JPH06198477A - Laser beam machine and its control method - Google Patents

Abstract

PURPOSE:To obtain the control method of a laser beam machine automatically controlling the height of a nozzle by a controller. CONSTITUTION:A mechanism is constituted so that the condenser lens 2 of a laser beam machine is possible to relatively move to a working nozzle 7. The position of a nozzle 7 to an object to be worked and the position of a lens 2 can be set within a working condition buffer. The position of the nozzle 7 to an object to be worked and the position of the lens 2 are controlled by using these set values.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus in which a lens and a nozzle can be driven independently and a control method thereof.

[0002]

2. Description of the Related Art Laser processing is a laser beam output / pulse frequency / duty, assist gas type / pressure, processing speed, processing shape, depending on the material / plate thickness of the target work, the type of processing, and the processing speed. It is necessary to optimize various conditions such as the position of the focus on the work and the height of the nozzle.

FIG. 5 shows a conventional control device in a laser processing apparatus. In the figure, 101 is a CPU that controls driving and screen input / output, 102 is a CRT that displays a screen, 103
Is an operation board that the operator inputs, 104 is a memory for storing data, 105 is a processing condition buffer that temporarily stores the processing conditions to be set, and 106 is a processing condition file that stores the processing conditions of various materials. 107 are machining program files for storing various machining programs, 10
8 is a height sensor input circuit for detecting the height of the nozzle, 1
Reference numeral 09 is a lens drive circuit for driving a lens, 110 is a Z-axis drive circuit for scanning a laser beam on a work, 1
Reference numeral 11 is a Y-axis drive circuit, and 112 is an X-axis drive circuit.

In this conventional control device, the processing condition buffer comprises processing speed, laser output, laser pulse frequency, laser pulse duty, processing gas type, processing gas pressure, and focus position data (information) as shown in FIG. The focus position is automatically controlled by the focus position data in the processing condition buffer.
However, regarding the nozzle height setting, since there is no nozzle height data in the processing condition buffer 105, the nozzle height data shown in FIG.
As shown in Fig. 5, the operator manually adjusts the height of the nozzle according to the selected buffer data in Fig. 5 by manually judging the material and plate thickness of the work before machining.

[0005]

Since the conventional laser processing apparatus is constructed and controlled as described above, it is necessary for the operator to confirm the setting conditions and adjust the height of the nozzle before starting the processing. there were. In addition, once processing is started, it is difficult to adjust the nozzle height during processing, so it is difficult to perform processing that requires changing the nozzle height during processing, such as cutting thick iron plates or stainless steel or aluminum. There was a problem that was.

[0006]

A laser processing apparatus according to a first aspect of the present invention includes means for moving up and down, left and right, and front and back relative to a work piece, and the inside thereof is guided from a laser oscillator. A cradle that allows the laser beam to pass through
A lens supported inside the mount so as to be movable in the axial direction of the laser beam passing through the mount, a nozzle having an opening through which the laser beam passes and attached to the end of the mount, and the nozzle In the laser processing apparatus, which comprises a detection means for detecting the relative distance of the workpiece and a controller, the controller controls the distance data of the nozzle from the workpiece, the focus of the workpiece and the lens. It has both the setting parts of the positional relationship data of and.

A laser processing apparatus according to a second aspect of the present invention is the laser processing apparatus according to the first aspect of the present invention, in which the mounting position of the nozzle is adjustable with respect to the mount.

According to a third aspect of the present invention, there is provided a laser machining apparatus control method, wherein in the laser machining apparatus according to the first or second aspect of the invention, the control device comprises: Data and (b) positional relationship data between the work piece and the lens focus are set, and (2) the height of the nozzle from the work piece detected by the detection means is calculated as (a) the work piece of the nozzle work piece. (3) using the focal length of the lens, the height of the nozzle from the work piece, and (b) the positional relationship data between the work piece and the lens focus, The distance of the lens from the workpiece is controlled.

[0009]

In the laser processing apparatus according to the first aspect of the present invention, (a) nozzle height data and (b) focus position data in the control device can be used as automatic control data.

The laser processing apparatus according to the second aspect of the invention makes it possible to adjust the position of the nozzle with respect to the mount.

According to a third aspect of the present invention, there is provided a method for controlling a laser machining apparatus, which automatically controls machining according to (a) nozzle height data and (b) focus position data which have been set.

[0012]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a processing head of a laser processing machine.
In the figure, 1 is a laser beam guided from a light source, 2 is a lens for condensing the laser beam 1, 3 is a lens mounting member which is slidably supported by a pedestal 6 via an O-ring 13.
Is a motor fixed to the mount, and 4 is a ball screw connected to the shaft of the motor 5, which is screwed to the lens mounting member 3 outside the mount. Reference numeral 7 denotes a nozzle, which is screw-engaged with a screw portion formed on the lower portion of the gantry 6. Reference numeral 14 is a sensor main body having a differential transformer 11 inside, and is a work 9
The nozzle height h is detected by the vertical position of the shaft 15 connected to the contactor 10 in contact with. Reference numeral 12 indicates the focus of the focused beam 8 focused by the lens 2, and g indicates the height of the focus 12 from the work 9. Further, the gantry can be moved three-dimensionally relative to the work.

Next, the operation will be described. The laser beam that has reached the lens 2 in the gantry 1 from the light source using optical means such as a mirror (not shown) forms a focal point 12 in the vicinity of the work 9 by the converging action of the lens 2. Nozzle 7 is pedestal 6
Is screwed to the lower end portion of the base 1, and moves in a three-dimensional space relative to the work 9 integrally with the gantry 1. In the laser processing, in order to protect the laser processing portion, it is usual to blow an assist gas from the outlet of the nozzle 7 toward the work 9. However, in order to maintain the processing conditions constant, the nozzle and the work are kept together. It is necessary to keep the distance h between them at a certain value. Therefore, the contact 10 and the differential transformer 11
The sensor 14 is used to control the position of the gantry 6 so that the nozzle-work distance h takes an appropriate value.

