JPH0292483A - Laser beam machine - Google Patents

Abstract

PURPOSE:To allow efficient laser beam processing by providing a distance measuring means which measures the distance between a nozzle tip and a work and a lens moving means which moves a lens in the direction of focusing the laser beam according to the signal of the measuring means. CONSTITUTION:An arm 100 of a robot brings the laser beam machine 1 near to a work W to be worked so as to face the work according to the work and measures the distance to the work by shooting the beam from a transmitter 31. An iron core ring 7 is pulled upward by energizing a solenoid 10a of the lens moving means 20 which receives the signal of a lever 32 if the contact part of the work projects slightly. The lens 4 is then moved upward to align the beam focus to the projecting part. The lens 4 is pulled down by the reverse operation if the contact part of the work is sunk. The laser beam fed through the arm 100 center of the robot is stopped down by the lens 4 and the welding and cutting of the work are thereby executed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a laser processing device mounted on a robot.

(Prior Art) In recent years, progress in industrial robots and laser processing equipment has been remarkable, and in particular, since cutting and welding methods using carbon dioxide laser beams have been put into practical use, these have been installed on vehicle assembly lines, etc.
It is well maintained.

For example, West German Published Patent Publication DE37008 describes a technology in which a laser processing machine is attached to the tip of a robot arm.
The one shown in 29^l is known.

(Problems to be Solved by the Invention) Since the laser processing machine according to the above technology is mounted on the arm of the robot, the laser processing machine is positioned or controlled in accordance with the teaching of the robot. This positioning is performed with extremely high precision.

On the other hand, in the case of a workpiece made by press bending a thin plate such as a vehicle body, the finishing accuracy is not good due to the springback effect, and the workpiece usually deviates from the standard profile by several millimeters.

Therefore, in conventional laser processing machines where position control is taught according to the reference profile of the workpiece,
The laser beam focus does not match the workpiece, and the energy density of the laser beam decreases, reducing processing accuracy.
Processing time will be extended.

In view of this inconvenience, if an attempt is made to move the laser processing machine to match the actual profile of the workpiece, the control and programming of the robot will become extremely complex, leading to an increase in the equipment cost of the robot.

Therefore, there is a strong need for a technology that can better match the laser beam focus to the workpiece profile while using conventional robot equipment.

(Means for Solving the Problems) In order to meet the above-mentioned needs, the present invention provides a laser processing device installed at the tip of a robot arm, and includes a distance measuring means for measuring the distance between the nozzle tip of the device and the workpiece, and a distance measuring device for measuring the distance between the nozzle tip of the device and the workpiece. The present invention is characterized in that a lens moving means for moving the lens according to a signal from the means is attached.

(Function) While controlling the position of the laser processing device using the robot arm according to the reference profile of the workpiece, the laser beam focus is moved in a direction that matches the workpiece according to the signal from the distance measuring means, thereby performing laser processing. Do it.

(Example) A preferred example of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a diagram of a laser processing apparatus according to the present invention, and the laser processing apparatus 1 is roughly divided into a robot arm 100 and a robot arm 100.
a hollow housing 2 fixed to the housing 2;
a tapered conical nozzle 3 connected to the housing 2, a lens 4 housed in the housing 2, a lens moving means 20 for moving the lens 4 in the direction of the laser beam axis (hereinafter referred to as the beam axis), and a lens moving means 20 attached to the nozzle 3. Distance measuring means 30
It consists of

The lens 4 is housed in a cylindrical lens holder 5 and fixed with a lens holding member 5a. The lens holder 5 is fitted into a cylindrical slide vibro, and an iron core ring 7 is further fitted around the outer periphery of the slide vibro. Note that a passage 5b through which assist gas passes is formed between the lens holder 5 and the slide vibro.

Therefore, the lens 4, lens holder 5, slide vibro, and iron core ring are an integral assembly that can be disassembled.

The outer surface of the slide vibro is finished sufficiently smoothly and is fitted into the first and second cylinders 8a and 8b, which are spaced apart in the beam axis direction. The iron core ring 7 is made to protrude outward from between the iron core ring 7 and the first and second biasing members 9.
It is held between a and 9b.

The iron core ring 7 is surrounded by first and second toroids 10a and 10b provided outwardly with a small gap.

These first and second threads 10a and 10b are assembled into the housing 2 so that the boundary between them coincides with the midpoint in the beam axis direction of the iron core ring 7 at the reference position.

Further, the biasing members 9a and 9b mutually bias the iron core ring 7 in a direction to push it out, and the biasing forces of both are balanced.
Position the lens 4 at the reference position.

The iron core ring 7 and the first and second biasing members 9a described above,
9b and the first and second treids 10a.

10b constitutes the lens moving means 20.

