JPH10305383A - Method and device for laser processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser processing method and device therefor which enables a stable laser processing, even when a focus point of a condensing lens slips delicately during copying due to up-and-down movements of a gap between the tip of a laser processing head and a work by holding a stable focus point through an adjustment of the slip. SOLUTION: This processing method comprises a laser processing head 3 which equips a gap sensor 7, and a condensing lens 13 inside. The activated gap sensor 7 controls the gap G between the work W and the tip of the head 3 stable, and condenses a laser beam LB by the condensing lens 13. Then, the laser processing head 3 irradiates the laser beam LB to the work W, and conducts the laser processing. Under this circumstance, the laser processing is to be conducted by synchronizing the distance between the condenser lens 13 and the work W to the gap G between the bottom end of the head 3 and the work W controlled by the sensor 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing method for performing laser processing on a work by controlling the gap between the tip (lower end) of the laser processing head and the work to be constant by a gap sensor provided in the laser processing head. It is to provide the device.

[0002]

2. Description of the Related Art Conventionally, a condenser lens is provided inside a laser processing head, and this condenser lens is positioned at a predetermined optimum position when preset. In addition, for example, a capacitance type gap sensor is provided at the outer peripheral portion at the tip (lower end) of the laser processing head, and when performing laser processing, the gap between the tip (lower end) of the laser processing head and the work is fixed. Laser processing is performed on the work.

[0003]

By the way, in the above-mentioned conventional laser processing head, since the condensing lens is merely positioned at a predetermined optimum position in advance, the thickness of the workpiece changes or the workpiece is being scanned. When the gap sensor moves up and down, the focal position of the condenser lens may be slightly shifted.

[0004] Therefore, in a state where the scanning of the gap sensor is unstable, the focal position of the condenser lens is slightly shifted, which may cause a processing defect. In addition, the frequency of plasma generation during clean cut (dross-free) may be high, or the amount of plasma generated may increase.

An object of the present invention is to provide a stable focus by adjusting the gap even if the gap between the tip of the laser processing head and the workpiece moves up and down during scanning and the focal position of the condenser lens is slightly shifted. An object of the present invention is to provide a laser processing method and a laser processing apparatus capable of performing stable laser processing while maintaining a position.

[0006]

According to a first aspect of the present invention, there is provided a laser processing method according to the first aspect of the present invention, wherein a gap sensor provided in a laser processing head is turned on to control a gap with a work to be constant. After condensing the laser beam with a condenser lens in the laser processing head,
In a laser processing method of performing laser processing on a work by irradiating a laser beam from a laser processing head onto the work, the gap sensor controls a gap between a lower end of the laser processing head and the work, and the condensing lens and the work. The laser processing is performed on the work by synchronizing and controlling the distances.

According to a second aspect of the present invention, there is provided a laser processing apparatus according to the present invention, in which a gap sensor provided in a laser processing head is turned on to control a gap between the laser processing head and a work to be constant. A laser processing apparatus for performing laser processing on a work by irradiating the work with a laser beam from a laser processing head after condensing the laser beam; and a vertical movement device for moving the condensing lens up and down; Position detection means for detecting the position of the lens, and a control device for giving a command to the up and down movement device to control the position of the condenser lens to an appropriate position based on the gap detected by the gap sensor,
It is characterized by comprising.

Therefore, according to the first and second aspects of the present invention, when laser processing is performed on a workpiece, the laser processing head is positioned in a state where the focal position of the condenser lens in the laser processing head is positioned at an optimum position. The gap between the tip and the work is controlled to be constant by a gap sensor provided in the laser processing head, and the work is laser-processed.

When the gap detected by the gap sensor fluctuates up and down, the amount of change in the gap is sent to the control device. When the moving device operates, the condenser lens moves in the vertical direction, and the amount of movement is detected by the position detecting means and reaches the optimal position, the vertical moving device is stopped, and the focal position of the condenser lens automatically moves to the optimal position. Is adjusted.

Therefore, even if the gap always changes, the focal position of the condenser lens is adjusted to the optimum position,
Stable laser processing is performed while maintaining a stable focus position.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Referring to FIG. 1, a laser processing head 3 of a laser processing apparatus 1 is moved, for example, in a horizontal direction in FIG. 1 and in a direction perpendicular to the plane of FIG. It is provided freely. At the tip (lower end) of the laser processing head 3, a nozzle 5 is detachably provided. On the outer peripheral portion of the laser processing head 3 in the vicinity of the nozzle 5, for example, a capacitance type gap sensor 7 is provided. The gap sensor 7 is connected via a sensor box 9 to an NC device 11 as a control device.

