A CAD approach to helical groove machining. Part 2: Numerical evaluation and sensitivity analysis

In practice, the flutes of end mills are ground using CNC grinding machines via controlling the grinding wheel's position and orientation to guarantee the designed flute parameters including rake angle, flute angle, helix angle, and core radius. However, for the previous researches, the designed flute profile was ground via building a specific grinding wheel with a free-form profile using two-axis CNC grinder. And, the free-form grinding wheel will greatly increase the manufacturing cost, which is too complicated to implement in practice. In this research, the flute-grinding processes were developed with a standard grinding wheel via five-axis CNC grinding operations. The mathematical representation of machined flute parameters was deduced in terms of the grinding wheel's position and orientation. The geometrical constraints to avoid interference and abnormal flute profile for the five-axis CNC fluting were first developed in this work. Finally, the difference between the designed flute parameters and the machined flute parameters were formulated as a constrained optimization problem so as to determine the wheel's position and orientation. The set of effective initial points for this optimization model was found mainly distributed the first quadrant of the contact area. The fminsearch function in Matlab toolbox was recommended to solve the optimization model due to its capability of handling discontinuity problem. The solution obtained in optimization model and the corresponding machined flute parameter were verified and compared with Boolean simulation in CATIA to confirm the validity and efficiency of the proposed approach. The results showed that the accuracy of machined flute parameters could achieve 1e-3 mm and 1e-2°, which satisfied the machining tolerance. This study provides a general solution for the CNC fluting operations and could be extended to grind complex surface of end mills in the future study.

“…(4) is first truncated within the cross section to obtain the flute profile by setting Z element as a constant shown in Eq. (6).…”

Section: Five-axis Flute-grinding Processesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A novel approach to determination of wheel position and orientation for five-axis CNC flute grinding of end mills

Wang

Chen

et al. 2015

“…The working surface of the cutter is composed of a toroid-shaped revolving surface, a revolving involute surface, and a cylindrical surface [2]. There are helical grooves [3] on the toroid-shaped revolving surface and the revolving involute surface, which provide the tool with its cutting function. Evaluating the contour quality of this kind of cutter should take the axis of the minimum circumscribed cylinder of the shank as the datum axis.…”

Section: Introductionmentioning

confidence: 99%

Models for evaluating the contour quality of revolving cutter with involute generator

Chen¹,

Hwang²

2004

The toroid-shaped helical cutter with an involute generator is a precision tool used in the machining of involute helical gears. Taking the axis of the minimum circumscribed cylinder of the measured points on the cylinder shank as the datum axis, this paper provides models of the minimum circumscribed involute revolving surface and the minimum circumscribed toroid-shaped revolving surface. This paper also presents models for evaluating the contour quality of a toroid-shaped cutter with an involute generator. The validity and accuracy of these models are confirmed by worked examples.

“…There exists several methods to compute interference errors (direct problem) and determine adapted tool profile (inverse problem) having a different complexity, approximation levels. Studies are also focused on the numerical aspect for computing solution and the sensitivity of algorithm to solve tool profile determination [11][12].…”

Section: Surfaces Machined With Form Tools and Interferencementioning

confidence: 99%

“…Worms, threads, flutes and grooves are mostly defined by helicoids which are mostly machined with a disk type tool [7][8][9][10][11][12][13][14][15] and sometimes with an axial type one [10]. There exists several methods to compute interference errors (direct problem) and determine adapted tool profile (inverse problem) having a different complexity, approximation levels.…”

Section: Surfaces Machined With Form Tools and Interferencementioning

confidence: 99%

Modeling of interferences during thread milling operation

Fromentin

Poulachon

2009

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible.This is an author-deposited version published in: https://sam.ensam.eu Handle ID: .http://hdl.handle.net/10985/7466 To cite this version :Guillaume FROMENTIN, Gérard POULACHON -Modeling of interferences during thread milling operation -The International Journal of Advanced Manufacturing Technology -Vol. 49, n°1, p.41-51 -2010 Any correspondence concerning this service should be sent to the repository Administrator : archiveouverte@ensam. eu 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Modeling of interferences during thread milling operation Abstract: Thread milling is becoming more and more employed as a technique for producing thread, due to its advantages for industrial manufacturing sectors, such as the aeronautics, aerospace, and energy industries. The thread milling operation is atypical and several aspects have to be taken into account to perform it in good conditions. As for milling or grinding worms, grooves, thread or others sculptured surfaces, in thread milling, there exists a geometrical interference between the tool and the nominal surface which would be obtained. Thread mills have quite complex geometry and their profile has an effect on the machined thread. The present study details geometrical aspects of the thread milling process. This article deals with the link between thread mill geometry and nominal thread profile. An approach is proposed to analyze the thread profile generated by the thread mill envelope. It is deduced that thread milling produces interferences, i.e. the machined thread profile is affected by an overcut. A method is proposed to correct this geometrical error in order to produce accurate thread. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 D mgt : maximum diameter of the generated thread E r : radial error between nominal and generated thread 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64