CN211234298U

CN211234298U - Main shaft radial rotation error measuring device based on cooperative target grating

Info

Publication number: CN211234298U
Application number: CN202020323889.8U
Authority: CN
Inventors: 刘阳; 张勇飞; 林杰; 金岸; 金鹏
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2020-03-16
Filing date: 2020-03-16
Publication date: 2020-08-11
Anticipated expiration: 2030-03-16

Abstract

A main shaft radial rotation error measuring device based on a cooperative target grating belongs to the technical field of manufacturing and measuring of precision instruments; in the device, a beam shaping device is fixed on the rotary end face of a measured spindle, an annular scale grating is fixed above the beam shaping device, a twill indicating grating is positioned above the annular scale grating, a photoelectric conversion device is fixed above the twill indicating grating, an electronic signal processing part is positioned above the photoelectric conversion part, a light source is positioned in the radial direction of the working face of the beam shaping device, and a collimation and beam expansion system is positioned between the light source and the beam shaping device; the beam shaping device is overlapped with the axis of the measured spindle, the annular scale grating is overlapped with the axis of the beam shaping device, the twill indicating grating is overlapped with the axis of the annular scale grating, and the photoelectric conversion component is overlapped with the axis of the twill indicating grating; by combining the cooperative target grating with the photoelectric conversion device, the manufacturing cost of the device is greatly reduced, and the measurement precision is improved.

Description

Main shaft radial rotation error measuring device based on cooperative target grating

Technical Field

The utility model relates to a radial gyration error measuring device, concretely relates to radial gyration error measuring device of main shaft based on cooperation target grating belongs to precision instruments and makes and measure technical field.

Background

The technical demand for high-speed spindles is increasing with the continuous development of semiconductor and ultra-clean processing technologies. The spindle speed range is increased from thousands of revolutions per minute to tens of thousands of revolutions per minute, the spindle axis accuracy is continuously improved, wherein the radial rotation error is improved from hundreds of micrometers to dozens of micrometers or even several micrometers. Therefore, the measurement of the radial rotation error of the high-speed spindle is more important. The main shaft rotation error is one of key indexes reflecting the dynamic performance of the machine tool, the minimum shape error, the surface quality and the roughness which can be achieved by the machine tool under an ideal processing condition can be predicted through testing and analyzing the rotation error, the main shaft rotation error can also be used for machine tool processing prediction and compensation control, the reason of the generated processing error is judged, the state monitoring and fault diagnosis of the machine tool are realized, and an important test basis is provided for the machine tool main shaft rotation error prediction and control.

At present, in the aspect of measuring radial rotation errors of a high-speed spindle, the spindle rotation speed of a spindle error analyzer SEA of a certain company can be higher than 60000rpm, and the measurement accuracy can reach 25 micrometers, but the measurement method is consistent with the method mentioned by GJB1801-93, the sampling frequency of a capacitive sensor is 10KHz at most, if the rotation speed reaches 60000rpm, the spindle axis point shaking frequency is 1KHz, according to the national military standard GJB1801-93 roundness evaluation standard, the sampling frequency of the capacitive sensor is at least higher than 128KHz, only a small wave number can be measured by 10KHz, and the high-frequency shaking quantity of a shaft system cannot be measured, so that high-accuracy measurement cannot be realized. Therefore, the method has important significance for researching the testing technology of the high-speed spindle rotation error.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a radial gyration error measuring device of main shaft based on cooperation target grating to there is the not enough problem of limitation in solving present high-speed main shaft radial gyration error measurement method.

A spindle radial rotation error measuring device based on a cooperative target grating comprises a light source assembly, a beam shaper, an annular scale grating, a twill indicating grating, a photoelectric conversion part and an electronic signal processing part;

the beam shaper is fixedly arranged on the rotary end face of the spindle to be measured, the beam shaper and at least one group of light source components are positioned in the same plane, the beam shaper is sequentially provided with an annular scale grating, a twill indicating grating, a photoelectric conversion part and an electronic signal processing part, and the beam shaper, the annular scale grating, the twill indicating grating, the photoelectric conversion part, the electronic signal processing part and the spindle to be measured are coaxially arranged.

Preferably: the light source component comprises a light source and a collimation and beam expansion system, the light source is positioned in the radial direction of the working face of the light beam shaper, the collimation and beam expansion system is arranged between the light source and the light beam shaper, and the collimation and beam expansion system is coaxial with the light beam generated by the light source.

The utility model discloses compare with current product and have following effect:

the utility model discloses according to radial gyration error measuring device, through combining cooperation target grating and photoelectric conversion device, turn into the radial gyration error of main shaft into the displacement of moire fringe, utilize photoelectric conversion device to have the characteristic of high sampling frequency, and the high sampling frequency capacitance sensor that does not adopt the value to reach million yuan measures high-speed main shaft developments radial gyration error, has greatly reduced measuring device's manufacturing cost, and this is one of the innovation point of difference prior art;

the utility model discloses an one of the core device is cooperation target grating, and grating measurement system based on moire fringe principle has many advantages such as measurement resolution is high, the precision is high, with low costs as a typical displacement sensor. The measurement accuracy is determined by the grid pitch of the cooperative target grating, and the measurement accuracy which is much higher than that obtained by a measurement device based on a capacitance sensor can be obtained by improving the line density of the cooperative target grating, which is the second innovation point of the difference from the prior art.

Drawings

FIG. 1 is a schematic structural diagram of a spindle radial rotation error measuring device based on a cooperative target grating according to the present invention.

