CN113751860A

CN113751860A - Method for confirming focus coordinate by laser section dotting

Info

Publication number: CN113751860A
Application number: CN202010488057.6A
Authority: CN
Inventors: 饶永; 马兴; 吴建荣; 陈松
Original assignee: Guizhou Zhenhua Qunying Electric Appliance Co Ltd(state-Owned No891 Factory)
Current assignee: Guizhou Zhenhua Qunying Electric Appliance Co Ltd(state-Owned No891 Factory)
Priority date: 2020-06-02
Filing date: 2020-06-02
Publication date: 2021-12-07
Anticipated expiration: 2040-06-02
Also published as: CN113751860B

Abstract

The invention discloses a method for dotting a section of a laser to confirm a focus coordinate, which comprises the following steps: step S01: adjusting the laser to enable the laser light emitting head to reach a default focus position; step S02: placing a workpiece right below a laser light-emitting head; step S03: adjusting laser parameters, and starting a laser to beat 1 point on a workpiece at a default focus position to be used as a reference point; step S04: sequentially dotting the workpiece at certain intervals by positive defocusing until the energy is obviously attenuated and stopping dotting; step S05: the light-emitting head returns to the reference point position, and then points are sequentially punched on the workpiece by taking the negative defocusing as a certain interval until the energy is obviously attenuated and the punching is stopped; step S06: and determining the actual focal position according to the melting depth of the points formed in the step S04 and the step S05, wherein the deepest point of the melting depth is the actual focal position. The method takes the maximum power density and the deepest dotting fusion depth of the focus position as the judgment basis, realizes longitudinal measurement, and has more accurate judgment result.

Description

Method for confirming focus coordinate by laser section dotting

Technical Field

The invention relates to a method for confirming a focal coordinate by dotting a section of a laser.

Background

The sealed relay adopts a laser sealing machine to carry out laser sealing on the assembled relay, and the process principle of the laser sealing process is a high-reliability fusion welding process which utilizes the high-energy heat of laser to instantly melt the same metal or a metal joint on microcosmic to recrystallize metal atoms and then connect the metal atoms together. The laser welding equipment mainly comprises a laser, a beam transmission part and a focusing system, wherein the first two parts can not be changed under normal conditions, and the third part can be changed under the influence of mechanical vibration and the like.

The parameters influencing the stability of the laser sealing and welding process are 5, which are respectively as follows: peak power, pulse width, frequency, workpiece running speed, defocus. The laser sealing welding device comprises a laser generator, a workpiece, a focal plane, a light outlet head, a laser sealing welding head, a laser generator, a laser welding head, a laser sealing welding head, a laser sealing welding head, a laser welding head and a laser sealing welding head, wherein the 3 parameters of peak power, pulse width and frequency are determined by the laser generator, the change can not occur under the normal condition, the operation speed of the workpiece is controlled by a numerical control program, the welding process can not be affected on the premise that the numerical control program edited in advance is not changed, the defocusing amount is the position relation of the focal plane relative to the surface of the workpiece, the defocusing amount can be slowly changed in the normal use process at ordinary times because of the light outlet head, and the energy density of the laser incidence to the metal surface is affected, and the laser sealing welding quality is finally affected.

In addition, because the Z axle (the light-emitting head is coaxial) of the numerical control guide rail part of laser sealing machine reciprocates in long-time use, outside optical system can take place slight change, can lead to the light-emitting head focus lens group to receive the influence to lead to the light-emitting focus position to change, and the focus changes then directly influences the sealing quality of relay, leads to the decay of the laser energy that workpiece surface received, finally causes the decline of product leakproofness quality and finished product to scrap in a large number.

Disclosure of Invention

In order to solve the problems that the quality of the sealing performance of a product is reduced and a large number of finished products are scrapped due to the fact that laser energy received by the surface of a workpiece is attenuated due to the fact that the position of a focal point of a laser changes in the prior art, the invention aims to provide a method for dotting a laser section to confirm a focal point coordinate, wherein the method can be used for positioning the focal point of the laser.

To achieve the object of the present invention, the method for confirming the focal coordinates by dotting the section of the laser provided herein comprises the following steps:

step S01: adjusting the laser to enable the laser light emitting head to reach a default focus position;

step S02: placing a workpiece right below a laser light-emitting head;

step S03: adjusting laser parameters, and starting a laser to beat 1 point on a workpiece at a default focus position to be used as a reference point;

step S04: sequentially dotting the workpiece at certain intervals by positive defocusing until the energy is obviously attenuated and stopping dotting;

step S05: the light-emitting head returns to the reference point position, and then points are sequentially punched on the workpiece by taking the negative defocusing as a certain interval until the energy is obviously attenuated and the punching is stopped;

step S06: and determining the actual focal position according to the melting depth of the points formed in the step S04 and the step S05, wherein the deepest melting depth point is the actual focal position.

Furthermore, the workpiece is an iron sheet.

Further, in step S02, the workpiece edge is placed at the center of the default focus spot.

The beneficial effects of the invention include:

1) the method provided by the invention takes the point with the largest power density and the deepest striking point melting depth as the judgment basis from the focus position, realizes longitudinal measurement, and takes each point striking on the workpiece as a contrast factor more obviously and has more accurate judgment result.

2) The iron sheet is adopted, so that the laser reflectivity is reduced, the response to the power difference after laser defocusing is sensitive, and the accuracy of a judgment result is further ensured.

