JPS59159291A

JPS59159291A - Laser focusing method

Info

Publication number: JPS59159291A
Application number: JP58034955A
Authority: JP
Inventors: Yasuyuki Yoshida; 康之吉田; Satoshi Suzuki; 智鈴木; Tsunetaka Hiromi; 広実　常登
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 1983-03-03
Filing date: 1983-03-03
Publication date: 1984-09-08

Abstract

PURPOSE:To focus a laser beam with high accuracy on a work in the stage of working by the laser beam by observing directly the focal position of the laser beam with a high resolving power image pickup device using a television as a monitor. CONSTITUTION:It is necessary to focus exactly a laser beam 1 onto the surface of a work in the stage of condensing the laser beam with a lens 2 and a performing welding, cutting, etc. of a work. The greater part of the beam 1 is reflected and attenuated by an attenuator 5 and thereafter the beam is condensed by the lens 2. A high resolving power image pickup device 4 such as an IR television camera or the like is placed near the focal position to pick up the focal image. The focal image 7 is directly observed with a monitor television 6. The exact focal position is decided with the television 6 by moving vertically the image pickup device, by which the focal position of the laser beam is detected easily with high accuracy.

Description

【発明の詳細な説明】不発、明は、レーデビームによるレーザ加工の除用、い
られるレーデ焦点合せ方法・に、、、、関す石。DETAILED DESCRIPTION OF THE INVENTION The present invention is related to the elimination of laser processing using a Radhe beam, and a new Radhe focusing method that can be used.

近年、レーザ溶接およびレーザ切断等Ω、区−ザ加工は
、高い精度で加工を行なうこと、がアきるなどの理由に
よシ、各種の技術分野で多用されている。このようなレ
ーザ加工では１．凸、レンズ等に、よ、シ、集光した。In recent years, laser processing such as laser welding and laser cutting has been widely used in various technical fields because of its ability to perform processing with high precision. In this type of laser processing, 1. The light was focused on a convex lens, etc.

レーザビームの焦点を被加工物の表面に正確にセヒトす
、る、必要があ、、ｂ　ｒ、　、、、、、：その焦点、
位置精度は通常許容値、とじて、±０．５ｍ前後であ、
ろ。　　　　　、　・・　、、、・、とこφで１．加、
、１用し−、、デビ、、−不の波長悼、赤外領域の、も
９が、多、く不可視、であるため、−慇的、には、焦、
点の位、置を正確（把握することは困難で、あ、る。、
作法では、第１図に、、委すように、集光、、レンズ、
２ど被加工物３と、Ｐ距、離Ｈ，を：変化させて・模、
般的にレーザビーム１を、照射して、溶接また。は、切
断を、行なっている。こ、の、模擬照、射によ、シ、最
も、加工性、の良い距離Ｈを求め１．、、このときし、
ニザビー、ム１の焦点と被、加工物３の、表面が＝致ｔ
、、たと判定す、る、、。−ｊ、、シて、集光レンズ２
の高さ方向、、の位置を固牢し１．その後来、際に被加
工物３吟、対して、溶接、、切断等のレーザ加工を行な
うこ：、とにな、る。、　５　　　　　、　　　　　　
　　　　　　、、　、　　、。It is necessary to accurately set the focus of the laser beam on the surface of the workpiece.
The positional accuracy is normally within the allowable value, approximately ±0.5m.
reactor. , . . , , , where φ is 1. Canada,
, 1, davi,, the wavelength mourning, the infrared region, the 9th, is so irregular, so -cheerful, impatient,
Accurate position of point (difficult to grasp, ah...
In terms of manners, as shown in Figure 1, condensing light, lenses,
2nd workpiece 3, P distance, distance H: change,
Generally, a laser beam 1 is irradiated to perform welding. is performing the cutting. Using this simulated irradiation, find the distance H with the best workability.1. ,,At this time,
Nizabi, the focus of mu 1 and the surface of workpiece 3 = hit t
It is determined that ,,. -j,, condenser lens 2
Fix the position of , in the height direction, 1. After that, laser processing such as welding and cutting is performed on the three workpieces. , 5,
,, , ,.

し、か、シ、なから、上記の、：ような、従、来のレー
ザ、焦点合せ、方法では１．実際の、溶接、切断等の、
加工風、前に、、かなシ、多くの焦点合せ用の溶接、切
断作業が柔要となシ・、秩業千程および材料：ｒ、、、
＜トな５，８層圓、ヵｔ６ケ魚７、ありえ。　　□　蛸
呵不発明準上記の事↑Ｗ、に鑑みてなされた■（や・社
、：：その、目的、は、レーザビーム加工において被加
工物に対しぞ焦点合せ用の加工を行表うことなく・、。However, in the conventional laser focusing method, as described above, 1. Actual welding, cutting, etc.
Machining style, front, Kana, many focusing welding, cutting work is flexible, Chichiyoshi thousand degrees and materials: r,,,
<Tona 5, 8 layer circle, Kat6kafish7, possible. □ This was done in view of the above ↑W ■(Ya・sha,:: The purpose is to perform focusing processing on a workpiece in laser beam processing. Without a doubt...

