JPS6320638B2 - - Google Patents

Abstract

PURPOSE:To enable laser marking with a simple construction at a high speed with high accuracy by mounting a device which positions a work in a small movable range at a high speed with high accuracy on a rough positioning device which moves over a wide range at a low speed. CONSTITUTION:A titled device consists of a positioning device 18 which moves over a wide range at a low speed and positions a work 6 with rough accuracy, a device 26 which is supported by said device 18 and positions the work in a small movable range at a high speed with high accuracy a driving device 23, a sensor 32 which measures the distance between said work and a condenser lens 12 and three control devices which hold the work 6 at the focal length of the lens 12. Said control devices drive the devices 18, 26 to perform marking operation and control the decive 23 by the feedback signal outputted from the sensor 32. The work 6 is marked at a high speed with high accuracy by the above- mentioned device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a laser beam marking device, and particularly to a laser beam marking device for large objects to be marked.

(Prior art) Conventional marking devices using laser light include those with a fixed irradiation unit and a marking target (hereinafter referred to as the target) placed on an XY table and moved, and those with a fixed irradiation unit and those with a fixed irradiation unit. There are two things that move the department. The latter allows for high-speed marking because the moving mechanism is not affected by the weight of the object.
The overall installation space is also small. This method is called a beam scanner method, and is called a galvano scanner method.
There is an XY scanner.

Fig. 1 shows a galvano type, which includes a driving device 1, a reflecting mirror 2 attached to it and rotating, a driving device 3, a reflecting mirror 4 attached to it and rotating around a rotation axis perpendicular to the reflecting mirror 2, and an optical axis. A condenser lens 5 that focuses on a plane at a certain distance regardless of the incident angle
(so-called f-theta lens). Then, the laser beam is received by the reflection mirror 2, and the rotation angle is controlled by the drive device 1 to scan in the X direction, and the laser beam is sent to the reflection mirror 4. The reflecting mirror 4 is controlled to rotate in a direction perpendicular to the reflecting mirror 2 by a driving device 3, and is scanned in the Y direction and sent to the lens 5. Lens 5 is XY with reflecting mirrors 1 and 2.
The laser beam scanned in the direction is focused on the surface of the object 6. However, although this mechanism has a small inertia of the drive unit and can mark quickly, the range is limited by the size of the lens 5.

Figure 2 shows the XY scanner, positioning mechanism 7
moves in the X-axis direction on a guide rail 8, and the positioning mechanism 9 moves on a guide rail 10 between the positioning mechanisms 7, 7.
to move in the Y-axis direction. Reference numeral 11 denotes a laser irradiation unit attached to the positioning mechanism 9, which moves over the object 6 in the XY directions.

FIG. 3 is an enlarged sectional view of the laser irradiation unit 11, which includes a condenser lens 12 and an oxygen intake port 13, and irradiates the object 6 by spraying oxygen from the lower end opening. This method uses oxygen and can mark deeper than the galvano type, but the larger the marking range, the larger the mechanism, and the inertia and high precision.
High-speed marking is difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a laser beam marking device that has a simple structure, can mark multiple locations on a large material, and can do so at high speed and with high accuracy.

[Structure of the invention]

(Means and effects for solving the problem) The present invention secures a wide marking area by providing a positioning device with coarse positioning accuracy for a large movable range, and eliminates the positional error of this positioning device by moving a small movable range at high speed and high speed. A positioning device that performs positioning with precision is used to correct the marking accuracy and speed, and a mechanism is provided to control the driving device that supports the condensing lens up and down using signals from the sensor.
This is a laser beam marking device that reliably holds the workpiece at the focal position of the condenser lens.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 4 showing a perspective view of the laser beam marking device of the present invention, the object 6 is shown on the conveyor 14.
A beam scanner 16, which will be described in detail later, is attached to a gutter 15, which is conveyed and positioned at right angles, and is provided perpendicularly above the conveyor 14. 1
A cable rack 7 includes cables to each driving section of the beam scanner 16 and fiber cables for laser beam transmission.

FIG. 5 is a detailed perspective view of the beam scanner 16.
The positioning device 18 is supported by a guide rail 19 provided on the garter 15, and the gear of a motor 21 attached to a frame 20 fixed to the positioning device 18 is a transverse gear with a long width of the conveyor attached to the garter 15. 43 and moves on the guide rail 19 in the X direction. Moreover, the positioning device 22
is loaded on the positioning device 18 and the motor 23 attached to the positioning device 22 and the positioning device 18
It moves in the Y direction with a gear 24 and a guide rail 25 attached to it.

Further, the positioning device 26 is provided on the positioning device 22 and moves in the X direction by a motor 27 fixed to the positioning device 26, a gear 28 attached to the positioning device 22, and a guide rail 29. As a result, the positioning devices 22 and 26 are compact and have low inertia.
It becomes a table.

Next, a processing head 30 is installed vertically in the middle of the positioning device 26, and is moved up and down by a motor 31 attached to the positioning device 26 and a gear 29 attached to the processing head 30.

FIG. 6 is a detailed view of the machining head 30, in which a gear 33 is vertically attached to the side via a support and is moved up and down by a motor 31. A height sensor 32 is fixed to the processing head 30 with a support 35 and a set screw 36. Further, there is a condensing lens 12 on the inside, and an optical fiber adapter on the top end.

