CN210859477U

CN210859477U - Laser tracker target ball assembly fixture

Info

Publication number: CN210859477U
Application number: CN201921573714.6U
Authority: CN
Inventors: 郑剑和
Original assignee: Suzhou Jiehui Intelligent Measurement Technology Co ltd
Current assignee: Suzhou Jiehui Intelligent Measurement Technology Co ltd
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2020-06-26
Anticipated expiration: 2029-09-20

Abstract

The utility model provides a laser tracker target ball assembly fixture, target ball assembly fixture contain mould and lower mould, are equipped with the locating piece that is located the frock center and is used for installing steel ball organism and retroreflector in the lower mould, install the horizontal locater in one side of locating piece, are fixed with the guide pillar on the lower mould, go up the mould and install on the guide pillar and go up the mould and can follow the guide pillar and reciprocate, upward be equipped with on the mould and be used for carrying out the locating surface of fixing a position to the target ball, be equipped with the vertical locater that equally is located the frock center on last mould. The utility model discloses can further improve the positioning accuracy of retroreflector and steel ball organism, reduce veneer assembly error as far as possible to this reduces target ball optics center error, optical device adopts unique quick and the assembly methods of batch high accuracy with spheroidal installation, makes the efficiency of assembly improve greatly, thereby reduces the cost of production.

Description

Laser tracker target ball assembly fixture

Technical Field

The utility model relates to a measuring instrument technical field, concretely relates to laser tracker target ball assembly fixture.

Background

The Laser Tracker (Laser Tracker) is a high-precision large-space three-dimensional measuring instrument, integrates advanced technologies such as a Laser ranging technology, a photoelectric detection technology, a precision mechanical technology, a computer and control technology, a modern numerical calculation theory and the like, tracks a space moving target (target ball) and measures a space three-dimensional coordinate of the target in real time. Generally, the system comprises a high-precision laser ranging module (an ADM absolute ranging module or an additional IFM laser interferometer), an azimuth grating encoder and a servo motor thereof, a pitch grating encoder and a servo motor thereof, a position sensing tracking module, a precision level meter, a meteorological station and the like. The method has the characteristics of high precision, high efficiency, real-time tracking measurement, quick installation, simple and convenient operation and the like, and is widely applied to three-dimensional industrial measurement of large-size objects such as aerospace ship heavy industry wind power automobile machinery and the like.

Target ball, SMR (SMR), also known as spherical hollow retroreflector, the core component is a cube corner retroreflector consisting of three high-precision mutually perpendicular optical reflecting surfaces, which is formed by gluing three pieces of glass (or machined by aluminum columns), the retroreflector is glued on a perforated high-precision stainless steel ball, reflects the beam of a laser tracker, provides the target for a laser tracking and ranging system, is similar to a three-coordinate spherical probe, and requires that the optical center of the retroreflector and the center of the steel ball be as coincident as possible in order to reduce the measurement error caused by the target ball, there is another form of target ball, the optical hollow cube corner is directly machined on the steel ball, and is made into three mutually perpendicular mirror surfaces, the mirror surfaces are generally plated with films (gold, silver or aluminum) because there is no inlay (glass or aluminum) as the reflective surface, the target ball can withstand some degree of impact (so as not to damage the surface of the ball).

According to the currently used technology, a high-precision steel ball is generally machined by stainless steel to form a ball body with a cavity, due to the limitation of the machinability of the steel ball in the prior art, the machinability of the steel ball limits the surface hardness of the steel ball to be not too high, the roundness can be adversely affected after the cavity machining, the surface of the steel ball needs to be subjected to a large number of frequent contact measurements with a workpiece, the steel ball is easy to wear and cause error increase, and therefore the steel ball is easy to scrap, and the outer surface needs to be re-machined to recover the due precision of the steel ball.

The optical retroreflector in the prior art adopts a very expensive device to perform long-period precision machining treatment and complex precision machining on aluminum materials to form an optical reflection mirror surface with extremely high requirements, so that the machining cost is high;

the assembly of the optics with the target sphere ball requires careful adjustment and testing by a high-level technician to glue the optics to the ball. The preparation requirement of the glue is extremely strict, the assembly and the gluing are carried out with high precision, the glue is required to have very high dimensional stability, the shrinkage rate is close to 0, the gluing performance is kept normal in the temperature range of-40 to 60 ℃, and meanwhile, the anti-vibration capability and the peeling strength are required to be quite high. In the existing gluing technology, the phenomenon of degumming of an optical device occurs, or the error is increased due to the fact that the optical center is greatly deviated after the optical device is used for a period of time, so that the target ball is discarded or only degraded to be used as a defective product.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a laser tracker target ball assembly fixture for the assembly degree of difficulty of solving the target ball is high, the assembly precision is poor, optical device takes place the displacement easily, comes unstuck, the not enough scheduling problem of precision.

The utility model provides a laser tracker target ball assembly fixture, this target ball assembly fixture contain mould and lower mould, are equipped with the locating piece that is located the frock center and is used for installing steel ball organism and retroreflector in the lower mould, install horizontal locater in one side of locating piece, are fixed with the guide pillar on the lower mould, go up the mould and install on the guide pillar and go up the mould and can follow the guide pillar and reciprocate, upward be equipped with on the mould and be used for carrying out the locating surface of fixing a position to the target ball, be equipped with the vertical locater that equally is located the frock center on last mould.

Further, the upper die is provided with a guide sleeve, and the upper die is arranged on the guide pillar through the guide sleeve.

Furthermore, the positioning surface is an arc surface matched with the surface of the target ball.

Furthermore, the arc center of the positioning surface is superposed with the center lines of the positioning block and the longitudinal positioning instrument.

