CN105242634A - Numerical control machine tool processing limit cutting depth predication method - Google Patents

Abstract

The invention provides a numerical control machine tool processing limit cutting depth predication method. The method comprises steps: an inner diameter and an outer diameter of a numerical control machine tool electric spindle, an inner diameter and an outer diameter of a tool handle and a diameter of a tool are acquired; an electric spindle finite element model, a tool handle finite element model and a tool finite element model are built; an electric spindle-tool handle-tool joint surface finite element model is built; modal testing and dynamic simulation are carried out, and a tool tip frequency response function is obtained; and according to the tool tip frequency response function, a limit cutting depth is obtained. The numerical control machine tool processing limit cutting depth predication method provided by the invention is a new joint dynamic characteristic simulation method, the electric spindle-tool handle-tool joint surface is simplified into a distribution spring, and on the basis of a parallel rotor modeling idea, a finite element method is adopted to complete finite element modeling of the spindle system. The method of the invention considers the connection form between joints more thoroughly and simulates contact stiffness generated by a different contact position respectively.

Description

A kind of numerically-controlled machine manufacturing limit cutting depth Forecasting Methodology

Technical field

The invention belongs to CNC processing technology field, specifically a kind of numerically-controlled machine manufacturing limit cutting depth Forecasting Methodology.

Background technology

Cutting stability during machine tooling is the important indicator weighing machine tooling performance always, in actual process, limit cutting depth be characterize cutting stability the most effectively, the most direct parameter, and can represent by drawing lobe figure, as shown in Figure 1, a cutting stability leaf lobe figure that () is single-mode system, the cutting stability leaf lobe figure that (b) is many-degrees of freedom system.B in figure _limindicate the maximum axial cutting depth without flutter processing, the region in figure more than lobe curve, working angles has flutter to occur, for instability is cut; At least limit cutting width b _lim(b below the horizontal dotted line that-crit is corresponding _lim<b _lim-crit) region, cutting state does not change with the speed of mainshaft, is all stable cutting; At b _limmore than the horizontal dotted line that-min is corresponding, along transverse axis (rotating speed n) stable region, direction appearance alternate with range of instability from left to right, cutting depth constantly increases from left to right with speed of mainshaft n, drop in lobe curve shadow region and cut for unstable, dropping between two shadow regions and cut for stable, is condition stability region.The calculating of limit cutting depth as shown in formula (1),

$b_{\lim }=\frac{-1}{2\&times;Z\&times;K_f\&times;G\left({\mathrm{\&omega;}}_c\right)}---\left(1\right)$

Wherein, Z is the cutter number of teeth; K _ffor Cutting Force Coefficient; G (ω _c) be system frequency response function real part.As can be seen from formula, except the cutter number of teeth and Cutting Force Coefficient, point of a knife point frequency response function is the key factor affecting cutting depth.

At present in the process of research cutting system point of a knife point frequency response function, the method of usual employing Dynamic Modeling emulation, through long-term research accumulation, back shaft is undertaken the construction of and is extensively approved the impact of system, and the emphasis of therefore modeling concentrates on main shaft bearing position.The simulation form of bearing, from simple spring damping model, arrives the kinetic model considering bearing characteristics; The introducing form of bearing, from rigidity and damping constant, arrives the power and displacement relation of considering the conditions such as rotating speed, friction and lubrication; High rotating speed brings out in addition gyroscopic couple, axle system and the impact of bearing ball centrifugal force on high-speed spindle system point of a knife point frequency response function are also embodied in modeling process.

But, along with the fast development of the sophisticated manufacturings such as Aero-Space, modern industry is to the continuous lifting of machine finish and product surface roughness requirements, the result causing traditional power modeling analysis to obtain cannot meet processing needs, so researcher starts again to think deeply the part being once left in the basket when setting up main shaft-handle of a knife-tooling system kinetic model or simplifying, the dynamics of main shaft-cutter handle combining part and handle of a knife-cutter joint portion is taken seriously gradually.Be interconnected the part playing transmission power and precision between main shaft, handle of a knife and cutter and be called main shaft-handle of a knife-cutter faying face.High-speed spindle system main shaft-handle of a knife faying face mostly is taper, and handle of a knife-cutter faying face mostly is cylindrical (as shown in Figure 2), for ensureing that axis system can operate safely and reliably, faying face needs to have high geometric accuracy, height repeats the characteristic such as precision and high rigidity that is installed, and therefore main shaft-handle of a knife-cutter faying face has important impact to high-speed spindle system dynamics.