In addition, in the figure, 9c is the first and second treid 10a, 10
2a is an energizing plug for supplying power to b, 2a is an assist gas joint for supplying assist gas, and 5c
. . . are openings through which assist gas is discharged.

Next, the configuration of the distance measuring means 30 will be described.

The distance measuring means 30 includes a bracket 3 erected on the nozzle 3.
A transmitter 3] and a receiver 32 are attached to a and 3g using bolts B and B, respectively.

Transmitter 3 above! emits a straight beam such as a laser beam, infrared ray, or gamma ray, and the receiver 32 is a beam receiving component that receives the beam and converts it into a current or voltage signal.

The operating principle of the transmitter 31 and receiver 32 will be explained in detail in FIG. It is reflected and reversed at Wc and reaches the beam receiving element 32c. Similarly, the beam reaches the receiving beam element 32a for the work surface Wu, and the beam receiving element 32e for the work surface WL, so that the beam mainly reaches one of the beam receiving elements 32a to 32e. identify whether it is in

Furthermore, in this embodiment, the transmitter 31 and the receiver 32 are mounted so that the intersection between the beam and the work surface, that is, the identification position, is near the intersection P (see FIG. 1) between the nozzle 3 and the work surface.

The operation of the laser processing apparatus having the above configuration will be described below.

The robot arm 100 positions the laser processing device 1 near the workpiece W depending on the target workpiece W.

Next, a beam is emitted from the transmitter 31 to measure the distance to the workpiece.

If there is a workpiece on the workpiece surface Wc described in FIG. , the position of the lens 4 is held only by the first and second biasing members 9a and 9b.

The arm 100 of the robot moves the laser processing device 1 according to the reference profile of the workpiece, and if the relevant part of the workpiece is slightly protruding from the workpiece surface Wu, the receiver 3
Upon receiving the signal No. 2, the lens moving means 20 moves the lens 4 in the manner described below.

The first treid 10a is energized and the iron core ring 7 is
Pull up the figure. The iron core ring 7 rises while applying a reaction force to the first biasing member 9a.

As mentioned earlier, the iron core ring 7 and the lens 4 are in an integral relationship, so the lens 4 rises and focuses the beam on the work surface W.
Match u.

On the other hand, when the part of the workpiece is slightly sunken and the workpiece surfaces W are mutually aligned, the second toroid 10b is energized, and this tob pulls down the iron core ring 7 and the lens 4.
Move the beam focus to the work surface WL.

The movement of the lens 4 is performed in a very short time, and the laser processing device 1 focuses the laser beam sent through the center of the arm 100 of the robot using the lens 4, and cuts the workpiece W with this laser beam with high energy density. Or welding. Note that during laser beam projection, at least assist gas is blown into the nozzle 3 through the assist gas joint 2a, the assist gas passage 5b, the opening 5c, and so on, and this assist gas is blown into the nozzle 3 at high speed. It collides with the workpiece and cuts the workpiece or cleans the welded part.

Note that as the magnetic force of the first treid 10a is strengthened, the iron core ring 7 compresses the first biasing member 9a and rises until it hits the lower end of the first cylinder 88. It is possible to set the ascending position of the iron core ring 7 narrowly by adjusting the power supply, and the iron core ring 7 is lowered by the second thread 10b and the second biasing member 9b.

In other words, the number of beam receiving elements of the receiver 32 of this embodiment is increased, or the distance is accurately measured using a distance measuring means with better resolution, and the lens 4 is moved the required amount in a predetermined direction in accordance with this signal. The focus of the laser beam can be well adjusted to the deformation of the workpiece.

In the above embodiment, since the lens moving means 20 is arranged concentrically with the lens 4 in the vicinity of the lens 4, the housing 2
does not have a large diameter, and the laser processing apparatus l can be configured compactly.

Furthermore, in this embodiment, since the distance between the tip of the nozzle 3 and the workpiece is constantly measured, the focusing efficiency is good.

(Effects of the Invention) As described above, the present invention reduces the burden on the robot because there is no need to move the entire laser processing device. , enables efficient laser processing.

[Brief explanation of drawings]

FIG. 1 is a diagram of a laser processing apparatus according to the present invention, and FIG. 2 is an operational diagram of a distance measuring means. 1...Laser processing device 3...Nozzle 4...Lens 20...Lens 8 Moving means 30...Distance measuring means 100...Robot arm

Claims (1)

[Claims] A laser processing device installed at the tip of a robot arm, the laser processing device being provided with distance measuring means for measuring the distance between the nozzle tip of the device and the workpiece, and further comprising:
A laser processing apparatus characterized by further comprising a lens moving means for moving a lens in a direction to match a laser beam focus with a workpiece in accordance with a signal from the distance measuring means.