JPH02108487A - Nozzle controller for laser beam machine - Google Patents

Abstract

PURPOSE:To reduce the consumption of the assistant gas and to perform high- precision laser beam machining without changing a nozzle by moving the position of the movable nozzle blowing out the assistant gas to such a direction that laser beam move relatively to a material to be worked. CONSTITUTION:The material 8 to be worked is irradiated with the laser beam 1 converged by a condenser lens 2 held by a structure of a working head 5 and the laser beams 1 is covered with a nozzle 6 installed to the working head 5 to work such as cut off, weld, etc., the material 8 to be worked while blowing out the assistant gas. In this laser beam machine, the nozzle 6 is movable and can be moved by a controller 10a through an actuator 11a. When the material 8 to be worked is worked, this movable nozzle 6 is moved by the controller in the relatively moving direction according to the moving speed of the laser beam 1 to the material 8 to be worked. By this method, the action of the assistant gas can be expanded as far as a position double the discrepancy between the central point of the tip of the nozzle 6 and the central point of the laser beam 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a nozzle control device for a laser processing machine that controls a nozzle that covers a laser beam passed through a condensing lens of the laser processing machine and blows out assist gas. be.

[Prior Art] In conventional laser processing machines, the condenser lens and the nozzle are generally arranged so that the optical axis of the laser beam and the center point of the nozzle coincide, and the distribution of the assist gas is kept constant. The machine performs desired processing such as cutting on the workpiece.

FIGS. 5 and 6 are longitudinal cross-sectional views of a structure that holds a condensing lens of a conventional laser processing machine, that is, a processing head portion, and an explanatory view of the nozzle tip thereof. In Figures 5 and 6,
1 is a laser beam oscillated from a laser oscillator (not shown); 2 is a condensing lens for condensing the laser beam 1 onto the workpiece 8; 3 is a lens holder for fixing the condensing lens 2; 4 is an adjustment knob for positioning the condensing lens 2 via the lens holder 3; 5 is a structure for holding the condensing lens 2 via the lens holder 3, that is, the processing head; and 6 is provided at the tip of the processing head 5. 7 is an assist gas supply device that is supplied between the condensing lens 2 and the nozzle 6 in the processing head 5; 8 is a workpiece to be processed by the laser beam 1; it can be attached to and removed from the table; is held in

Next, the operation of this laser processing machine will be explained.

As shown in FIG. 6, the tip of the nozzle 6 that blows out the assist gas has a perfect circular cross section, and the center or optical axis of the laser beam 1 that horizontally irradiates the workpiece 8 from above and the upper nozzle. 6, the lens holder 3 to which the condensing lens 2 is fixed is moved by operating the adjustment knob 4. Then, no matter which direction the processing head 5 moves relative to the horizontal plane of the workpiece 8 placed on the table, the assist gas is stabilized so that it covers the laser beam 1 passed through the condenser lens 2. We are making sure that we can supply it to you.

Also, as shown in Japanese Utility Model Application Publication No. 176891/1989,
By connecting the nozzle to the processing head with a flexible pipe through which assist gas passes, and moving the nozzle using a nozzle moving fitting, the center of the laser beam that has passed through the condenser lens is aligned with the center of the nozzle tip. Some did it like this.

[Problem to be solved by the invention] Conventional laser processing machines are configured as described above, and the center of the laser beam that passes through the condenser lens is aligned with the center of the nozzle that blows out the assist gas. In order to maintain a constant pressure and increase the supply amount, the diameter of the nozzle tip must be increased, which necessitates replacing the nozzle, which is a tedious task and reduces the consumption of assist gas. There was a problem that there were many.

This invention was made to solve the above-mentioned problems, and it eliminates the need for nozzle replacement and reduces the consumption of assist gas, while also allowing processing such as cutting with high processing accuracy. The purpose is to obtain a nozzle control device for a laser processing machine.

[Means for Solving the Problems 1] A nozzle control device for a laser processing machine according to the present invention provides a nozzle movement actuator between a structure such as a processing head that holds a condensing lens and a movable nozzle, and controls the nozzle movement actuator. The nozzle is moved by operating the actuator in a direction in which the laser beam passed through the condensing lens moves relative to the workpiece.

