CN103162807A - System for testing compound vibration of machine tool - Google Patents

Abstract

The invention discloses a system for testing compound vibration of a machine tool. The system comprises the machine tool with a spindle (9) and a working table (26) and a compound vibration testing device matched with the spindle (9) and the working table (26) and is characterized in that (a) points A and B are selected on one side of the surface of the spindle (9) and symmetrically positioned on the upper and lower parts of a plane of the spindle (9), a strongly reflective material is coated at a circumference on which the points A and B are positioned and which takes the axis of the spindle (9) as the center of a circle, a fixed point is selected on the working table (26), and a strongly reflective material is coated on the fixed point; and (b) the compound vibration testing device comprises an optical system which consists of a helium-neon laser, a plurality of polarization light-splitters, a plurality of reflectors, a plurality of photoelectric detectors and a plurality of lenses. According to the system, the spindle compound vibration condition and a vibration measurement system of the working table are integrated to form a complete vibration measurement system, and various vibration components on assigned cross sections of the spindle and working table of the machine tool can be simultaneously detected.

Description

Lathe compound vibration test macro

Technical field the invention belongs to the optical measurement field, specifically a kind ofly the vibration of machine tool chief axis and worktable is carried out the system of composite measurement based on laser-Doppler vibration measuring principle.

The vibration that produces during the work of background technology lathe can cause the amplitude of main shaft or worktable to exceed the scope of permission, so not only can affect the dynamic accuracy of lathe and the quality of part to be processed, but also can reduce production efficiency and cutting wear, vibrate and even can reduce the usability of lathe when violent, when serious, will make the lathe cisco unity malfunction.Therefore, very important to machine vibration test and monitoring running state.

Traditional machine vibration is measured and is mainly passed through contact type measurement, dual mode is arranged usually: the first reflects the vibration of lathe indirectly by the vibration survey of lathe static part, what this kind method reflected is the synthesis oscillation of lathe whole service process, can not directly obtain the true vibrational state of machine tool chief axis and worktable; It two is that various sensors are installed on respectively on the main shaft and worktable of lathe, and measured signal need transmit by wireless transmit mode or collector ring.But this mode has certain interference to the vibrational state of lathe itself on the one hand, and also very inconvenience of the installation of sensor on the other hand affects when spindle operation greatly especially.Therefore study a kind of more suitably machine vibration measuring method imperative.

Laser-Doppler vibration measuring technology is a kind of remote noncontact vibration measurement technique, and has the advantages such as detection sensitivity is high, dynamic detection range large, strong adaptability.although it detects principle and has proposed more than 50 year, but only there are several offshore companies that general commercialization detection system is provided at present, the laser-Doppler vibration detection of various different purposes still has very large development space, a kind of full optical fiber laser Doppler vibrometer is disclosed for No. 201110385923.X as Chinese patent application, utilize optical Doppler effect to pass through Z orientation measurement assembly, directions X is measured assembly, Y-direction is measured assembly and is recorded respectively vibrating object three-dimensional vibration velocity, this invention is completed vibrating object three-dimensional vibration velocity by each assembly combination and is measured.Yet so far there are no, this detection technique is applied to the bibliographical information of the monitoring running state of the noncontact vibration survey of machine tool chief axis and worktable and lathe.

Therefore this detection technique is applied to the noncontact vibration survey of machine tool chief axis and worktable and the monitoring running state of lathe is significant.

Summary of the invention the objective of the invention is to design for overcoming traditional contact vibration measurement method to the deficiency of machine vibration measurement the laser Doppler measuring optical system that realizes the test of lathe compound vibration.This system can measure the Vibration Condition of transverse vibration, axial vibration, twisting vibration and the worktable of machine tool chief axis.

