JPS63299881A - Condensing apparatus for laser beam - Google Patents

Abstract

PURPOSE:To improve the efficiency of laser beam machining and to obtain a smoother machined surface by dividing a condensing lens into a plurality of pieces and setting different focal lengths peculiar to them. CONSTITUTION:The condenser lens 5 of laser beam is divided into a plurality of lenses 5a-5c, etc., and their focal lengths are set so that they are longer and longer from the lens 5a to the lens 5c. The laser beam 1 enters the divided condenser lenses and is condensed respectively into 5a, 5b and 5c. In this case, when a material 3 to be worked is moved from right to left, first the surface of the material 3 to be worked 3 is cut at the focal position 4a. Then, it is cut in sequence at focal lengths 4b, 4c and machining is finished at a focal position 4c. Since each simple lens 5a-5c takes charge of its own machining section, the efficiency of laser beam machining is improved to obtain smooth machined surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a laser beam focusing device suitable for use in a laser processing device.

(Prior Art) Generally, in a laser processing device, a laser beam transmitted from a laser oscillator is focused by a condensing lens held in a lens holder and irradiated onto the workpiece to perform processing. A laser beam focusing device is configured by the lens holder and the focusing lens.

Conventionally, this type of laser beam focusing device is configured as shown in FIG. 2, and is provided between a laser oscillator (not shown) and a workpiece 3. During operation, the laser beam 1 transmitted from the laser oscillator is focused at a focal point It4 on the workpiece 3 by a condenser lens 2 held in a lens holder (not shown), and cutting or welding.

(Problems to be Solved by the Invention) In the conventional laser beam focusing device as described above, there is one focusing lens 2, and there is also one focusing position of the laser beam. Therefore, when cutting the thick workpiece 3, a high-output laser beam is required, resulting in poor processing efficiency. Furthermore, the cut surface may be jagged or the cutting width may be different between the front and back sides of the workpiece 3.

SUMMARY OF THE INVENTION An object of the present invention is to provide a laser beam focusing device that significantly improves processing efficiency when cutting a thick workpiece.

[Configuration of the Invention (Means for Solving the Problems) The present invention provides a laser that includes a condensing lens that condenses laser light transmitted from a laser oscillator, and a lens holder that holds this condensing lens. The laser beam concentrating device is characterized in that the condensing lens is divided into two or more parts, each of which has a different focal length.

(Function) According to the present invention, when cutting a thick workpiece, the processing efficiency is significantly improved and the shape of the processed surface can be made smoother.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

The laser beam focusing device according to the present invention is constructed as shown in FIG. 1, and the same parts as in the conventional example (FIG. 2) are given the same reference numerals.

That is, the laser beam focusing device is provided between a laser oscillator (not shown) in the laser beam processing device and the workpiece 3, and a focusing lens 5 is held by a lens holder (not shown). There is.

In this case, the condenser lens 5 is divided into two or more parts, each having a different focal length. In this embodiment, for example, there are three single lenses 5a and 5b.

It is divided into 5C. Then, each lens unit 5a, 5
The focal positions of lenses b and 5c are located at positions 4a, 4b, and 4C, respectively, and the focal lengths become longer in order.

Now, during operation, the laser beam 1 transmitted from the laser oscillator is divided into 4a14b by the divided condenser lens 5.
, 4c. When the workpiece 3 moves from right to left in FIG. 1, the surface of the workpiece 3 is first cut at the focal point @4a.

Next, the middle of the surface of the workpiece 3 is cut at the focal point 4b, and finally the back side of the front surface of the workpiece 3 is cut at the focal point [4C].

(Modification) In the above embodiment, the case where the condensing lens 5 is divided into three parts has been explained as an example, but it goes without saying that similar effects can be obtained if the condensing lens 5 is divided into two parts or more.

[Effects of the Invention] According to the present invention, the condenser lens 5 is divided into two or more parts, each having a different focal length, so when cutting the workpiece 3, processing is performed at each focal position. The parts are divided and cut. As a result, processing efficiency is significantly improved. Moreover, the shape of the processed surface (cut surface) can also be made smooth.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a laser beam condensing device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional laser beam concentrating device. 1... Laser light, 3... Workpiece, 5... Condensing lens. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Scope of Claims] A laser beam focusing device comprising a focusing lens that focuses laser light transmitted from a laser oscillator and a lens holder that holds this focusing lens, wherein the focusing lens includes two focusing lenses. 1. A laser beam condensing device characterized by being divided into the above parts and each having a different focal length.