FIG. 2 is a schematic diagram of the structure of a ring scale grating.

Fig. 3 is a schematic diagram of a diagonal indicating grating structure.

FIG. 4 is a flow chart of a spindle radial rotation error measurement method based on a cooperative target grating according to the present invention.

In the figure: the device comprises a light source 1, a collimation and beam expansion system 2, a light beam shaper 3, an annular scale grating 4, a twill indicating grating 5, a photoelectric conversion part 6, an electronic signal processing part 7 and a measured spindle 8.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1 to 4, the device for measuring the spindle radial rotation error based on the cooperative target grating of the present invention includes a light source assembly, a light beam shaper 3, an annular scale grating 4, a twill indicating grating 5, a photoelectric conversion component 6, and an electronic signal processing component 7;

the light beam shaper 3 is fixedly arranged on the rotary end face of the measured spindle 8, the light beam shaper 3 and at least one group of light source components are positioned in the same plane, an annular scale grating 4, a twill indicating grating 5, a photoelectric conversion part 6 and an electronic signal processing part 7 are sequentially arranged on the light beam shaper 3, and the light beam shaper 3, the annular scale grating 4, the twill indicating grating 5, the photoelectric conversion part 6, the electronic signal processing part 7 and the measured spindle 8 are coaxially arranged.

Further: the light source component comprises a light source 1 and a collimation and beam expansion system 2, the light source 1 is located in the radial direction of the working face of a light beam shaper 3, the collimation and beam expansion system 2 is arranged between the light source 1 and the light beam shaper 3, and the collimation and beam expansion system 2 is coaxial with light beams generated by the light source 1.

The light source can be a laser (matched with the wavelength of the photodiode), the collimation beam expanding system can be a laser collimation beam expanding lens group, the light beam shaper can be a pyramid prism, the photoelectric conversion device can be a photodiode, and the electronic signal processing component can be a signal processing circuit and an upper computer.

The working mode is that the method comprises the following steps:

step a, determining the position of a uniform angle radius according to the number of light sources, wherein the uniform angle radius is a radius which equally divides a 180-degree central angle into n parts, and n is the number of the light sources;

b, adjusting the positions of the light source and the collimation and beam expansion system to enable the collimation and beam expansion system to be coaxial with the light beam generated by the light source, and enabling the light beam emitted by the light source to vertically enter the equal angle radius of the annular scale grating after passing through the collimation and beam expansion system and a light beam shaping device;

c, adjusting the distance between the annular scale grating and the twill indicating grating to enable transmitted light generated by the annular scale grating to pass through the twill indicating grating to form moire fringes;

d, adjusting the photoelectric conversion component to enable moire fringes generated by the twill indicating grating to form a clear pattern on the photoelectric conversion component;

e, the measured main shaft rotates at a constant speed at an angular speed theta rad/s;

f, continuously recording the light and shade change information of the moire fringes within the time length T by the electronic signal processing part;

step g, synthesizing the radial displacement vector of the annular scale grating at the moment according to the change condition of the Moire fringes;

h, evaluating the radial rotation error of the measured spindle according to the radial displacement vector of the annular scale grating;

a flow chart of this mode of operation is shown in fig. 4.

Wherein:

the following relation exists between the sampling time T of the electronic signal processing part and the detected spindle rotation angular speed theta in the step f: t is 2 pi/theta;

the vector synthesis in step g comprises the following steps:

step g1, combining every two straight lines of adjacent equal angular radii according to the number n of the light sources to form (n-1) coordinate systems, wherein the included angle between two axes of the coordinate systems is alpha, wherein: α ═ pi/n;

step g2, carrying out vector synthesis pairwise according to the detected radial displacement, wherein the synthesized vector is the radial rotation error of the main shaft to be detected under the coordinate system, and the synthesized vector and the radial displacement detected on the equally divided radial line have the following relation:

wherein A is₁，A₂A is respectively a radial displacement mode and a synthetic vector mode in the directions of two coordinate axes, α is an included angle of the two coordinate axes, β and theta are respectively included angles of the synthetic vector and the two radial displacements;

step h, evaluating the radial rotation error E of the spindle (1) to be tested as follows: e max (a).

This embodiment is only illustrative of the patent and does not limit the scope of protection thereof, and those skilled in the art can make modifications to its part without departing from the spirit of the patent.

Claims

1. A spindle radial rotation error measuring device based on a cooperative target grating is characterized in that: the device comprises a light source component, a light beam shaper (3), an annular scale grating (4), a twill indicating grating (5), a photoelectric conversion component (6) and an electronic signal processing component (7);

the light beam shaper (3) is fixedly arranged on the rotary end face of a measured spindle (8), the light beam shaper (3) and at least one group of light source components are located in the same plane, an annular scale grating (4), a twill indicating grating (5), a photoelectric conversion part (6) and an electronic signal processing part (7) are sequentially arranged on the light beam shaper (3), the annular scale grating (4), the twill indicating grating (5), the photoelectric conversion part (6), the electronic signal processing part (7) and the measured spindle (8) are coaxially arranged.

2. A cooperative-target-grating-based spindle radial rotation error measurement apparatus as claimed in claim 1, wherein: the light source assembly comprises a light source (1) and a collimation and beam expansion system (2), the light source (1) is located in the radial direction of the working face of a light beam shaper (3), the collimation and beam expansion system (2) is arranged between the light source (1) and the light beam shaper (3), and light beams generated by the collimation and beam expansion system (2) and the light source (1) are coaxial.