The laser processing head 3 is provided with a lens block 15 on which a condenser lens 13 is mounted. The lens block 15 is guided by a guide 17 extending in the vertical direction and moved in the vertical direction. Things. Moreover, a rack 19 extending vertically is integrally provided on the left side of the lens block 15. A pinion 21 is meshed with the rack 19, and the pinion 21 is a focus control motor 23 as a vertical movement device.
Are connected to the output shaft 25.

The focus control motor 23 is provided with an encoder 27 as position detecting means. The encoder 27 and the focus control motor 23 are connected to the NC device 11. The lower end of the nozzle 5 detected by the gap sensor 7 and the work W
A correction device 29 is provided for moving the position of the condensing lens 13 up and down based on the up and down movement (fluctuation) of the gap G to optimize the focal position of the condensing lens 13.

With the above configuration, the laser processing head 3 is moved to a desired position on the work W by moving the laser processing head 3 with respect to the work W to be processed, for example, in the horizontal direction in FIG. . In this state, the laser beam LB oscillated by a laser oscillator (not shown) is condensed by the condensing lens 13 in the laser processing head 3, and then is irradiated from the nozzle 5 toward the work W. Laser processing will be performed.

During the laser processing, the gap sensor 7 is turned on to control the gap G between the lower end of the nozzle 5 and the work W to be constant, thereby performing the laser processing. In addition, the gap G detected by the gap sensor 7
Fluctuates up and down, the fluctuation amount of the gap G becomes N
When taken into the correction device 29 of the C device 11, the correction device 29 uses the focus control motor 23
Is given, the focus control motor 23 is driven, and the lens block 15 moves up and down via the output shaft 25, the pinion 21 and the rack 19, so that the condenser lens 13 moves up and down. Movement amount is encoder 27
Is detected and fed back to the NC device 11 to automatically adjust the focal position of the condenser lens 13 to an optimal position, the focus control motor 23 is stopped.

Thus, even if the gap G always fluctuates, the focal position of the condenser lens 13 is adjusted to an optimum position, so that a stable focal position is maintained and stable laser processing can be performed. .

The present invention is not limited to the above-described embodiment of the invention, but can be embodied in other forms by making appropriate changes. The control device may be an external control device other than the NC device 11. A focus control motor 23 is used as a vertical movement device.
Alternatively, instead of the rack 19 and the pinion 21, a drive device using another drive motor, gear, or the like may be used.

[0019]

As will be understood from the above embodiments of the present invention, according to the first and second aspects of the present invention, when laser processing is performed on a work, a condensing lens provided in a laser processing head. With the focal position of the laser processing head positioned at the optimum position, the gap between the tip of the laser processing head and the work is controlled to be constant by a gap sensor provided in the laser processing head, and laser processing is performed on the work.

When the gap detected by the gap sensor fluctuates up and down, the amount of fluctuation of the gap is sent to the control device. When the moving device is activated, the condensing lens moves up and down and the amount of movement is detected by the position detecting means and reaches the optimum position, the moving device is stopped and the focal position of the condensing lens is automatically adjusted to the optimum position. Can be adjusted.

Therefore, even if the gap always changes, the focal position of the condenser lens is adjusted to an optimum position,
A stable focus position is maintained, and stable laser processing can be performed.

[Brief description of the drawings]

FIG. 1 is a front view of a laser processing apparatus embodying the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser processing device 3 laser processing head 5 nozzle 7 gap sensor 11 NC device (control device) 13 condenser lens 15 lens block 19 rack 21 pinion 23 focus control motor (vertical movement device) 27 encoder (position detecting means) 29 Correction device LB Laser beam G Gap W Work

Claims (2)

[Claims] 1. A laser processing head, wherein a gap sensor provided in a laser processing head is turned on to control a gap between the laser processing head and a laser beam, and a laser beam is condensed by a condenser lens in the laser processing head. In the laser processing method of performing laser processing on the work by irradiating the work with a laser beam from the laser beam, the gap sensor controls the gap between the lower end of the laser processing head and the work and the distance between the condensing lens and the work. A laser processing method, wherein a laser processing is performed on a work by controlling the laser processing in synchronization. 2. A laser processing head, wherein a gap sensor provided in the laser processing head is turned on to control a gap between the laser processing head and a laser beam to be condensed by a condenser lens in the laser processing head. A laser processing apparatus that performs laser processing on a work by irradiating the work with a laser beam from a vertical movement device that moves the condensing lens up and down, position detecting means for detecting a position of the condensing lens, A control device for giving a command to the vertically moving device to control the position of the condenser lens to an appropriate position based on the gap detected by the gap sensor. .