JPS61189892A - Laser beam machining - Google Patents

Abstract

PURPOSE:To improve machining accuracy and cutting efficiency by setting the relative speed between a torch and an object to be machined as the function of the radius of curveture of a graphic and the time constant of a driving system. CONSTITUTION:The maximum laser beam machining speed F of a laser beam cutting matching within the is given as assured range necessary dimensional accuracy the functional of the time constant tau of the driving system and the radius of curveture (r) of the graphic as shown by formula I in which alpha is a proportional constant and (m) and (n) are a positive constant respectively. When a laser beam cutting operation is performed following the graphic a curve having the radius of curveture exists at all times. In such a case, the laser beam cutting speed is controlled with a maximum cutting speed given by formula I to perform the cutting operation along the curveture. Thus, overall cutting speed is raised, and because the time constant of the driving system is taken into account, the machining accuracy is improved, thereby resulting in an improvement in the machining performance.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、レーザ光により金属材料・無機材料・有機材
料等各種広範囲な材料に対して複雑形状図形を高速・高
精度に切断するレーザ加工方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a laser processing method for cutting complex shapes at high speed and with high precision in a wide range of materials such as metal materials, inorganic materials, and organic materials using laser light. It is something.

従来の技術 一般に薄板材料をレーザ切断する場合には、単純な直線
切断速度は非常に速い。しかし、曲率半径の小さい曲線
を含む図形に対しては、切断図形の寸法精度を確保する
場合にはその切断速度を低減させる必要のあることが認
められていたが、その程度は経験に頼っていた。2. Description of the Related Art In general, when laser cutting thin sheet materials, the speed of simple straight line cutting is very high. However, for shapes that include curves with a small radius of curvature, it has been recognized that the cutting speed must be reduced in order to ensure the dimensional accuracy of the cut shape, but the degree to which this should be reduced depends on experience. Ta.

発明が解決しようとする問題点 そこで、このような異なる曲率を含む複雑図形の切断で
は加工速度を低目に設定しがちであり、切断能率を低下
させることが多かった。Problems to be Solved by the Invention Therefore, when cutting such complex shapes that include different curvatures, the machining speed tends to be set low, which often reduces cutting efficiency.

問題点を解決するための手段 本発明は前記問題点を解決するために、被加工物とレー
ザ切断用トーチとの相対速度を図形構成要素の曲率半径
および駆動系時定数の函数として与えることを特徴とし
たものである。Means for Solving the Problems In order to solve the above-mentioned problems, the present invention proposes to give the relative speed between the workpiece and the laser cutting torch as a function of the radius of curvature of the graphical component and the time constant of the drive system. This is a characteristic feature.

作　　用 発明者らは研究の結果、複雑図形を構成する要素として
の円弧の曲率半径が小さいほど加工速度。As a result of research, the inventors found that the smaller the radius of curvature of the arc, which is an element that makes up a complex figure, the faster the processing speed.

を小さくすることにより形状寸法精度が向上し、同時に
駆動系時定数が小さいほど加工速度を大きくすることが
できることを実証し１寸法精度を保証できる最大加工速
度は〔１〕式の函数で得られることを見出した。It has been demonstrated that the shape and dimension accuracy improves by decreasing the drive system time constant, and at the same time, the machining speed can be increased as the drive system time constant decreases.The maximum machining speed that can guarantee one dimension accuracy is obtained by the function of equation [1]. I discovered that.

Ｆ＝α・τ１・ｒｏ　　　・・・・・・・・・・・・〔
１〕ここに、Ｆは加工速度であり、αは比例定数、では
駆動系時定数、ｒは切断図形構成要素の曲率半径を示し
、ｍ　、　ｎは正の定数である０寸法精度が悪くて良い
場合には、αの値を大きくでき、加工速度は速くするこ
とができる。F=α・τ1・ro ・・・・・・・・・・・・
1] Here, F is the machining speed, α is the proportionality constant, is the drive system time constant, r is the radius of curvature of the cutting figure component, and m and n are positive constants. In good cases, the value of α can be increased and the processing speed can be increased.

このため、曲率半径に応じた加工速度の最大速度を常に
数式よシー義的に求まることになり寸法精度を保証でき
る最高能率の加工が達成できた０この新しい加工方法は
、従来実施されている図形形状に応じて経験的に加工速
度を低減させる方法では全く見逃されてきたものであっ
て、この新事実の発見は、複雑図形を実際に高速加工す
るに際してははなはだ重要な意義を持つものである。For this reason, the maximum machining speed according to the radius of curvature can always be determined mathematically and logically, making it possible to achieve the highest efficiency machining that can guarantee dimensional accuracy. This has been completely overlooked by methods that empirically reduce the machining speed according to the shape of the figure, and the discovery of this new fact is of great significance when actually machining complex figures at high speeds. be.

