JPH07108466B2 - Laser processing equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a laser processing apparatus, and more particularly to a laser processing apparatus having a gap sensor on the tip side of a processing head. The present invention relates to a laser processing device which is intended to absorb only by controlling.

[Prior Art] Conventionally, there is known a laser processing apparatus provided with a gap sensor on the tip side of a processing head.

A drive unit for moving the gap sensor in the optical axis direction is provided, and the drive unit is controlled by a main numerical control unit that controls other drive units of the entire laser processing apparatus.

[Problems to be Solved by the Invention] However, if the main numerical control device controlling the other driving devices of the entire laser processing apparatus controls the driving device in the gap sensor, the numerical control device is inevitably complicated. At the same time, there is a problem that the response speed for sensing the gap between the gap sensor and the work is slow.

[Means for Solving the Problems] In view of the conventional problems as described above, the present invention provides three X-axis, Y-axis, and Z-axis orthogonal to each other under the control of a numerical controller.
A holder provided for a machining head whose movement is controlled in the dimension is provided so as to be movable up and down, a tip is provided with a nozzle tip, and a gap sensor for detecting a gap between the nozzle tip and a workpiece to be laser-machined is provided in the holder. And a motor for moving the holder up and down is installed and provided on the machining head, and the motor is configured to keep the gap constant based on the detection of the gap sensor regardless of the numerical controller. The motor is configured to be controlled, and the motor is provided with a spring for supporting the own weight of the holder to suppress the load applied to the motor regardless of the angle of the processing head.

[Operation] In the above configuration, when the movement control of the machining head in the three-dimensional directions of X, Y, and Z is performed under the control of the numerical controller, the gap between the nozzle tip provided in the machining head and the work is It is detected by the gap sensor, the motor is controlled so as to keep the gap constant, and the gap sensor and the like are moved up and down by driving the motor.

The control of the motor is performed regardless of the numerical control device, and the vertical movement of the gap sensor is performed without vertically moving the entire machining head, so that the vertical movement having a high responsiveness to the detection of the gap sensor is performed.

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

Referring to FIG. 1, FIG. 2 and FIG. 3, a plurality of (for example, four) columns 3 are erected on the floor surface of the floor 1.
A support plate 5 is placed on the column 3. X on both sides of the support plate 5 in the left-right direction in FIG.
A plurality of (for example, two) X-axis guides 7 are attached in the axial direction.

A plurality of (for example, two) support plates 9 are attached between the two X-axis guides 7 in the Y-axis direction which is the left-right direction in FIG.
Supports.

An X-axis carriage 11 that moves in the X-axis direction is mounted over the two X-axis guides 7, and a Y-axis carriage 13 is placed on the X-axis carriage 11.

The Y-axis carriage 13 is moved in the Y-axis direction along a guide 15 surface provided in parallel to the side of the X-axis carriage 11. The Z-axis column 17 is mounted in the Z-axis direction, which is the vertical direction and is substantially in the center of the Y-axis carriage 13.
Is moved in the Z-axis direction along a guide mounted in the Y-axis carriage 13. A machining head 19 is attached to the tip end side of the Z-axis column 17 as shown in FIGS. 1 and 3.

The laser beam is emitted from the nozzle tip 21 attached to the tip of the processing head 19 as shown in FIG.

As shown in FIG. 2, the work W is placed in a working area 23 provided below the X-axis guides 7 and the support plates 9. A safety cabin 25 for covering each device is provided around the machine body.

A pneumatic unit device 27, a numerical control device 29, and a laser oscillator power supply device 31 are arranged outside the machine body as is apparent from FIGS. 1 and 2, and the numerical control device 29 is an X axis, Y (not shown). It is connected to each drive device for the axis and the Z axis to control each drive.

As shown in FIGS. 1 and 2, a laser oscillator head 33 is mounted on the right support plate 9 and is connected to the laser oscillator power supply device 31 via a connecting pipe 35.