The technical solution used in the present invention is: a kind of lathe compound vibration test macro comprises that the compound vibration proving installation with main shaft (9) and worktable (26) coordinate is characterized in that with the lathe of main shaft (9) and worktable (26):

A, select A, B 2 points in the surperficial side of main shaft (9), it is upper and lower that A, B two point symmetry ground are positioned at main shaft (9) surface level, 2 places of A, B scribble strong reflective material take main shaft (9) axle center on the circumference in the center of circle, and in the upper fixed point of selecting of worktable (26), coat strong reflective material in this fixed point;

The composition of b, compound vibration proving installation is: be provided with a laser instrument (19), polarization spectroscope (18) is housed on the light path of laser instrument (19);

catoptron (20) is housed on the reflected light path of polarization spectroscope (18), polarization spectroscope (21) is housed on the reflected light path of catoptron (20), catoptron (30) is housed on the reflected light path of polarization spectroscope (21), polarization spectroscope (28) is housed on the reflected light path of catoptron (30), catoptron (22) is housed on the reflected light path of polarization spectroscope (28), photodetector (29) is housed on the reflected light path of catoptron (22), lens (25) are housed on the transmitted light path of polarization spectroscope (28), the upper fixed point of selecting of worktable (26) is positioned on the transmitted light path of lens (25), polarization spectroscope (24) is housed on the transmitted light path of polarization spectroscope (21), catoptron (23) is housed on the reflected light path of polarization spectroscope (24), photodetector (27) is housed, on the transmitted light path of the transmitted light path that the fixed point of selecting on worktable is positioned at polarization spectroscope (24) simultaneously after through lens (25) on the reflected light path of catoptron (23),

polarization spectroscope (17) is housed on the transmitted light path of polarization spectroscope (18), catoptron (1) is housed on the reflected light path of polarization spectroscope (17), polarization spectroscope (2) is housed on the reflected light path of catoptron (1), catoptron (16) is housed on the reflected light path of polarization spectroscope (2), polarization spectroscope (12) is housed on the reflected light path of catoptron (16), catoptron (4) is housed on the reflected light path of polarization spectroscope (12), photodetector (13) is housed on the reflected light path of catoptron (4), lens (8) are housed on the transmitted light path of polarization spectroscope (12), and the intersection point as the circumference in the center of circle take main shaft (9) axle center at main shaft (9) surface level and A, B 2 places is positioned on the transmitted light path of lens (8), polarization spectroscope (6) is housed on the transmitted light path of polarization spectroscope (2), catoptron (5) is housed on the reflected light path of polarization spectroscope (6), photodetector (11) is housed on the reflected light path of catoptron (5), and intersection point is positioned at the transmitted light path of polarization spectroscope (6) simultaneously again on the light path after lens (8) transmission,

Polarization spectroscope (14) is housed on the transmitted light path of polarization spectroscope (17), catoptron (3) is housed on the reflected light path of polarization spectroscope (14), lens (7) are housed on the reflected light path of catoptron (3), and the A point is positioned on the transmitted light path of lens (7); Lens (10) are housed on the transmitted light path of polarization spectroscope (14), and the B point is positioned on the transmitted light path of lens (10);

Also be provided with the photodetector (15) of the scattered light of surveying 2 of A, B in the compound vibration proving installation.

Further scheme is: strong reflective material is glass microballoon, in order to strengthen dispersion effect.

Further scheme is: laser instrument (19) is helium-neon laser (19).

Native system also should be built signal system and optics vibration-isolating platform, the attached rod member of various supports etc. routinely.In building systematic procedure, key is to note the unified adjustment of optical focusing system, optical device layout etc., makes the light beam that converges to the corresponding light electric explorer interfere.

Advantage of the present invention is: this optical system can composite measurement goes out the compound vibration situation of lathe.Innovation of the present invention mainly is the Vibration-Measuring System of the measurement of machine tool chief axis compound vibration and worktable integrated, forms a complete Vibration-Measuring System, can detect simultaneously the various oscillating components of machine tool chief axis and worktable.By the cross section that continuous change detects, can complete the Measurement and analysis to lathe body vibration state, this raising to machine tool capability is significant.