Be illustrated in figure 2 the enlarged drawing of main shaft-handle of a knife-cutter faying face broken section, as can be seen from the figure, 2 parts are comprised: a part is electro spindle-handle of a knife faying face 5 at main shaft-handle of a knife-cutter faying face, it is the part that handle of a knife 2 inserts electro spindle 3, the tapered surface of contact of this part, produces friction force by the drag link mechanism direct effect of electro spindle 3; Another part is handle of a knife-cutter faying face 4, and be the part that cutter 1 inserts handle of a knife 2, this part is cylinder contacts face, plays the effect of aligned cutting tool 1, and cutter 1 is generally fixed with holding screw.

The existing method setting up main shaft-handle of a knife-cutter joint portion kinetic model comprises be rigidly connected model and concentrated spring model, these modeling pattern are that joint portion dynamics is represented by a constant rigidity value, although this joint portion modeling pattern ignores the way progress to some extent of joint portion than tradition, but be still in the trial stage to the description of joint portion dynamics, the joint portion kinetic model set up cannot accurate simulation main shaft-handle of a knife-cutter joint portion on the impact of high-speed spindle system point of a knife point frequency response function.

Summary of the invention

For the deficiency that prior art exists, the invention provides a kind of numerically-controlled machine manufacturing limit cutting depth Forecasting Methodology.

Technical scheme of the present invention is:

A kind of numerically-controlled machine manufacturing limit cutting depth Forecasting Methodology, comprising:

Step 1, obtain the diameter of the internal diameter of electric main shaft of digital control machine tool and external diameter, the internal diameter of handle of a knife and external diameter, cutter;

Step 2, set up electro spindle finite element model, handle of a knife finite element model, cutter finite element model;

Step 2-1, diameter according to the internal diameter of the internal diameter of electric main shaft of digital control machine tool and external diameter, handle of a knife and external diameter, cutter, select Timoshenko beam element to set up finite element model, the finite element model of handle of a knife, the finite element model of cutter of electro spindle respectively;

Step 2-2, divide electro spindle-handle of a knife faying face, handle of a knife-cutter faying face structure with multidiameter form, form electro spindle-handle of a knife faying face shaft part except electro spindle shaft part, handle of a knife shaft part, cutter shaft part and handle of a knife-cutter faying face shaft part;

Step 2-3, at electro spindle shaft part near handle of a knife one end, handle of a knife shaft part increases a transition shaft part respectively near cutter one end, prepare for realizing rotor-support-foundation system group collection matrix in parallel;

Step 2-4, to electro spindle shaft part, handle of a knife shaft part and cutter shaft part order carry out nodal scheme, set up electro spindle finite element model, handle of a knife finite element model, cutter finite element model respectively;

Step 3, set up electro spindle-handle of a knife-cutter faying face finite element model;

Step 3-1, select spring distribution density, spring radical, spring rate and damping, set up the distributed spring model of electro spindle-handle of a knife-cutter faying face according to electro spindle-handle of a knife faying face and multidiameter that handle of a knife-cutter faying face divides;

Step 3-2, the rigidity of electro spindle-handle of a knife faying face, handle of a knife-cutter faying face and damping are distributed to every root spring according to spring distribution density, form the distributed spring damping model of electro spindle-handle of a knife-cutter faying face;

Step 3-3, by the distributed spring damping model of electro spindle-handle of a knife-cutter faying face and electro spindle finite element model, handle of a knife finite element model, cutter finite element model group collection, foundation is outer rotor with main shaft, handle of a knife is internal rotor, the finite element model of the two-in-parallel rotor-support-foundation system that handle of a knife is outer rotor, cutter is internal rotor, namely considers the complete high-speed spindle system finite element model of electro spindle-handle of a knife-cutter faying face feature;

Step 4, carry out mould measurement and dynamics simulation, obtain point of a knife point frequency response function;

The complete high-speed spindle system finite element model that step 4-1, utilization are set up carries out mould measurement and dynamics simulation;

Step 4-2, utilize mode test result and dynamical simulation results to contrast, revise the quantity and the spring distribution density that obtain distributed spring in complete high-speed spindle system finite element model;

Step 4-3, mode and response analysis are carried out to revised complete high-speed spindle system finite element model, obtain point of a knife point frequency response function;

Step 5, obtain limit cutting depth according to point of a knife point frequency response function.