簡単で高Ｍ度のレーザー−ム：の焦点合せを行なうこと
ができる后−ザ蕪蔗□合１方法を提供すること、にある
。The object of the present invention is to provide a simple method for focusing a high-M laser beam.

以下図面を参照して不発□明の一実施例について説明す
、乞。第２□図は本発明に係る構成を示すもので、４は
高分解能撮像□装置で、集光レンズ２を通して照射され
るし」ザビー人１の光軸に垂門に股、置□される７こ□
の□場合□、レーザビーム１はｉ表器５で十分に減蓑さ
れた後、集光レンズ２全通して集光、される。さらに、
６はテレビモニタ、で１．、高１分解能撮像装置４．今
らのレーザビー′　ム１の像７を表示する。高分解能撮
像装置４とし、工は、ビジコン、赤外線テレビモニタ、
、焦電ビジコン等の電子線管型またはＣＣＤ　、亦外Ｃ
ＣＤ、ＭＯ８型撮像素子等の固体型などがあシ、感度波
長、分解能的に適正なものを適宜選定すること、旨：１
−１・ −にカる。′ １酢：□と、ｊヤような構成において、動作を説明する
。An embodiment of the unexploded □mei will be described below with reference to the drawings. Figure 2 shows a configuration according to the present invention, in which 4 is a high-resolution imaging device, which irradiates light through a condensing lens 2, and is placed on the optical axis of the Zabi person 1 at the entrance. 7□
In the case □, the laser beam 1 is sufficiently attenuated by the i-tablet 5 and is then focused through the entire condenser lens 2. moreover,
6 is a TV monitor, and 1. , high resolution imaging device 4. The image 7 of the current laser beam 1 is displayed. The high-resolution imaging device 4 includes a vidicon, an infrared television monitor,
, electron beam tube type such as pyroelectric vidicon or CCD, extra C
There are solid-state types such as CDs and MO8 type image sensors, etc., and the appropriate one in terms of sensitivity wavelength and resolution should be selected as appropriate: 1
It goes to -1・-. ' 1 Vinegar: Explain the operation in the configurations like □ and j ya.

１：１１１１Ｖ　７　ｆ　″−１を減竺器”１十分に、減衰させた、
、後、集光レン−ｅ２に而して撮、像、装置□４に集光
さ１□１せる。そして、撮像装置４を上下方向に移動させること
によシ、テレビモニタ６上のレーザビーム像７の大きさ
は変化する。即ち、作業者はテレビモニ□り６に・よシ
、□し・−・ザビー・・ム・１の・集光状況を直接観察
することが□でき□る。テレビモニタ６上のレーザビー
ム像２が最も小さくなった１１−１１とき、撮像装置４の撮像面がルニザビーム１の焦点と一
致：したことを示す。□しだがって、□そのときの撮像
装置４の位置裳被加工物の表面がくるよづに被々ロエ、
物をセットす゛ることによシ、し”　　　　　１．、”
’Ｉ’・　　′１−．′、・・−ザビーム１の焦点合せ
、が高い精度で行なわれ：′・、：たことになる。なお、撮摩装置イの撮像面と被□１１１
１　Ｊ　　１　　　　　　　　：りｕ工竺シａ工平面♀
高さ：：々肉位置を四−にするためには、両者の絶対位
置を計測する必要がある。これについては、所定の基準
水平線を設けて□おき、その基準よ）撮像面または被加
工１の表面までの鉛直万両距離を機械方式□または□光
学式□′（光マイクロ等）′、磁気式′、□：工７′４
イ□ゲロ等の非接触方式で高精度に計測すればよ匠。□
□具体□的に本発明を□適用した例を以下に示す。1:1111 V 7 f″−1 attenuated by “1” enough,
After that, the light is captured by the condensing lens e2, and the light is focused on the device □4. By moving the imaging device 4 in the vertical direction, the size of the laser beam image 7 on the television monitor 6 changes. That is, the operator can directly observe the light convergence situation of the TV monitor 6 and the camera 1. When the laser beam image 2 on the television monitor 6 becomes the smallest (11-11), the imaging surface of the imaging device 4 coincides with the focus of the luniza beam 1. □Therefore, □The position of the imaging device 4 at that time is such that the surface of the workpiece is
By setting things up."1."
'I'・'1-. ′, . . . - The focusing of the beam 1 is performed with high precision: ′, . In addition, the imaging surface of the imaging device A and the subject □111
1 J 1: ri u construction sheet a construction plane ♀
Height: In order to set the height to 4-, it is necessary to measure the absolute positions of both. For this purpose, set a predetermined reference horizontal line □, and use the mechanical method □, □optical method □′ (optical micro, etc.)′, or magnetic Formula', □: 7'4
□It would be better to measure with high precision using a non-contact method such as vomit. □
□Specific examples in which the present invention is applied are shown below.

