Numeric value control device and numeric value control program
Patent Information
- Application Number
- DE112022007187
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-07-27
- Publication Date
- 2025-03-20
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a numerical control device for controlling a machine tool. BACKGROUND
[0002] Among the machine tools, there are some that perform relative movement of a processing nozzle and a workpiece and irradiate a laser beam from the processing nozzle onto the processing surface of the workpiece, thereby performing laser processing of the processing surface.
[0003] Among the numerical controllers for controlling such machine tools, there are some that detect a “gap amount” as the shortest distance from the machining nozzle to the machining surface and compensate the gap amount to a desired gap amount by feedback control or the like based on the detected gap amount. Citation listPatent document
[0004] Patent Document 1: Japanese Unopposed Patent Application, Publication No. 2017-111661 DISCLOSURE OF THE INVENTION Problems to be solved by the invention
[0005] The inventors focused on the fact that a problem illustrated below may occur. Hereinafter, a two-dimensional direction along a processing surface is referred to as the "processing surface direction," a direction orthogonal to the processing surface is referred to as the "normal direction," and a direction of laser radiation through a processing nozzle is referred to as the "radiation direction."
[0006] In laser machining, there may be a case where a laser beam is irradiated with the irradiation direction inclined relative to the normal direction, such as in edge processing to form a V-shaped groove in the cross section. In this case, a workpiece and a processing nozzle may deviate from the desired relative positions, and a gap amount may deviate from a desired gap amount. When the relative positions of the workpiece and the processing nozzle in the direction of the processing surface are controlled in the above state, the relative positions of the processing nozzle and the workpiece deviate from the desired relative positions in the normal direction. Since the irradiation direction is inclined relative to the normal direction, a laser beam position on the processing surface also deviates from a desired irradiation position due to the deviation in the normal direction.
[0007] Even if the gap amount is compensated by a relative movement of the processing nozzle and the workpiece in the radiation direction from the above state, only the gap amount is compensated to the desired gap amount, but the laser beam position on the processing surface remains in a deviated position and is not compensated to the desired radiation position because the direction of the relative movement is the radiation direction.
[0008] The present disclosure has been made in view of the above situation, and an object thereof is to make it possible to perform compensation of a laser beam position on a machining surface as well as compensation of a gap amount. Means to solve the problems
[0009] A numerical control device of the present disclosure is a numerical control device for controlling a machine tool, wherein the machine tool performs a relative movement of a machining nozzle and a workpiece and radiates a laser beam from the machining nozzle onto a machining surface of the workpiece, thereby performing laser machining on the machining surface, the numerical control device comprising a gap amount detecting unit that obtains a gap amount as the shortest distance from the processing nozzle to the processing surface; a normal calculation unit that calculates a normal direction of the machining surface; a movement amount calculation unit that calculates a movement amount in the normal direction as a movement amount to set the gap amount to a desired gap amount by causing the machining nozzle and the workpiece to move relatively in the calculated normal direction; and a gap compensation unit that compensates the gap amount to the desired gap amount by causing the machining nozzle and the workpiece to move relatively in the normal direction based on the calculated movement amount.
[0010] According to the numerical control device of the present disclosure, it is possible to perform compensation of the position of the laser radiation on the processing surface and compensation of the gap amount by causing the processing nozzle and the workpiece to move relatively not in the laser radiation direction but in the normal direction of the processing surface at the time of compensating the gap amount.
[0011] A numerical control program according to the present disclosure is a numerical control program that causes a computer to act as: a numerical control device for controlling a machine tool, wherein the machine tool performs a relative movement of a machining nozzle and a workpiece and radiates a laser beam onto a machining surface of the workpiece from the machining nozzle, thereby performing laser machining on the machining surface, the numerical control program further causes the computer to act as: a gap amount detecting unit that obtains a gap amount as the shortest distance from the processing nozzle to the processing surface; a normal calculation unit that calculates a normal direction of the machining surface; a movement amount calculation unit that calculates a movement amount in the normal direction as a movement amount to set the gap amount to a desired gap amount by causing the machining nozzle and the workpiece to move relatively in the calculated normal direction; and a gap compensation unit that compensates the gap amount to the desired gap amount by causing the machining nozzle and the workpiece to move relatively in the normal direction based on the calculated movement amount.
