Tool orientation optimization and location determination for four-axis plunge milling of open blisks

2019

Symmetry

Disk milling strategy has been applied in grooving for decades for its capacity to provide huge milling force on difficult-to-cut material. However, basic research on the tool orientation of the disk milling cutter for the disk milling process on the milling free surface, especially on the free surface of the blisk, is still lacking in previous studies. In this study, the minimum residual amount after the disc milling process is used as an optimization target to obtain the optimal tool orientation of the disc cutter. To address the problem mentioned above, a torque balance method, including a torque balance algorithm and concentric circle ray point (CCRP) method is proposed. The torque calculation and torque balance problem are solved by the torque balance algorithm and the problem of generating random points to cause torque symmetry is solved in the CCRP method. Based on the secondary development of UG NX software, a series of tool orientation of disk milling cutter are calculated. Finally, the torque balance method is compared with steepest descent method, Newton method, and conjugate gradient method in the aspects of calculation accuracy, operation speed, and convergence speed. However, both the calculation speed and the convergence speed are better than the other three algorithms. Compared with the other three methods, the operation speed of the torque balance method is reduced by 0.35 times, 1.5 times, and 2.25 times. The results prove the feasibility of the torque balance method in solving the problem of tool orientation optimization of the disk milling cutter.

Section: Of 20mentioning

confidence: 99%

Tool Orientation Optimization for Disk Milling Process Based on Torque Balance Method

2019

Symmetry

“…When a cutter feeds in the tool axis direction, the contacting area of cutter bottom and uncut material varied with the feeding depth. A current technique challenge was to calculate the tool orientation and locations (called plunger paths) in four-axis rough plunging of open blisks, so that the residual raw material left on the blades after roughing was closed to the specified value [11]. Klocke et al [12] presented a multi-criteria assessment approach to deal with turbine disc slotting process.…”

Section: Introductionmentioning

confidence: 99%

Multi-Objective Parameter Optimization for Disc Milling Process of Titanium Alloy Blisk Channels

2019

Symmetry

The blisk has been widely used in modern high performance aero-engines of high thrust-weight ratio. Disc milling process provides a reliable way to improve the efficiency of the blisk milling. The process parameters of disc milling have crucial effects on the milling efficiency and physical property of blisk. In this paper, material removal rate, cutter life and thickness of residual stress layer are regarded as optimization targets the key process parameters such as spindle speed, cutting depth and feed speed are optimized. Based on the grey relational analysis, the multi-objective optimization problem is transformed into a single objective optimization problem. At the same time, the problem of non-symmetry influence of key process parameters on optimization targets can be solved. And the influence weight of material removal rate, cutter life and thickness of residual stress layer on the grey relational grade (GRG) are calculated according to principal component analysis. The second order prediction model of GRA is developed by response surface method. On the basis of verifying the accuracy of the model, the influence mechanism of the process parameters coupling on the gray correlation degree is analyzed the optimal process parameter combination is obtained as spindle speed with 81.92 rpm, cutting depth with 5.88 mm and feed rate with 66.0823 mm/min. The experimental research show that the optimal process parameter combination can effectively improve the material removal rate and cutter life and reduce the thickness of residual stress layer.

“…Blisks are the most important and critical components in gas turbine engines, which could reduce the weight obviously and improve the efficiency significantly [2]. Recently, there emerging many novel methods for blisk manufacturing.…”

Section: Introductionmentioning

confidence: 99%

Structure design and rotation control of the disc milling head in blisk manufacturing

Zhao

Huang

Int J Adv Manuf Technol

2016

Blisks are the most important and critical components in the gas turbine engines, which could reduce the weight obviously and improve the efficiency significantly. To achieve high efficient machining of the titanium-based blisk, a powerful and composite processing method is proposed and structure of disc milling head with high stiffness and high precision is designed, including mechanical transmission, electrical system, rotating control, locking device, and tool changer. Then, static and dynamic analyses are carried out for the disc milling head, and calculation results show that the static and dynamic performances are perfect, which satisfy the processing requirements. Considering friction and backlash in the worm gear transmission, parameters perturbation in the electrical control system, and process noise and measurement noise in the system have serious impact on the positioning precision of disc milling rotation system, a robust sliding mode control (SMC) algorithm based on linear quadratic optimal control (LQC) is proposed. Based on the traditional LQC, introduce the state estimation based on Kalman filter and control input, improve the system state space model, and define a new sliding surface equation, then, a robust SMC based on LQC is finished. Simulation and experiment results show that the designed controller is robust to the nonlinearities and uncertainties in the rotation control system of disc milling head and can achieve high positioning precision.