And information extracting device generally need to be added or reequip to traditional machine vibration detection method on lathe, tends to be subject to the restriction of objective condition, and for example rotary main shaft does not allow to shut down sensor installation, and vibration has brought difficulty to Real-Time Monitoring for this.This laser-Doppler vibration-testing optical system adopts one road light beam multiplex light splitting, make this system to measure the pure twisting vibration of machine tool chief axis, simultaneously also can measure and decompose the resultant vibration of twisting vibration and transverse vibration, axial vibration, and vibration that can also measuring machine bed worktable, thereby expanded greatly the range of application of vibration monitoring, realized that the compound vibration of machine tool chief axis and worktable is measured.In addition, this system does not need lathe is added or the repacking information extracting device, compares with classic method, and this vibration test system range of dynamic measurement is large, real-time, is easy to realize on-line monitoring.

Description of drawings

Fig. 1 is the schematic diagram of the embodiment of lathe compound vibration test macro.

In figure, code name is respectively: 1, catoptron; 2, polarization spectroscope; 3, catoptron; 4, catoptron; 5, catoptron; 6, polarization spectroscope; 7, lens; 8, lens; 9, main shaft; 10, lens; 11, photodetector; 12, polarization spectroscope; 13, photodetector; 14, polarization spectroscope; 15, photodetector; 16, catoptron; 17, polarization spectroscope; 18, polarization spectroscope; 19, helium-neon laser; 20, catoptron; 21, polarization spectroscope; 22, catoptron; Device; 28, polarization spectroscope; 29, photodetector; 30, catoptron.

Embodiment

Further describe formation of the present invention and principle of work below in conjunction with Fig. 1.But the invention is not restricted to the following example.

As Fig. 1, a kind of lathe compound vibration test macro comprises the lathe with main shaft 9 and worktable 26, and the compound vibration proving installation that coordinates with main shaft 9 and worktable 26 is characterized in that:

A, select A, B 2 points in the surperficial side of main shaft 9, it is upper and lower that A, B two point symmetry ground are positioned at main shaft 9 surface levels, 2 places of A, B scribble strong reflective material take main shaft 9 axle center on the circumference in the center of circle, and select a fixed point on worktable 26, coat strong reflective material in this fixed point;

The composition of b, compound vibration proving installation is: be provided with a laser instrument 19, polarization spectroscope 18 is housed on the light path of laser instrument 19;

Catoptron 20 is housed on the reflected light path of polarization spectroscope 18, polarization spectroscope 21 is housed on the reflected light path of catoptron 20, catoptron 30 is housed on the reflected light path of polarization spectroscope 21, polarization spectroscope 28 is housed on the reflected light path of catoptron 30, catoptron 22 is housed on the reflected light path of polarization spectroscope 28, photodetector 29 is housed on the reflected light path of catoptron 22, lens 25 are housed on the transmitted light path of polarization spectroscope 28, and the fixed point of selecting on worktable 26 is positioned on the transmitted light path of lens 25; Polarization spectroscope 24 is housed on the transmitted light path of polarization spectroscope 21, catoptron 23 is housed on the reflected light path of polarization spectroscope 24, photodetector 27 is housed on the reflected light path of catoptron 23, and the fixed point of selecting on worktable is positioned at the transmitted light path of polarization spectroscope 24 simultaneously through on the transmitted light path after lens 25;

Polarization spectroscope 17 is housed on the transmitted light path of polarization spectroscope 18, catoptron 1 is housed on the reflected light path of polarization spectroscope 17, polarization spectroscope 2 is housed on the reflected light path of catoptron 1, catoptron 16 is housed on the reflected light path of polarization spectroscope 2, polarization spectroscope 12 is housed on the reflected light path of catoptron 16, catoptron 4 is housed on the reflected light path of polarization spectroscope 12, photodetector 13 is housed on the reflected light path of catoptron 4; Lens 8 are housed on the transmitted light path of polarization spectroscope 12, and the intersection point as the circumference in the center of circle take main shaft 9 axle center at main shaft 9 surface levels and A, B 2 places is positioned on the transmitted light path of lens 8; Polarization spectroscope 6 is housed on the transmitted light path of polarization spectroscope 2, catoptron 5 is housed on the reflected light path of polarization spectroscope 6, photodetector 11 is housed on the reflected light path of catoptron 5, and intersection point is positioned at the transmitted light path of polarization spectroscope 6 simultaneously again on the light path after lens 8 transmissions;