Adopt above-mentioned the utility model discloses technical scheme's beneficial effect is: the utility model discloses a laser tracker target ball assembly fixture further improves the positioning accuracy of retroreflector and steel ball organism through this assembly fixture's use, reduces veneer assembly error as far as possible to this reduces target ball optics center error, and optical device adopts unique quick and the assembly methods of batch high accuracy with spheroidal installation, makes the efficiency of assembly improve greatly, thereby reduces the cost of production.

Drawings

Fig. 1 is a schematic structural diagram of a first embodiment of the present invention;

FIG. 2 is a schematic view of the embodiment of the present invention after a target ball is installed;

FIG. 3 is a Zygo interferogram.

In the figure:

1-upper mould; 2-lower mould; 3-positioning a block; 4-a transverse positioning instrument; 5-guide pillar; 6-positioning surface; 7-guide sleeve; 8-steel ball machine body; 9-a retroreflector; 10-longitudinal positioning instrument.

Detailed Description

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention.

As shown in fig. 1, the embodiment of the utility model provides a laser tracker target ball assembly fixture has been proposed, this target ball assembly fixture contains mould 1 and lower mould 2, be equipped with the locating piece 3 that is located the frock center and is used for installing steel ball organism 8 and retroreflector 9 in the lower mould 2, install horizontal locater 4 in one side of locating piece 3, be fixed with guide pillar 5 on lower mould 2, it installs on guide pillar 5 and go up mould 1 and can follow guide pillar 5 and reciprocate to go up mould 1, it installs guide pin bushing 7 to go up mould 1, it installs through guide pin bushing 7 to go up mould 1 on the guide pillar 5, upward be equipped with the locating surface 6 that is used for fixing a position the target ball on mould 1, the arcwall face that locating surface 6 agrees with the target ball surface is equipped with the vertical locater 10 that is located the frock center equally on last mould 1, the arc center of locating. By using the assembly tool, the positioning accuracy of the retroreflector 9 and the steel ball machine body 8 is further improved, so that the optical center errors of the target ball, namely the transverse error and the longitudinal error, are reduced.

Use the laser tracker target ball that above-mentioned assembly fixture produced to need carry out optical testing, optics center error test result is shown as table 1, in addition the test of relevant other parameters is seen figure 3, figure 3 is the Zygo interferogram, adopts the Zygo interferometer to measure the multinomial index of laser tracker target ball and obtains the result of 3, has dihedral angle error in the result, and the synthetic angle error, detection results such as central wave front distortion, it shows to use the embodiment of the utility model provides an in the embodiment of the target ball frock and the produced laser tracker target ball of target ball assembly method accord with each item test requirement.

Serial number	Mirror type	Numbering	Optical center error/mm
				1	SMR1.5in	JHM6007	0.005
2	SMR0.5in	JHM8027	0.003

TABLE 1

The following description of experimental parameter terms related to target spheres:

dihedral Angle error (Dihedral-Angle error): on the three reflecting surfaces of an ideal cube corner, the angle between two adjacent mirror surfaces is exactly 90 degrees. Whereas the actual cube corner reflecting surfaces always differ from each other by 90 degrees from the theoretical angle, the difference is typically measured in arc seconds. This difference is called dihedral angle error.

Maximum laser integrated angle error (Max Beam development): theoretically, a laser beam should be coaxial with the incident beam and form 180 degrees after being reflected back through the target sphere. Due to the manufacturing error of the retroreflector, the actually reflected light beam always has an error of several arc seconds with the incident light beam, and the errors of the incident light beam and the incident light beam are different, wherein the error of the maximum laser reflection angle is called as the maximum laser synthetic angle error.

Central wavefront distortion: including effects due to flatness of the panel and dihedral angle errors, both of which affect the wavefront of the laser beam returning from the reflector. Since the laser beam reflected by the laser tracker requires the return path, in the reflection area of the target ball, the area with the diameter of about 7mm near the central point is the most concentrated place of the laser beam energy, and the wave front distortion value is the key.

Polarization error: laser light reflected back into the laser, whether inside an Interferometer (IFM) or an Absolute Distance Meter (ADM), may be sensitive to polarization. If the laser tracker is sensitive to polarization, the reflective properties of the mirror coating of the target sphere become important. The target ball therefore requires a relevant quantitative test to know the polarization properties of the produced target ball.

Optical center error: the optical center error is one of the key indicators of the quality of target ball manufacture. It can be decomposed into lateral and longitudinal errors. The lateral error refers to the radius between the orbit circle of the optical reflection center and the target ball rotation center (sphere center point) after the target ball rotates around the axis of the opening circle for a circle at the fixed magnetic base. Longitudinal error, the deviation of the reflection center from the center of the steel ball of the target ball along the axial direction of the opening circle.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. The utility model provides a laser tracker target ball assembly fixture which characterized in that: the target ball assembling tool comprises an upper die and a lower die, wherein a positioning block which is located at the center of the tool and used for installing a steel ball machine body and a retroreflector is arranged in the lower die, a transverse position indicator is installed on one side of the positioning block, a guide pillar is fixed on the lower die, the upper die is installed on the guide pillar, the upper die can move up and down along the guide pillar, a positioning surface used for positioning a target ball is arranged on the upper die, and a longitudinal position indicator which is also located at the center of the tool is arranged on the upper die.

2. The laser tracker target ball assembly fixture of claim 1, characterized in that: the upper die is provided with a guide sleeve, and the upper die is arranged on the guide pillar through the guide sleeve.

3. The laser tracker target ball assembly fixture of claim 1, characterized in that: the positioning surface is an arc surface matched with the surface of the target ball.

4. The laser tracker target ball assembly fixture of claim 3, characterized in that: the arc center of the positioning surface is superposed with the center lines of the positioning block and the longitudinal positioning instrument.