Beneficial effect:

Numerically-controlled machine manufacturing limit cutting depth Forecasting Methodology provided by the invention is a kind of new joint portion dynamics analogy method, electro spindle-handle of a knife-cutter faying face is reduced to distribution spring, and based on the idea about modeling of rotor in parallel, adopt finite element method to complete the finite element modeling of axis system.This method not only can consider the type of attachment between joint portion more fully, can also simulate respectively the contact stiffness that different contact position produces simultaneously.

Accompanying drawing explanation

Fig. 1 is cutting stability leaf lobe figure, the cutting stability leaf lobe figure that (a) is single-mode system, the cutting stability leaf lobe figure that (b) is many-degrees of freedom system;

Fig. 2 is the enlarged drawing of main shaft-handle of a knife-cutter faying face broken section, wherein, and 1-cutter, 2-handle of a knife, 3-electro spindle, 4-handle of a knife-cutter faying face, 5-electro spindle-handle of a knife faying face;

Fig. 3 is the adjacent cells group collection schematic diagram of the specific embodiment of the invention;

Fig. 4 is the two-in-parallel rotor-support-foundation system matrix group collection schematic diagram of the specific embodiment of the invention;

Fig. 5 is the electric chief axis system schematic diagram of the specific embodiment of the invention, 6-main shaft-bearing combining part;

Fig. 6 is the distributed spring model of the electro spindle-handle of a knife-cutter faying face of the specific embodiment of the invention; Wherein (a) structure diagram for utilizing distributed spring to simulate electro spindle-handle of a knife faying face, (b) is the finite element model of electro spindle-handle of a knife faying face, 7-spring-damping element;

Fig. 7 is the electro spindle-handle of a knife joint surface unit stiffness matrix group collection schematic diagram of the specific embodiment of the invention;

Fig. 8 is the electro spindle-handle of a knife faying face spring-damping element structural drawing of the specific embodiment of the invention;

Fig. 9 is the numerically-controlled machine manufacturing limit cutting depth Forecasting Methodology process flow diagram of the specific embodiment of the invention;

Figure 10 is the complete high-speed spindle system finite element model of the consideration electro spindle-handle of a knife-cutter faying face feature of the specific embodiment of the invention;

Figure 11 is the test system structure block diagram of the specific embodiment of the invention;

Figure 12 is the simulation result of the specific embodiment of the invention and the comparison diagram of test figure;

Figure 13 is the different distributions formula spring model simulation simulation result of Contact characteristics and the comparison diagram of test figure of the specific embodiment of the invention.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is elaborated.

A kind of numerically-controlled machine manufacturing limit cutting depth Forecasting Methodology, as shown in Figure 9, comprising:

Step 1, obtain the diameter of the internal diameter of electric main shaft of digital control machine tool and external diameter, the internal diameter of handle of a knife and external diameter, cutter;

Step 2, set up electro spindle finite element model, handle of a knife finite element model, cutter finite element model;

Using numerically-controlled machine as take electro spindle as outer rotor, handle of a knife is internal rotor, the two-in-parallel rotor-support-foundation system that handle of a knife is outer rotor, cutter is internal rotor, in the finite element discretization process of two-in-parallel rotor-support-foundation system, serial number is carried out to cell node, and at outer rotor ending place increase by one section of transition section, internal rotor continue transition section numbering, the cross section information (comprising length, external diameter and internal diameter) of transition section is arbitrarily given.First group collection process writes out quality and the stiffness matrix of all unit comprising transition section, then the group collection of global matrix is carried out, subsequently the quality of transition section and stiffness matrix are removed from the matrix after group collection, form mass matrix M and the stiffness matrix K of two-in-parallel rotor-support-foundation system.