Polarization spectroscope 14 is housed on the transmitted light path of polarization spectroscope 17, catoptron 3 is housed on the reflected light path of polarization spectroscope 14, lens 7 are housed on the reflected light path of catoptron 3, the A point is positioned on the transmitted light path of lens 7; Lens 10 are housed on the transmitted light path of polarization spectroscope 14, and the B point is positioned on the transmitted light path of lens 10;

Also be provided with the photodetector 15 of the scattered light of surveying 2 of A, B in the compound vibration proving installation.

Strong reflective material is glass microballoon.Laser instrument 19 is helium-neon lasers 19.

During concrete enforcement, native system also should be built signal system and optics vibration-isolating platform, the attached rod member of various supports etc. routinely.In building systematic procedure, key is to note the unified adjustment of optical focusing system, optical device layout etc., makes the light beam that converges to the corresponding light electric explorer interfere.

Principle of work is:

The 632.8nm laser that is sent by helium-neon laser 19 is separated into the light beam that the two-way light intensity equates after polarization spectroscope 18, transmitted light beam wherein is used for machine tool chief axis 9 vibration surveys, and other one tunnel folded light beam is used for the vibration survey of platen 26.

Machine tool chief axis 9 vibration surveys: the transmitted light beam of 632.8nm laser through being separated into after polarization spectroscope 18 that is sent by helium-neon laser 19 is separated into the light beam that the two-way light intensity equates after polarization spectroscope 17, transmitted light beam wherein is used for the twisting vibration of machine tool chief axis and measures, other one tunnel light beam that equates, transmitted light beam wherein is used for the twisting vibration of machine tool chief axis to be measured, and other one tunnel folded light beam is through being used for machine tool chief axis 9 transverse vibration V after catoptron 1 _xWith axial vibration V _yMeasure.

The twisting vibration measuring beam is divided into by spectroscope 14 and catoptron 3 parallel beam that two beam intensities equate, horizontal direction incides two symmetric points A, the B up and down on machine tool chief axis 9 surfaces, machine tool chief axis 9 surfaces scribble glass microballoon, these 2 very strong surface scattering is arranged after laser beam can produce Doppler shift, and scattered light (in figure, dotted line represents) returns on spectroscope 14 along Yuan Lu and interferes, and completed reception and the detection of interference signal by bias voltage photodetector 15.1 can find out with reference to the accompanying drawings, and machine tool chief axis 9 not only has rotation, also has translation V.

According to the Doppler shift principle, frequency displacement all can occur in the light of returning from two symmetric points A, B scattering, and frequency shift value is respectively:

$f_A=\frac{2}{\mathrm{\λ}}\·\stackrel{\→}{i}\·(\stackrel{\→}{V}+{\stackrel{\→}{V}}_1)---\left(1\right)$

$f_B=\frac{2}{\mathrm{\λ}}\·\stackrel{\→}{i}\·(\stackrel{\→}{V}+{\stackrel{\→}{V}}_2)---\left(2\right)$

In two formulas, f _A, f _BIt is respectively the Doppler shift value of scattered beam A, B;

It is the vector of unit length (supposing that herein two incident lights are absolute parallel) on the incident beam direction.

