JP4828374B2 - Laser processing equipment - Google Patents

Description

  The present invention relates to a laser processing apparatus that performs laser processing of a workpiece at a predetermined position while retracting and approaching the workpiece with respect to the workpiece.

  In a laser processing apparatus, when laser processing is performed at a plurality of positions on a workpiece, the workpiece is laser processed by moving a processing nozzle (processing head) from the current processing position to the next processing position. When moving the machining nozzle from the current machining position to the next machining position on the workpiece, first move the machining nozzle away from the current machining position and move the machining nozzle away from the workpiece, then approach the machining nozzle to the next machining position. I am letting. When approaching the machining nozzle to the next machining position, for example, the machining nozzle is brought close to the next machining position, and then a capacitive non-contact sensor (depending on the distance between the machining nozzle and the workpiece) The machining nozzle is moved to a desired machining position (lowered immediately below) while avoiding collision between the machining nozzle and the workpiece using a sensor for measuring the electrostatic capacity.

  The laser processing machine described in Patent Document 1 moves the Z axis by a predetermined amount at a predetermined speed when the processing nozzle reaches the processing end point of the processing shape, and then moves the X and Y axes to the processing start point direction of the next processing shape. Has been moved to. Then, the Z-axis feed direction is reversed between the machining end point and the machining start point, and when the gap between the workpiece and the machining nozzle reaches a predetermined amount, the gap sensor is activated and gap control (processing following the workpiece) is started. is doing.

JP 2004-1067 A

  However, in the above conventional technique, when the workpiece height differs between the retreat start position (current machining position) of the machining head (machining nozzle) with respect to the workpiece and the next machining position due to warping or sinking of the workpiece, There is a problem that the machining head may collide with the work before performing the gap control. For this reason, there is a problem that it is difficult to realize stable machining of the workpiece.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a laser processing apparatus that performs stable laser processing of a workpiece while avoiding a collision between the processing head and the workpiece.

In order to solve the above-described problems and achieve the object, the present invention performs laser processing by moving a processing head that irradiates a laser beam to a processing point on a workpiece and completes laser processing of the processing point. When the next machining point is to be laser machined later, the machining head that has completed the laser machining of the machining point is retracted to the retreat position located on the upper side of the workpiece, and then approached to the next machining point to perform the next machining point. In a laser processing apparatus that performs laser processing of a machining point, the relative position between the workpiece and the machining head is controlled, and at the time of the approach, the oblique descent control is performed so that the machining head is obliquely lowered onto the next machining point. A position control unit that uses the shortest distance between the machining surface of the workpiece and the machining head as distance information. Comprising a distance detection unit, wherein the position control unit, when starting the oblique lowering control, the machining head starts position control of the machining head on the basis of the distance information which the distance detection unit detects The next machining point is approached.

  According to the present invention, when approaching the next machining point from the retreat position, the scanning information of the machining head is controlled using the distance information between the machining surface of the workpiece and the machining head. Can be avoided and stable laser processing can be started.

  Embodiments of a laser processing apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment FIG. 1 is a perspective view showing a laser processing apparatus according to an embodiment of the present invention. The laser processing apparatus includes a processing table 2 movable in the X-axis direction, a processing head 3 that irradiates a workpiece 104 with a laser beam, a processing nozzle 4 that is attached to the tip of the processing head 3 and functions as an electrostatic sensor, and a processing head 3, a processing machine body 1 having a Z-axis unit 5 that moves the Z-axis unit 5 in the Z-axis direction, and a Y-axis unit 6 that moves the Z-axis unit 5 in the Y-axis direction, a laser oscillator 8 that emits a laser beam, and a processing machine The NC control unit 7 that controls the main body 1 and the laser oscillator 8 is used to process the workpiece 104 placed on the processing table 2.

  The laser processing apparatus according to the embodiment of the present invention has a copying retreat function (a function of performing a copying operation while avoiding a collision between the processing nozzle 4 and the workpiece 104). The copying evacuation function here is one function (a distance (gap amount) between the machining nozzle 4 and the workpiece 104) that is implemented by a copying control unit (a copying control unit 25 described later) mounted on the NC control unit 7. The operation of bringing the machining nozzle 4 closer to the workpiece 104 using the detection result).

  The laser beam emitted from the laser oscillator 8 is guided to the machining head 3 by an optical system (not shown), and is irradiated onto the workpiece 104 from the tip of the machining nozzle 4 provided in the machining head 3. In the laser machining apparatus, the machining table 2 on which the workpiece 104 is placed is moved in the X-axis direction by the command of the NC control unit 7, and the machining head 3 is moved in the Y-axis direction by the Y-axis unit 6. 104 processes a desired two-dimensional shape.

  Next, a detailed configuration of the laser processing apparatus will be described. FIG. 2 is a functional block diagram showing the configuration of the laser processing apparatus. The laser processing apparatus includes an operation unit 110, a processing machine main body 1, an NC control unit (position control unit) 7, and a laser oscillator 8.

  The operation unit 110 includes information input means such as a touch panel, a mouse, and a keyboard, and receives predetermined instruction information (such as a processing program for processing the workpiece 104 and information regarding the workpiece 104) input from the operator. The operation unit 110 inputs instruction information input from the operator to the NC control unit 7.

  The NC control unit 7 controls the operation of the laser oscillator 8 and the processing machine main body 1 based on the processing program input from the operation unit 110 by the operator. Specifically, the NC control unit 7 controls the ON / OFF of the laser oscillator 8 based on the machining program input from the operation unit 110 by the operator, the operation control of the machining table 2 provided in the machine body 1, Operation control of the Z-axis unit 5 and the Y-axis unit 6 for moving the machining head 3 is performed.