Suppose an outer rotor p unit, an internal rotor q unit, then whole two-in-parallel rotor-support-foundation system has p+q+1 unit, and nodes is N, N=p+1+1+1+q+1.Because each node has 6 degree of freedom, each unit has 2 nodes, therefore the quality of each unit and stiffness matrix are 12 × 12 rank square formations, and group collection carries out with stacking pattern as shown in Figure 3 between adjacent cells, then total 6N the degree of freedom of whole two-in-parallel rotor-support-foundation system (comprising transition section), the stiffness matrix obtaining whole system is 6N × 6N rank; From the matrix obtained, remove 12 × 12 square formations of transition section after group has collected, form the complete quality of two-in-parallel rotor-support-foundation system and stiffness matrix, as shown in Figure 4.

Step 2-1, diameter according to the internal diameter of the internal diameter of electric main shaft of digital control machine tool and external diameter, handle of a knife and external diameter, cutter, Timoshenko beam element is selected to set up finite element model, the finite element model of handle of a knife, the finite element model of cutter of electro spindle respectively, wherein electro spindle finite element model comprises main shaft-bearing combining part, and simulates with spring-damping element;

Step 2-2, divide electro spindle-handle of a knife faying face, handle of a knife-cutter faying face structure with multidiameter form, form electro spindle-handle of a knife faying face shaft part except electro spindle shaft part, handle of a knife shaft part, cutter shaft part and handle of a knife-cutter faying face shaft part;

Step 2-3, at electro spindle shaft part near handle of a knife one end, handle of a knife shaft part increases a transition shaft part respectively near cutter one end, prepare for realizing rotor-support-foundation system group collection matrix in parallel;

Step 2-4, to electro spindle shaft part, handle of a knife shaft part and cutter shaft part order carry out nodal scheme, set up electro spindle finite element model, handle of a knife finite element model, cutter finite element model respectively;

Step 3, set up electro spindle-handle of a knife-cutter faying face finite element model;

Because electro spindle-handle of a knife-cutter faying face is not self-existent, but the key component in complete axis system, therefore, the modeling of faying face also will combine with axis system modeling.Utilize rotor-support-foundation system thought in parallel, set up the distributed spring model of electro spindle-handle of a knife-cutter faying face, and the parameters such as the layout density (representing with the distance between adjacent springs) of the quantity of spring of determining to distribute, spring, spring rate and damping.Wherein the quantity of distributed spring and spring distribution density need to utilize experimental test result and simulation result to carry out contrast correction and obtain.

It is outer rotor that electro spindle-handle of a knife-cutter faying face constitutes with electro spindle, handle of a knife is internal rotor, handle of a knife outer rotor, cutter are the two-in-parallel rotor-support-foundation system of internal rotor, Fig. 5 is electric chief axis system schematic diagram, below for electro spindle-handle of a knife faying face, the analogy method of electro spindle-handle of a knife-cutter faying face dynamics is described.As shown in Figure 6, (a) for utilizing the structure diagram of distributed spring analog main shaft-handle of a knife taper faying face, (b) is the finite element model of electro spindle-handle of a knife faying face.Electro spindle finite element model comprises main shaft-bearing combining part 6, and simulates with spring-damping element 7.

Step 3-1, select spring distribution density, spring radical, spring rate and damping, set up the distributed spring model of electro spindle-handle of a knife-cutter faying face according to electro spindle-handle of a knife faying face and multidiameter that handle of a knife-cutter faying face divides;

Step 3-2, the rigidity of electro spindle-handle of a knife faying face, handle of a knife-cutter faying face and damping are distributed to every root spring according to spring distribution density, form the distributed spring damping model of electro spindle-handle of a knife-cutter faying face;

Suppose that electro spindle-handle of a knife (taper) faying face is divided into n ladder shaft part, n+1 switching node, respectively with the node i on electro spindle, i+1 ..., node j on i+n and handle of a knife, j+1 ... j+n represents.Due to corresponding two internodal relative motions, the bonding force Δ F of coupling on electro spindle node _p(p=i, i+1 ... i+n) the bonding force Δ F and on handle of a knife node _q(q=j, j+1 ... j+n) be respectively:

${\mathrm{\&Delta;F}}_i=K_{coup}{X}_i+C_{coup}{\stackrel{\&CenterDot;}{X}}_i-K_{coup}{X}_j-C_{coup}{\stackrel{\&CenterDot;}{X}}_j$