Two bundles have the scattered light f of frequency displacement _A, f _BOn the photosurface of bias voltage photodetector 15, optical frequency mixing can occur, cause the voltage of bias voltage photodetector 15 outputs to be modulated by this mixing frequency difference, the mixing frequency difference is:

$f_D=f_A-f_B=\frac{2}{\mathrm{\λ}}\·\stackrel{\→}{i}\·({\stackrel{\→}{V}}_1-{\stackrel{\→}{V}}_2)---\left(3\right)$

Be the vector of unit length on machine tool chief axis 9 axis directions, N is rotational speed, has:

${\stackrel{\→}{V}}_1=2\mathrm{\πN}({\stackrel{\→}{R}}_1\×\stackrel{\→}{Z}),$ ${\stackrel{\→}{V}}_2=2\mathrm{\πN}({\stackrel{\→}{R}}_2\×\stackrel{\→}{Z})---\left(4\right)$

Got by formula (4):

${\stackrel{\→}{V}}_1-{\stackrel{\→}{V}}_2=2\mathrm{\πN}({\stackrel{\→}{R}}_1-{\stackrel{\→}{R}}_2)\×\stackrel{\→}{Z}=2\mathrm{\πN}(\stackrel{\→}{\mathrm{BA}}\×\stackrel{\→}{Z})---\left(5\right)$

Formula (5) substitution formula (3) is got:

$f_D=\frac{4\mathrm{\π}}{\mathrm{\λ}}\·N\·\stackrel{\→}{i}\·(\stackrel{\→}{\mathrm{BA}}\×\stackrel{\→}{Z})=\frac{4\mathrm{\π}}{\mathrm{\λ}}\·N\·(\stackrel{\→}{i}\×\stackrel{\→}{\mathrm{BA}})\·\stackrel{\→}{Z}=\frac{4\mathrm{\π}}{\mathrm{\λ}}\·N\·d\·\cos \mathrm{\γ}---\left(6\right)$

In formula (6), γ represents is angle between incident light place plane normal and machine tool chief axis axis.Make that β is the interplanar angle of axis and incident light place of machine tool chief axis, γ=90 °-β is arranged so, this formula substitution formula (6) is had

$f_D=\frac{4\mathrm{\π}}{\mathrm{\λ}}\·d\·N\·\sin \mathrm{\β}---\left(7\right)$

If the machine tool chief axis axis is vertical with plane, incident light place, namely

So can obtain:

$f_D=\frac{4\mathrm{\πd}}{\mathrm{\λ}}\·N---\left(8\right)$

Can get from formula (8):

1) bias voltage photodetector 15 output signal modulating frequency f _DBeing directly proportional to the transient speed N of machine tool chief axis, is that transient speed is measured;

2) as can be seen from Figure 1 machine tool chief axis has translation component V, but f _DBut irrelevant with V, also the rotation with axial float, diameter run-out and other direction of machine tool chief axis all has nothing to do, and the torsional oscillation of main shaft is reached fully with the translation vibration information separate;

3) f _DIrrelevant with the radius-of-curvature of main shaft, namely irrelevant with the cross sectional shape of tested main shaft, make it can be particularly suitable for the torsional vibration measurement of the noncircular cross section rotors such as cam, gear;

4) f _DLocation independent with incident beam to the measured axis xsect does not need complicated light path adjustment.

Laterally, the axial vibration measuring beam is separated into the identical light beam of the parallel intensity of two-way after polarization spectroscope 2.Wherein folded light beam is passed through catoptron 16, polarization spectroscope 12 successively, the directive lens 8 again, another Reuter's irradiating light beam passes through polarization spectroscope 2,6, lens 8 successively, then they be radiated at the middle part surface of machine tool chief axis 9 and be scattered (dotted line represents scattered light), and detector 13 and bias voltage photodetector 11 are completed reception and the detection of interference signal respectively.Can detect thus machine tool chief axis 9 measured point transverse vibration V _xWith axial vibration V _ySituation.

The signal that the bias voltage photodetector collects is namely known the synthesis oscillation situation of machine tool chief axis 9 again through functions such as the demonstration of signal processing system settling signal and analyses.