FIG. 7 shows a block diagram of the control device of this embodiment. In the figure, the drive control section 38 includes a logic judgment unit 39, a data storage unit 40, and a sensor analysis unit 41. 42 is a motor drive unit, 44 is a speed detector, 45 is a position detector, 4
6 is a laser control section. The driving method of this laser beam marking device is a servo control method.

That is, the continuous marking coordinates stored in the data storage unit 40 are processed by the logical judgment unit 3.
9, the difference between this target coordinate data and the current coordinate is calculated, and a preset speed command value corresponding to this difference is selected and transmitted to the motor drive unit 42. Motor drive unit 42
controls the rotational speed of the motors 21, 23, and 27 using a signal from the speed detector 44. Further, the logical judgment unit 39 receives the feedback signal from the position detector 45 and determines the speed transmitted to the unit 42 when the difference between the previously calculated target coordinates and the current coordinates becomes 0 (that is, when movement to the target coordinates is completed). Abort the command and complete positioning. Further, the sensor decomposition unit 41 receives the output of the height sensor 32,
A speed command is transmitted to the motor drive unit 42 to drive the motor 31 so that the object 6 comes within the focal length of the condensing lens 12, thereby controlling the movement of the processing head 30.

Next, the control operation of the laser beam marking device configured as described above will be explained with reference to the flowchart shown in FIG.

First, the object 6 to be marked is placed on the conveyor 14.
is placed and positioned at a predetermined position, and the marking operation begins.

That is, in step (hereinafter referred to as S) 47, the processing head 30 is lowered, and in S48, the cycle is repeated until the object 6 is positioned at the focal point of the condenser lens 12. When positioning is complete, emit a laser beam with S49. Read the coordinate data with S50, and S51
The process monitors whether the data has ended or not, and if it has, branches to step S63 to stop laser output, and then pulls up the processing head in S64. If there is data, the coordinate data is compared with the current position in S52, the amount of movement on the X-axis and the Y-axis is calculated, and the amount is stored in the X-axis movement counter.

In S53, the X-axis movement counter and the maximum movement amount of the positioning device 26 are compared, and if the content of the X-axis movement counter is small, the positioning device 22, 26 is moved in S54.
Issue a movement command to. Accumulate the amount of movement in S55, and
is compared with the movement counter to monitor movement completion,
Repeat the cycle until the movement is complete. When the movement is completed, the current coordinates are updated in S57, and the process returns to repeat the marking operation. If it is S53,
If the content of the axis movement counter is larger than the maximum movement amount of the positioning device 26, the positioning device 26 is returned to the origin in S58, and a movement command is issued to the moving devices 22 and 18 in S59. The amount of movement is accumulated in S60, and the remaining amount of movement is calculated in S61.

Next, in S62, the remaining movement amount and the positioning device 18 are determined.
, and if the content of the remaining movement amount is small, branch to the positioning device 22,
6 starts moving. If the amount of remaining movement is large, repeat the cycle. Here, the minimum movement amount of the positioning device 18 is determined by the positioning accuracy,
This error is interpolated with this accuracy when the positioning device 26 moves. That is, the stopping accuracy of the positioning device 26 is made sufficiently higher than that of the positioning device 18.

〔Effect of the invention〕

As described above, according to the laser beam marking device of the present invention, a positioning mechanism with a small movable range that has small inertia and moves at high speed and high precision is mounted on a positioning mechanism that moves over a large movable range at low speed and with coarse positioning accuracy. When the command value is larger than the maximum movement amount, that is, when the drawing command is large, the positioning mechanism is moved at low speed and with low precision. Then, by switching the movement command to a highly accurate mechanism before this minimum movement amount, that is, the maximum allowable value of the accuracy limit,
It is possible to obtain a laser beam marking device that can easily and accurately mark multiple locations on a material with a large marking range, such as a steel plate material.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the mechanism of a conventional galvano scanner, Fig. 2 is a diagram showing the mechanism of a conventional XY scanner, Fig. 3 is a partial sectional view of Fig. 2, and Fig. 4 is an embodiment of the present invention. 5 is a partial detail view of FIG. 4, FIG. 6 is a diagram showing the main parts of FIG. 5, FIG. 7 is a block diagram of the control device, and FIG. 7 is a flowchart showing the operation contents of FIG. 7. 6... Marking object, 14... Conveyor, 18, 22, 26... Positioning device, 21,
23, 27, 31... motor, 30... machining head, 32... height sensor, 38... drive control section, 42... motor drive unit, 44... speed detector, 45... position detector.

Claims (1)

[Scope of Claims] 1. A laser beam marking device that marks a workpiece conveyed by a conveyor by irradiating a laser beam with the laser beam, the laser beam marking device is provided on the conveyor and moves between the widths of the conveyor at right angles to the conveyor, and includes a position detector. a first X-axis table provided with a position detector; a Y-axis table provided on the first X-axis table with a position detector; and a Y-axis table provided on the Y-axis table and smaller than the first X-axis table. A second X-axis table that is positioned with high range and high precision and has a position detector, and a sensor that is movable up and down on the second X-axis table and that detects the distance between the workpieces is attached to the laser processing. a head, the first X-axis table, the Y-axis table, and the second
a motor with a speed detector that drives the X-axis table and the laser processing head, respectively; a motor drive unit that controls the speed of each of the motors using signals from each of the speed detectors; 1. A laser beam marking device comprising: a drive control section that controls the processing head and each of the tables to set positions by driving the motor in response to a signal from a laser beam marking device.