15 results about "Stability lobes" patented technology

The invention provides a thin-wall structural part milling chatter suppression method and device based on main shaft rotating speed parameter adaptive regulation and control, electronic equipment and a storage medium. According to a stability lobe graph, a rotating speed area is divided, and a continuous variable rotating speed dominant area and a discrete variable rotating speed dominant area are determined; if the milling chatter is in a low-speed area, sine continuous variable-speed modulation is adopted, modulation parameters are optimized based on an energy minimization criterion, and a continuous variable-speed curve is generated; if the target is in the high-speed area, calculating a stable target rotating speed according to a phase difference matching condition, and generating a discrete rotating speed sequence through low-pass filtering and saturation constraint processing; and when the stability improvement amplitude is lower than a threshold value, the rotating speed is divided into a discrete variable rotating speed dominant area, and a discrete variable rotating speed strategy is adopted. An additional vibration suppression device or hardware transformation is not needed, and the method has the advantages of being easy and convenient to implement and low in cost and has the remarkable effect in the aspect of improving machining stability and efficiency.

The invention discloses a digital twinning-based chatter prediction method for a complex blade type cutter in a machining process, and the method comprises the following steps: S1, simulating a milling process of the complex blade type cutter based on a digital twinning model, and obtaining a meshing region CWE of the cutter and a workpiece in the machining process; s2, the rotation period of the cutter and a cutting edge participating in cutting are discretized, meshing information of the cutter and a workpiece in the machining process is extracted, and a chatter stability lobe graph of the complex-edge-type cutter under the given working condition is obtained through calculation in combination with the attribute of a machined material and the dynamic characteristics of the cutter; and S3, comparing the stability lobe diagrams of the cutters with different blade types, and selecting the cutter with the optimal blade type under the given working condition. According to the chatter prediction method for the complex blade type cutter machining process based on digital twinning, on the basis of a digital twinning model, calculation and analysis are conducted by dispersing the cutter rotation period and the blade in combination with the material and cutter characteristics, and a stability lobe graph is drawn.

The application discloses a kind of thin-walled part double-sided milling processing system dynamics modeling method, the coupling effect between the tool radial vibration and the vibration in the thickness direction of thin-walled part is considered first in the method, the dynamic cutting thickness corresponding to each blade microelement of milling cutter located on the two sides of thin-walled part is calculated, then the dynamic cutting force acting on tool-thin-walled part system is calculated.The cutting force perpendicular to the thickness direction of the two sides of thin-walled part is applied to the milling cutter on the two sides respectively, the resultant force of the cutting force in the thickness direction of thin-walled part is applied to thin-walled part itself, the dynamics control equation of thin-walled part double-sided milling processing system is established, and the stability solution is carried out to the equation.Compared with the given document, the coupling effect between the tool radial vibration and the vibration in the thickness direction of thin-walled part is considered in the application to establish the cutting force and dynamics model of thin-walled part double-sided milling processing system, and the prediction accuracy of thin-walled part double-sided milling stability lobe diagram is improved.

The application discloses an aviation part machining process optimization method, device, medium and program product, and relates to the field of machining. The aviation part machining process optimization method comprises the following steps: acquiring milling parameter orthogonal test data of an aircraft feature part; drawing a milling stability lobe diagram of the aircraft feature part according to the milling parameter orthogonal test data and a zero-order frequency domain method; creating a feature part machining process parameter library according to the milling stability lobe diagram of the aircraft feature part and the milling parameter orthogonal test data of the aircraft feature part; and performing aircraft part module pre-machining experiments according to the type of the feature part of a current aircraft part to be machined and the feature part machining process parameter library, so as to obtain optimized machining correlation data of the current aircraft part to be machined. The technical scheme of the embodiment of the application can guarantee the machining efficiency of the aircraft structural part, and simultaneously consider the cost and machining precision.

The invention discloses a milling chatter stability domain prediction method and system based on an approximate analysis method, and the method comprises the steps: employing a Fourier approximation method to represent a milling steady-state response based on a milling direction coefficient and a time delay characteristic in a milling dynamic model; applying small disturbance to the steady-state response, substituting the steady-state response into the milling dynamic model, and obtaining a milling stability analysis expression by applying a Galerkin process; substituting the bifurcation condition into the stability analysis expression based on the characteristics of the stability domain boundary corresponding to the milling stability bifurcation condition, and deducing an approximate implicit analytical expression of the milling stability boundary; solving the implicit analytical expression by adopting a numerical continuation method to obtain a stability boundary expressed by rotating speed-cutting depth; according to the method, the stability lobe graph is obtained, the problems of initial continuation point selection and transition between lobes with different stability in the solving process are solved, complete and accurate construction of the stability lobe graph is achieved, theoretical guidance of flutter-free working conditions is provided for milling, and the method has important engineering application value.