  The NC control unit 7 has a function of controlling the copying operation of the machining head 3 with respect to the workpiece 104 (a copying control unit 25 described later). The copying control unit 25 performs a copying operation of the laser machining apparatus (of the machining table 2). Operation control, operation of the machining head 3). Specifically, the copying control unit 25 starts controlling the copying operation simultaneously with the start of the operation of moving the processing head 3 close to the processing table 2 while lowering the processing head 3. The copying control unit 25 moves the machining head 3 on the machining table 2 (XY position) while lowering the machining head 3 in the Z-axis direction after the machining head 3 reaches a predetermined position (possible copy start possible positions L and M described later). ) Is moved (simultaneously moved in the X-axis direction, the Y-axis direction, and the Z-axis direction) (hereinafter referred to as an oblique downward movement). Thereafter, the copying control unit 25 moves the machining head 3 closer to the machining position on the machining table 2 (work 104) only by the lowering operation of the machining head 3 in the Z-axis direction (hereinafter, referred to as a direct downward movement).

  Based on an instruction from the NC control unit 7, the processing machine body 1 controls the operation of the processing table 2 (movement control of the processing table 2 in the X-axis direction), and the operation control of the Y-axis unit 6 (Y-axis of the processing head 3). Direction movement control), operation control of the Z-axis unit 5 (movement control of the machining head 3 in the Z-axis direction), and the like.

  The laser oscillator 8 performs laser ON / OFF processing and the like based on an instruction from the NC control unit 7. The laser beam emitted from the laser oscillator 8 is sent to the processing machine main body 1 and is obliquely emitted from the processing head 3 (processing nozzle 4) of the processing machine main body 1 to the workpiece 104.

  Next, the configuration of the movement axis (the movement axis of the machining head 3 and the movement axis of the machining table 2) for moving the relative position of the machining head 3 with respect to the workpiece 104 will be described. FIG. 3 is a perspective view showing a configuration of each moving shaft provided in the laser processing apparatus.

  The machining head 3 (machining nozzle 4) is attached to the tip of the Z-axis unit 5 (on the workpiece 104 side), and the Z-axis unit 5 that moves the machining head 3 in the Z-axis direction is connected to the Y-axis 24. ing.

  The Z bearing 103 moves the machining head 3 in the Z direction (arrow Z direction in the figure) by driving the servo motor SM3, and the Y bearing 102 drives the machining head 3 in the Y direction (arrow Y in the figure by driving the servo motor SM2). The X bearing 101 moves the machining table 2 in the X direction (arrow X direction in the figure) by driving the servo motor SM1.

  The electrostatic sensor detects the capacitance between the workpiece 104 and the processing nozzle 4 as a voltage. The servo motors SM1 to SM3 are driven based on a drive signal from the NC control unit 7 or a sensor signal (detection signal) from the electrostatic sensor. In the machining head 3 and the machining table 2, the distance between the workpiece 104 and the machining nozzle 4 is not closer than a predetermined distance (a distance corresponding to the position of the machining head 3 with respect to the workpiece 104) based on a sensor signal from the electrostatic sensor. It is driven by servo motors SM1 to SM3. Thus, the position (movement path) of the machining nozzle 4 with respect to the machining table 2 is controlled so that the laser beam spot follows the machining line 105. In the present embodiment, the copying operation is not performed only by the downward movement just below, but the copying operation (approach operation) is performed by both the diagonal downward movement and the direct downward movement. That is, the machining nozzle 4 is lowered while following the oblique approach when moving the X axis and the Y axis.

  Next, a detailed configuration of the copying control unit 25 included in the NC control unit 7 shown in FIG. 2 will be described. FIG. 4 is a block diagram illustrating a detailed configuration of the copying control unit. The copying control unit 25 has a function of controlling the distance between the workpiece 104 and the machining nozzle 4 (the position of the machining nozzle 4 in the Z-axis direction) using an electrostatic sensor disposed in the vicinity of the machining nozzle 4. And an A / D converter 11, a nozzle height data converter 12, a command movement amount generator 13, and a servo amplifier 14.

  The A / D converter 11 performs A / D (Analogue / Digital) conversion on the sensor signal (signal related to the distance between the workpiece 104 and the machining nozzle 4 (voltage indicating the capacitance)) detected by the electrostatic sensor, and after the conversion Is input to the nozzle height data converter 12.

  The nozzle height data converter 12 converts (calculates) the signal input from the A / D converter 11 into data of the height (distance) of the machining nozzle 4 with respect to the workpiece 104. The nozzle height data converter 12 calculates the current height of the machining nozzle 4 (distance between the workpiece 104 and the machining nozzle 4) with respect to the workpiece 104 using, for example, the relationship between the voltage and the nozzle height shown in FIG. .

  The command movement amount creation unit 13 calculates the height of the machining nozzle 4 calculated by the nozzle height data conversion unit 12 and the set distance (nozzle height) between the machining nozzle 4 being processed and the workpiece 104 specified by the machining program. Difference) (copy height data). The command movement amount creation unit 13 uses the input difference data and the retraction amount data set in advance for each movement operation of the processing nozzle 4 (retraction amount data necessary for the processing nozzle 4) to process the processing nozzle. Information (command movement amount) for commanding the movement amount 4 is created. The command movement amount creation unit 13 sets the command movement amount so that the height of the machining nozzle 4 matches the preset nozzle height data (so that the difference between the height of the machining nozzle 4 and the nozzle height data becomes zero). create. The command movement amount creation unit 13 inputs the created command movement amount to the servo amplifier 14.

  The servo amplifier 14 transmits the command movement amount to the servo motor SM3. The servo motor SM3 moves the machining head 3 in the Z-axis direction by a distance corresponding to the command movement amount. The scanning control unit 25 controls the scanning height of the machining nozzle 4 by repeating the control process of the machining head 3 at a predetermined cycle. Here, the electrostatic sensor, the A / D conversion unit 11, and the nozzle height data conversion unit 12 correspond to the distance detection unit described in the claims.

