The mechanisms of bell mouth formation in gundrilling when the drill rotates and the workpiece is stationary. Part 2: the second stage of drill entrance

Astakhov, V. P.

doi:10.1016/s0890-6955(02)00051-2

Cited by 9 publications

(6 citation statements)

References 3 publications

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“…This can be caused by insufficient backtaper applied during drill manufacturing and/or due to inaccuracies in the gundrilling system. Moreover, when static or entrance stability of the tool is insufficient [4,18,19], this edge experiences additional side cutting that leads to its rapid deterioration. This type of wear is the least desirable because a substantial amount of tool material should be ground on re-sharpening to restore the drill.…”

Section: Tool Wear Paternsmentioning

confidence: 99%

“…Inferior drill design, alignment problems, and improper selection of the optimal bushing diameter causes drill entrance instability and thus bushing excessive wear, particularly in the region adjacent to the hole entrance. Moreover, it is found that, under the same feed, the length of the bell mouth (the tapered entrance part of drilled holes) is three to five times shorter and the diameter error is four to eight times smaller when using the newly-designed drills compare to the ordinary drill [18,19,21]. The level of vibrations during the tool entrance was estimated by the effective acceleration, which is measured using accelerometers installed on the workpiece.…”

Section: Test Resutlsmentioning

confidence: 99%

See 1 more Smart Citation

Deep-hole Tools

2010

Springer Series in Advanced Manufacturing

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This chapter discusses classification, geometry, and design of deep-hole drills. The concept of self-piloting is explained. The system approach to deep-hole machining is introduced and common system issues are discussed with examples. The major emphasis is placed on gundrills. A number of simple design rules are proposed and explained with examples. The conditions of free penetration of the drill into the hole being drilled are explained. The geometry consideration is systemically related to MWF flow and thus the concept of the optimum MWF flow rate is explained. A number of novel design concepts are revealed. This chapter also discusses system consideration in experimental study of gundrill parameters. It is demonstrated that tool life is a complex function not only of geometry parameters and machining regime alone but also of their combination. Tool geometry optimization using the Hooke and Jeeves method is also discussed.

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Section: Tool Wear Paternsmentioning

confidence: 99%

Section: Test Resutlsmentioning

confidence: 99%

Deep-hole Tools

2010

Springer Series in Advanced Manufacturing

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“…The preliminary gundrilling tests have shown [12] that the cutting regime (the cutting speed, v and feed, f) and the parameters of the tool geometry should be considered as the input variables. Tool life is to be considered as the output parameter.…”

Section: Design Matrixmentioning

confidence: 99%

Tool life testing in gundrilling: an application of the group method of data handling (GMDH)

Astakhov¹,

Galitsky²

2005

International Journal of Machine Tools and Manufacture

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“…Jung J [8] ，Wang Y [9] established a mathematical drilling force model of gun drills based on the energy principle and micro cutting tools, and the correctness of the model were verified by drilling experiments. Astakhov et al [10] studied the formation principle of trumpet mouth under gun drilling. Galitsky et al [11] established a tool life model for gun drilling by group data analysis method (GMDH) including tool angle parameters and process parameters, which was a relatively perfect tool life prediction model.…”

Section: Introductionmentioning

confidence: 99%

Research on Deep-hole Drilling Quality of High-strength Steel With Slender Gun Drill

Liang¹,

Li²,

Yan³

et al. 2021

Preprint

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There are a lot of problems exist in the processing of long and thin deep hole gun drilling of high strength steel, such as insufficient of the machining mechanism and characteristics of gun drilling, difficulty in selecting machining parameters, unknown influence mechanism of machining parameters on drilling force, drilling temperature and machining quality. In this paper, 42CrMo high strength steel is selected as the workpiece material. A numerical model of cutting force is established based on the mechanism of gun drill, and then the finite element simulation and processing test are carried out. The results show that the cutting force decreases with the increase of cutting speed, and increases with the increase of feed speed; the error between the theoretical and actual value is less than 10%. Cutting speed and feed speed have a great influence on machining quality, and the cutting fluid pressure mainly affects the surface roughness.

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The mechanisms of bell mouth formation in gundrilling when the drill rotates and the workpiece is stationary. Part 2: the second stage of drill entrance

Cited by 9 publications

References 3 publications

Deep-hole Tools

Deep-hole Tools

Tool life testing in gundrilling: an application of the group method of data handling (GMDH)

Research on Deep-hole Drilling Quality of High-strength Steel With Slender Gun Drill

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