Next, the processing head 19 is attached to the lower portion of the Z-axis column 17. More specifically, as shown in FIGS. 4 and 5, a hollow support block 37 is attached to the lower portion of the Z-axis column 17. A hollow cylindrical body 39 extending in the vertical direction is fitted into and integrated with the hollow support block 37.

A gear 41 is supported via a bearing 43 at a portion of the hollow support block 37 facing downward from the central portion, and a rotating body 45 is fitted and supported by a hollow cylindrical body 39 below the gear 41. The upper part of the rotating body 45 is pressed by a disk-shaped pressing member 47. A bearing 49 is interposed between the hollow cylindrical body 39 and the lower portion of the rotating body 45. A drive motor (referred to as an A-axis drive motor) 51 for rotating the rotating body 45 is provided on the right side of the hollow support block 37 in FIG.

A pinion 53 is attached to the output shaft of the A-axis drive motor 51 and meshes with the gear 41. The disk-shaped ring 55 is a holding member for covering the gear 41 and the pinion 53.
Integrated on 47.

Therefore, by driving the A-axis drive motor 51,
The rotating body 45 is rotated via the pinion 53 and the gear 41 as shown by the arrow. At the bottom of the hollow cylindrical body 39, a hollow press nut 57 for pressing the bearing 49 is provided.
Is inserted in the lower part of the.

As is apparent from FIG. 4, a support plate 61 supporting the first mirror 59 is attached to the inclined portion 45A formed on the lower right side of the rotating body 45, and the support plate 61 is provided outside the support plate 61. A first radiator 63 is attached.

In the lower left side portion 45B of the rotary body 45, a horizontal tubular projection portion 69 of a fixed tubular body 67 provided in the processing head 19 is rotatably supported via bearings 65A and 65B. A gear 71 is integrally fitted to the left side of the cylindrical projection 69.
A pinion 73 meshes with the gear 71 as shown in FIG. The pinion 73 is attached to the output shaft of a drive motor (referred to as B-axis drive motor) 75.

Therefore, when the B-axis drive motor 75 is driven, the cylindrical body 67 is rotated about the axis of the cylindrical protrusion 69 via the pinion 73 and the gear 71, so that the machining head 19 rotates about the horizontal axis. To be rotated.

The drive control of the A-axis drive motor 51 and the B-axis drive motor 75 described above is controlled by the main numerical control device 29 of the laser processing apparatus, similarly to the drive control of the drive motors in the X-axis, Y-axis and Z-axis. There is.

A support plate 79 supporting the second mirror 77 is attached to the inclined portion 67A formed on the upper left side of the tubular body 67,
A second radiator 81 is attached to the outside of the support plate 79. The processing head 19 covering the second radiator 81.
The slider member 83 is attached.

A drive motor (referred to as a C-axis drive motor) 85 for moving the processing head 19 in the optical axis direction is attached to the upper portion of the slider member 83. As is apparent from FIGS. 4 and 5, a pinion 87 is attached to the C-axis drive motor 85 via an output shaft, and a rack 89 meshes with the pinion 87. The rack 89 is fixed to a mounting plate 91 integrated with the gear 71.

A tubular guide member 93 is vertically movably fitted and supported in the lower portion of the tubular body 67, and a hollow holder 99 is integrally attached to the lower portion of the guide member 93. And this holder
The lower part of the slider member 83 is integrally attached to 99. Further, as shown in FIG. 5, a linear guide 95 is interposed between the slider member 83 and the gear 71 to linearly guide the slider member 83.

An electrostatic capacitance type gap sensor 97 is integrally attached to the lower portion of the holder 99. Gap sensor 97
Is fixed to the holder 99 with bolts 101.

The nozzle tip 21 is attached to the tip of the gap sensor 97. Therefore, when the C-axis drive motor 85 is driven, the pinion 87 rotates. Since the pinion 87 meshes with the rack 89 and the rack 89 is fixed to the mounting plate 91, the C-axis drive motor 85 itself moves up and down.

When the C-axis drive motor 85 moves up and down, the slider member
Since 83 is integrated with the C-axis drive motor 85, the slider member 83 is guided by the linear guide 95 to move up and down. When the slider member 83 moves up and down, the gap sensor 97 moves up and down via the holder 99.