${\mathrm{\&Delta;F}}_j=K_{coup}{X}_j+C_{coup}{\stackrel{\&CenterDot;}{X}}_j-K_{coup}{X}_i-C_{coup}{\stackrel{\&CenterDot;}{X}}_i$

${\mathrm{\&Delta;F}}_{i+1}=K_{coup}{X}_{i+1}+C_{coup}{\stackrel{\&CenterDot;}{X}}_{i+1}-K_{coup}{X}_{j+1}-C_{coup}{\stackrel{\&CenterDot;}{X}}_{j+1}$

${\mathrm{\&Delta;F}}_{j+1}=K_{coup}{X}_{j+1}+C_{coup}{\stackrel{\&CenterDot;}{X}}_{j+1}-K_{coup}{X}_{i+1}-C_{coup}{\stackrel{\&CenterDot;}{X}}_{i+1}---\left(2\right)$

.

.

.

${\mathrm{\&Delta;F}}_{i+n}=K_{coup}{X}_{i+n}+C_{coup}{\stackrel{\&CenterDot;}{X}}_{i+n}-K_{coup}{X}_{j+n}-C_{coup}{\stackrel{\&CenterDot;}{X}}_{j+n}$

${\mathrm{\&Delta;F}}_{j+n}=K_{coup}{X}_{j+n}+C_{coup}{\stackrel{\&CenterDot;}{X}}_{j+n}-K_{coup}{X}_{i+n}-C_{coup}{\stackrel{\&CenterDot;}{X}}_{i+n}$

Wherein, K _coupand C _couprepresent coupling stiffness and the damping of electro spindle-handle of a knife faying face respectively.Rigidity between the node of often pair of relative motion and damping matrix use K respectively _cand C _crepresent, arrange and become matrix form:

Be divided at electro spindle-handle of a knife faying face place and be furnished with n+1 root spring-damping element, each spring-damping element can use the matrix representation in formula (3), by n+1 spring rate matrix group collection in electro spindle-handle of a knife-handle of a knife system stiffness matrix, as shown in Figure 7.

The coupling stiffness of electro spindle-handle of a knife faying face and damping as shown in Figure 8, comprise translation rigidity k _c, translation damping c _cand rotational stiffness k _θ, rotary damping c _θ, concrete form is such as formula shown in (4).

$\begin{array}{cc}{K}_{coup}=\left[\begin{array}{cccccc}0& 0& 0& 0& 0& 0\\ 0& k_{yy}& k_{yz}& 0& 0& 0\\ 0& k_{zy}& k_{zz}& 0& 0& 0\\ 0& 0& 0& k_{\mathrm{\&theta;}}& 0& 0\\ 0& 0& 0& 0& 0& 0\\ 0& 0& 0& 0& 0& 0\end{array}\right]& C_{coup}=\left[\begin{array}{cccccc}0& 0& 0& 0& 0& 0\\ 0& c_{yy}& c_{yz}& 0& 0& 0\\ 0& c_{zy}& c_{zz}& 0& 0& 0\\ 0& 0& 0& c_{\mathrm{\&theta;}}& 0& 0\\ 0& 0& 0& 0& 0& 0\\ 0& 0& 0& 0& 0& 0\end{array}\right]\end{array}---\left(4\right)$

Step 3-3, by the distributed spring damping model of electro spindle-handle of a knife-cutter faying face and electro spindle finite element model, handle of a knife finite element model, cutter finite element model group collection, foundation is outer rotor with electro spindle, handle of a knife is internal rotor, the finite element model of the two-in-parallel rotor-support-foundation system that handle of a knife is outer rotor, cutter is internal rotor, namely considers the complete high-speed spindle system finite element model of electro spindle-handle of a knife-cutter faying face feature;

Step 4, carry out mould measurement and dynamics simulation, obtain point of a knife point frequency response function;

The complete high-speed spindle system finite element model that step 4-1, utilization are set up carries out mould measurement and dynamics simulation;

Step 4-2, utilize mode test result and dynamical simulation results to contrast, revise the quantity and the spring distribution density that obtain distributed spring in complete high-speed spindle system finite element model;

Step 4-3, mode and response analysis are carried out to revised complete high-speed spindle system finite element model, obtain point of a knife point frequency response function;

Step 5, obtain limit cutting depth according to point of a knife point frequency response function.