  Next, the processing procedure of the copying operation of the laser processing apparatus will be described. FIG. 6 is a flowchart showing the processing procedure of the copying operation of the laser processing apparatus. When the laser processing apparatus finishes laser processing at a predetermined processing position, the NC control unit 7 stores a retreat code (information indicating a retreat operation (movement path or movement speed) of the machining head 3) from the machining program (NC program). ) Is read (step S10). The retreat code (M199, M189, etc.) here is information set in advance based on the surface shape (unevenness, etc.) of the workpiece 104, the movement distance of the machining head 3, and the like.

  Next, the NC control unit 7 determines whether the machining head 3 with respect to the workpiece 104 is based on information indicating whether or not to perform oblique evacuation and oblique approach preset by the user (valid evacuation and oblique approach valid / invalid). It is determined whether or not the oblique retraction operation and the oblique approach operation of the machining head 3 to the workpiece 104 (oblique downward movement, direct downward movement) are effective (step S20).

  The oblique retracting operation here is an operation in which the machining head 3 is lifted in an oblique direction (a direction not parallel to the Z-axis direction) from the machining end point on the workpiece 104 and retracted, and the machining head 3 is moved from the machining end point. While moving in the Z-axis direction, movement in the X-axis direction and the Y-axis direction is also performed.

  The oblique approach operation here is an operation of moving the machining head 3 (the machining head 3 located at machining start possible positions L and M described later) after retreating from the machining end point to the next machining start point. Yes, the machining head 3 moves in the X-axis direction and the Y-axis direction (slanting downward movement) while moving in the Z-axis direction from the retracted position, and then only moves in the Z-axis direction (directly downward movement). .

  When the NC control unit 7 determines that the oblique retraction operation of the machining head 3 with respect to the workpiece 104 and the oblique approach operation of the machining head 3 with respect to the workpiece 104 are effective (Yes in step S20), the laser machining apparatus with an alarm or manual stop It is determined whether or not it is a restart after the machining process is stopped (step S30).

  If the restart is not performed after the processing of the laser processing apparatus is stopped (No at Step S30), the NC control unit 7 controls the servo motors SM1 to SM3 to move the processing head 3 and the processing table 2 so that the processing head 3 To perform an oblique retreat operation. Further, the NC control unit 7 controls the servo motors SM1 to SM3 to move the machining head 3 and the machining table 2, and causes the machining head 3 to perform an oblique approach operation.

  When performing the oblique downward movement in the oblique approach operation, the NC control unit 7 controls the servo motors SM1 and SM2 to move the machining head 3 and the machining table 2 in the XY directions, while the scanning control unit 25 moves the servo motor. SM3 is controlled to move the machining head 3 in the Z direction (lowering with a copying operation). In addition, when performing a downward downward movement in the oblique approach operation, the scanning control unit 25 of the NC control unit 7 controls the servo motor SM3 to move the machining head 3 in the Z-axis direction (lowering with the scanning operation). (Step S40).

  When the NC control unit 7 determines that the oblique retraction operation of the machining head 3 with respect to the workpiece 104 and the oblique approach operation of the machining head 3 with respect to the workpiece 104 are not effective (No in step S20), the normal copying operation (directly downward movement) The conventional copying operation is performed only when the copying operation is performed. That is, during the oblique downward movement, the machining nozzle 4 is moved to a predetermined coordinate value set in advance without performing the copying operation of the machining nozzle 4 (approach while detecting the distance of the machining nozzle 4 with respect to the workpiece 104). Then, the copying control unit 25 performs the copying operation of the machining nozzle 4 only during the downward and downward movement (step S50).

  Also, in the case of restarting after stopping the processing process of the laser processing apparatus (step S30, Yes), a normal copying operation (a copying operation with only a downward movement) is performed (step S50). When the oblique approach process and the normal copying operation after the oblique retreat are finished, the NC control unit 7 ends the copying operation of the machining head 3 and starts laser machining of the workpiece 104.

  Next, detailed processing procedures of the diagonal evacuation process and the diagonal approach process will be described. FIG. 7 is a flowchart showing a processing procedure of the diagonal retreat process and the diagonal approach process. When the laser processing at the predetermined processing position is completed, the laser processing apparatus first performs an oblique retreat process as a process for moving the processing nozzle 4 to the next processing position (step S110). The oblique withdrawal process of the machining nozzle 4 is performed by the NC control unit 7 controlling the servo motors SM1 to SM3.

  Here, the movement path of the processing nozzle 4 during the oblique retraction process will be described. The moving path of the machining nozzle 4 during the oblique retraction process is an area where the machining nozzle 4 may collide with the workpiece 104 (an area where the machining nozzle 4 is not allowed to enter (intrusion prohibited area)), and the maximum of the machining nozzle 4 It is set based on the moving speed, the maximum moving speed of the machining table 2, and the like.

  FIG. 8 and FIG. 9 are diagrams for explaining an area where entry of the machining head is not permitted. The entry prohibition areas Z1 and Z2 that do not allow entry of the machining nozzle 4 are formed on the surface shape of the workpiece 104, the machining end point (position where oblique retraction starts) A1, the machining start point (position where oblique approach processing ends) B1, and the like. Set based on. Invasion prohibition areas Z1 and Z2 are set in the upper part from machining end point A1 to the next machining start point B1.

  The intrusion prohibited areas Z1 and Z2 are movement angles at which the machining nozzle 4 may collide with the work 104 during the oblique retreat process, and movements at which the machining nozzle 4 may collide with the work 104 during the oblique approach process. The angle and the processing nozzle 4 are set based on the height h1 (following retraction position) when moving the processing nozzle 4 in the XY plane direction (in-plane direction parallel to the processing surface of the workpiece 104).

  The intrusion prohibited area Z1 in FIG. 8 is a path (R1) above the area where intrusion is not permitted during oblique retraction processing, a path (R2) when moving the processing nozzle 4 in the XY plane direction at a height h1, This is an area surrounded by a straight line connecting the path (R3) at the upper part of the area where entry is not permitted during the approach process, the path (R4) of the downward movement and the machining start point B1 and the machining end point A1.