The control of the C-axis drive motor 85 is controlled by a control unit, which will be described later, separately from the main numerical control unit 29, independently of the control of the A-axis drive motor 51 and the B-axis drive motor 75 described above. A cylindrical holding member 107 for holding the condenser lens 105 is fitted in the holder 99 of the gap sensor 97.

Therefore, the laser beam LB is output from the laser oscillator head 33 shown in FIGS. 1 and 2, passes through the Z-axis column 17, the rotating body 45, and is reflected at a right angle by the first mirror 59. Further, the second mirror 77 also reflects downward at a right angle. Next, the laser beam LB is condensed by the condensing lens 105 and is irradiated from the nozzle tip 21 as shown in FIG. 4 to subject the work W to laser processing.

C-axis drive motor 85 for moving the processing head 19 in the optical axis direction
As shown in FIG. 6, the torque motor 109
Is built in. A potentiometer 113 is directly connected to one end side of the torque motor shaft 111 of the torque motor 109, and a counterbalance spiral spring 115 of a counterbalance device is directly connected to the other end side of the torque motor shaft 111.

Therefore, the counterbalance spiral spring 115 supports the own weight of the holder 99 itself and suppresses the load applied to the C-axis drive motor 85 regardless of the angle of the processing head 19 rotated by the B-axis drive motor 75. .

In the processing head 19, as shown in FIG.
7 and oscillator circuit board 119 are built in, and gap sensor 97
Is guided to the oscillation circuit board 119 by the Teflon cable 121. The Teflon cable 121 is the laser beam L
It is a material that can withstand the reflected heat of B.

Therefore, the gap sensor 97 detects the gap g between the workpiece W and the sensor control unit described later.
In 123, the gap g is kept constant.

The control of the gap g from the work W by the gap sensor 97 is controlled by the sensor control unit 123 independent of the main numerical control device 29.

More specifically, FIGS. 7 and 8 show the flow of feedback signal generation for driving the machining head 19 in response to changes in the gap g. When the nozzle tip 21 is located at the proper gap g, the analog input in FIG. 7 becomes OV and the C-axis drive motor 85 does not drive.

However, when the gap g changes due to deformation of the work W, positioning error, etc., the electric capacitance C between the gap sensor 97 and the work W changes as shown in FIG. The electric capacitance C is calculated based on C = ε · s / g (where ε: permittivity.s: area, g: gap (distance)). The change amount of the electric capacitance C is used as the oscillation circuit 119 of the sensor control unit 123.
The oscillation frequency f is changed by taking in.

The oscillation frequency f is (However, L: inductance) This oscillating frequency f is taken into the modulation circuit 117, and only the frequency change Δf generated in the oscillating circuit 119 is taken out by the modulation circuit 117 and changed into a digital rectangular wave, and then the frequency counter circuit
It is taken in by 125.

In this frequency counter circuit 125, by counting the number of rectangular waves that enter a certain sampling time,
Parallel digital signals are generated. By inputting this digital signal into the D / A converter 127, a voltage as position feedback of the gap sensor 97 is output.

On the other hand, due to the above position feedback, the torque motor 109
Is started, a change occurs in the output voltage from the potentiometer 113 directly connected to the torque motor shaft 111, the voltage generated in the transient state is used as the speed feedback, and the servo amplifier is determined by the difference from the position feedback signal. This is the reference voltage for 129.

As a result, when the torque motor 109 rotates and the nozzle tip 21 is positioned in a certain set proper gap, the position feedback, that is, the sensor control unit.
The output from 123 becomes 0V and the C-axis drive motor 85 stops.

The CNC input / output unit 131 connected to the sensor control unit 123 plays the role of a switch for enabling or disabling the above-mentioned functions.

Therefore, the gap sensor 97 detects the gap g between the nozzle tip 21 and the work W, and the sensor control unit 123 controls the C-axis drive motor 85 so as to keep it at a predetermined constant gap. It is processed.