On VMC0540d Super High-speed Milling machining center, this method is realized in present embodiment, the HCS150 type electro spindle of German GMN company installed by this machining center, this electro spindle maximum speed can reach 42000r/min, peak power output 30kW, and BBT50-MEGA32D-165 handle of a knife is installed and HLXX32 scabbles straight shank end mill.Set up the electro spindle-handle of a knife-cutter finite element model considering faying face according to actual electrical axis system structure, as shown in Figure 10, in figure, 1-29 segment table shows spindle motor unit, and 31-54 segment table shows handle of a knife unit, and 56-66 segment table shows knife unit; 30 sections and 55 segment tables show transition section; 66 segment tables show point of a knife point; 4 sections, 5 sections, 12 sections, 19 sections and 20 segment tables show electro spindle interior support bearing; 21-29 section and corresponding 31-39 segment table show electro spindle-handle of a knife faying face; 48-54 section and corresponding 56-62 segment table show handle of a knife-cutter faying face.The concrete size of electro spindle, handle of a knife, cutter is as shown in table 1, table 2, table 3.

Table 1 electro spindle size/mm

Table 2 handle of a knife size/mm

Table 3 slotting cutter size/mm

PULSE system is Denmark Br ü el & the first in the world noise that company released in 1996, vibration multi-analyser system, can carry out simultaneously hyperchannel, in real time, FFT, CPB, the analysis such as total level value.PULSE system platform comprises software and hardware two parts.Hardware components is 17 passage Portable Data-Acquisition System 3560-C of B & K company, and software section is that 7700 type platform softwares combine with ME ' the scope analysis software of VibrantTechnology company.Gather the 4525B type three-dimensional acceleration transducer that response signal utilizes B & K company.In present embodiment, employing power hammer encourages electric chief axis system, select plastics tup, gather pumping signal and use force snesor 8206-001, sensor and signal amplifier are all integrated in the middle of power hammer, main testing apparatus lists in table 4, and test system building as shown in figure 11.

The main testing apparatus table of table 4

What utilization proposed sets up electro spindle-handle of a knife-cutter faying face model and utilizes rotor thought in parallel to complete the foundation of whole electric chief axis system model, the response of computing system subsequently, obtains point of a knife point frequency response function.Figure 12 shows that the comparison diagram of simulation result and test figure, as can be seen from the figure, the simulation result that distribution spring connecting analog faying face model specific rigidity connects is closer to test data.Figure 13 is the different distributions formula spring model simulation simulation result of Contact characteristics and the comparison diagram of test figure, as can be seen from the figure 5 sections of distributed springs are than the simulate effect of 10 sections of distributed springs closer to test findings, illustrate that the impact of the arrangement form of distributed spring on electric chief axis system point of a knife point frequency response function is comparatively obvious.

Table 5 lists the different simulation result of modeling method of faying face and the difference of test figure, comprises the spring connection that is rigidly connected, concentrates spring to connect and distributes, and also studied the distribution form of distribution spring to the impact of electric chief axis system natural frequency simultaneously.Due to the existence of the inevitable artificial interference factor in environment, operating mode, boundary condition and test process in process of the test, test result does not embody rigid mode vibration, and testing the mode result that obtains still can the inherent characteristic of image study object qualitatively.As can be seen from the table, suppose that faying face is that rigidly connected simulation result differs comparatively large, wherein maximum difference 158% with experimental test result, the error of minimum also existence 82.65%; And concentrate the simulation result in spring and distributed spring-loaded floating die quasi-step matrix face compared with being rigidly connected more close to experimental test result; Wherein distributed spring analog result is than concentrated spring simulation better effects if.Layout of spring form is larger on simulation result impact, simulation result and the test figure of 5 sections of distribution springs contrast, control errors is within 5%, more even more ideal than 10 sections of distribution spring analog results, this is because it is close faying face to be divided into other element lengths in the length of each unit after 5 sections and system, therefore simulation result is more close actual, it can be said that the arrangement form of bright distribution spring is not more close better, but with system in other element lengths are close is advisable.