  The path (R1) is set outside the area where the machining nozzle 4 may collide with the workpiece 104 before the machining nozzle 4 reaches the retreat position K having the height h1 from the machining end point A1. The path (R1) and the machining surface of the workpiece 104 form any angle within an angle of 0 degrees to 90 degrees. The retreat position K here is a position that is located on the upper side of the workpiece 104 and that specifies the distance from the machining surface of the workpiece 104.

  The path (R2) is set at the upper portion of the height h1 when the machining nozzle 4 is moved in the in-plane direction (XY plane direction) parallel to the machining surface of the workpiece 104 without moving in the Z-axis direction. The route (R2) is a route from the retreat position K to a position where the oblique approach may be started (a position where copying can be started L). The scanning start possible position L here is a possibility that the machining nozzle 4 may collide with the workpiece 104 when the machining nozzle 4 is moved from the height h1 to the permission point Y1 (relay position) of the direct downward movement. There is no position.

  In the path (R3), the machining nozzle 4 collides with the workpiece 104 until the machining nozzle 4 reaches the upper part of the next machining start point B1 (permission point Y1 for direct downward movement described later) from the position L at which copying can be started. Set outside the possible area. The path (R3) and the machining surface of the workpiece 104 form any angle within the range of 90 to 180 degrees.

  The route (R4) is a route from the position where the start of the downward movement is permitted (permission point Y1 for the downward movement) to the machining start point B1. The path (R4) and the processed surface of the workpiece 104 form an angle of 90 degrees.

  When the distance between the machining end point A1 and the machining start point B1 is closer than a predetermined value, machining is performed between the machining end point A1 and the machining start point B1 approximately between the machining end points A1 and the machining start point B1. The nozzle 4 may not rise to the height h1. In such a case, the oblique approach processing may be performed without raising the machining nozzle 4 to the intermediate point in the machining surface (retracting obliquely) and then raising the machining nozzle 4 to the height h1. When performing such approach processing, for example, an intrusion prohibited area Z2 shown in FIG. 9 is set.

  The intrusion prohibited area Z2 shown in FIG. 9 includes a route above the area that is not allowed to enter during the oblique retreat process (R11), a route above the area that is not allowed to enter during the oblique approach process (R12), This is an area surrounded by a straight line connecting the path (R13) and the machining start point B1 and the machining end point A1.

  In the path (R11), there is a possibility that the machining nozzle 4 may collide with the workpiece 104 before the machining nozzle 4 reaches the copying start possible position (retreat end position) M on the intermediate point in the machining surface from the machining end point A1. Set outside an area. The path (R11) and the processed surface of the workpiece 104 form any angle within an angle of 0 degrees to 90 degrees.

  The path (R12) is set outside the area where the machining nozzle 4 may collide with the workpiece 104 when the machining nozzle 4 is lowered in an oblique direction from the position M at which copying can be started to the permission point Y1 for the downward movement. Is done. The path (R12) and the machining surface of the workpiece 104 form any angle within an angle of 90 to 180 degrees. The route (R13) is a route from the permission point Y1 of the downward movement to the machining start point B1. The path (R13) and the processed surface of the workpiece 104 form an angle of 90 degrees.

  In the present embodiment, the NC control unit 7 controls the movement path of the machining nozzle 4 so that the machining nozzle 4 does not enter the entry prohibition areas Z1, Z2. The NC control unit 7 controls the moving speed of the machining nozzle 4 so that the movement of the machining nozzle 4 is completed in as short a time as possible.

  During the oblique retraction process, the NC control unit 7 drives the servo motor SM3, for example, with a large output (for example, maximum output) greater than or equal to a predetermined value to set the machining nozzle 4 to a predetermined rapid feed speed (in the NC program) in the Z axis direction. Move at a speed that does not need to be set). At this time, the NC control unit 7 moves the machining nozzle 4 in the XY plane at a predetermined fast feed speed along the shortest path in the XY plane between the machining end point A1 and the machining start point B1. That is, the machining nozzle 4 is moved in the Z-axis direction at a predetermined rapid feed speed, and the machining nozzle 4 is moved in the Y-axis direction or along the X-axis direction of the machining table 2 along the movement path in the XY plane direction. At least one of the movements is set to a predetermined rapid feed speed. Note that the rapid feed speed here is a speed set based on the performance of the laser processing apparatus and the like, and is a speed equal to or higher than a predetermined value. For example, the NC control unit 7 moves the machining nozzle 4 at the maximum speed in the Z-axis direction and at the maximum speed in at least one of the Y-axis direction and the X-axis direction. In the following description, a case where the rapid feed speed of the machining nozzle 4 is the maximum speed will be described.

  The NC control unit 7 determines whether or not the machining nozzle 4 has been raised in the Z-axis direction by the set retracting amount (height h1) after starting the oblique retracting process (for example, has reached the retracting position K), It is determined whether or not the processing nozzle 4 has reached the origin position in the Z-axis direction. The origin position in the Z-axis direction of the machining nozzle 4 here is a position where the machine coordinate value in the Z-axis direction is zero. For example, the machining nozzle 4 is used below the origin position (negative machine coordinate value). Here, the NC control unit 7 determines whether or not the machining nozzle 4 has reached the origin position in the Z-axis direction so that the machining nozzle 4 is not used above the origin position.

  The NC control unit 7 stops the movement of the machining nozzle 4 in the Z-axis direction when the machining nozzle 4 rises in the Z-axis direction by a preset retraction amount (height h1) (Step S120, Yes). The movement of the processing nozzle 4 is limited to only the X-axis direction and the Y-axis direction (in the XY plane) (step S130).

  In addition, when the machining nozzle 4 reaches the origin position in the Z-axis direction (step S120, Yes), the NC control unit 7 stops the movement of the machining nozzle 4 in the Z-axis direction and moves the machining nozzle 4 to the X-axis. The direction is limited only to the Y-axis direction (step S130).