□ど”の適用□例では、薄□板突合せ溶□接におけ・る
：レーザ１ビ」ム□焦点合せ方法め場合で□ある。まず
ミ溶接１に用いたレーザ□は、Ｃ０２レーザ（出力１０
６０Ｗ）であるが、焦点合せの際にはビ―ｒ減衰器□に
よシｌＷ以下に出力□を低下させる□。その後□、集：
光ルン、ズを通してｊｍｌｍ素像にし」ザビーム雀集□
光させ、焦点位置検出を行なう。こめ場合、撮像素□子
には□赤外ＣＣＤセンサを用いて、テレビモニタ”上で
レーザビームの集光状態□を観察する。撮像素子はビー
ム焦点近蓚で鉛直方向１〇−程度の範囲で移動させＦビ
ーム径の′変化を測定□し、その結果を第３図妊示す。An example of its application is in butt welding of thin plates: Laser 1 beam focusing method. First, the laser □ used for mi-welding 1 was a C02 laser (output 10
60W), but when focusing, the output □ is reduced to less than 1W by the Be-r attenuator □. Then □, collection:
Lightrun, make it into a JMLM image through Zu” The Beam Sparrow Collection □
The focus position is detected by emitting light. In this case, use an infrared CCD sensor as the image sensor to observe the condensed state of the laser beam on a TV monitor. The change in the F beam diameter was measured, and the results are shown in Figure 3.

ビーム径の最小値をとる領域は、焦点近傍約壬０，５−
の範囲□に限定される。そして、撮像面の高さ方向１の
絶□対位置を光学式□測長−Ｃ測長精度±０．□１１−
）で把−した後、撮像面め代シに実際の被加工物をセッ
トする。この場合、被加工物の高さ方向の絶対位・置を
上記撮像面と一致さ□昼た・：後、レーザ溶接を行々う
。このレーザ溶接の場合には、・ビーム減衰益金し―：
ザ光路よシ取□外すこ□とは当然である。The region where the beam diameter takes the minimum value is approximately 0.5-
Limited to the range □. Then, the absolute □ position of the imaging surface in the height direction 1 is determined by optical □ length measurement-C length measurement accuracy ±0. □11-
), then set the actual workpiece on the imaging surface. In this case, laser welding is performed after the absolute position of the workpiece in the height direction coincides with the above-mentioned imaging plane. In the case of this laser welding, the beam attenuation benefit is:
It goes without saying that it must be removed from the optical path.

□以上詳述したように″本発明に１れば、ゾーザ加工に
お・けるレー・ザ漁点合せ□方法におい七、レーザビー
ムの価直断□面：を・高分解能撮像装置で・直接観察し
、□レーザビーにめ集光状態およびその焦点位置を漱実
に検出１す不ど□とがで：きる＝した示っ七ミー被加工
物に対□しそ焦点合せ用の加工を行なうことな□く、簡
単で□高精膚めレーザビームの焦点合せを行なう：こと
がで□きるもので奈る−６□As detailed above, the present invention has one advantage: the method for laser fishing point alignment in laser processing, and the direct cross-section of the laser beam using a high-resolution imaging device. Observe and carefully detect the condensed state and focal position of the laser beam. □ Easy and □ High-definition laser beam focusing: What you can do □ - 6

[Brief explanation of the drawing]

鯖１′図は従来のレーザ焦点合せ方法を説明するためめ
構成図、第′２″図□は本発明の・一実施例に係るゾニ
１ザ焦点合せ方□法を□説：明けるだめの構成図□、第
３図は第′２図の□具体・的適用例を説明するだめの撮
゛像面尚さに対□するレーザビーム径の測定値を示子図
□であ□る。 ′１：）心・集：′光しツズ、３・・・被加工物、４・
・・高分解能撮像装置、５・・・減衰器、６・・・テレ
ビモニタ。出願人復代理人　　弁理士　鈴　江　武　彦第１図第２図４７９−Figure 1' is a block diagram for explaining a conventional laser focusing method, and Figure 2' is a diagram showing a laser focusing method according to an embodiment of the present invention. The configuration diagram □ and FIG. 3 are diagrams □ showing the measured values of the laser beam diameter relative to the imaging plane □ for explaining a specific example of application in □ of FIG.'2. '1:) Heart/Collection: 'Light Tsuzu, 3... Workpiece, 4.
... High-resolution imaging device, 5... Attenuator, 6... Television monitor. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 1 Figure 2 479-

Claims

[Claims]

A step of irradiating the surface of the workpiece with the Y-the beam that has passed through the condensing lens, and a step of directly observing the vertical cross section of the Lede beam that has passed through the condensing lens using a high-resolution imaging device. Based on this observation result, the diameter of the laser beam is minimized as the distance between the condenser lens and the high-resolution imaging device changes. Adjust the position so that it matches the surface of the workpiece. A laser focusing method comprising: and a process.