JPH0453631B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser processing device for forming countless irregularities into a precise pattern by irradiating the surface of a workpiece such as a rolling roll with a laser beam.

[Conventional technology]

In recent years, the surface of a rolling roll is irradiated with a pulsed laser beam to form countless irregularities on the roll surface, and by using a roll on which the irregularities are formed during the temper rolling process after annealing the cold rolled steel sheet,
A method has been adopted in which the uneven pattern on the roll surface is transferred to the surface of the steel plate. This method using a laser beam differs from the uneven pattern formed by the conventional shot blasting method using steel balls, in that the size of each unevenness is uniform over the entire surface of the roll, and the adjacent unevenness is Since the pitch is constant, it has the characteristic that the sharpness of the steel plate surface treated by this method after painting is improved.

An example of such a conventional processing apparatus using a laser beam will be explained with reference to FIGS. 2 and 3.

In the figure, reference numeral 1 denotes a rolling roll as a workpiece, which is rotatably supported by support stands 2 and 3. Reference numeral 4 denotes a drive unit which applies rotational force to the support base 3 via a power transmission unit 5 to rotate the rolling roll 1. 6 is a base on which the above-mentioned parts 2 to 5 are installed.

Reference numeral 7 denotes a laser oscillator, which is attached to a cart 10 that is movable on rails 9 provided on a base 8. The rail 9 is provided parallel to the axis of the mill roll 1, so that the carriage 10 can move parallel to the surface of the mill roll. Reference numeral 11 denotes a transmission duct, which serves as a path for guiding the laser beam emitted from the laser oscillator 7 to the condensing lens 12. A reflecting mirror 13 is provided inside the bent part of the duct to reflect the laser beam. , the surface of the rolling roll 1 is irradiated through a condensing lens 12.

The laser beam converged by the condenser lens 12 is passed through a mechanical chopper 14, which is beam chopper means, through a through hole (not shown) provided at the tip of the torch 16 to which the condenser lens 12 is attached. It is designed to focus on the rolling roll 1. The disk-shaped mechanical chopper 14 has slits arranged around its circumference through which the laser beam can pass, and this disk is rotated at high speed using a separate means to pulse the laser beam and irradiate it onto the rolling roll 1. By doing so, countless small recesses are formed at a constant pitch on the surface of the roll. 15 is a gas nozzle which is an assist gas spraying means, and its tip is connected to a mechanical tipper 1.
It is provided so as to open immediately near the outer peripheral end of 4,
From here, roll 1 of assist gas (e.g. O ₂ ).
By spraying toward the upper laser beam focal position, the shape of the minute recess to be drilled is formed uniformly and to the required depth.

[Problem that the invention seeks to solve]

However, with such conventional processing equipment, the assist gas cannot be sprayed perpendicularly to the surface of the workpiece, and the tip of the gas nozzle is configured to be close to the mechanical chopper. (1) The assist gas is blown in an oblique direction, distorting the shape of the hole formed by the laser.
(2) The flow of the assist gas is disturbed by the wind pressure generated by the high-speed rotation of the tipper, and it does not work effectively on the workpiece surface. (3) The mutual positional relationship between the tipper and the gas nozzle is the hole shape formed by laser. However, there were various problems such as the fact that the adjustment was delicate and time consuming.

This invention has been made in view of these conventional problems, and solves the above problems by, for example, providing a beam choppering means on the side opposite to the workpiece with respect to the condensing lens. It is an object.

[Means for solving problems]

The present invention provides a laser processing apparatus that includes a condensing lens provided on a torch, a beam choppering means, and an assist gas spraying means, in order to process a workpiece by irradiating the workpiece with a laser beam in a pulsed manner. A condensing lens that converges a laser beam on the entrance side of the condensing lens and a lens that diffuses the laser beam converged by the condensing lens are disposed, and between the condensing lens and the diffusing lens, The specified invention is characterized in that, as the beam choppering means, a chopper disk for pulsing the focused laser beam is arranged, and furthermore, an assist gas spraying means is provided along the optical axis of a condensing lens provided on the torch. The invention is a combined invention of a laser processing device in which the laser beam is sprayed onto a workpiece.

[Effect]

Since a chopper disk is placed as a beam chopper between the condenser lens and the diffuser lens, which are arranged on the entrance side of the condenser lens provided on the torch, the laser beam emitted from the laser oscillator is The beam is pulsed before entering a condensing lens in the torch and is directed through the torch onto the workpiece. In addition, the assist gas is blown onto the surface of the workpiece along the optical axis of the condensing lens provided on the torch, and therefore the direction in which the assist gas is blown and the direction in which the laser beam is irradiated are the same. Since the Chiyotsupa disk is separated from the assist gas spraying part with a condensing lens provided on the torch interposed between them, the wind pressure generated by the high speed rotation of the Chiyotupa disk does not affect the gas blowing, so the workpiece can be processed easily. The hole shape formed on the surface of the object is not distorted and becomes a precise uneven pattern.