  When the movement of the machining nozzle 4 in the Z-axis direction is stopped and the machining nozzle 4 is moved only in the X-axis direction or the Y-axis direction, the NC control unit 7 determines the position of the machining nozzle 4 in the X direction or the Y direction. It is determined whether or not the position at which the oblique approach is started (the scanning start possible position L) has been reached (step S140). The NC control unit 7 continues to determine whether or not the processing nozzle 4 has reached the scanning start possible position L until the processing nozzle 4 reaches the scanning start possible position L.

  Here, the movement path when the machining nozzle 4 performs the oblique retraction process will be described. FIG. 10 is a view for explaining an oblique retreat path of the machining nozzle. FIG. 10 shows an oblique retreat path of the machining nozzle when the entry prohibition area Z1 is set.

  The path (2) shown in FIG. 10 moves the machining nozzle 4 at the maximum movement speed (Z-axis direction) and moves the machining nozzle 4 along the movement path in the XY plane direction while moving the machining nozzle 4 in the Y-axis direction. In this case, at least one of the above movement or the movement of the machining table 2 in the X-axis direction is set to the maximum speed. In this case, when the machining nozzle 4 reaches the height h1 (retracted position), the machining nozzle 4 is moved to a position where scanning can be started L in the XY plane.

  When the machining nozzle 4 or the machining table 2 is moved at the maximum speed, and the machining nozzle 4 enters the intrusion prohibition area Z1 (the machining nozzle 4 moves with respect to the movement speed of the machining nozzle 4 in the Z-axis direction). When the movement speed in the X-axis direction and the Y-axis direction is high) (when the speed ratio is larger than a predetermined ratio), the movement of the machining nozzle 4 is controlled along the entry prohibition area Z1 (path (1)). . Specifically, the machining nozzle 4 is moved along the movement path in the XY plane direction while moving the Z-axis direction of the machining nozzle 4 at the maximum movement speed. At this time, the moving speed of the processing nozzle 4 in the Y-axis direction and the moving speed of the processing table 2 in the X-axis direction are suppressed so that the processing nozzle 4 does not enter the intrusion prohibited area Z1. Then, when the processing nozzle 4 reaches the height h1 (retracted position), the processing nozzle 4 is moved to the scanning start possible position L in the XY plane. When the processing nozzle 4 reaches the scanning start possible position L, the NC control unit 7 starts an oblique approach process of the processing nozzle 4 (step S160).

  On the other hand, if the machining nozzle 4 does not rise in the Z-axis direction by the set retraction amount (height h1) in the process of step S120 (step S120, No), the NC control unit 7 It is determined whether or not the processing surface intermediate point has been reached in the XY plane (step S150).

  If the processing nozzle 4 has not reached the intermediate point in the processing surface in the movement path (No at Step S150), the NC control unit 7 continues the oblique retraction process of the processing nozzle 4 (Step S110). When the processing nozzle 4 reaches the processing surface intermediate point in the movement path (step S150, Yes), the NC control unit 7 sets the processing surface intermediate point as a copying start possible position (retraction end position) M. 4 is started (step S160). Note that the position (height) corresponding to a preset retraction amount (height h1), the origin position in the Z-axis direction, and the position at the same height as the intermediate point in the processing surface are the retraction positions described in the claims. Corresponding to

  Here, the movement path when the machining nozzle 4 performs another oblique retraction process (retraction process when passing through the intermediate point in the processing surface) different from FIG. 10 will be described. FIG. 11 is a diagram for explaining another oblique retreat path of the machining nozzle. FIG. 11 shows an oblique retreat path of the machining nozzle when the entry prohibition area Z2 is set.

  The path (4) shown in FIG. 11 moves the machining nozzle 4 at the maximum movement speed (Z-axis direction) and moves the machining nozzle 4 along the movement path in the XY plane direction while moving the machining nozzle 4 in the Y-axis direction. In this case, at least one of the above movement or the movement of the machining table 2 in the X-axis direction is set to the maximum speed.

  When the processing nozzle 4 reaches the same height (retracted position) as the intermediate point (processing start possible position M) in the processing surface between the processing end point A1 and the processing start point B1, the movement of the processing nozzle 4 in the Z-axis direction is stopped. Then, the machining nozzle 4 is moved to the scanning start possible position M in the XY plane. When the processing nozzle 4 reaches the scanning start possible position M, the oblique approach processing of the processing nozzle 4 is started.

  When the machining nozzle 4 or the machining table 2 is moved at the maximum speed, and the machining nozzle 4 enters the intrusion prohibition area Z1 (the machining nozzle 4 moves with respect to the movement speed of the machining nozzle 4 in the Z-axis direction). When the movement speed in the X-axis direction and the Y-axis direction is high), the movement of the machining nozzle 4 is controlled along the entry prohibition area Z2 (path (3)). Specifically, the machining nozzle 4 is moved along the movement path in the XY plane direction while moving the Z-axis direction of the machining nozzle 4 at the maximum movement speed. At this time, the moving speed of the processing nozzle 4 in the Y-axis direction and the moving speed of the processing table 2 in the X-axis direction are suppressed so that the processing nozzle 4 does not enter the intrusion prohibited area Z1. Then, when the processing nozzle 4 reaches the intermediate point in the processing surface (following start possible position M) (retreat position), the oblique approach processing of the processing nozzle 4 is started.

  As the oblique approach process of the machining nozzle 4, the NC control unit 7 moves the machining nozzle 4 from the scanning start possible position L or the scanning start possible position M to the permission point Y <b> 1 for the downward movement downward (oblique downward movement).

  Here, the movement path of the machining nozzle 4 during the oblique downward movement will be described. The movement path of the machining nozzle 4 during the oblique downward movement is an area where the machining nozzle 4 may collide with the workpiece 104 (invasion prohibition areas Z1, Z2), the maximum movement speed of the machining nozzle 4, and the maximum of the machining table 2. It is set based on the moving speed.