[0012] According to the numerical control program of the present disclosure, it is possible to have a computer function as the numerical control device of the present disclosure. In this case, it is possible to perform compensation for the laser beam position on the processing surface and compensation for the gap amount, similar to the numerical control device of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram showing a numerical control device of a first embodiment; Fig. 2 is a side view showing a situation where a laser beam is irradiated obliquely to a machining surface; Fig. 3 is a side view showing a case where a workpiece is in the situation of Fig. 2 has deviated in a normal direction. Fig. 4 is a side view showing the gap compensation in a comparative example; Fig. 5 is a side view showing the gap compensation in the present embodiment; Fig. 6 is a schematic diagram showing the numerical control device from a different angle than that of the Fig. 1 shows; Fig. 7 is a schematic diagram showing a numerical control device of a second embodiment; Fig. Fig. 8 is a side view showing a state in which a first machining area is selected as the current machining area; and Fig. 9 is a side view showing a state in which a second machining surface is selected as the current machining surface. PREFERRED EMBODIMENT OF THE INVENTION
[0013] Embodiments of the present disclosure will be described below with reference to the drawings. However, the present disclosure is not limited to the following embodiments and can be implemented with appropriate changes within a range that does not deviate from the spirit of the present disclosure. [First embodiment]
[0014] First, a configuration of a numerical control device 50 of the present embodiment will be described with reference to Fig. 1. The numerical control device 50 controls a machine tool 90 through a command containing numerical information. Hereinafter, three directions that intersect at right angles are referred to as an "X direction," a "Y direction," and a "Z direction." Specifically, the X direction and the Y direction are two directions that intersect at right angles in a horizontal plane, and the Z direction is a vertical direction.
[0015] The machine tool 90 includes a nozzle holder unit 71 that holds a machining nozzle 72, and a workpiece holding unit 81 that holds a workpiece 82. The machine tool 90 causes the machining of the nozzle 72 and the workpiece 82 to move relative to each other by causing the nozzle holder unit 71 and the workpiece holder unit 81 to move relative to each other. Specifically, the relative movement includes all or part of the relative movement in the X direction, the relative movement in the Y direction, the relative movement in the Z direction, the relative movement around the X direction, the relative movement around the Y direction, and the relative movement around the Z direction. Each of the relative movements can be performed by moving the machining nozzle 72, by moving the workpiece 82, or by moving both the machining nozzle 72 and the workpiece 82.
[0016] The machine tool 90 performs laser machining by irradiating a laser beam Lb from the machining nozzle 72 onto the workpiece 82. Hereinafter, a direction in which the laser beam Lb is irradiated from the machining nozzle 72 is referred to as a “radiation direction I.” Further, hereinafter, a surface of the workpiece 82 onto which the laser beam Lb is irradiated is referred to as a “machining surface S”; a two-dimensional direction along the machining surface S is referred to as a “machining surface direction sX, sY”; and a normal direction of the machining surface S is referred to as a “normal line sZ.” Further, hereinafter, the shortest distance between the tip part of the machining nozzle 72 and the machining surface S, that is, the distance between the normal line sZ, is referred to as a “gap amount G.”
[0017] The processing nozzle 72 includes a gap amount detecting device 78 for detecting the gap amount G. The gap amount detecting device 78 detects the gap amount G based, for example, on the capacitance between the tip of the processing nozzle 72 and the workpiece 82.
[0018] The numerical control device 50 is configured to accept a machining program input by a user or the like, and controls the machine tool 90 based on the input machining program. The numerical control device 50 includes an analysis unit 21, a processing unit 22, and a drive unit 27. The analysis unit 21 evaluates the input machining program. The processing unit 22 calculates, based on a result of the analysis unit 21, a movement amount of the nozzle holder unit 71 and the workpiece holding unit 81 to machine the nozzle 72 and the workpiece 82 into the desired relative positions. The drive unit 27 outputs an operation command to the machine tool 90 based on a result of the calculation by the processing unit 22.
[0019] The numerical control device 50 further includes a gap amount detection unit 33 and a gap compensation unit 36. The gap amount detection unit 33 receives the gap amount G detected by the gap amount detection unit 78 from the gap amount detection unit 78. Based on the gap amount G obtained by the gap amount detection unit 33, the gap compensation unit 36 compensates the gap amount G to a desired gap amount Go by performing feedback control or the like.
[0020] Next, a problem to be solved in the present embodiment will be explained with reference to the Fig. 2 to 4.
