻钻削力的数学模型的有效性。
[Abstract]:With the development of engineering material and coating technology, the indexable shallow hole drill has been widely used in the actual production. However, there are some differences in the quality of its drilling and foreign mature products, in which the problem of the radial force of the indexable shallow hole drill is the most important factor affecting the drilling quality. Compared with the twist drill, the indexable shallow hole drill has better drilling quality, lower axial force, higher cutting speed and feed speed, . However, due to the asymmetric layout of the indexable shallow hole drill insert, it is easy to lead to an unbalanced radial force in the drilling process, and excessive radial force can cause the drill bit to vibrate and the drilling quality can be reduced. Low. Therefore, how to minimize the radial force of the indexable shallow hole in the drilling process becomes the close of the design and optimization of the indexable shallow hole drill In this paper, the shear plane shear is calculated on the basis of a non-equipartition shear zone model In this paper, a right-angle cutting theory is applied to the modeling of single-edge bevel cutting in combination with the equivalent plane method, and the cutting force of the single-edge bevel cutting is cut according to the relationship between the cutting force and the cutting force between the right-angle cutting and the single-edge bevel cutting. In order to analyze the radial force of the indexable shallow hole in the drilling process, the cutting edge of the indexable shallow hole drill is discretized into a series of small bevel cut. Based on the analysis of the geometric angle of the indexable shallow hole, the cutting force of the indexable shallow hole drill is analyzed based on the cutting force transformation relation between the bevel cutting and the drilling, and the number of the radial force of the indexable shallow hole drill is established. In the end, the drilling test of several sets of different cutting parameters of the aluminum alloy Al7050-T7451 is carried out, and the validity of the mathematical model established in this paper is obtained by the comparison of the numerical calculation and the drilling test results. line verification. The main purpose of this paper is to The contents are as follows:1. An indexable shallow hole with two WCMX blades is used as the research object in this paper, and the geometric angle of the indexable shallow hole drill (the rake angle, the blade inclination angle and the main declination angle, etc.) is established. The geometric angle of the indexable shallow hole drill is analyzed in the radial direction of the bit, and the geometric angle of the indexable shallow hole drill is analyzed by the vector method. A comparison is made.2. The shear zone model is used to calculate the shear stress. The shear stress on the surface. In the shear zone, the constitutive relation of the material is represented by the Johnson-Cook equation, and the shear zone material is combined with the control equation of speed, strain, stress and temperature in the shear zone, and the shearing is solved by the numerical method. The shear stress on the surface is then applied to the modeling of the single-edge bevel cutting by the equivalent plane method, and the single-edge bevel cutting is equivalent to a series of parallel planes parallel to the equivalent plane. the right-angle cutting sheet and cutting the single-edge bevel cut according to the relationship of the cutting force between the right-angle cutting sheet and the single-edge bevel cutting parallel to the equivalent plane 3. The cutting edge of the indexable shallow hole drill is discretized into a series of small, single-edge oblique angles. The invention relates to a discrete process of a cutting unit, on the basis of analyzing the geometrical angle of the indexable shallow hole drill, a single-edge oblique angle cutting is used as a basic model, and the indexable shallow-hole drill bit can be drilled according to the cutting force transformation relation between the single-edge oblique angle cutting unit and the indexable shallow hole drill. The drilling force of the hole is analyzed, the drilling force of the drill hole of the indexable shallow hole is obtained by the numerical integral summation of the micro-element drilling force, and the indexable shallow hole is finally established. The radial force calculation model of the drill is given.4. The drilling test of several sets of different cutting parameters is carried out on the aluminum alloy Al7050-T7451, and the established calculation indexable shallow hole drill can be verified by the comparison of the numerical calculation and the test result.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG52

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