  The NC controller 7 moves the machining nozzle 4 at the maximum speed in the Z-axis direction by, for example, driving the servo motor SM3 with the maximum output during the oblique descending movement process. At this time, the NC control unit 7 moves the machining nozzle 4 in the XY plane at the maximum speed along the shortest path in the XY plane between the machining end point A1 and the machining start point B1. That is, the machining nozzle 4 is lowered at the maximum movement speed in the Z-axis direction, and the machining nozzle 4 is moved in the Y-axis direction or along the X-axis direction of the machining table 2 along the movement path in the XY plane direction. Set at least one of the movements to maximum speed.

  In the present embodiment, the scanning control unit 25 of the NC control unit 7 performs scanning control during the diagonally descending movement process. When the oblique descending movement process is started, the electrostatic sensor detects a signal related to the distance between the workpiece 104 and the machining nozzle 4 and inputs the signal to the A / D conversion unit 11 as a sensor signal.

  The A / D converter 11 performs A / D conversion on the sensor signal detected by the electrostatic sensor, and inputs the converted digital signal to the nozzle height data converter 12. The nozzle height data conversion unit 12 converts the signal input from the A / D conversion unit 11 into data on the height of the machining nozzle 4 with respect to the workpiece 104.

  The command movement amount creation unit 13 uses the difference between the height of the machining nozzle 4 calculated by the nozzle height data conversion unit 12 and the nozzle height data specified by the machining program, and preset retraction amount data. To create a command movement amount. The command movement amount creation unit 13 inputs the created command movement amount to the servo amplifier 14. The servo amplifier 14 transmits the command movement amount to the servo motor SM3. The servo motor SM3 moves the machining head 3 in the Z-axis direction by a distance corresponding to the command movement amount. Here, the copying control unit 25 lowers the machining head 3 while performing copying control to the height of the permission point Y1 for the downward movement.

  The NC control unit 7 determines whether or not the machining nozzle 4 has reached the permission point Y1 for the downward movement immediately below (step S170). If the machining nozzle 4 has not reached the permitted point Y1 for direct downward movement (step S170, No), the NC control unit 7 is inclined to the machining nozzle 4 until it reaches the permitted point Y1 for direct downward movement. Make the approach move diagonally downward.

  Here, the movement path when the machining nozzle 4 moves obliquely downward will be described. FIG. 12 is a diagram for explaining a movement path when the machining nozzle performs an oblique downward movement. FIG. 12 shows an oblique downward movement path of the machining nozzle 4 when the entry prohibition area Z1 is set.

  When the moving speed of the processing nozzle 4 in the X-axis direction and the Y-axis direction is slower than the moving speed of the processing nozzle 4 in the Z-axis direction (when the speed ratio is smaller than a predetermined ratio), the processing nozzle 4 and the processing table When 2 is moved at the maximum speed, the processing nozzle 4 enters the intrusion prohibited area Z1. Therefore, in such a case, the movement of the machining nozzle 4 is controlled along the intrusion prohibited area Z1 (path (5)). Specifically, the machining nozzle 4 is moved along the path (5) while moving the machining nozzle 4 in the Y-axis direction and moving the machining table 2 in the X-axis direction at the maximum movement speed. At this time, the moving speed of the machining nozzle 4 in the Z-axis direction is suppressed so that the machining nozzle 4 does not enter the intrusion prohibited area Z1. As a result, the NC control unit 7 moves the machining nozzle 4 to the permission point Y1 for the downward movement right below.

  When the movement speed of the machining nozzle 4 in the Z-axis direction is slower than the movement speed of the machining nozzle 4 in the X-axis direction and the Y-axis direction (when the speed ratio is smaller than a predetermined ratio), the machining nozzle 4 is moved to XY. The process of moving in the plane direction (height h1) may be extended. In this case, the NC control unit 7 moves the machining nozzle 4 by moving the scanning start position (the scanning start position N1) closer to the machining start point B1 than the scanning start possible position L. Then, the NC control unit 7 moves the machining nozzle 4 to the permission point Y1 for the downward movement immediately below (path (6)).

  The scanning start possible position N1 here is a position in the same XY plane as the scanning start possible position L. For example, even if the movement speed of the machining nozzle 4 in the Z-axis direction is set to the maximum speed, the machining nozzle 4 moves downward and downward. Is set to a position that can be moved to the permitted point Y1 by the shortest route.

  Further, when the machining nozzle 4 moves to the scanning start possible position M by performing the oblique retreat process (retreat process when passing through the intermediate point in the work surface) of FIG. 11, the same as the oblique downward movement path of FIG. The machining nozzle 4 is moved to the permission point Y1 for the downward movement just below by the movement path.

  FIG. 13 is a diagram for explaining a movement path when another oblique lowering movement of the machining nozzle is performed. FIG. 13 shows an oblique downward movement path of the machining nozzle when the entry prohibition area Z2 is set.

  Similarly to the movement path of FIG. 12, the movement path of FIG. 13 also has an entry prohibition area when the movement speed of the machining nozzle 4 in the X-axis direction and the Y-axis direction is slower than the movement speed of the machining nozzle 4 in the Z-axis direction. The movement of the machining nozzle 4 is controlled along Z1 (path (7)).

  In addition, when the movement speed of the machining nozzle 4 in the Z-axis direction is slower than the movement speed of the machining nozzle 4 in the X-axis direction and the Y-axis direction, the processing nozzle 4 is moved in the XY plane direction (height h1). It may be added or extended. In this case, the NC control unit 7 moves the machining nozzle 4 by moving the scanning start position (the scanning start position N2) closer to the machining start point B1 than the scanning start possible position L. Then, the NC control unit 7 moves the machining nozzle 4 to the permission point Y1 for the downward movement right below.

  The scanning start possible position N2 here is a position in the same XY plane as the scanning start possible position L. For example, even if the movement speed of the machining nozzle 4 in the Z-axis direction is the maximum speed, the machining nozzle 4 moves downward and downward. Is set to a position that can be moved to the permitted point Y1 by the shortest route.