[Effects of the Invention] As will be understood from the above description of the embodiments, in short, the present invention, under the control of the numerical control device (29), is a three-dimensional direction of X-axis, Y-axis, and Z-axis orthogonal to each other. A workpiece (W) provided with a holder (99) equipped to a machining head (19) whose movement is controlled to move up and down, a nozzle tip (21) at the tip, and laser machining with the nozzle tip (21). A gap sensor (97) for detecting a gap (g) between the holder (99) and the motor (85) for moving the holder (99) up and down is provided on the machining head (19). It is mounted and installed, and controls the motor (85) so as to keep the gap (g) constant based on the detection of the gap sensor (97) regardless of the numerical control device (29). And the angle of the machining head on the motor Regardless those formed by providing a spring for supporting the weight of the holder in order to suppress the load applied to the motor.

As is clear from the above configuration, in the present invention, the movement control of the machining head 19 in the X, Y, and Z-axis directions is performed by the numerical controller 29.
Is done by.

Further, the gap sensor 97 having the nozzle tip 21 at the tip and detecting the gap g between the nozzle tip 21 and the workpiece W to be laser processed is provided in the holder 99 provided on the processing head 19 so as to be vertically movable. A motor 85 for moving the holder 99 up and down is attached to the processing head 19. The control of the motor 85 is based on the detection of the gap sensor 97 regardless of the numerical control device 29.
Is configured to be held constant.

That is, in the present invention, the gap g is fixed by vertically moving the holder 99 that is vertically movable on the machining head 19 instead of moving the machining head 19 itself up and down to keep the gap g constant. Since the structure is designed to be held at, it is easy to reduce the weight of the portion that moves up and down.

Further, since the motor 85 for moving the holder 99 up and down is controlled regardless of the numerical control device 29, the responsiveness to the detection of the gap sensor 97 can be improved, and the holder 99 and the like are lightweight. In addition to this, the accuracy of maintaining the gap g constant is further improved, and more accurate laser processing can be performed.

Further, in the present invention, since the spring 115 for supporting the own weight of the holder 99 is provided to suppress the load applied to the motor 85 regardless of the angle of the processing head 19, for example, when the processing head 19 is in the vertical state or Even in the horizontal state, the movement control of the holder 99 can be quickly performed based on the detection of the gap sensor 97, the responsiveness is good regardless of the inclination angle of the processing head 19, and the gap g The control of can be performed quickly and accurately with good responsiveness.

[Brief description of drawings]

FIG. 1 is a front view of a laser processing apparatus according to the present invention. FIG. 2 is a plan view of FIG. FIG. 3 is a side view of FIG. FIG. 4 is a front sectional view around the processing head. FIG. 5 is a partial sectional view taken along the arrow V in FIG. FIG. 6 is an explanatory diagram showing a driving state of the processing head. FIG. 7 is a block section for explaining the control of the gap sensor. FIG. 8 is a block diagram of the sensor control unit section. [Description of Symbols Representing Main Parts of Drawing] 19 ... Machining head, 21 ... Nozzle tip 29 ... Main numerical control device, 85 ... C-axis drive motor 97 ... Gap sensor, 109 ... Torque motor 113 ... Potentiometer 115 ... Counter Balance spiral spring 123… Sensor control unit

Claims (1)

[Claims] 1. A holder (99) equipped with a machining head (19) which is controlled to move in a three-dimensional direction of X-axis, Y-axis and Z-axis which are orthogonal to each other under the control of a numerical control device (29). The holder is provided with a nozzle tip (21) movably provided, and a gap sensor (97) for detecting a gap (g) between the nozzle tip (21) and a workpiece (W) to be laser-machined. A motor (85) for mounting and dismounting on the holder (99) for moving the holder (99) up and down is mounted and mounted on the machining head (19), and the gap sensor is provided regardless of the numerical controller (29). Based on the detection of (97), the motor (85) is controlled so as to keep the gap (g) constant, and the motor (85) is related to the angle of the machining head (19). Without controlling the load on the motor (85), Laser processing apparatus characterized by comprising providing a da (99) spring (115) for supporting the weight of the.