In order to set the nozzle distance to an appropriate value, the distance between the lens 2 and the work 9 in the pedestal changes as the distance between the pedestal and the work changes, and the distance between the focus 12 and the work 9 changes. Change. Since the distance between the focus 12 and the work 9 also has a value suitable for the processing content, the motor 5 is used to control this distance. That is, as the motor 5 rotates, the ball screw 4 connected to the motor shaft rotates, and the lens mounting member 3 screw-engaged with the ball screw 4 moves inside the gantry while holding the lens. Thereby, the distance g between the focus 12 and the work 9 is controlled.

Next, the positional relationship between the lens and the nozzle will be described. Since the lens 2 has a focal length 1 as shown in FIG. 2, the beam 8 transmitted through the lens 2 is focused below the lens 2 by a distance l. Since the sum of the distance g from the surface of the work 9 to this focal position and the focal length 1 is equal to the distance from the work 9 to the lens 2, the distance from the lower end of the nozzle 7 to the lens 2 is m and the nozzle 7 from the work 9 is The following formula is established between the height h and the height h. l + g = m + h

On the other hand, the configuration of the control device of the laser processing apparatus is shown in FIG. 5 as in the conventional example. When machining, the operator operates the operation board 103, reads the machining program from the machining program file 106 to the memory 104, and the operator inputs the material and plate thickness of the work 9,
The processing condition data is read from the processing condition file 106 into the processing condition buffer 105. The processing condition buffer 105 is composed of 5 sets of data consisting of 8 data items and 8 data as shown in FIG. When the machining program is started according to the operator's input, one of the five sets of data in the machining condition buffer is selected according to the machining program. The control device controls the laser processing device in accordance with the selected processing condition data.

As shown in FIG. 4, after the machining is started, the machining condition data is read into the machining condition buffer 105, and the machining condition is selected from the machining condition buffer 105. The movement of the nozzle 7 (movement of the pedestal 6) and the movement of the lens 2 are controlled so that the following expressions are satisfied for the position data G and the height data H of the nozzle 7. h = H m = 1 + GH

As described above, by controlling the height h of the nozzle and the mounting position of the lens 2, it is possible to match the height of the nozzle with the processing condition data.
The focus position data of the planned processing condition data can be adjusted without being affected by the height h of the nozzle.
In addition, in the present invention, not only the sensor 7 having a contactor but also a non-contact type sensor based on electrostatic capacitance can be used. Other sensors having a principle other than the above may be used as long as they can measure the distance. Furthermore, lens 2
The same effect can be obtained by driving a drive device such as a solenoid or a hydraulic circuit as well as the motor 5.

[0019]

According to the present invention, since the height of the nozzle is automatically adjusted by the control device, it is not necessary for the operator to adjust the height of the nozzle before starting the processing, and the labor can be reduced. . In addition, since the nozzle height can be automatically adjusted by the controller even during machining, it is necessary to change the nozzle height relative to the workpiece during machining. There is an effect that it becomes possible.

[Brief description of drawings]

FIG. 1 is a sectional view of a processing head according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a processing head work, a nozzle, a lens, and a focal length according to an embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a processing condition data buffer in one embodiment of the present invention.

FIG. 4 is a flow chart of a method of controlling nozzle height and focus position in one embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a control device of a laser processing apparatus according to an embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of a processing condition data buffer in a conventional example.

FIG. 7 is a flow chart of a method of controlling nozzle height and focus position in a conventional example.

[Explanation of symbols]

 1 Laser Beam 2 Lens 3 Lens Mounting Member 4 Ball Screw 5 Lens Drive Motor 6 Frame 7 Nozzle 8 Focused Beam 9 Workpiece (Workpiece) 10 Contactor 11 Differential Transformer 12 Focus 13 O-ring 14 Sensor Body 15 Differential Transformer Axis 101 CPU 102 CRT 103 Operation board 104 Memory 105 Processing condition buffer 106 Processing condition file 107 Processing program file 108 Height sensor input circuit 109 Lens drive circuit 110 Z-axis drive circuit 111 Y-axis drive circuit 112 X-axis drive circuit g From work Distance to focus position h Nozzle height from work m Distance from lens tip to lens mounting position G Selected focus position data H Selected nozzle height data L Lens focal length K Nozzle mounting adjustment Determined by Constant

Claims (3)

[Claims] 1. Up and down, left and right, relative to a work piece,
A mount having means for moving back and forth, a mount through which a laser beam guided from a laser oscillator passes, and a lens movably supported in the mount in the axial direction of the laser beam passing through the mount. In the laser processing apparatus including a nozzle having an opening through which the laser beam passes and attached to the end of the gantry, a detection unit that detects a relative distance between the nozzle and the workpiece, and a controller. The laser processing apparatus is characterized in that the control device has setting portions for both distance data of the nozzle from the workpiece and positional relationship data of the workpiece and the focal point of the lens. 2. The laser processing apparatus according to claim 1, wherein the mounting position of the nozzle is adjustable with respect to the pedestal. 3. The laser processing apparatus according to claim 1, wherein the control device includes (1) inside, (a) distance data from the workpiece of the nozzle, (b) the workpiece and the lens focus. (2) The height of the nozzle from the work piece detected by the detection means is controlled by using the distance data from the work piece of the nozzle (a) as a target value. 3) Controlling the distance of the lens from the workpiece by using the focal length of the lens, the height of the nozzle from the workpiece, and (b) the positional relationship data between the workpiece and the lens focus. And a method for controlling a laser processing apparatus.