CN112033287A

CN112033287A - Optical lens center thickness measuring and positioning clamp

Info

Publication number: CN112033287A
Application number: CN202010779499.6A
Authority: CN
Inventors: 冯志镖
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-08-05
Filing date: 2020-08-05
Publication date: 2020-12-04

Abstract

The invention relates to a positioning fixture for measuring the central thickness of an optical lens, which comprises an elastic positioning fixture, an elastic sheet and an air source cavity, wherein the elastic positioning fixture, the elastic sheet and the air source cavity are sequentially arranged from top to bottom, a petal-type elastic chuck is arranged on the elastic positioning fixture, and an air source enters the air source cavity to deform or reset the elastic sheet so as to control the elastic chuck of the elastic positioning fixture to open or clamp. According to the positioning fixture for measuring the central thickness of the optical lens, disclosed by the invention, the optical lens is fixed by utilizing the elastic positioning fixture arranged on the air source cavity, and the elastic sheet is deformed or reset by entering the air source cavity through the air source so as to control the elastic chuck of the elastic positioning fixture to open or clamp, so that the functions of putting in, clamping, fixing and taking out the optical lens are realized.

Description

Optical lens center thickness measuring and positioning clamp

Technical Field

The invention relates to the technical field of positioning fixtures, in particular to a measuring and positioning fixture for measuring the center thickness of an optical lens.

Background

In the optical field, three basic parameters of an optical lens are central thickness, refractive index and curvature radius, wherein the error of processing the central thickness of the optical lens is an important factor influencing the imaging of an optical system. For example, in high-precision optical system products such as aviation and aerospace, strict requirements are imposed on the tolerance of an optical lens, and the optical axis deflection angle, radial deflection and axial clearance of the optical lens need to be accurately calculated according to the central thickness of the optical lens in a lens; therefore, optical lens center thickness measurement is an important parameter.

At present, the detection of the central thickness of an optical lens is an important link in the production of the optical lens, and the traditional method adopts a contact measurement method, namely manual contact measurement, and the detection method has the advantages of low precision, long time consumption, easy scratching of the optical lens and incapability of realizing real-time online measurement. The other non-contact measurement adopts an optical principle-a chromatic aberration confocal principle to avoid the above problems, the detection result is more accurate, and the specific operation is to place the optical lens under the light beam of the measuring instrument for measurement by adopting a manual or mechanical arm. However, some fields require the measurement accuracy of the central thickness of the optical lens to be less than or equal to 6 μm. Because the terminal surface variety of optical lens piece is various, mostly biconvex, biconcave, crescent curved surface and plane, in the measurement process, optical lens piece takes place to rock or off normal easily for optical lens piece's central point puts and can not be on same straight line with the light beam of measuring apparatu, and measurement accuracy reduces by a wide margin and can't reach above-mentioned measurement accuracy's requirement. Therefore, it is an urgent technical problem to be solved in the art to provide a fixture which can prevent the optical lens from shaking or deviating during the measurement process, and ensure that the center position of the optical lens cannot be in the same straight line with the light beam of the measuring instrument, thereby improving the measurement accuracy of the non-contact optical lens thickness measuring instrument.

Disclosure of Invention

The invention aims to solve the defects of the prior art and provide the optical lens center thickness measuring and positioning clamp which can prevent the optical lens from shaking or deviating in the measuring process and improve the measuring precision of the non-contact optical lens thickness measuring instrument.

The technical scheme adopted by the invention is as follows: optical lens piece center thickness measurement positioning fixture includes from last to the elastic positioning fixture, flexure strip and the air supply cavity that sets gradually down, the elastic positioning fixture on be provided with the collet of petal formula, thereby the air supply gets into the air supply cavity and makes the flexure strip warp or reset the collet of control elastic positioning fixture and open or press from both sides tightly.

Preferably, 4-8 clamping pieces are circumferentially distributed on the elastic clamping head, the clamping pieces surround a clamping head for clamping the optical lens, and gaps exist between the adjacent clamping pieces; and an upright post for opening the chuck is arranged below the elastic chuck, and the bottom of the upright post is contacted with the upper surface of the elastic sheet.

Preferably, a circumferential platform for holding the optical lens is arranged in the elastic chuck; the elastic chuck is provided with a mounting plate for mounting the elastic positioning clamp at the joint of the clamping piece and the upright post in a radially outward extending manner.

Preferably, the elastic positioning clamp is detachably connected with the air source cavity through a positioning clamp locking piece.

Preferably, the top of the positioning clamp locking part is provided with a fixing plate for fixing the elastic positioning clamp, and the fixing plate is provided with a clearance position which is matched with the mounting plate of the elastic positioning clamp in shape; the elastic positioning clamp can be separated from the positioning clamp locking piece when the mounting plate of the elastic positioning clamp rotates to the position avoiding position.