  When the machining nozzle 4 reaches the right downward movement permission point Y1 (Yes in step S170), the NC control unit 7 sets the movement target position of the machining nozzle 4 from the right downward movement permission point Y1 to the machining start point on the workpiece 104. Change to B1. Thus, the approach position of the machining nozzle 4 is changed to a position where laser machining is actually performed (laser machining nozzle height position) (step S180).

  The NC control unit 7 moves the machining nozzle 4 downward and downward (approach) to the nozzle height position for laser machining (a newly set approach position (machining start point B1)) (step S190).

  The NC control unit 7 determines whether or not the processing nozzle 4 has reached the nozzle height position for laser processing (step S200). If the processing nozzle 4 has not reached the nozzle height position for laser processing (No in step S200), the NC control unit 7 is directly below the processing nozzle 4 until the processing nozzle 4 reaches the nozzle height position for laser processing. Move down.

  14 and 15 are diagrams illustrating an example of a movement path of the processing nozzle 4. FIG. 14 shows oblique evacuation processing and oblique approach processing when the intrusion prohibited area Z1 shown in FIG. 8 is set. Here, the movement of the machining nozzle 4 is controlled along the intrusion prohibited area Z1.

  Specifically, first, the oblique retreating process of the machining nozzle 4 is performed by controlling the movement of the machining nozzle 4 from the machining end point A1 to the retreat position K having the height h1. The movement path from the processing end point A1 to the retreat position K corresponds to the path (1) shown in FIG. Thereafter, the machining nozzle 4 is moved in the XY plane direction at a height h1 from the retreat position K to the copying start possible position L.

  Then, the oblique lowering movement process of the machining nozzle 4 is performed from the scanning start possible position L to the permission point Y1 for the downward movement, and the machining nozzle 4 is moved from the direct downward movement permission point Y1 to the machining start point B1 (laser machining position). Directly descending movement processing is performed.

  FIG. 15 shows oblique evacuation processing and oblique approach processing when the intrusion prohibited area Z2 shown in FIG. 9 is set. Here, the movement of the machining nozzle 4 is controlled along the entry prohibition area Z2.

  Specifically, first, the oblique retraction process of the machining nozzle 4 is performed by controlling the movement of the machining nozzle 4 from the machining end point A1 to the scanning start possible position M. The movement path from the processing end point A1 to the copying start possible position M corresponds to the path (3) shown in FIG.

  Thereafter, the processing nozzle 4 is obliquely moved downward from the scanning start possible position M to the permission point Y1 for the downward movement, and the processing nozzle 4 is moved from the permission point Y1 for the downward movement to the processing start point B1 (laser processing position). The process of moving down immediately below is performed.

  In the present embodiment, the copying operation is performed when the oblique downward movement process and the direct downward movement process are performed. Since the copying operation is performed during the diagonally descending movement process, the moving speed of the machining nozzle 4 during the diagonally descending movement process may be slower than the moving speed of the machining nozzle 4 during the diagonally retracting process. For this reason, there are cases where the moving angle (the rising angle and the lowering angle) of the processing nozzle 4 is different between the oblique retraction process and the diagonally descending movement process of the processing nozzle 4. In this case, the copying start position may be changed according to the difference amount or angle ratio of the movement angle of the processing nozzle 4. For example, the copying start position N1 shown in FIG. 12 may be brought close to the copying start possible position L in the XY plane on the height h1. Further, the copying start position N2 shown in FIG. 13 may be brought close to the copying start possible position M in the XY plane on the height h1.

  When the processing nozzle 4 reaches the nozzle height position for laser processing (Yes in step S200), the laser processing apparatus ends the oblique retraction process and the oblique approach process, and starts laser processing at a new processing start point B1. .

  As described above, the laser processing apparatus performs the copying operation (approach operation) when performing the oblique downward movement process and the direct downward movement process, so that the workpiece 104 is warped (sinked) or has a step to complete the processing. Even when the heights of the point A1 and the machining start point B1 are different, the collision between the machining nozzle 4 and the workpiece 104 can be avoided.

  Here, the movement path of the machining nozzle 4 when the machining end point A1 and the machining start point B1 are different will be described. FIGS. 16 and 17 are diagrams for explaining the movement path of the machining nozzle when the height differs between the movement points.

  FIG. 16 shows oblique evacuation processing and oblique approach processing when the entry prohibition area Z1 shown in FIG. 8 is set. Here, the movement of the machining nozzle 4 is controlled along the intrusion prohibited area Z1.

  In addition, FIG. 17 shows oblique evacuation processing and oblique approach processing when the entry prohibition area Z2 shown in FIG. 9 is set. Here, the movement of the machining nozzle 4 is controlled along the entry prohibition area Z2.

  As shown in FIG. 16 and FIG. 17, even when the machining start point B1 is higher than the machining end point A1, the copying operation is performed when performing the diagonally descending movement process. When the distance between and becomes a predetermined value or less (position P), the movement of the machining nozzle 4 in the Z-axis direction is stopped and moved to the permission point Y1 for the downward movement right below (movement in the XY plane).

  In the present embodiment, the laser processing apparatus has been described with respect to the case where the workpiece 104 moves in the X-axis direction and the processing head 3 moves in the Y-axis direction and the Z-axis direction. The machining head 3 may be moved in the X-axis direction, the Y-axis direction, and the Z-axis direction. Further, the machining head 3 may be fixed and the workpiece 104 may be moved in the X-axis direction, the Y-axis direction, and the Z-axis direction. In these cases, the same effect as the laser processing apparatus of the present embodiment can be obtained.

  Further, the copying operation of the processing nozzle 4 may be applied to an apparatus other than a laser processing apparatus using a laser beam. For example, the present invention may be applied to a processing machine that processes a workpiece while changing the relative position between the processing head and the workpiece, such as a plasma processing machine using plasma wind or a water jet processing machine using water flow.

