JP2684988B2 - Laser head copy sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a laser head of a laser processing machine for cutting a plate work.

[0002]

2. Description of the Related Art In a laser beam machine, a distance between a nozzle of a laser torch and a work is kept constant so that a focal point is located on the surface of the work, so that good cutting can be performed. In order to keep the distance between this nozzle and the work constant, a laser sensor is provided on the laser head to detect minute irregularities and curvatures of the work, and to ascend and descend to follow the work surface for reliable cutting. I was able to do it. Contact sensors and non-contact sensors are used as this scanning sensor.The contact sensor positions the contact on the surface of the work and moves the work. The contact slides on the work surface and moves up and down. The nozzle is moved up and down by converting it to an electric signal, and the non-contact type sensor arranges a capacitance type sensor around the nozzle or uses the nozzle itself as a capacitance sensor to measure the capacitance between the workpiece and the sensor. The nozzle was controlled up and down so as to be constant.

However, when scanning control is performed using the above-mentioned contact type sensor, since the contactor is in contact with the upper surface of the work, the surface of the work may be scratched, and the material having a soft surface or a mirror-finished work. In such cases, the contact control sensor could not control the copying. Further, it is limited to the conductive metal that the scanning control can be performed by using the capacitance type non-contact type sensor. For this reason, conventionally, the above-mentioned sensor has been replaced depending on the material of the workpiece before the laser processing operation is started.

[0004]

Since the above-mentioned replacement work needs to be carried out every time the material of the work material changes, the original machining work is frequently performed for the replacement work work especially in a work environment handling a large number of products. It was interrupted, which was a cause of reduced efficiency. Therefore, the present invention provides a laser processing machine that does not require the above replacement work.

[0005]

The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described. That is, a contact-type sensor that performs a copying operation by contacting the work surface of the work, a non-contact sensor that performs a copying operation without contacting the work surface of the work, and a contact sensor and a non-contact sensor are selected. When using the switching device and the non-contact type sensor
The contact type sensor so that it does not touch the work surface.
And a lifting device for raising the temperature of the non-contact type sensor, wherein the contact type sensor is connected to the non-contact type sensor and the non-contact type sensor is connected to the non-contact type sensor. The contact sensor is a sensor using electrostatic capacitance.

[0006]

Next, the operation will be described. By using the above means, it is judged at the start of cutting processing whether it is a conductive work or a non-conductive work, and a non-contact type sensor or a contact type sensor is selected, and the sensor detects unevenness and curvature of the work. Then, the workpiece surface is processed. During this processing, the non-contact type sensor is surrounded by the probe of the contact type sensor, so that it is protected from obstacles during working.

[0007]

Next, an embodiment of the present invention will be described. FIG. 1 is a plan view of a laser processing machine, FIG. 2 is a cross-sectional view of a laser head and a control block diagram. In FIG. 1, the laser processing machine of this embodiment is a compound machine of a punch press. The turrets 3 are arranged vertically opposite to each other on the lower frame 1 and the upper frame 2 projecting to the front of the column erected on the rear portion of the lower frame 1, and several sets of punches and dies are attached to the upper and lower turrets 3. The punch is lowered by the up-and-down drive of the ram 4 so that punching can be performed. On the other hand, a laser duct 5 guided from a laser oscillator 6 is provided on the upper surface of the upper frame 2, and the front end of the laser duct 5 communicates with a laser head 7 arranged at the front part of the ram 4.

A center table 8 is fixedly arranged on the front portion of the lower frame 1, side tables 9L and 9R are arranged on both sides of the center table 8, and the side tables 9L and 9R are connected to a carriage 10. The side tables 9L and 9R and the carriage 10 can be simultaneously slid in the front-back (Y-axis) direction by rotating the screw shaft by driving the motor M2 by driving the motor M2. Further, a cross slide 11 is arranged on the rail of the carriage 10 so as to be slidable on the rail in the left and right (X axis) direction by driving a motor M1 provided on one side of the carriage 10. Further, work holders 12, 12 for sandwiching a work such as a plate material are arranged at the rear part of the cross slide 11, and the work holder 12
・ Work W clamped by 12 is cross slide 1
1 left and right (X axis) sliding, side table 9L
By sliding 9R in the front-back (Y-axis) direction, it can be conveyed to arbitrary vertical and horizontal positions, and sheet metal processing can be performed by punching or laser.

The laser head 7 is, as shown in FIG.
The upper guide cylinder 14 communicating with the laser duct 5 is fixed to the rod 15a of the lifting device 15, and the lifting device 15
Drives the servo motor 15a to expand and contract the rod 15a so that the laser head 7 can be moved up and down. However, instead of the rod, the screw shaft is rotated to rotate the laser head 7.
You can also make it possible to move up and down. The servomotor 15a is connected to the controller 16, and the controller 16 calculates a signal from a sensor for detecting the displacement of the work W, which will be described later, and controls so as to move up and down according to the surface height of the work W. .

The laser head 7 is provided with a lens 17 for converging a laser beam at the upper axial center thereof.
The focus of the lens 17 is on the surface of the work W, and a nozzle 20 is arranged at the lower end of the laser head 7. The nozzle 20 also functions as a non-contact sensor as an electrode and is attached to a mounting cylinder 21. Connected to the output connector 22 and connected to the controller 16 via the amplifier 24.
Is connected to The periphery of the nozzle 20 is surrounded by a guard electrode 23, and the guard electrode 23
Makes the electric field from the nozzle 20 to the work W directional to prevent the electric field from being generated in any direction from the nozzle 20 so that only a predetermined work surface can be detected without being affected by the outside. The height of the nozzle 20 can be accurately detected. The nozzle 20 and the guard electrode are insulated from each other.