[Function] The nozzle control device according to the present invention can change the center point position of the tip of the movable nozzle in proportion to the moving speed of the laser beam with respect to the workpiece, thereby increasing the assist by the diameter of the tip of the nozzle. The assisting effect of the gas can be made equivalent to the assisting effect of a conventional nozzle whose tip diameter is twice the amount of deviation between the center point of the nozzle tip and the center point of the laser beam.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

In FIGS. 1 and 2, 1 is a laser beam, 2 is a condensing lens, 5 is a processing head which is a structure holding the condensing lens 2, and 6 is an X-axis inside the processing head 5.

A movable nozzle 8 is a workpiece supported movably in the Y-axis direction, and the processing head 5 and the table holding the workpiece 8 are moved relative to each other in the X-axis and Y-axis directions. It is composed of 9a.

9b is a speed detector in the X-axis and Y-axis directions of the laser beam 1 relative to the workpiece 8; 10a and 10b are speed detectors 9a and 9b
a control unit that inputs and amplifies the detected value from the input signal and outputs a signal that moves the nozzle 6 in the X-axis and Y-axis directions, lla and ll;
b is provided between the processing head 5 and the nozzle 6 and is operated by the signals output from the control section 10a and tab.
This is a laminated piezoelectric actuator for moving the nozzle in the axial and Y-axis directions.

Next, the operation of the nozzle control device according to this embodiment will be explained. As shown in FIG. 3, the tip of the movable nozzle 6 is a perfect circle, and the X-axis of the processing rod 5 or the table holding the workpiece 8 during processing of the workpiece 8 with the laser beam l. , the speed of movement in the Y-axis direction is measured by speed detectors 9a, 9.
Detected by b and inputted to the control units 10a and 10b, commands are independently given to the laminated piezoelectric actuators lla and llb, respectively, and the operation of these actuators lla and llb causes the center point of the laser beam 1 and the nozzle 6 to be The center point of the tip 6a of the nozzle 6 moves in proportion to the moving speed in the moving direction with respect to a reference position where the center point of the tip of the nozzle 6 coincides with the center point of the tip. Therefore, it is possible to supply assist gas similar to the process using the nozzle 6b having a large diameter tip as shown by the chain line in FIG.

In this embodiment, the nozzle 6 also has speed detectors 9a and 9.
Since it moves in proportion to the detected value by b, as shown in FIG. 4, the flow of the workpiece 8 melted by the laser beam 1 flows in the direction of cutting progress due to the flow 7a of the assist gas. Therefore, the cutting speed can be faster than that of conventional methods, and the workpiece 8 can be cut even if it is thick. This can be done with a small amount of assist gas.

In addition, in this invention, the movement of the laser beam in the X-axis and Y-axis directions is performed by one or the other of the processing head and table, and also by moving one of the processing head and table in the X-axis direction and the other in the Y-axis direction. You may let them.

[Effects of the Invention] As described above, according to the present invention, an actuator for moving the nozzle is provided between the structure that holds the condensing lens for laser light and the movable nozzle that blows out the assist gas, and the actuator for moving the nozzle is Since the actuator is operated to move the movable nozzle in the direction in which the laser beam moves relative to the workpiece, the center point position of the tip of the movable nozzle is adjusted in proportion to the moving speed of the laser beam relative to the workpiece. By being able to change the nozzle, unlike conventional nozzles, there is no need to replace the nozzle, and by using a nozzle with a small diameter at the tip, less assist gas can be used effectively to perform high-precision machining at low cost. It has the effect of being able to

[Brief explanation of the drawing]

FIG. 1 is a control system diagram showing a nozzle control device of a laser processing machine according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of a processing head portion of a laser processing machine equipped with the nozzle control device shown in FIG. 1. , Figure 3 is an explanatory diagram of the tip of the movable nozzle, and Figure 4 is an explanatory diagram of the tip of the movable nozzle.
FIG. 5 is a longitudinal sectional view of the processing head portion of a conventional laser processing machine, and FIG. 6 is an illustration of the nozzle tip of the same. DESCRIPTION OF SYMBOLS 1... Laser light, 2... Condensing lens, 5... Processing head (structure holding a condensing lens), 6... Nozzle, 7... Assist gas supply device, 8... ...Workpiece, 9a, 9b...Speed detector, 10a, 10b...
- Control unit, 11a, llb... laminated piezoelectric actuator for nozzle movement. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Figure 1

Claims (1)

[Claims] A structure that holds a condensing lens for laser light, a movable nozzle that covers the laser beam that has passed through the condensing lens and blows out assist gas, and an actuator for moving the nozzle that is provided between the movable nozzle and the structure. and a control section that operates the actuator to move the movable nozzle in a direction in which the laser beam moves relative to the workpiece.