新型深孔钻的结构开发与研究

发布时间：2018-08-15 18:56

【摘要】：随着高速切削加工技术的快速发展，高速钻削（high speed drilling，HSD）技术也受到了广泛关注。深孔钻作为深孔加工关键装备，在高速钻削方面却鲜有成果。为了满足高速钻削加工，需要一款在高速运动中保持平稳钻削、能够实现高效排屑和高效降温的深孔钻。利用高速切削技术、流体知识和深孔加工技术三种技术，重新设计深孔钻结构，并且研究它在高速钻削中的运动状态。深孔加工过程中，工件内部空间非常狭窄。深孔钻结构既要保证有足够空间留给排屑通道，又要保证在大进给量时有足够的刚度。经典深孔钻为了解决上面所提到的问题，设计出了大小不对称排屑通道，偏离了回转中心。这样的结构在高速运动中振动幅度较大，导向条磨损严重,不利于高速钻削。而在有限的空间内，本人以刚体系统动平衡为入手点，重新分布切削刃位置，改变排屑流道角度，开发出适用于高速钻削的新型深孔钻。以下是介绍本论文三个关键点：（1）采用四段对称式切削刃结构。每个切削刃关于中心对称，形成两对方向相反，大小相等的力偶，产生转动效果。确保新型深孔钻静平衡和动平衡，实现高速平稳钻削。（2）创新设计出冲击流道，解决经典BTA钻在喉部形成漩涡不利于冲刷切屑的情况。通过改变排屑流道角度，缩小喉部扇形面积，使经典BTA钻喉部的压力损失系数ξ值5.1降低为2.0，有利于切削液高效排屑。（3）新型深孔钻模态分析。高速钻削中存在着许多激振源。通过仿真软件进行模态分析出钻体的固有频率，避开激振源（主要是高速钻床）频率。本文阐述了新型深孔钻结构的创新性。并在结构强度分析、排屑流道优化和模态分析三个方面，进行数值分析。为新型深孔钻的结构优化设计提供了理论依据。
[Abstract]:With the rapid development of high speed cutting (HSM) technology, high-speed drilling (high speed drilling technology has been paid more and more attention. As the key equipment of deep hole drilling, deep hole drilling has little achievement in high speed drilling. In order to meet the requirement of high speed drilling, we need a deep hole drill which can keep steady drilling in high speed motion and realize high efficiency chip removal and high efficiency cooling. The structure of deep hole drilling is redesigned by using high speed cutting technology, fluid knowledge technology and deep hole machining technology, and its motion state in high speed drilling is studied. In the process of deep hole machining, the inner space of workpiece is very narrow. The deep hole drilling structure should not only keep enough space for chip-removing passage, but also ensure enough rigidity in large feed. In order to solve the problem mentioned above, the large and small asymmetric chip-discharge channel is designed, which deviates from the center of rotation. This kind of structure has a large vibration amplitude in high speed movement and serious wear of guide strip, which is not favorable to high speed drilling. In the limited space, I take the dynamic balance of rigid body system as the starting point, redistribute the cutting edge position, change the chip-discharge flow channel angle, and develop a new type of deep hole drill suitable for high speed drilling. The following are the three key points of this paper: (1) the four-segment symmetrical cutting edge structure is adopted. Each cutting edge is symmetrical in relation to the center and forms a couple of equal sizes opposite to each other, producing a rotational effect. To ensure the static balance and dynamic balance of the new type of deep hole drilling, to realize high speed and steady drilling. (2) to design a new impact channel to solve the problem that the vortex formed in the throat of the classic BTA drill is not conducive to scouring the chip. By changing the angle of the chip-draining channel and reducing the area of the throat sector, the pressure loss coefficient of the classic BTA drill throat is reduced to 2.0, which is beneficial to the efficient chip removal of cutting fluid. (3) Modal analysis of the new type of deep hole drilling. There are many exciting sources in high speed drilling. The natural frequency of drill body is analyzed by simulation software to avoid exciting source (mainly high speed drilling machine) frequency. This paper describes the innovation of the new deep hole drill structure. Numerical analysis is carried out in three aspects: structural strength analysis, chip-discharge channel optimization and modal analysis. It provides a theoretical basis for the structural optimization design of the new type of deep hole drill.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG52

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