Platen 26 vibration surveys: the folded light beam of 632.8nm laser through being separated into after polarization spectroscope 18 of being sent by helium-neon laser 19 then is separated into the identical light beam of the parallel intensity of two-way by after polarization spectroscope 21 and catoptron 30 after catoptron 20.Wherein transmitted light beam is through polarization spectroscope 24, the directive lens 25 again, another Reuter's irradiating light beam is through polarization spectroscope 28, lens 25, they all are radiated at the surface of platen 26 and are scattered (platen 26 surfaces are coated glass microballoon and strengthened dispersion effect), scattered light (dotted line represents) is respectively at polarization spectroscope 28,24 and interfere through catoptron 22,23 light beam, and completed reception and the detection of interference signal by bias voltage photodetector 529 and bias voltage photodetector 27.Can detect the transverse vibration V of platen 26 measured points thus _xWith axial vibration V _ySituation.

This optical system can composite measurement goes out the compound vibration situation of lathe thus.

Claims (3)

1. lathe compound vibration test macro comprises that the compound vibration proving installation with main shaft (9) and worktable (26) coordinate is characterized in that with the lathe of main shaft (9) and worktable (26):

A, select A, B 2 points in the surperficial side of main shaft (9), it is upper and lower that A, B two point symmetry ground are positioned at main shaft (9) surface level, 2 places of A, B scribble strong reflective material take main shaft (9) axle center on the circumference in the center of circle, and in the upper fixed point of selecting of worktable (26), coat strong reflective material in this fixed point;

The composition of b, compound vibration proving installation is: be provided with a laser instrument (19), polarization spectroscope (18) is housed on the light path of laser instrument (19);

catoptron (20) is housed on the reflected light path of polarization spectroscope (18), polarization spectroscope (21) is housed on the reflected light path of catoptron (20), catoptron (30) is housed on the reflected light path of polarization spectroscope (21), polarization spectroscope (28) is housed on the reflected light path of catoptron (30), catoptron (22) is housed on the reflected light path of polarization spectroscope (28), photodetector (29) is housed on the reflected light path of catoptron (22), lens (25) are housed on the transmitted light path of polarization spectroscope (28), the upper fixed point of selecting of worktable (26) is positioned on the transmitted light path of lens (25), polarization spectroscope (24) is housed on the transmitted light path of polarization spectroscope (21), catoptron (23) is housed on the reflected light path of polarization spectroscope (24), photodetector (27) is housed, on the transmitted light path of the transmitted light path that the fixed point of selecting on worktable is positioned at polarization spectroscope (24) simultaneously after through lens (25) on the reflected light path of catoptron (23),

polarization spectroscope (17) is housed on the transmitted light path of polarization spectroscope (18), catoptron (1) is housed on the reflected light path of polarization spectroscope (17), polarization spectroscope (2) is housed on the reflected light path of catoptron (1), catoptron (16) is housed on the reflected light path of polarization spectroscope (2), polarization spectroscope (12) is housed on the reflected light path of catoptron (16), catoptron (4) is housed on the reflected light path of polarization spectroscope (12), photodetector (13) is housed on the reflected light path of catoptron (4), lens (8) are housed on the transmitted light path of polarization spectroscope (12), and the intersection point as the circumference in the center of circle take main shaft (9) axle center at main shaft (9) surface level and A, B 2 places is positioned on the transmitted light path of lens (8), polarization spectroscope (6) is housed on the transmitted light path of polarization spectroscope (2), catoptron (5) is housed on the reflected light path of polarization spectroscope (6), photodetector (11) is housed on the reflected light path of catoptron (5), and intersection point is positioned at the transmitted light path of polarization spectroscope (6) simultaneously again on the light path after lens (8) transmission,

Polarization spectroscope (14) is housed on the transmitted light path of polarization spectroscope (17), catoptron (3) is housed on the reflected light path of polarization spectroscope (14), lens (7) are housed on the reflected light path of catoptron (3), and the A point is positioned on the transmitted light path of lens (7); Lens (10) are housed on the transmitted light path of polarization spectroscope (14), and the B point is positioned on the transmitted light path of lens (10);

Also be provided with the photodetector (15) of the scattered light of surveying 2 of A, B in the compound vibration proving installation.

2. lathe compound vibration test macro according to claim 1, it is characterized in that: strong reflective material is glass microballoon.

3. lathe compound vibration test macro according to claim 1, it is characterized in that: laser instrument (19) is helium-neon laser (19).

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