3) The edge of the workpiece is placed to the center position of the default focus spot, so that the fusion depth sizes of points with different defocusing amounts can be visually embodied, the visual longitudinal comparison of the fusion depths of the points with different focal lengths is realized, the difference is obvious, and the focus position can be conveniently and accurately found.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

FIG. 1 is a schematic diagram of a method for confirming focus coordinates by laser section dotting according to the present invention;

FIG. 2 is a schematic view of a workpiece after dotting by the method of the present invention;

in the drawings: 1-laser beam, 2-laser focus, 3-workpiece, 4-datum.

Detailed Description

Exemplary embodiments will now be described more fully with reference to the accompanying drawings. The exemplary embodiments, however, may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. In the drawings, the size of some of the elements may be exaggerated or distorted for clarity. The same reference numerals denote the same or similar structures in the drawings, and thus detailed descriptions thereof will be omitted.

Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the subject matter of the present disclosure can be practiced without one or more of the specific details, or with other methods, components, etc. In other instances, well-known structures, methods, or operations are not shown or described in detail to avoid obscuring aspects of the disclosure.

Fig. 1 shows the principle of the method for confirming the focal coordinates by dotting the section of a laser provided by the invention, the laser emitted by the laser forms a laser beam 1 after being focused, when the laser focus 2 of the laser beam 1 is superposed and vertical to the surface of a workpiece 3, the energy of a spot formed by the laser beam 1 is maximum, the depth of fusion is deepest, the energy of the spot formed by positive defocusing and negative defocusing is not larger than that of the laser focus 2, and the depth of fusion is not deeper than that of the laser focus 2. The invention utilizes the principle to provide a method capable of positioning the focal position of a laser, which comprises the following steps:

step S02: placing a workpiece 3 right below a laser light-emitting head;

step S03: adjusting laser parameters, and starting a laser to beat 1 point on the workpiece 3 at a default focus position to be used as a reference point 4;

step S04: sequentially dotting the workpiece 3 at certain intervals by positive defocusing until the energy is obviously attenuated and stopping dotting;

step S05: the light-emitting head returns to the reference point position, and then dotting is sequentially performed on the workpiece 3 by taking the negative defocusing as a certain interval until the energy is obviously attenuated and the dotting is stopped, as shown in fig. 1;

The "significant energy attenuation" described in steps S04 and S05 is the significant energy attenuation caused by the fact that the laser beam strikes the iron piece without the fire, but may be another phenomenon in which the energy is significantly attenuated.

Installing the above steps, wherein the laser parameters adjusted in step S03 are frequency of 1Hz and average power of 10W; the metal sheet 1 is dotted with the dotting interval of 0.1mm in the steps S04 and S05, eight points are dotted respectively in the positive defocusing and the negative defocusing, and the penetration of each point is shown in table 1.

TABLE 1 iron sheet dotting depth gauge

The workpiece 3 for dotting may be made of any metal, but in order to ensure that the laser energy is absorbed by the metal, it is preferable to use a metal having a low reflectivity for the laser, such as iron. In order to absorb the laser energy more fully, smooth iron sheets are adopted, and the positioning accuracy is improved. The size of the iron sheet is set according to practical conditions, such as length, width and height of 50mm multiplied by 30mm multiplied by 2.5 mm.

In addition, the interval between the positive and negative defocusing points in step S04 and step S05 may be greater than 0.1mm or less than 0.1 mm.

When dotting the workpiece 3, any position on the workpiece 3 may be used, such as the center line position, the position of one-third of the workpiece 3, or the position of two-thirds of the workpiece 3, but in order to facilitate intuitive judgment of the penetration depth of each point, it is preferable to dotte the edge of the workpiece 3, so in step S02, the edge of the workpiece 3 is placed at the center of the default focal spot, and the laser is caused to dotte the edge of the workpiece 3.

After the actual focus position is found by the method provided by the invention, the distance between the default focus position and the actual focus position can be judged, the default focus is set to coincide with the actual focus after the distance between the actual focus and the default focus is judged, then the lens is adjusted to be in the clearest state, so that the light emitting head of the laser is positioned at the actual focus position, and the problems that the sealing quality of the relay is directly influenced due to the change of the light emitting focus position of the laser, the energy of laser received by the surface of a workpiece is attenuated, the sealing quality of the product is finally reduced, and a large amount of finished products are scrapped are solved.

The present disclosure has been described in terms of the above-described embodiments, which are merely exemplary of the implementations of the present disclosure. It must be noted that the disclosed embodiments do not limit the scope of the disclosure. Rather, variations and modifications are possible within the spirit and scope of the disclosure, and these are all within the scope of the disclosure.

Claims

1. A method for confirming a focus coordinate by laser section dotting is characterized by comprising the following steps:

step S02: placing a workpiece right below a laser light-emitting head;

2. The method of claim 1, wherein the method comprises: in step S02, the workpiece edge is placed at the center of the default focal spot.

3. The method for confirming the focal coordinates of a laser section point according to claim 1 or 2, wherein: the workpiece is an iron sheet.

4. The method of claim 3, wherein the method comprises: the iron sheet is a smooth iron sheet.

5. The method of claim 3, wherein the method comprises: the length, width and height of the iron sheet are 50mm multiplied by 30mm multiplied by 2.5 mm.

6. The method for confirming the focal coordinates of a laser section point according to claim 1 or 2, wherein: and the dotting interval of the step S04 is 1 mm.

7. The method for confirming the focal coordinates of a laser section point according to claim 1 or 2, wherein: and the dotting interval of the step S05 is 1 mm.