[0021] As in Fig. 2, in machining, there may be a case where a laser beam is irradiated with the irradiation direction I inclined relative to the normal direction sZ, such as in edge processing to form a V-shaped groove in the cross section. In this case, the workpiece 82 and the processing nozzle 72 may deviate from the desired relative positions, and the gap amount G may deviate from the desired gap amount Go. When the relative positions of the workpiece 82 and the processing nozzle 72 in the direction of the processing surface sX, sY are controlled in the above state, the relative position of the workpiece 82 relative to the processing nozzle 72 deviates from a desired position 82o shown in Fig. 3 is marked by a dashed line, to a position 82, which is in Fig. 3 is indicated by a solid line. In other words, the relative positions of the processing nozzle 72 and the workpiece 82 deviate from the desired relative positions in the normal direction sZ. Since the radiation direction I is inclined relative to the normal direction sZ, a laser beam position P on the processing surface S also deviates from a desired radiation position Po due to the deviation of the relative positions in the normal direction sZ.
[0022] It is assumed that from the above state, the processing nozzle 72 and the workpiece 82 are relatively moved in the irradiation direction I to compensate the gap amount G, as shown in a comparative example in Fig. 4 shows. In this case, only the gap amount G is compensated to the desired gap amount Go, but the irradiation position P on the machining surface S remains in the deviated position and is not compensated to the desired irradiation position Po because the direction of relative movement is the irradiation direction I.
[0023] To solve the above problem, the numerical control device 50 further comprises a normal calculation unit 44 and a movement amount calculation unit 45 as shown in Fig. 1. The normal calculation unit 44 detects a rotation angle θ from a predetermined reference state for the workpiece 82 to calculate the normal direction sZ based on the machining program.
[0024] In particular, as in Fig. As shown in Figure 2, the normal calculation unit 44 calculates the normal direction sZ based on a reference normal direction sZo as the normal direction sZ at the time when the workpiece 82 is in the reference state and the rotation angle θ from the reference state of the workpiece 82 based on the machining program. In other words, the reference normal direction sZo rotated by the rotation angle θ is the normal direction sZ.
[0025] Specifically, for example, it is assumed that the workpiece 82 is rotated about the X direction when the Z direction is the reference normal direction sZo, as shown in Fig. 2. A unit vector (Xu, Yu, Zu), that is, a vector whose absolute value in the normal direction sZ is "1" in this case, can be represented by the following formula 1. The normal calculation unit 44 obtains the normal direction sZ by calculating the unit vector (Xu, Yu, Zu). [XuYuZu]=[1000cosθ−sinθ0sinθcosθ]
[001] =[0−sinθcosθ]
[0026] The movement amount calculation unit 45 calculates a “movement amount V in the normal direction” as the relative movement amount of the processing nozzle 72 and the workpiece 82 in the normal direction sZ to Fig. 3 to compensate for the gap amount G to the desired gap amount Go. Specifically, the movement amount V in the normal direction can be determined, for example, from a difference between the gap amount G and the desired gap amount Go and an angle of the radiation direction I relative to the normal direction sZ.
[0027] The gap compensation unit 36 calculates a movement vector (Xv,Yv,Zv) in the normal direction by multiplying the unit vector (Xu,Yu,Zu)=(0,-sinθ,cosθ) represented by the above formula 1 by the movement amount V in the normal direction, as shown in the following formula 2. [XvYvZv]=V×[0−sinθcosθ]
[0028] By acting on the drive unit 27, the gap compensation unit 36 causes the processing nozzle 72 and the workpiece 82 to move relatively in the X-direction, the Y-direction, and the Z-direction, respectively, by the components of the motion vector in the normal direction (Xv, Yv, Zv). In this case, the processing nozzle 72 and the workpiece 82 move relatively in the normal direction sZ by the movement amount V in the normal direction, as shown in Fig. 5. The gap amount G is compensated to the desired gap amount Go and the laser beam position P on the processing surface S is compensated to the desired beam position Po.
[0029] As in Fig. As shown in Fig. 6, for example, the numerical control device 50 shown above is mainly configured with a computer Cp and a numerical control program 50p. The computer Cp includes a CPU, a RAM, a ROM, and the like. The numerical control program 50p is a program that causes the computer Cp to operate as a numerical control device 50 in cooperation with the computer Cp. The numerical control program 50p includes an analysis program 21p, a processing program 22p, a drive program 27p, a normal calculation program 44p, a movement amount calculation program 45p, a gap amount detection program 33p, and a gap compensation program 36p.
