JPS6130294A - Laser light condenser - Google Patents

Abstract

PURPOSE:To obviate the exertion of the pressure of an auxiliary gas on a compression ring and to prevent the generation of permanent deformation by positioning the side where the compression ring is positioned to face a lens to the condensing side of the lens and passing the auxiliary gas to the condensing side of a holder. CONSTITUTION:The lens 2 is attached in such a direction where the same side of the compression ring 11 for applying the holding force of the lens 2 to said lens is brought to the condensing side. A nozzle 6 is provided to a mount 13 and the auxiliary gas 5 is passed therethrough. The holding force acts therefore in the direction to cover the deformation of an indium wire 8 with time. The processing performance is thus stabilized as a result of the stable holding of the lens 2 and the contribution is made to the extended life of the lens.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a laser focusing device.

Conventional configuration and its problems Laser focusing devices use lenses to focus the beam output from a laser oscillation device, and the resulting high-density energy is irradiated onto the workpiece together with an auxiliary gas. cutting, drilling and welding.

It is applied to laser processing equipment that performs processing such as.

As mentioned above, laser processing involves cutting and /8-tangential processing by irradiating the workpiece with a high-energy-density laser beam focused to a spot size using a lens or spherical mirror, etc. However, in addition, an auxiliary gas is usually used for the purpose of improving processing efficiency, protecting the lens, etc.

FIG. 2G shows an embodiment of a conventional laser focusing device. Of course, the laser beam 1 emitted from the laser oscillator passes through the lens 2.
The light is narrowed down to a spot 3 on the order of wavelength. The workpiece 4 is irradiated with the high-density energy of this spot 3, and an auxiliary gas 5 at a constant pressure according to the processing purpose is applied.
By spraying from the opening 6a of the nozzle 6, processing efficiency is improved, the lens 2 is cooled, and flying debris from the workpiece 4 is prevented from entering. Furthermore, as shown in FIG. 2, it also plays the role of removing dross 7 generated when cutting metal.

As a holding means for the lens 2, the curvature of the lens 2 is a diameter,
There are many variations depending on the focal length, material, etc., and in order to cope with this, wires 8 made of indium, which is a soft metal, are generally arranged around the periphery of both surfaces of the lens. The indium wire 8 has the functions of sealing the auxiliary gas 5, acting as a heat transfer medium to the lens holder 9, and holding the lens 2 uniformly. In addition, the indium wire 8 is connected to the lens 2
To prevent draughts such as protrusion into the inside of the lens 2 due to deformation that occurs when the lens is installed, leakage of the auxiliary scrap 5 due to the misalignment of the placement position, and rattling due to a decrease in the holding pressure of the lens 2 due to deformation of the material over time. , are embedded in grooves 9a, 10a whose dimensions are slightly smaller than the cross-sectional area of the indium wire 8 used. This groove 9a,
10a is provided at the receiving stage 9b of the lens boulder 9 and the guide link 10.

Further, in order to obtain a constant pressure for fixing the lens 2 to the lens boulder 9, a compression ring 11 and a fixing ring 12 are used in which several sulins) are arranged in the axial direction and slid in the circumferential direction. The slit 11) of the compression ring 11 is set so that a specified holding pressure is applied to the lens 2 when the fixing ring 12 is tightened until the slit width becomes zero.

In this way, the lens 2 is assembled into a unit in the lens holder 9, and is handled as a lens unit when replacing or cleaning the lens. Although the lens unit is assembled to the mount 13, the lens holder 9 has a structure in which its fixed position relative to the mount 13 can be changed in order to adjust for variations in focal length between lenses.

The 0 link 14 is for shielding the auxiliary gas 5, and the lock ring 15 is for fixing the position of the lens bolt 9 and at the same time preventing the lens unit from moving slightly against the pressure from the auxiliary gas 5.