In this way, the nozzle 20 controls the electrostatic capacitance generated between the nozzle 20 and the conductive work W to be constant. That is, the capacitance type sensor can detect only a conductive metal, and in the case of a conductive metal, a capacitance is generated between the nozzle 20 and the work W,
The capacitance is proportional to the area and inversely proportional to the distance between the electrodes. Therefore, when the distance between the nozzle 20 and the workpiece W changes, the voltage also changes. Therefore, the voltage is detected, amplified by the amplifier 24, and input to the controller 1 so that the displacement becomes zero. The servo motor 15b
Is controlled so that the height from the work W is constant. In this embodiment, the optimum height (1.5 mm)
In this case, the output is set to 0V.

A lifting device 26 is provided on the side surface of the guide cylinder 14.
And a vertical position detection sensor 27 are attached, and the lifting device 2
The controller 1 is composed of a solenoid or a cylinder (pneumatic or hydraulic or electric cylinder).
6, the vertical position detection sensor 27 is an optical or magnetic linear encoder, an electromagnetic induction type differential transformer, or the like, and is connected to the controller 16 via an amplifier 31.

Further, the lifting rod 26a of the lifting device 26
A probe ring 29 is fixed to the lower end of the elevating rod 27a of the vertical position detecting sensor 27.
The intermediate portions of a and 27a are supported by the linear bearings 30 and 30 so as to prevent lateral shake and the like, and the nut 32 is screwed to the elevating rod 27a (or the elevating rod 26a), and the nut 32 and the linear bearing A spring 33 is externally fitted on the elevating rod 27a between 30 to urge the probe ring 29 downward so that the probe ring 29 is always in contact with the work W at the time of detection. The probe ring 29 has an opening 29a at its center so that the laser head 7 can penetrate through the opening 29a so as not to interfere with the laser head 7 when moving up and down. It is composed of a smooth member so that it does not get scratched when sliding.

The controller 16 is a copying control unit of the means for controlling the entire laser processing machine,
At the time of processing, first, the laser head 7 is moved down to determine that the work W is conductive when an electrostatic capacitance is generated between the laser head 7 and the nozzle 20, and no electrostatic capacitance is generated. If the work W is determined to be a conductive work W, and if it is a conductive work W, the lifting device 26 is operated to move the lifting rod 2
6a is moved up, the probe ring 29 is moved up, and the motors M1 and M2 are driven to move the work W in the X direction or the Y direction while cutting the laser beam from the laser oscillator 6 into a desired shape. In doing so, the height of the work W is detected by the nozzle 20 which is a non-contact sensor, and the controller 16 compares and calculates the height with the set height, and the servo motor 15b of the lifting device 15 is adjusted so as to reach the set height. The laser head 7 is operated to move up and down.

Further, in the case of cutting the non-conductive work W, the elevating device 26 is operated to lower the elevating rod 26a, and the probe ring 29 as a contact sensor is attached to the work W.
When the work W is moved in the X direction or the Y direction by being brought into contact with the upper part and driven by the motors M1 and M2, the probe ring 29 moves up and down following the height of the surface of the work W, and its displacement is the vertical position. It is detected by the detection sensor 27, calculated by the controller 16, and the servo motor 15b of the elevating device 15 is actuated to raise and lower the laser head 7 so as to reach the set height as described above. According to the above embodiment, the nozzle 20 detects whether the workpiece is conductive or non-conductive and automatically selects both sensors. Therefore, for example, the type of workpiece is set and input to the control unit before machining. Compared with the type that selects both sensors,
No need to input work type. In addition, even if the surface of the work is protected by an insulator or a protective film is formed, the sensor is automatically selected and it is not necessary to change the setting of the work type. , You can work efficiently. However, it is needless to say that the operator can switch the selection switch before the working operation without detecting conductivity or non-conductivity by the nozzle 20.

[0016]

As described above, the present invention has the following advantages. That is, since it is configured as in claim 1, the contact type sensor and the non-contact type sensor are selected according to the work to be machined, it is not necessary to replace the copying apparatus, and both types are continuously operated without stopping the machine. It can be used by switching and can work efficiently.

Since the probe of the contact type sensor is configured to surround the non-contact type sensor as in the second aspect, only the probe is constructed to be strong, and other components, workpieces or works. It is also possible to prevent the non-contact sensor from being damaged due to a collision with a hole or the like.

Since the differential transformer is used as the contact-type sensor as described in claim 3, a large stroke can be obtained and sufficient accuracy can be obtained, and the electrostatic capacity is used as the non-contact-type sensor. The conductive member and the non-conductive member can be discriminated from each other, and the contact type sensor and the non-contact type sensor can be selected.

[Brief description of the drawings]

FIG. 1 is a plan view of a laser processing machine.

FIG. 2 is a sectional view and a control block diagram of a laser head.

[Explanation of symbols]

 W work 6 Laser oscillator 7 Laser head 15 Lifting device 16 Controller 20 Nozzle (non-contact type sensor) 26 Lifting device 27 Vertical position detection sensor (differential transformer) 29 Probe ring

Claims (3)

(57) [Claims] 1. A contact-type sensor for performing a copying operation in contact with a work surface of a work, a non-contact type sensor for performing a copying operation without contacting the work surface of the work, and these contact-type sensors and non-contact sensors When using the switching device for selecting and using the non-contact sensor,
Place the contact sensor at a position where it does not contact the work surface
A laser head copy sensor equipped with an elevating device . 2. The scanning sensor of a laser head according to claim 1, wherein the probe of the contact type sensor is arranged so as to surround the periphery of the non-contact type sensor. 3. The laser head scanning sensor according to claim 1, wherein the contact type sensor is a sensor using a differential transformer, and the non-contact type sensor is a sensor using electrostatic capacitance.