[0030] The analysis program 21p causes the computer Cp to operate as the analysis unit 21. The processing program 22p causes the computer Cp to function as the processing unit 22. The drive program 27p drives the computer Cp as the drive unit 27. The normal calculation program 44p causes the computer Cp to function as the normal calculation unit 44. The movement amount calculation program 45p causes the computer Cp to function as the movement amount calculation unit 45. The gap amount detection program 33p causes the computer Cp to function as the gap amount detection unit 33. The gap compensation program 36p causes the computer Cp to function as the gap compensation unit 36.
[0031] The configuration and effects of the present embodiment are summarized below.
[0032] The normal calculation unit 44 calculates the normal direction sZ of the machining surface S. The movement amount calculation unit 45 calculates the "movement amount in the normal direction V" to cause the machining nozzle 72 and the workpiece 82 to move relatively in the calculated normal direction sZ to compensate the gap amount G to the desired gap amount Go. The gap compensation unit 36 compensates the gap amount G to the desired gap amount Go by causing the machining nozzle 72 and the workpiece 82 to move relatively in the normal direction sZ by the calculated movement amount V in the normal direction.Thus, it is possible to compensate not only the gap amount G but also the laser beam position P on the processing surface S by causing the processing nozzle 72 and the workpiece 82 to move relatively not in the radiation direction I but in the normal direction sZ at the time of compensating the gap amount G.
[0033] The normal calculation unit 44 calculates the normal direction sZ based on the reference normal direction sZo as the normal direction sZ at the time when the workpiece 82 is in the predetermined reference state and the rotation angle θ from the reference state of the workpiece 82 based on the machining program. Therefore, it is possible to calculate the normal direction sZ simply and efficiently.
[0034] The numerical control device 50 is mainly configured with the computer Cp and the numerical control program 50p, and the numerical control program 50p causes the computer Cp to function as the numerical control device 50. Therefore, it is possible to use the computer Cp to implement the numerical control device 50 of the present embodiment. [Second embodiment]
[0035] Next, a second embodiment will be described with reference to the Fig. 7 to 9. In the present embodiment, points different from the first embodiment will be described mainly based on the first embodiment, and the description of points identical or similar to the first embodiment will be omitted as appropriate.
[0036] In the present embodiment, machining is performed on a plurality of surfaces of the workpiece 82. Therefore, the workpiece 82 has a plurality of machining surfaces S as shown in Fig. 7. Therefore, the numerical control device 50 further includes a current machining surface switching unit 43. The current machining surface switching unit 43 selects one of the plurality of machining surfaces S as a current machining surface Sc based on the predetermined shape of the workpiece 82 and the rotation angle θ from the reference state of the workpiece 82.
[0037] Specifically, the workpiece 82 has the shape of a square prism, for example, whose two end faces are rectangular in the X direction. In other words, the workpiece 82 is rectangular in the X direction, as shown in Fig. 8. Viewed in the X direction, the workpiece 82 has a first machining surface S1 as the machining surface S on a long side, a second machining surface S2 as the machining surface S on a short side, a third machining surface S3 as the machining surface S on the opposite side of the first machining surface S1, and a fourth machining surface S4 as the machining surface on the opposite side of the second machining surface S1.
[0038] Specifically, for example, it is also assumed here that the workpiece 82 is rotated about the X direction when the Z direction is the reference normal direction sZo, similar to the example shown in the first embodiment. Here, a state in which a "first normal direction sZ1," which is the normal direction sZ of the first machining surface S1, is the reference normal direction sZo, is assumed as the "reference state," and an angle of the first normal direction sZ1 relative to the reference normal direction sZo is assumed as the "rotation angle θ of the workpiece 82."
[0039] As in Fig. As shown in Figure 8, when the rotation angle θ of the workpiece 82 is between -45° and 45°, the current machining surface switching unit 43 selects the first machining surface S1 as the current machining surface Sc. However, when the rotation angle θ of the workpiece 82 is between 45° and 135°, the second machining surface S2 is selected as the current machining surface Sc, as shown in Figure 8. Fig. 9. Furthermore, when the rotation angle θ of the workpiece 82 is between 135° and 225°, the third machining surface S3 is selected as the current machining surface Sc. Furthermore, when the rotation angle θ of the workpiece 82 is between 225° and 315°, the fourth machining surface S4 is selected as the current machining surface Sc.