However, this laser focusing device has a compression ring 11
Since the holding force (direction M) applied to the lens 2 by the lens 2 and the pressure (direction N) of the auxiliary gas 5 applied to the lens 2 during processing are opposite in direction, the force that the lens 2 receives from the auxiliary gas 5 is due to the compression ring. If the holding force is greater than 11, compression ring 1
As a result, the lens 2, which had been pressed against the lens boulder 9 by overcoming the holding force of the lens 1, is lifted. That is, the compression ring 11 will be deformed by the auxiliary gas 5 at a pressure higher than the specified pressure, causing permanent deformation. This is an important problem when high auxiliary gas pressures are required, such as when cutting stainless steel plates.

The permanently deformed compression ring 11 uses a specified pressing force to cover the rattling of the lens attachment part that occurs as the indium wire 8 deforms to the spherical surface of the lens 2 over time, that is, as the fitting progresses. It loses its function. This is because the auxiliary gas 5 leaks from the outer periphery of the lens 2 during processing.
Alternatively, the lens 2 itself may be rattled by the pressure of the auxiliary gas 5, which may be a cause without adversely affecting the lens life or processing performance.

In such a situation, there is currently no effective solution to this problem other than aligning the fixing ring 12 to eliminate wobbling at the lens mounting portion.

OBJECTS OF THE INVENTION The present invention has been made in order to improve the above-mentioned conventional drawbacks, and an object of the present invention is to provide a laser focusing device in which permanent deformation of a compression ring due to gas pressure is prevented.

Structure of the Invention The present invention is characterized in that the side of the lens where the compression ring is located is the condensing side of the lens, and the auxiliary gas is passed through the condensing side of the holder.

Since the direction of the pressure applied to the lens by the auxiliary gas matches the direction of the pressure applied to the lens by the compression ring, the pressure of the auxiliary gas is not applied to the compression link.

Therefore, no permanent deformation occurs in the compression ring.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. That is, the receiving stage 9 of the lens holder 9 is placed in such a way that the lens 2 is sandwiched therebetween.
b and a groove 9a in the guide ring 10.

10a is provided, and an indium wire 8 is embedded therein. Compression ring 11. The structure of holding the lens 2 with a constant force by the fixing ring 12 is the same as the conventional one, but
The difference is that the mounting direction of the lens 2 is reversed, that is, the same side as the compression ring IX that provides the holding force of the lens 2 is set as the condensing side, and the mount 13 is provided with a nozzle 6 to allow the auxiliary gas 5 to pass through. Other parts common to those in FIG. 1 are given the same reference numerals and their explanations will be omitted.

The problem with the conventional structure is that when the gas pressure applied to the lens 2 during processing is large, excessive force is applied to the compression ring 11, which should be used below the specified pressure. There is no problem as long as it does not directly affect the compression ring 11. That is, by arranging the compression ring 11 on the condensing side of the lens 2 as shown in FIG. 1 and making sure that the set height of the compression ring 11 is within the elastic limit, the above-mentioned deformation of the indium wire 8 over time can be prevented. A holding force acts in the covering direction. Further, even if the pressure of the auxiliary gas 5 is set high for processing purposes, the stress is directly transmitted to the lens holder 9, so that it has no relation to the magnitude of the holding force of the compression ring 11.

This means that the holding force of the compression ring 11 is smaller than that of the conventional structure, leading to a reduction in internal strain constantly applied to the lens periphery. Therefore, it contributes to stabilizing the processing performance based on stable holding of the lens 2 and to extending the life of the lens.

Effects of the Invention As described in Section 2, according to the present invention, permanent deformation of the compression ring due to gas pressure can be prevented, and processing performance can be stabilized by stabilizing the lens holding position.

Furthermore, the lifespan of the lens can be extended by reducing the lens holding pressure, eliminating the need for additional tightening work.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional example. 2...Lens, 8...Indium wire, 9...
Lens holder, 10... Guide 'ring, 11...
Compression ring, 12... fixed ring

Claims (1)

[Claims] a housing that accommodates a lens; an auxiliary gas nozzle body disposed on the condensing side of the lens of the housing;
A laser condenser comprising: an adjustment mechanism for aligning the central axis of the nozzle body with the optical axis of the beam focused by the lens; and a nozzle chip that is detachably attached to the tip of the nozzle body and forms a nozzle hole. Device.