〔Example〕

The present invention will be explained below based on the drawings. FIG. 1 is a diagram showing an embodiment of the present invention. Note that although FIG. 2 is an overall view of a conventional example of a laser processing apparatus, the parts other than those shown in FIG. 1 are the same as the present embodiment.

First, the configuration of the embodiment will be explained with reference to FIG.
31 is a condensing lens with a focal length of ₁ , which condenses the laser beam emitted from the laser oscillator 7 and whose direction is changed by 90 degrees by the reflecting mirror 13. 32 is a diffusing lens with a focal length of ₂ , and condensing lens 31
They are arranged so that they are on the same optical axis y with a distance of ₁ + ₂ between them. The laser beam focused by the condensing lens 31 becomes parallel light by the diffusing lens 32, enters the condensing lens 12 provided on the torch 26, is condensed again, and passes through the through hole 2 at the tip of the torch 26.
6a and is projected onto the surface of the rolling roll 1, which is the workpiece.

24 is a chiyotsupa disk similar to the conventional example,
A plurality of slits are arranged circumferentially, and a motor M rotates it at high speed. This tipper disk 24 is installed at a position where the beam most converges, approximately between the condensing lens 31 and the diffusing lens 32, and rotates at high speed to repeatedly pass and block the laser beam in extremely short cycles. It is designed to pulse the laser beam.

25 is an assist gas supply port such as O ₂ provided in the torch 26, and the gas that has entered the torch 26 is injected onto the surface of the roll 1 through the through hole 26a. Further, the optical axes y of the condensing lenses 31, 12 and the diffusing lens 32 and the center of the through hole 26a are arranged in a straight line.

Next, the action will be explained.

A rolling roll 1, which is a workpiece, is mounted on support stands 2 and 3 and rotated as in the conventional example.

Next, the laser beam emitted from the laser oscillator 7 passes through the transmission duct 11, is bent by the reflecting mirror 13, enters the condensing lens 31, and is condensed, and the condensed beam is directed to the rotating chopper disk. 2
4 becomes a pulse, and then the diffusion lens 3
2, becomes a parallel beam, enters the condensing lens 12 provided on the torch 26, is condensed again by this lens, passes through the through hole 26a of the torch 26, and is projected onto the surface of the rolling roll 1 so as to be almost focused. be done.
This projected pulsed beam causes roll 1
A minute concave hole of a certain shape is formed on the surface, and the concave hole is finished with an appropriate depth and uniform shape by the assist gas blown out from the through hole 26a along the optical axis of the condenser lens 12. It will be subsidized.

Also, a trolley 10 on which the laser oscillator 7 is mounted
The laser beam moves parallel to the axis of the roll 1 on the rail 9, so that the laser beam
By moving in parallel along the surface and rotating the roll 1 at a constant speed, countless concave holes are regularly bored on the surface of the roll 1, creating an accurate pattern over the entire surface of the roll 1. can be formed.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects can be obtained. In other words, (1) the flow of assist gas is not affected by the rotation of the chopper disk, so the shape of the concave hole is stable, and the chopper disk can be rotated at high speed, especially to increase machining efficiency. (2) Since the assist gas is blown along the optical axis of the condensing lens, the countless concave holes regularly formed on the surface of the workpiece are uniformly formed without being distorted. (3) In the past, it was not easy to adjust the focal position of the condenser lens and the mutual positions of the tipper and gas nozzle, and it took a lot of time, but in this example, it is only necessary to adjust the focal position of the condenser lens. , workability has been greatly improved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the main parts of the embodiment according to the present invention, and Fig. 2 is an overall view of a laser processing device, showing a conventional example, except for the parts shown in Fig. 1. FIG. 3 is a top view of the configuration and is an explanatory view of the main parts in the conventional example. DESCRIPTION OF SYMBOLS 1... Workpiece (rolling roll), 12... Condenser lens, 24... Beam choppering means (chopper disk), 26... Torch, 25... Assist gas supply port, 31... Condensing light Lens, 32...diffusion lens, y...optical axis.

Claims (1)

[Scope of Claims] 1. A laser processing device equipped with a condensing lens provided on a torch, a beam choppering means, and an assist gas spraying means in order to process a workpiece by irradiating the workpiece with a laser beam in a pulsed manner. A condensing lens for converging a laser beam and a diffusing lens for diffusing the laser beam converged by the condensing lens are disposed on the entrance side of the condensing lens, and a combination of the condensing lens and the diffusing lens is provided. A laser processing apparatus characterized in that a chopper disk for pulsing the focused laser beam is disposed between the two beam chips as the beam chippering means. 2. In a laser processing device equipped with a condensing lens provided on a torch, a beam choppering means, and an assist gas spraying means in order to process a workpiece by irradiating the workpiece with a laser beam in a pulsed manner, the condensing lens A condensing lens for converging a laser beam and a diffusing lens for diffusing the laser beam converged by the condensing lens are disposed on the entrance side of the condensing lens, and the beam tip is disposed between the condensing lens and the diffusing lens. A chopping disk for pulsing the focused laser beam is arranged as the picking means, and the assist gas spraying means sprays the workpiece onto the workpiece along the optical axis of the condensing lens provided on the torch. A laser processing device characterized by being provided as follows.