The invention particularly relates to an industrial robot milling stability prediction method considering structural nonlinearity. The industrial robot milling stability prediction method comprises the steps that frequency response functions under different exciting forces are obtained through a modal test experiment; performing fairing processing on the frequency response function to obtain a frequency response function after fairing; identifying modal parameters by using a frequency domain decomposition method; in combination with the identified modal parameters, obtaining a fitting model of the exciting force and the modal mass, the modal stiffness and the modal damping; based on a fitting model of the exciting force and the modal mass, the modal stiffness and the modal damping, establishing a mapping database of the nonlinear modal parameters and the exciting force in each direction; and based on the mapping database of the nonlinear modal parameters and the exciting force in each direction, establishing a dynamic differential equation of the compensation mapping model, and solving the dynamic differential equation of the compensation mapping model through a full discrete method to obtain a milling stability lobe graph. By means of the method, stability prediction under different feeding speeds in the milling machining process of the robot can be achieved.

This application discloses an anti-chatter machining optimization method and system for deep cavity milling of welded structural components for engineering machinery. The method includes: constructing a digital twin of the welded structural component of the engineering machinery containing the welding residual stress field; performing a deep cavity milling chatter stability pre-simulation based on the digital twin to determine the limiting depth of cut of the three-dimensional stability lobe diagram; constructing a multi-objective optimization model based on the limiting depth of cut and the digital twin, and solving for the optimized cutting parameters; the multi-objective optimization model uses spindle speed, feed rate, depth of cut, and tool extension length as optimization variables, with the objectives of maximizing material removal rate and minimizing surface roughness and vibration energy, and the constraints include chatter stability constraints, machine tool power constraints, machine tool torque constraints, surface roughness constraints, and tool life constraints.

The present invention provides a method for predicting the milling stability of thin-walled parts with multiple mass points and multiple modes considering the modal coupling effect, which includes the following steps: meshing the milling cutter and the thin-walled part to establish a multi-mass-point and multi-mode milling dynamics model; considering the modal coupling effect of each mass point and introducing a multi-order modal vibration mode matrix to correct the milling dynamics model; calculating the change of the instantaneous cutting-in angle and cutting-out angle according to the action of the milling cutter helix angle on the cutting surface of the cutter tooth and the thin-walled part micro-element; establishing a state space equation with periodic time delay according to the multi-mass-point and multi-mode milling dynamics model of the thin-walled part considering the modal coupling effect; constructing a reconstructed Newton-Cotes fitting method to calculate the transfer matrix according to the periodic time delay term of the discretized state space equation; outputting a three-dimensional stability lobe diagram according to the transfer matrix reduction and dimension reduction method and improving the output efficiency.

The invention discloses a damping modeling method for a milling process of a thin-wall component under multi-factor speed direction change, which belongs to the technical field of electromechanics, and comprises the following steps of: firstly, representing a chip load matrix and a force coordinate transformation matrix according to an actual cutting speed influenced by a multi-directional vibration effect in a feeding direction, a feeding normal direction and a cutter shaft direction of a milling system; then, based on a periodic milling force expression and Taylor expansion simplification processing at a forced vibration position, solving of a milling dynamic force component, a process damping force component and a static force component is carried out, a cutting resultant force matrix is obtained, finally, a cutting resultant force expression is substituted into a milling system dynamics control equation, solving is carried out according to a time domain semi-discrete method, and a milling system dynamic control equation is obtained. According to the stability lobe graph of the damping effect in the milling process of the thin-wall component, the multi-factor speed direction change is considered, and the application range of the model under different working conditions is remarkably widened.

The application provides a kind of thin-walled structure milling chatter suppression method and device based on spindle speed parameter adaptive control, electronic equipment, storage medium, according to stability lobe diagram, determine continuous variable speed dominant area and discrete variable speed dominant area, form complete variable speed milling chatter suppression method: if in low speed area, use sine continuous variable speed modulation, optimize modulation parameters based on energy minimization criterion and generate continuous variable speed curve;If in high speed area, calculate stable target speed according to phase difference matching condition, and generate discrete speed sequence through low-pass filtering and saturation constraint processing;When stability improvement amplitude is lower than threshold value, the speed is divided into discrete variable speed dominant area, and discrete variable speed strategy is used.The application does not need additional vibration suppression device or hardware modification, has the advantages of simple implementation and low cost, and has significant effect in improving machining stability and efficiency.