Preferably, the positioning clamp locking piece is in threaded connection with the air source cavity.

Preferably, the elastic positioning clamp is made of a POM (polyoxymethylene resin) plastic material through integral molding, and the POM is commonly called as steel.

Preferably, the number of the clamping pieces of the elastic clamping head is six.

Preferably, the elastic sheet is an elastic steel sheet.

Preferably, the top of the air source cavity is provided with an upper opening, and the elastic sheet can detachably seal the upper opening; the gas source cavity is also provided with a gas inlet and outlet hole for gas to enter or discharge from the gas source cavity.

Preferably, the elastic piece is detachably arranged at the upper opening of the air source cavity through the pressing fixing piece.

Preferably, the pressing fixing piece and the air source cavity are locked by threads or screws.

Preferably, the inner side surface of the top of the air source cavity is provided with inner teeth or a boss provided with tooth holes, and the pressing fixing piece is provided with adaptive outer teeth on the contact surface with the air source cavity or is provided with corresponding screws for correspondingly locking and fixing according to the tooth holes arranged on the mounting holes and the boss.

Preferably, the gas source cavity radially extends inwards at the upper opening to form a circumferential step for clamping the elastic sheet, and the pressing fixing piece fixes the elastic sheet on the circumferential step in a thread locking or screw locking mode.

Compared with the prior art, the invention has the following advantages:

1. the positioning fixture for measuring the central thickness of the optical lens is mainly used for positioning the excircle of the optical lens and ensuring that the axis of the optical lens is coaxial with a light beam of a measuring instrument. The optical lens is fixed by the elastic positioning clamp arranged on the air source cavity, and the air source enters the air source cavity to deform or reset the elastic sheet so as to control the elastic chuck of the elastic positioning clamp to open or clamp, thereby realizing the functions of putting in, clamping, fixing and taking out the optical lens. The design ensures that the optical lens does not shake or deviate in the measuring process and the central position of the optical lens and the light beam of the measuring instrument are on the same straight line. The design not only realizes repeated positioning, but also can improve the measurement precision of the non-contact optical lens thickness measuring instrument so as to meet the requirement of the measurement precision. The measuring and positioning clamp of the invention is matched with a light beam measuring instrument, the measuring precision can be less than or equal to 6 mu m, and the measuring precision is high. In addition, the mode of usable manipulator cooperation air supply is put into elastic positioning anchor clamps with optical lens, can avoid artificial optical lens that contacts, reduces optical lens's spoilage by a wide margin.

2. According to the positioning fixture for measuring the central thickness of the optical lens, the elastic positioning fixture is integrally formed by the POM plastic material, so that the optical lens can be effectively prevented from being scratched in the process of putting in or taking out the optical lens.

3. According to the optical lens center thickness measuring and positioning clamp, the elastic positioning clamp is detachably connected with the air source cavity through the positioning clamp locking piece. When optical lenses with different diameters need to be measured, the elastic positioning clamp can be separated from the locking part of the positioning clamp only by rotating the elastic positioning clamp and enabling the mounting plate to rotate to the clearance position, and the elastic positioning clamp is replaced to the elastic positioning clamp with the size matched with the optical lens to be measured. The design is simple, convenient and quick to operate and wide in application range.

Drawings

Fig. 1 is a front view of the present invention.

Fig. 2 is a sectional view taken along a-a of fig. 1.

Fig. 3 is a schematic structural view of the elastic positioning jig.

Fig. 4 is a schematic view of the bottom structure of the elastic positioning jig.

Fig. 5 is a top view of the resilient positioning clip.

Fig. 6 is a perspective view of a resilient positioning clip.

FIG. 7 is a schematic diagram of a gas source chamber.

FIG. 8 is a schematic view of the positioning clamp lock.

The numbers in the figures indicate:

1-elastic positioning clamp, 11-elastic chuck, 111-clamping piece, 112-circumferential platform, 113-mounting plate, 12-upright post, 2-elastic piece, 3-air source cavity, 32-air inlet and outlet hole, 33-air pressure cavity, 34-circumferential step, 4-positioning clamp locking piece, 41-fixing plate, 411-vacancy avoiding position, 5-pressing fixing piece and 6-measuring instrument light beam.

