JPH0787995B2 - Laser processing machine - Google Patents

Description

The present invention relates to a laser beam machine equipped with a sensor for measuring a distance between a machining head and a workpiece.

[Prior Art] FIG. 3 is a system configuration diagram of a conventional laser processing machine.
In the figure, (1) is the base of the processing table,
(2) is a table base that is movable in a linear direction on the base (1) (here, the linear axis is the X axis),
(3) is a motor for moving the table base (2) in the X-axis direction, and (4) is a table which is movable on the table base (2) in a direction orthogonal to the X-axis by a motor (not shown) (here, This linear axis is the Y axis.), (5) is the X axis,
A lifting body that moves up and down in a direction orthogonal to each of the Y axes (here,
This lifting axis is the Z axis. ), (6) is a cover for protecting the lifting body (5), (7) is a processing head attached to the tip of the lifting body (5), (8) is a frame body that supports the Z-axis portion, ( 9) is a laser oscillator that outputs laser light, (1
Reference numeral (0) is a laser beam guide tube, (11) is a controller for a laser processing machine having a built-in numerical controller (NC), and (15) is a workpiece.

The laser light is output from the laser oscillator (9), guided through the laser light guide tube (10), condensed by the lens inside the processing head (7), and placed on the table (4) to be processed. The object (15) is irradiated. At this time, the processing gas is injected at the same time. The number of laser processing machine control devices (11) drives the X, Y, Z axes to move the relative position of the processing head (7) and the table (4) and controls the output of laser light and the like, ) Is processed into a desired shape.

Further, in laser processing, it is important to position the focal point of the laser light focused by the lens at an appropriate position with respect to the workpiece (15). Therefore, a sensor for measuring the distance between the machining head and the workpiece is attached to the machining head (7), and the position of the machining head (7) or the position of the lens is moved by this signal to adjust the focus of the workpiece. A copying function is provided to automatically position the position so that the position becomes the set position. This function is also called a focus positioning function or a height control function, and is a known function in a general laser processing machine.

FIG. 4 shows a block diagram of this copying function. In the figure, (12) is a control unit in the control device (11), and (1
3) is a servo amplifier, (14) is a motor, (15) is a compound, (16) is a means for storing a set value for the distance L between the machining head (7) and the workpiece (15), and (17) is A sensor for measuring the distance L, and (18) is an amplifier for sensor signals.

The sensor (17) outputs a signal corresponding to the distance L and is input to the control device (11) via the sensor amplifier (18). In the control device (11), the distance indicated by the signal and the set distance previously stored in the set value storage means (16) are processed in the control unit (12) so that the difference becomes zero. The drive command is output via (13) and the motor (14)
Is driven to move up and down the position (Z axis) of the processing head (7).

This copying function can be implemented by instructing ON / OFF in the NC program.

In the NC program, if there is a command to move the axes such as the X and Y axes and a command to enter the copying function at the same time, both movements are processed,
Movement commands for axes such as the X and Y axes and Z axis vertical movement by the copying function are simultaneously performed. Therefore, for example, when the X-axis movement command is issued after the copying function is entered by the NC program, the machining head (7) moves in the X-axis direction, and at the same time, the machining function causes Z The axis moves up and down.

Next, a processing flow in the control unit (12) is shown in FIG.

In step (S1), move commands such as X and Y axes are processed,
The movement amount of each axis is calculated. In step (S2), it is determined whether or not a copy function ON command has been issued. If the copying function is not on, the movement amount calculated in step (S1) is output to the servo amplifier (13) in step (S5). When the copying function is turned on, the above-mentioned copying function processing is performed in step (S3) to calculate the amount of movement so that the distance between the workpiece and the processing head becomes a set value. At step (S4), the movement amounts at steps (S1) and (S3) are added, and at step (S5), output to the servo amplifier (13). In step (S6), it is determined whether the commanded movement is completed, and if it is not completed, the above processing is repeated.

Next, a method of using the copying function at the start of processing will be described.

In laser processing, drilling called piercing is performed at the start of processing, and then the processing head is moved to process a workpiece into a desired shape.

Fig. 6 shows an example of the NC program at the start of machining and the movement of the machining head. When the machining head (7) is at the position (7a) and the copying function is instructed by N1 of the NC program, the distance between the machining head (7) and the workpiece (15) is increased by the copying function. It descends to the position (7b) where it reaches the set value. next
The N2 of the NC program turns off the copying function, and the N3 outputs laser light and processing gas to perform piercing. After piercing is completed, the copy function is added again at N4. After that, the copying function is turned on. Start moving at N5 and move to the desired shape. The reason why the copying function is temporarily turned off before piercing is to prevent malfunction of the distance sensor due to scattering of spatter during piercing.

[Problems to be Solved by the Invention] Since the conventional laser processing machine is configured as described above, there is a problem that the copying function must be temporarily cut off during piercing, and the program becomes complicated. There were also the following issues. That is, as shown in FIG. 6, during piercing, deposits (19) formed by sputtering
In this case, the distance sensor (17) detects the deposit (19) when the copying function is turned on in N4 of the program, and issues an alarm that the workpiece is too close. Alternatively, the processing head (7) was raised by the height of the deposit (19), and the focus position of the laser beam was not aligned, resulting in processing failure.