The invention relates to a blisk blade tip grinding method and a blisk assembly. The method comprises the steps that a blisk is provided; providing a plurality of elastic constraining pieces; any two blades in the m blades of the blisk are respectively surrounded and fastened with the elastic restraining pieces, n layers of elastic restraining pieces are surrounded and fastened along the height direction of the blades, and n is greater than or equal to 1, so that each blade is elastically restrained; and the blade tip of the blade is ground. According to the method, the non-predictive or uncontrollable grinding problem can be effectively avoided, the blade grinding state is stabilized, the rotor blisk grinding qualification rate is increased, and the actual performance requirement of an engine is met.

The invention discloses a method and a system for predicting a frequency response function of an offset rotating and swinging head based on a spinor transformation matrix. The method comprises the following steps of: establishing a frequency response function prediction model with two sub-structures connected with rotating shafts; according to the frequency response function prediction models of the two substructures with the rotating shafts connected, obtaining knife handle end frequency response function prediction models in the rotating and swinging states of the offset type rotating and swinging head; a machine tool spindle end frequency response function prediction model in any rotating and swinging state is obtained through the frequency response function matrixes of the machine tool spindle end in the four orthogonal attitudes; and through a substructure coupling method, obtaining a frequency response function prediction model under any cutter handle-cutter combination. According to the invention, on one hand, the problem that the frequency response function difference is large due to the change of the rotating and swinging posture of the offset rotating and swinging head is solved, and on the other hand, the problem that the frequency response function needs to be tested again due to frequent tool changing in the machining process of large curved surface parts is solved; and a certain foundation is laid for accurate calculation of the stability lobe graph of the boring and milling machine.

The utility model discloses a shockproof connecting structure with a blade shaft penetrating through a wind wheel circular frame, and relates to the technical field of wind power generation, the shockproof connecting structure comprises the wind wheel circular frame, a horizontal shaft support circular frame and the blade shaft, the wind wheel circular frame is fixed outside the horizontal shaft support circular frame, and the wind wheel circular frame is provided with a through hole for mounting the blade shaft; blades are fixedly installed at the positions, on the inner side and the outer side of the wind wheel round frame, of the blade shaft, a pulling piece is arranged at the end, close to the horizontal shaft support round frame, of the blade shaft and connected with the horizontal shaft support round frame, and a shockproof assembly used for stabilizing the blades is arranged on the blade shaft. The vibration of the blades can be weakened or even eliminated, long-term rigid collision between the blades and the wind wheel circular frame is prevented, and the phenomena of bracket breakage and serious potential safety hazard factors caused by screw looseness are reduced.

The application provides a method and device for improving the stability of side milling of a thin-walled part, and belongs to the technical field of ultrasonic vibration machining.The method comprises the following steps: determining the amplitude and frequency required by an ultrasonic vibration assisted milling device, designing the device, and exciting the device; analyzing the separation law and characteristics of ultrasonic longitudinal torsional vibration, and determining a cutting thickness expression; constructing a dynamic milling force model of ultrasonic longitudinal torsional vibration based on the cutting thickness expression; establishing an ultrasonic longitudinal torsional vibration milling thin-walled part dynamics model based on the dynamic milling force model of ultrasonic longitudinal torsional vibration; performing a modal experiment on the ultrasonic vibration assisted milling system, and obtaining the modal parameters of the thin-walled part; then, performing a groove milling experiment and calibrating the milling force coefficient; obtaining the machining parameters, tool parameters and ultrasonic vibration parameters of the thin-walled part to be side milled; then, solving the ultrasonic longitudinal torsional vibration milling thin-walled part dynamics model, and obtaining a stability lobe diagram; and the stability, machining precision and machining quality of the milling of the thin-walled part are improved.

The application discloses a complex blade type cutter machining process chatter prediction method based on digital twinning, which comprises the following steps: S1, based on the digital twinning model, the milling process of the complex blade type cutter is simulated, and the meshing area CWE of the cutter and the workpiece in the machining process is obtained; S2, the cutter rotation period and the cutting blade participating in cutting are discretized, the meshing information of the cutter and the workpiece in the machining process is extracted, the material properties and the dynamic characteristics of the cutter are combined, and the chatter stability lobe diagram of the complex blade type cutter under a given working condition is calculated and obtained; S3, the stability lobe diagrams of different blade type cutters are compared, and the optimal blade type cutter under the given working condition is selected. The complex blade type cutter machining process chatter prediction method based on digital twinning disclosed by the application is based on the digital twinning model, the cutter rotation period and the blade are discretized, the material and the cutter characteristics are combined for calculation and analysis, and the stability lobe diagram is drawn.