The specific implementation mode is as follows:

for the purpose of enhancing the understanding of the present invention, the present invention will be described in further detail with reference to the accompanying drawings and embodiment examples. The invention can be implemented by:

referring to fig. 1-8, the optical lens center thickness measuring and positioning fixture comprises an elastic positioning fixture 1, an elastic sheet 2 and an air source cavity 3 which are sequentially arranged from top to bottom, wherein an air pressure cavity is arranged inside the air source cavity 3, and the air source cavity 3 is made of a metal material. The top of the air source cavity 3 is provided with an upper opening, and the elastic sheet 2 can detachably seal the upper opening; the gas source cavity 3 is also provided with a gas inlet and outlet hole 32 for gas to enter or discharge from the gas source cavity. The elastic positioning fixture 1 is provided with a petal-type elastic chuck 11, an upright post 12 for opening the chuck is arranged below the elastic chuck 11, and the bottom of the upright post 12 is in contact with the upper surface of the elastic sheet 2. The air inlet and outlet hole 32 is connected with an air source, air is supplied to the air source cavity 3 for pressurization and pressure maintaining, and air is discharged for pressure reduction, so that deformation and reset of the elastic sheet 2 are controlled, and the elastic chuck 11 of the elastic positioning clamp 1 is further controlled to open or clamp. The specific principle is as follows: when an optical lens needs to be put in or taken out, gas enters the gas source cavity 3 from the gas inlet and outlet hole 32 to generate pressure, at the moment, the pressure is maintained in the gas source cavity 3 to ensure that the elastic sheet 2 is expanded and deformed, the upright post 12 is pushed up by the elastic sheet 2, the upright post 12 pushes the elastic chuck 11 to slightly open, after the mechanical arm of the measuring instrument puts the optical lens into the elastic chuck 11, the gas in the gas source cavity 3 is discharged, the elastic sheet 2 resets, the thrust on the lower end face of the upright post 12 is reduced and naturally resets, and the tension on the elastic chuck 11 is reduced and naturally resets, so that the edge of the optical lens is clamped by the self stress of the elastic chuck. At the moment, the central axis of the clamped optical lens is basically overlapped with the light beam of the measuring instrument, so that the requirement of measuring precision is met.

The elastic chuck 11 is designed in a petal type, that is, 4 to 8 clamping pieces 111 are circumferentially distributed on the elastic chuck 11, the clamping pieces 111 enclose a chuck for clamping an optical lens, and the number of the clamping pieces 111 of the elastic chuck 11 in the preferred embodiment of the invention is six. The number of the clamping pieces 111 is too small, and the required air pressure is large; the clip 111 is easily broken due to the excessive number of clips 111. Gaps are formed between adjacent jaws 111 to allow collet 11 to expand slightly when subjected to upward thrust.

The inside of the elastic chuck 11 is provided with a circumferential platform 112 for holding the optical lens. When the collet 11 is slightly expanded, the optical lens is placed in the collet 11, and the circumferential platform 112 holds the bottom edge of the optical lens.

The elastic clamping head 11 is provided with a mounting plate 113 which is used for mounting the elastic positioning clamp 1 and extends outwards in the radial direction at the joint of the clamping piece 111 and the upright post 12. The elastic positioning clamp 1 is detachably connected with the air source cavity 3 through a positioning clamp locking piece 4. The top of the positioning clamp locking part 4 is provided with a fixing plate 41 for fixing the elastic positioning clamp 1, and the fixing plate 41 is provided with a clearance 411 which is adaptive to the mounting plate 113 of the elastic positioning clamp 1 in shape; the elastic positioning clamp 1 can be separated from the positioning clamp locking piece 4 when the mounting plate 113 is rotated to the space 411. When optical lenses with different diameters need to be measured, the elastic positioning clamp 1 only needs to be rotated, so that the mounting plate 113 can be separated from the positioning clamp locking part 4 when being rotated to the clearance 411, and the elastic positioning clamp 1 with the size corresponding to the optical lens to be measured can be replaced. The design is simple, convenient and quick to operate and wide in application range.

The elastic positioning clamp 1 is made of POM plastic materials through integral forming. POM is a linear polymer without side chains, high density, and high crystallinity. The elastic positioning clamp 1 made of the material has the required elasticity, so that the upright post 12 of the elastic positioning clamp 1 can be slightly expanded after receiving upward thrust, and has the characteristics of high hardness, high rigidity and high wear resistance.

The elastic sheet 2 is an elastic steel sheet, also called a spring steel sheet. The elastic steel sheet mainly has good elasticity and can work under the dynamic load environment condition. The material has high fatigue strength and long service life under the repeated action of load; and has sufficient toughness and plasticity to prevent sudden brittle failure under the action of impact force.