The present invention has been made in order to solve the above problems, and does not require a complicated program, and also generates unnecessary alarms and processing defects caused by deposits at the start of processing. An object of the present invention is to obtain a laser processing machine capable of preventing the above.

[Means for Solving the Problems] First, a laser beam machine according to the present invention includes a distance sensor that measures a distance between a processing head and a workpiece, and an output signal of the distance sensor is applied to the workpiece. In a laser processing machine having a copying function for controlling the position of the focal point of laser light to a set value, the copying function is invalid until the set distance is moved in the first movement after piercing. , Is valid when the set distance is moved.

Secondly, the copying function is invalidated from the start of piercing to the movement of a set distance after piercing.

[Operation] By disabling the copying function during piercing, even if the distance sensor malfunctions due to scattering of spatter, the copying function can be disabled. Therefore, it is not necessary for the program to temporarily turn off the copying function during piercing.

Next, in the first movement after piercing, the scanning function is disabled until the set distance is moved, and the set distance is made longer than the distance where spatter is deposited, so that the processing head is not affected by spatter deposition. After moving to a range that does not exist, the copying function is turned on, so unnecessary alarms and machining defects do not occur.

[Embodiment] As one embodiment of the present invention, FIG. 1 shows a flow of processing for invalidating the copying function until the set distance is moved, and then automatically enabling the copying function. In step (S1), movement commands for the X and Y axes are processed to calculate the movement amount of each axis. In step (S2), it is determined whether or not a copy function ON command has been issued. When the copy function is included, step (S
If it is not the movement immediately after piercing in 8), the process proceeds to step (S3), after which the same processing as in the conventional example of FIG. 5 is performed. In the case of movement immediately after piercing, in step (S9), the movement distance up to the present is compared with the distance preset as a parameter. If this movement distance is less than or equal to the set distance, proceed to step (S5) and step (S1)
Only the movement amount of is output and the copying function is disabled. If the moving distance exceeds the set distance, the process proceeds to step (S3) and the copying function process is performed. Next, in step (S4), the movement amounts of steps (S1) and (S3) are added, and the result is output to the servo amplifier in step (S5). In step (S6), it is determined whether or not the commanded movement is completed, and if it is not completed, the above processing is repeated.

An example of a method of determining whether the movement is immediately after piercing in step (S8) will be described.

If there is a code that means piercing in the NC program, the first movement command after that code will be the movement immediately after piercing, and therefore it is possible to make a determination.

However, even if the process shown in FIG. 1 is executed, if another command with no movement is received from the completion of the piercing to the first movement command, the copying function becomes effective during that time, and the spatter is accumulated. An alarm may occur.

In order to prevent this, FIG. 2 shows a flow of processing for invalidating the copying function from the start of piercing to the movement of a set distance after piercing.

Steps (S1) to (S9) are the same as in FIG. If it is not the first movement after piercing in step (S8), it is determined in step (S10) whether or not there is movement after piercing. If NO, the copying function process is not performed and the process proceeds to step (S5). If there is another command that does not move until the first movement command after piercing, the copying function is not enabled through this path, so the above alarm does not occur.

In the above embodiment, the two-dimensional laser processing machine is taken as an example, but a similar effect can be obtained with a three-dimensional laser processing machine.
Further, the distance sensor may be of any type such as a capacitance type or an optical type.

[Effects of the Invention] According to the present invention as described above, in the first movement after piercing, the copying function is disabled until the set distance is moved, and then automatically enabled, or piercing is started. From time to time, after piercing, the copying function is disabled from beginning to end until the set distance is moved.Therefore, unnecessary alarms and processing defects due to spatter buildup during or before piercing or moving after piercing. It is possible to prevent the occurrence of the occurrence without complicating the NC program.

[Brief description of drawings]

1 and 2 are diagrams showing a processing flow of a copying function according to an embodiment of the present invention, FIG. 3 is a system configuration diagram of a conventional laser processing machine, and FIG. 4 is a block configuration diagram of a conventional copying function, FIG. 5 is a conventional process flow diagram, and FIG. 6 is an explanatory diagram of a conventional method of using the copying function at the start of machining. (1) …… Base (2) …… Table base (3) …… Motor (4) …… Table (5) …… Lifting body (6) …… Cover (7) …… Machining head (8) …… Frame (9) …… Laser oscillator (10) …… Laser light guide tube (11) …… Control device (12) …… Control unit (13) …… Servo amplifier (14) …… Motor (15) …… Workpiece (16) …… Set value storage means (17) …… Distance sensor (18) …… Sensor signal amplifier In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] 1. A distance sensor for measuring a distance between a processing head and a work piece is provided, and a focus position of a laser beam with respect to the work piece is controlled to a set value by an output signal of the distance sensor. In a laser processing machine having a copying function, the above-mentioned copying function is a means which is invalidated until the set distance is moved in the first movement after piercing, and is thereafter effective. Machine. 2. A distance sensor for measuring a distance between a processing head and a work piece is provided, and a focus position of a laser beam with respect to the work piece is controlled to a set value by an output signal of the distance sensor. A laser processing machine having a copying function, wherein the copying function is means that is invalidated from the start of piercing to the movement of a set distance after the piercing until it is moved.