JP2562030B2 - Processing speed controller for laser processing machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a machining speed control device capable of improving a machining locus accuracy and a machining speed in a laser beam machine.

[Prior Art] FIG. 4 and FIG. 5 are diagrams showing a configuration diagram and a speed pattern of a conventional device.

In FIG. 4, (1) is a carbon dioxide laser oscillator,
The carbon dioxide laser light is output while being cooled by the cooling device (2).

(4) is an optical path for transmitting the carbon dioxide laser light to the processing head (5) on the optical scanning table (6).

(8) is a processing table for carrying the workpiece to the processing surface (7).

 (3) is a smoke exhaust device that exhausts smoke during processing.

Reference numeral (11) is connected to the operation panel (9) and the control panel (10) to control the positioning of the processing head (5), control the output of laser light emitted from the processing head (5), and laser light. This is a control device that automatically performs ON / OFF control of.

(12) is a work collector for collecting the work, and (13) is a visible light laser for confirming the working locus.

According to the conventional device having the above structure, the operator can operate the operation panel (9).
When the control panel (10) is operated, the control device (11) is actuated, the workpiece is placed on the processing table (8) and is carried to the processing surface (7), and the optical scanning table (6 ) And the machining head (5) are driven and controlled in the X and Y directions, and the laser light emitted from the machining head (5) is focused on the machining surface (7) and focused on the workpiece. The processing of the work piece is performed.

In the above conventional device, in order to maintain the accuracy of the machining locus, the machining head (5) is driven based on the acceleration / deceleration pattern shown in FIG.

That is, when processing is performed linearly from point A to point B and point C, before and after the bending point (point B) of the processing path, the processing head is placed at the position of the bending point so that the processing path falls within the set accuracy range. The speed of (5) was set to zero.

[Problems to be Solved by the Invention] As described above, in the conventional apparatus, since the processing speed is set to zero at the bending point of the processing locus, the average processing speed becomes slow.

The present invention has been made in order to solve the above-mentioned drawbacks, and processing of a laser processing machine capable of increasing the processing speed of a bending point within a range in which the accuracy of the path before and after the bending point of the processing path is within a set accuracy range. The purpose is to obtain a speed control device.

[Means for Solving the Problem] A processing speed control device for a laser processing machine according to the present invention is a processing locus formed by connecting a first point to an nth point by a plurality of line segments. Is processed from the first point to the n-th point,
-2) The processing speed condition corresponding to the speed pattern in which the processing speed of the processing head at the point (provided that m ≦ n) is not zero is set from the (m-2) th point to the m-th point. It is constant throughout the deceleration up to the th point
The lower of the machining speed calculated by setting the machining speed at the second point to zero and the machining speed based on the numerical table specified according to the bend angle of the bending point formed by the two line segments. The processing speed is calculated based on the precondition that the processing speed of the microcomputer is calculated and stored, and the interface circuit that outputs the processing speed condition corresponding to the speed pattern from the microcomputer as a drive signal is output from the interface circuit. The machining speed of the machining head on the machining locus is controlled by the generated drive signal.

[Operation] According to the present invention having the above-described configuration, the machining head is controlled using a speed pattern that does not make the machining speed zero at the bending point of the machining trajectory, so that the average machining speed is improved while maintaining desired accuracy. You can

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

The overall external structure is the same as that shown in FIG.

FIG. 2 is a diagram showing a relationship between a machining trajectory and an acceleration / deceleration pattern when a curved linear machining trajectory from point A to point B, point C, point D, and point E is machined with laser light. . This acceleration / deceleration pattern is devised so that the machining speed at the points B, C, and D does not become zero, and machining can be performed within the set accuracy range.

FIG. 1 shows a drive circuit of a machining head (5) by a microcomputer (20) incorporated in the control device (11) of FIG.

The microcomputer (20) inputs the processing data,
The processing speed condition corresponding to the acceleration / deceleration pattern is calculated and stored.

(21) is an interface circuit which inputs the above-mentioned processing speed condition and outputs a drive signal for the processing head (5).

(22) and (23) are a machining head driving X-axis servomotor and a machining head drive for receiving a driving signal from the interface circuit (21) to drive the machining head (5) through the optical operation table (6). Y-axis servo motor for use.

According to this embodiment having the above configuration, the processing speed condition corresponding to the acceleration / deceleration pattern is input to the interface circuit (21) from the microcomputer (20) to which the program including the processing data is input, and the interface circuit (21). The drive signal from the X-axis servo motor (2
2) and the Y-axis servomotor (23) for driving the processing head, the optical scanning table (6) and the processing head (5) are driven and controlled in the X and Y directions, and the irradiation is performed from the processing head (5). The workpiece is processed by the generated laser light.