[0040] The Fig.The normal calculation unit 44 shown in Figure 7 calculates the normal direction sZ of the selected current processing surface Sc. The movement amount calculation unit 45 calculates the movement amount V in the normal direction to compensate for the gap amount G in the calculated normal direction sZ to the desired gap amount Go. The gap compensation unit 36 causes the processing nozzle 72 and the workpiece 82 to move relatively in the normal direction sZ of the current processing surface Sc by the calculated movement amount V in the normal direction. As a result, similar to the first embodiment, the gap amount G is compensated to the desired gap amount Go, and the laser beam position P is also compensated to the desired irradiation position Po.
[0041] According to the present embodiment, the current machining surface switching unit 43 selects one of the plurality of machining surfaces S as the current machining surface Sc based on the rotation angle θ of the workpiece 82. The normal calculation unit 44 calculates the normal direction sZ of the current machining surface Sc. The gap compensation unit 36 causes the machining nozzle 72 and the workpiece 82 to move relatively in the normal direction sZ of the current machining surface Sc. Therefore, even in a case where the workpiece 82 has a plurality of machining surfaces S, such as a case where the workpiece 82 is a square pipe, it is possible to respond to this without changing the settings for the machining surface S. [Other embodiments]
[0042] The above-described embodiments can be modified, for example, as follows. The numerical control device 50 can be configured with a controller dedicated to numerical control, instead of being configured primarily with the computer Cp and the numerical control program 50p. EXPLANATION OF REFERENCE SYMBOLS 44 Normal calculation unit 45 Movement amount calculation unit 50 Numerical control device 50p numerical control program 72 processing nozzle 82 Workpiece 90 machine tool Cp Computer G Gap amount Go desired gap amount S processing area sZ normal direction sZo reference normal direction θ Rotation angle of the workpiece
Claims
[1] A numerical control device for controlling a machine tool, wherein the machine tool performs a relative movement of a machining nozzle and a workpiece and radiates a laser beam from the machining nozzle onto a machining surface of the workpiece, thereby performing laser machining on the machining surface, the numerical control device comprising: a gap amount detecting unit that obtains a gap amount as the shortest distance from the processing nozzle to the processing surface; a normal calculation unit that calculates a normal direction of the machining surface; a movement amount calculation unit that calculates a movement amount in the normal direction as a movement amount for setting the gap amount to a desired gap amount by causing the machining nozzle and the workpiece to move relative to each other in the calculated normal direction; and a gap compensation unit that compensates the gap amount to the desired gap amount by causing the machining nozzle and the workpiece to move relative to each other in the normal direction based on the calculated movement amount in the normal direction. [2] A numerical control device according to claim 1, wherein the numerical control device controls the machine tool based on a machining program; and the normal calculation unit calculates the normal direction based on a reference normal direction as the normal direction at a time when the workpiece is in a predetermined reference state, and calculates a rotation angle from the reference state of the workpiece based on the machining program. [3] A numerical control device according to claim 1 or 2, wherein the machining surface of the workpiece comprises a plurality of machining surfaces; the numerical control device comprises a current machining surface switching unit, wherein the current machining surface switching unit selects one of the plurality of machining surfaces as a current machining surface based on the rotation angle of the workpiece; the normal calculation unit calculates a normal direction of the current processing surface; and The gap compensation unit causes the machining nozzle and the workpiece to move relatively in the normal direction of the current machining surface. [4] Numerical control program to start a computer to function as: a numerical control device for controlling a machine tool, wherein the machine tool performs a relative movement of a machining nozzle and a workpiece and irradiates a laser beam from the machining nozzle onto a machining surface of the workpiece, thereby performing laser machining on the machining surface, wherein the numerical control program further causes the computer to function as: a gap amount detecting unit that obtains a gap amount as the shortest distance from the processing nozzle to the processing surface; a normal calculation unit that calculates a normal direction of the machining surface; a movement amount calculation unit that calculates a movement amount in the normal direction as a movement amount for setting the gap amount to a desired gap amount by causing the machining nozzle and the workpiece to move relative to each other in the calculated normal direction; and a gap compensation unit that compensates the gap amount to the desired gap amount by causing the machining nozzle and the workpiece to move relative to each other in the normal direction based on the calculated normal direction movement amount.