  Further, an intermediate point in the processing surface that is an intermediate point between the processing end point A1 and the processing start point B1 is set according to the amount of difference or the angle ratio of the moving angle between the slanting retreating processing and slanting descent movement processing of the processing nozzle 4. Also good. Further, an intermediate point in the processing surface, which is an intermediate point between the processing end point A1 and the processing start point B1, is set according to the height (distance in the Z-axis direction from the workpiece 104) of the permission point Y1 for the downward movement right below. May be.

  Further, in the present embodiment, during the direct downward movement processing (path (R4)) from the direct downward movement permission point Y1 to the machining start point B1, the machining nozzle is at an angle of 90 degrees with respect to the machining surface of the workpiece 104. Although the case of moving 4 has been described, the machining nozzle 4 may be moved at an angle other than 90 degrees (for example, 80 degrees) with respect to the machining surface of the workpiece 104.

  As described above, according to the embodiment, since the scanning control of the machining nozzle 4 is performed during the oblique approach, the machining nozzle even when the machining end point A1 and the machining start point B1 are different in height. 4 and the workpiece 104 can be avoided from colliding with each other. As a result, it is possible to obtain a laser processing apparatus that can smoothly retreat the processing nozzle 4 and can start stable laser processing of the workpiece 104 at the next processing point.

  Further, since the machining nozzle 4 rises substantially directly above (Z-axis direction) by increasing the ascent speed of the machining nozzle 4 in the Z-axis direction faster than the movement speed in the X-axis direction and the Y-axis direction, Collisions can be avoided and quick movement to the next machining position is possible.

  Further, since the retreat height of the machining nozzle 4 is limited to the set retreat amount or the origin position, it is possible to omit a waste retreat process of the work nozzle 4 with respect to the workpiece 104 and perform efficient retreat processing. Is possible.

  Further, since the oblique retreat process is terminated at the intermediate point in the machining surface and the oblique approach process is started, the machining nozzle 4 can be quickly moved to the next machining position (machining start point B1) through a short path. .

  As described above, the laser processing apparatus according to the present invention is suitable for the retracting process and approach process of the processing head with respect to the workpiece.

It is a perspective view which shows the laser processing apparatus concerning embodiment of this invention. It is a functional block diagram which shows the structure of a laser processing apparatus. It is a perspective view which shows the structure of each moving axis with which a laser processing apparatus is provided. It is a block diagram which shows the detailed structure of a copying control part. It is a figure which shows the relationship between a voltage and nozzle height. It is a flowchart which shows the processing procedure of the copying operation | movement of a laser processing apparatus. It is a flowchart which shows the process sequence of the diagonal evacuation process and the diagonal approach process. It is FIG. (1) for demonstrating the area which does not permit the penetration | invasion of a process head. It is FIG. (2) for demonstrating the area which does not permit the penetration | invasion of a process head. It is FIG. (1) for demonstrating the diagonal evacuation path | route of a process nozzle. It is FIG. (2) for demonstrating the diagonal evacuation path | route of a process nozzle. It is FIG. (1) for demonstrating the movement path | route at the time of a process nozzle performing diagonally downward movement. It is FIG. (2) for demonstrating the movement path | route at the time of a process nozzle performing diagonally downward movement. It is a figure (1) which shows an example of the movement path | route of a process nozzle. It is FIG. (2) which shows an example of the movement path | route of a process nozzle. It is FIG. (1) for demonstrating the movement path | route of a process nozzle in case height differs between movement points. It is FIG. (2) for demonstrating the movement path | route of the process nozzle in case height differs between movement points.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing machine body 2 Processing table 3 Processing head 4 Processing nozzle 5 Z-axis unit 6 Y-axis unit 7 NC control part 8 Laser oscillator 11 A / D conversion part 12 Nozzle height data conversion part 13 Command movement amount creation part 14 Servo amplifier 25 Scanning control unit 104 Work 105 Processing line 110 Operation unit SM1 to SM3 Servo motor

Claims (5)

When the machining head for irradiating the laser beam is moved to the machining point on the workpiece for laser machining, and the next machining point is laser machined after the laser machining of the machining point is completed, the laser at the machining point is used. In a laser processing apparatus for laser processing the next processing point by approaching the next processing point after retracting the processing head that has been processed to the retreat position located on the upper side of the workpiece,
While controlling the relative position of the workpiece and the machining head, and at the time of the approach, a position control unit that uses an oblique lowering control that obliquely descends the machining head onto the next machining point;
A distance detection unit that detects, as distance information, the shortest distance between the machining surface of the workpiece and the machining head;
With
The position control unit starts position control of the processing head based on the distance information detected by the distance detection unit when starting the oblique descending control, and causes the processing head to approach the next processing point. The laser processing apparatus characterized by the above-mentioned. In the approach, the position control unit is positioned above the next processing point by simultaneously moving the processing head in a direction perpendicular to the processing surface of the workpiece and in a direction in the processing surface of the workpiece. The machining head is lowered obliquely toward the workpiece by the oblique lowering control to the relay position, and then the machining head is lowered from the relay position to the next machining point to approach the machining head to the next machining point. Let
The position control unit is configured to perform the processing based on the distance information detected by the distance detection unit when performing the oblique lowering control of the processing head and when lowering the processing head from the relay position to the next processing point. The laser processing apparatus according to claim 1, wherein the head position is controlled.   3. The laser processing apparatus according to claim 1, wherein the retracted position is a position that designates a distance from a processing surface of the workpiece on an upper side of the workpiece.   The retracted position is a position between a processing point where laser processing has been completed and the next processing point, and the moving speed of the processing head when the processing head is retracted to the retracted position and the next position from the retracted position. 3. The laser processing apparatus according to claim 1, wherein the position is set in accordance with a moving speed of the processing head when the processing head approaches the processing point.   The laser according to any one of claims 1 to 4, wherein the position control unit sets the moving speed of the processing head to a predetermined rapid feed speed and retracts the processing head to the retracted position. Processing equipment.

Images