In order to process within the desired accuracy range while keeping the machining speed as high as possible without making the machining speed zero at each of B point, C point, D point, for the machining locus ▲ ▼, the first 4 points, ABCD
It is necessary to pay attention to the points, and the details will be described below (this is the same even when there are many inflection points). The algorithm is shown in FIG.

In order to prevent the processing speed from reaching zero at each point, it is impossible to determine how much speed should be taken by focusing only on the line segment ▲ ▼. If ▼ is a very short line segment and there is only a line segment up to point C, it becomes impossible to smoothly stop at point C when the speed at point B is set to a constant value.

Therefore, in this algorithm, paying attention to the 4th point,
It is necessary to determine the machining speed of the spots. When the second point is determined, the speed of the third point is determined by paying attention to the fifth point, and this is repeated to generate the acceleration / deceleration pattern of the machining trajectory.

 An example is shown below.

In line segment ▲ ▼ in Fig. 2, first, line segment ▲ ▼
The speed V _B at point B (second point) of is calculated. At this time, it is assumed that the velocity at point D (4th point) is V _D = 0, and line segment ▲ ▼
The velocity pattern is generated from the point toward the point _C, and the velocity V _C at the point _C is obtained.

 This calculation formula is as follows.

a = ev / nv (1) ev: Velocity of 4th point (V _{D in} this case) nv: Slope coefficient of velocity pattern Q: Transfer amount within reference time l: Line segment length (▲ ▼ in this case) dmax: Velocity of 3rd point (V in this case) _C ) a, b, c: Variables, so Vc = dmax.

However, there are cases where the calculated speed Vc thus calculated exceeds the maximum speed as the physical permissible speed of the actual drive system machine. In that case, i) If Vc <maximum speed Vc = dmax ii) When Vc ≧ maximum speed Vc = maximum speed.

Next, the bending angle θ _C at the point _C is calculated, and based on the data actually measured by the laser processing machine used for processing (data unique to each laser processing machine), the bending angle and the corresponding bending angle, Calculate the speed at θ _C from the numerical table that defines the relationship with the maximum speed in the range where the desired trajectory accuracy can be maintained, compare this with Vc above, and set a smaller value to C
The speed of the point.

From this, the above operation is performed again based on this Vc, and ev: Velocity of the 3rd point (Vc in this case) l: Line segment length (▲ ▼ in this case) is inserted into equations (1) to (3) The dmax at the next point B is calculated. Further, θ _B is calculated from the bending angle at point _B , compared with a numerical table, and a smaller value is taken as V _B. Therefore, the speeds of V _A and V _B are known, the initial speed and the terminal speed of the two points A and B are determined, and if they are moved corresponding to the acceleration / deceleration pattern, the speed will not be 0 at the bending point B. Can be processed.

This procedure is performed for the following four points B, C, D, and E to determine the speed at point C, and the remaining points C, D, and E determine the speed at point D.

In this way, if the processing speed component is calculated in advance by the microcomputer (20) from the line segment length and bending angle of the drawing according to the cutting pattern, the optimum processing speed pattern can be obtained.

[Advantages of the Invention] As described above, according to the present invention, the machining speed at the bending point of the machining trajectory is set as high as possible without impairing the accuracy of the machining trajectory, in other words, without damaging the machining accuracy of the workpiece. It is possible to obtain a processing speed control device for a laser processing machine in which the processing time is shortened.

[Brief description of drawings]

FIG. 1 is a portion of a machining head drive circuit by a microcomputer according to an embodiment of the present invention, and FIG. 2 is a relation between a plurality of point speed patterns in which the velocity is not zero at a bending point and a machining trajectory according to the embodiment of the present invention. 3 is an algorithm flowchart of an embodiment of the present invention, FIG. 4 is a laser processing machine and control device,
FIG. 5 is a view showing a velocity pattern in which the velocity is zero at the bending point B used in the conventional device. In the figure, (1) is a laser oscillator, (5) is a processing head, (6) is an optical scanning table, (7) is a processed surface, and (8).
Is a processing table, (11) is a control device, (20) is a microcomputer, and (21) is an interface circuit.

Claims (1)

(57) [Claims] 1. A machining locus formed by connecting a first point to an nth point by a plurality of line segments is machined from the first point to the nth point. In this case, the (m−2) th point (provided that m ≦ n)
The processing speed condition corresponding to the speed pattern in which the processing speed of the processing head in FIG.
-2) formed by two line segments and the machining speed obtained by the calculation that the deceleration from the point m to the point m is constant and the machining speed at the point m is zero. Corresponding to the microcomputer that calculates and stores the value based on the precondition that the lower processing speed is selected from the processing speed based on the numerical table specified according to the bending angle of the bending point, and the speed pattern from this microcomputer. And an interface circuit for outputting the processing speed condition as a drive signal, wherein the processing speed on the processing locus of the processing head is controlled by the drive signal output from the interface circuit. Processing speed control device.