The natural frequency contrast table of the different faying face model of table 5 and test figure

Electro spindle-handle of a knife-cutter faying face modeling is the Important Problems of research high-speed spindle system dynamic perfromance, and groundwork and conclusion comprise:

1) method utilizing distributed spring to carry out analog electrical main shaft-handle of a knife-cutter faying face dynamics is proposed, and set up axis system finite element model based on rotor-support-foundation system in parallel, and cook up the complete axis system finite element modeling flow process comprising electro spindle-handle of a knife-cutter faying face modeling;

2) can draw according to Simulation and test comparative analysis, for the modeling method of electro spindle-handle of a knife-cutter faying face, distributed spring model specific rigidity connects and concentrates spring model closer to experimental test result, more effective to the simulation of electro spindle-handle of a knife-cutter faying face;

3) arrangement form of distribution spring is not more close better, but is advisable with the similar length of other unit of system, and faying face modeling now can reflect actual conditions the most truly.

Suitable layout of spring is selected to realize distributed spring model, the practical situations of high speed electric principal shaft system can be reflected the simulation of electro spindle-handle of a knife-cutter faying face dynamics more truly, to high speed electric principal shaft system stability analysis, there is guiding significance.

Claims (2)

1. a numerically-controlled machine manufacturing limit cutting depth Forecasting Methodology, is characterized in that, comprising:

Step 1, obtain the diameter of the internal diameter of electric main shaft of digital control machine tool and external diameter, the internal diameter of handle of a knife and external diameter, cutter;

Step 2, set up electro spindle finite element model, handle of a knife finite element model, cutter finite element model;

Step 2-1, diameter according to the internal diameter of the internal diameter of electric main shaft of digital control machine tool and external diameter, handle of a knife and external diameter, cutter, select Timoshenko beam element to set up finite element model, the finite element model of handle of a knife, the finite element model of cutter of electro spindle respectively;

Step 2-2, divide electro spindle-handle of a knife faying face, handle of a knife-cutter faying face structure with multidiameter form, form electro spindle-handle of a knife faying face shaft part except electro spindle shaft part, handle of a knife shaft part, cutter shaft part and handle of a knife-cutter faying face shaft part;

Step 2-3, at electro spindle shaft part near handle of a knife one end, handle of a knife shaft part increases a transition shaft part respectively near cutter one end, prepare for realizing rotor-support-foundation system group collection matrix in parallel;

Step 2-4, to electro spindle shaft part, handle of a knife shaft part and cutter shaft part order carry out nodal scheme, set up electro spindle finite element model, handle of a knife finite element model, cutter finite element model respectively;

Step 3, set up electro spindle-handle of a knife-cutter faying face finite element model;

Step 3-1, select spring distribution density, spring radical, spring rate and damping, set up the distributed spring model of electro spindle-handle of a knife-cutter faying face according to electro spindle-handle of a knife faying face and multidiameter that handle of a knife-cutter faying face divides;

Step 3-2, the rigidity of electro spindle-handle of a knife faying face, handle of a knife-cutter faying face and damping are distributed to every root spring according to spring distribution density, form the distributed spring damping model of electro spindle-handle of a knife-cutter faying face;

Step 3-3, by the distributed spring damping model of electro spindle-handle of a knife-cutter faying face and electro spindle finite element model, handle of a knife finite element model, cutter finite element model group collection, foundation is outer rotor with main shaft, handle of a knife is internal rotor, the finite element model of the two-in-parallel rotor-support-foundation system that handle of a knife is outer rotor, cutter is internal rotor, namely considers the complete high-speed spindle system finite element model of electro spindle-handle of a knife-cutter faying face feature;

Step 4, carry out mould measurement and dynamics simulation, obtain point of a knife point frequency response function;

Step 5, obtain limit cutting depth according to point of a knife point frequency response function.

2. numerically-controlled machine manufacturing limit cutting depth Forecasting Methodology according to claim 1, it is characterized in that, the concrete steps of described step 4 are as follows:

The complete high-speed spindle system finite element model that step 4-1, utilization are set up carries out mould measurement and dynamics simulation;

Step 4-2, utilize mode test result and dynamical simulation results to contrast, revise the quantity and the spring distribution density that obtain distributed spring in complete high-speed spindle system finite element model;

Step 4-3, mode and response analysis are carried out to revised complete high-speed spindle system finite element model, obtain point of a knife point frequency response function.