一般に高速で直角部を移動する場合には、第１図に例示
するように、コーナ部には微小なＲがつくのは避けられ
ない。このＲの程度は駆動系の時定数と移動速度に左右
される。（コーナ部を正確に位置決めする場合には停止
する必要がある。）また、第２図に示す円の例では始終
端位置Ｓは同じであるために必ず位置決めされることか
ら、定常速度部では半径誤差Δｒの円弧であるが、前記
始終端Ｓ近傍では真円とは異なった尖った形状になる。Generally, when moving at a right angle at high speed, it is inevitable that a small radius will be formed at the corner, as illustrated in FIG. The degree of this R depends on the time constant and moving speed of the drive system. (To position the corner accurately, it is necessary to stop.) In addition, in the example of the circle shown in Figure 2, the starting and ending positions S are the same, so the positioning is always done, so in the steady speed section, Although it is a circular arc with a radius error Δr, it has a pointed shape different from a perfect circle near the start and end ends S.

この時の半径誤差は高速加工なほど大きくなり、寸法精
度が悪くなる。The radius error at this time becomes larger as the processing speed increases, and dimensional accuracy deteriorates.

なお、駆動系時定数のうちには、一般的には機械的な立
上り時定数とフィードバック制御ループゲインが含まれ
る。Note that the drive system time constant generally includes a mechanical rise time constant and a feedback control loop gain.

また、ここに示す函数は必ずしも連続函数とは限らず、
一般には、半径ｒの場合分けによる不連続な函数となっ
てもよい。Also, the functions shown here are not necessarily continuous functions,
In general, it may be a discontinuous function depending on the case of the radius r.

実施例 （実施例１） 前記直角部（第１図）の場合には、〔１〕式にｒ−ｍｏ
を代入するとＦ＝ｏとなシ、コーナ部で一旦停止する必
要があることがわかる。Example (Example 1) In the case of the right angle part (Fig. 1), r-mo is added to the formula [1].
By substituting F=o, it can be seen that it is necessary to temporarily stop at the corner.

（実施例２） 前記単円（第２図）に対して、加工速度変化時の半径誤
差Δｒの評価結果例を第３図に示す。円の半径は１０Ｍ
、駆動系時定数は３０ｍＢ一定とした。実験結果は計算
値とほぼ一致しており、寸法精度を与えることによシ最
大加工速度が推定できることがわかる。(Example 2) FIG. 3 shows an example of the evaluation results of the radius error Δr when the machining speed changes for the single circle (FIG. 2). The radius of the circle is 10M
The drive system time constant was kept constant at 30 mB. The experimental results almost agree with the calculated values, indicating that the maximum machining speed can be estimated by providing dimensional accuracy.

発明の効果 以上の説明から明らかなようＫこの発明は、レーザ切断
の実用拡大上、大きな隘路となっていた種々の異なる曲
率半径を有する図形切断時の高精度高速加工方法を迅速
確実に実現するものであり、現在実用途上にあるレーザ
加工分野、特に高速板金加工に新たな発展を開拓したも
ので極めて有益な発明である。Effects of the Invention As is clear from the above explanation, this invention quickly and reliably realizes a high-precision, high-speed processing method for cutting shapes with various different radii of curvature, which has been a major bottleneck in expanding the practical use of laser cutting. This is an extremely useful invention that pioneers new developments in the field of laser processing, which is currently in practical use, particularly in high-speed sheet metal processing.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図はレーザ加工による直角部の加工形状を示す正面
図、第２図は同レーザ加工による円の加工形状を示す正
面図、第３図は本発明のレーザ加工方法による円の加工
において加工速度と半径誤代理人の氏名　弁理士　中　
尾　敏　男　ほか１名第１図 第２図Fig. 1 is a front view showing the processed shape of a right angle part by laser processing, Fig. 2 is a front view showing the processed shape of a circle by the laser processing, and Fig. 3 is a front view showing the processed shape of a circle by the laser processing method of the present invention. Speed and Radius Wrong Agent Name Patent Attorney Medium
Toshio O and one other person Figure 1 Figure 2

Claims (1)

【特許請求の範囲】[Claims] 異なる曲率を持つ図形に沿って被加工物をレーザ切断す
る場合、前記被加工物とレーザ切断用トーチとの相対速
度を前記図形構成要素の曲率半径および駆動系時定数の
函数として与えることを特徴とするレーザ加工方法。When a workpiece is laser cut along shapes having different curvatures, the relative speed between the workpiece and the laser cutting torch is given as a function of the radius of curvature of the shape component and a drive system time constant. Laser processing method.