The positioning clamp locking piece 4 is in threaded connection with the air source cavity 3. The elastic piece 2 is detachably arranged at the upper opening of the air source cavity through the pressing fixing piece 5. The pressing fixing piece 5 is in threaded connection with the air source cavity 3, namely, the inner side face of the top of the air source cavity 3 is provided with inner teeth, and the pressing fixing piece 5 is provided with adaptive outer teeth on the contact surface with the air source cavity 3. The gas source cavity 3 is provided with a circumferential step 34 extending inwards and radially at the upper opening for clamping the elastic sheet 2. The pressing fixing piece 5 fixes the elastic piece 2 on the circumferential step 34 in a thread locking mode, and at the moment, the circumferential step 34 supports the circumferential edge of the elastic piece 2; when gas enters the gas source cavity 3, the elastic steel sheet is pressed to form a closed gas pressure cavity together with the inside of the gas source cavity 3. During installation, the elastic steel sheet is firstly placed on the circumferential step 34 of the air source cavity 3, the pressing fixing piece 5 is rotated to lock the elastic steel sheet at the upper opening of the air source cavity 3, and then the inner teeth of the positioning clamp locking piece 4 and the outer teeth on the air source cavity 3 are screwed to the pre-tightening position. The elastic positioning clamp 1 is placed into a gap formed by the pressing fixing piece 5 and the positioning clamp locking piece 4 through the gap avoiding position 411 of the positioning clamp locking piece 4, and the positioning clamp locking piece 4 is screwed tightly, so that the elastic positioning clamp 1 is pressed by the inner end face of the positioning clamp locking piece 4 and the upper end face of the pressing fixing piece 5.

Finally, it should be noted that: the above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that are within the spirit and principle of the present invention are intended to be included in the scope of the present invention.

Claims

1. Optical lens piece center thickness measurement positioning fixture, its characterized in that includes from last elastic positioning fixture (1), flexure strip (2) and air supply cavity (3) that set gradually extremely down, elastic positioning fixture (1) on be provided with spring chuck (11) of petal formula, thereby the air supply gets into in air supply cavity (3) and makes spring strip (2) warp or reset spring chuck (11) of control elastic positioning fixture (1) and open or press from both sides tightly.

2. The optical lens center thickness measuring and positioning fixture according to claim 1, wherein 4-8 clamping pieces (111) are circumferentially distributed on the elastic clamping head (11), the clamping pieces (111) enclose the clamping head for clamping the optical lens, and gaps exist between the adjacent clamping pieces (111); an upright post (12) for expanding the chuck is arranged below the elastic chuck (11), and the bottom of the upright post (12) is in contact with the upper surface of the elastic sheet (2).

3. The optical lens center thickness measuring and positioning fixture as claimed in claim 2, wherein a circumferential platform (112) for holding the optical lens is arranged inside the elastic collet (11), and a mounting plate (113) for mounting the elastic positioning fixture (1) is radially extended outwards from the elastic collet (11) at the connection position of the clamping piece (111) and the upright (12).

4. The fixture for measuring and positioning the central thickness of an optical lens according to any one of claims 1 to 3, wherein the elastic positioning fixture (1) is detachably connected with the air source cavity (3) through a positioning fixture locking member (4).

5. The optical lens center thickness measuring and positioning fixture as claimed in claim 4, wherein a fixing plate (41) for fixing the elastic positioning fixture (1) is arranged at the top of the positioning fixture locking member (4), and a clearance (411) with a shape corresponding to the mounting plate (113) of the elastic positioning fixture (1) is arranged on the fixing plate (41); the elastic positioning clamp (1) can be separated from the positioning clamp locking piece (4) when the mounting plate (113) rotates to the space avoiding position (411).

6. The optical lens center thickness measurement positioning fixture of claim 5, wherein the positioning fixture locking member (4) is in threaded connection with the air supply cavity (3).

7. The optical lens center thickness measuring and positioning fixture according to claim 1, 2, 3, 5 or 6, wherein the number of the clamping pieces (111) of the elastic clamping head (11) is six.

8. The fixture for measuring and positioning the central thickness of an optical lens according to claim 1, 2, 3, 5 or 6, wherein the elastic sheet (2) is an elastic steel sheet.

9. The optical lens center thickness measuring and positioning fixture according to claim 1, 2, 3, 5 or 6, wherein the top of the air source cavity (3) is provided with an upper opening, and the elastic sheet (2) detachably seals the upper opening; the gas source cavity (3) is also provided with a gas inlet and outlet hole (32) for gas to enter or discharge from the gas source cavity.

10. The optical lens center thickness measuring positioning fixture according to claim 9, wherein the elastic sheet (2) is detachably disposed at the upper opening of the air source cavity through a pressing fixture (5); air supply cavity (3) at last opening part inwards radially extend and have circumference step (34) that are used for joint flexure strip (2), compress tightly mounting (5) fix flexure strip (2) on circumference step (34) through the mode of screw thread locking or screw locking.