WO2022019865A1

WO2022019865A1 - Light centralizer for fiber laser cutting machines

Info

Publication number: WO2022019865A1
Application number: PCT/TR2021/050655
Authority: WO
Inventors: Kanber SEDEF; Aamish Umar; Ibrahim SAT
Original assignee: Dener Mak. San. Ve Tic. Ltd. Sti.
Priority date: 2020-07-20
Filing date: 2021-06-25
Publication date: 2022-01-27
Also published as: EP4182114A4; TR202011526A2; EP4182114A1

Abstract

The present invention is a centralizer mechanism (100) for automatically adjusting of laser light, produced for cutting metal and similar materials in fiber laser cutting machines (M), while the laser light is passing through the nozzle (121) of the processing head, wherein light axial adjustment motor box (110) is provided which is connected to the laser cutting head (120) and which has at least two sensitive step motors used for adjusting through the user screen (140) automatically or by the user in the direction of X and Y axes for centering the light; contactless automatically focused automatic laser light centralizer system (130) is provided which has light axial adjustment motor box (110) and laser cutting head (120) assembled one on the other and which corresponds and adjusts the laser cutting head (120) with the camera (133) by pushing the slide (132) connected to the spring (131) for centering the laser light; a user screen (140) is provided for corresponding the laser cutting light, which passes through the nozzle (121) and having reduced voltage, to the camera (134) as the centralizer mechanism (100) compresses the slide (132) connected to the spring (131) when the light centering command comes on the user side through the computer unit and for bringing the fiber cutting light source view (141), which is outside of the position area (142) where the fiber light source must exist in the nozzle diameter (143), to the position area (142) where the fiber light source must exist.

Description

LIGHT CENTRALIZER FOR FIBER LASER CUTTING MACHINES

TECHNICAL FIELD

The present invention relates to a centralizer mechanism which provides making adjustment in an automatic manner without needing any apparatus, housing or holder when passing through the nozzle of the processing head having adjustment mechanism for laser light produced for cutting metal and similar materials in fiber laser cutting machines.

KNOWN STATE OF THE ART

Fiber laser cutting machine is a laser cutting machine where the fiber laser generator thereof is used as light source. In sheet processing machines, the laser used as the latest technology is the fiber laser named also as “ytterbium” laser. Fiber lasers are preferred particularly because of more rapid cutting and energy efficiencies thereof when compared with C02 lasers. Laser rays generated in the resonator of the fiber laser cutting machine are carried by fiber cable and are transferred to the processing surface. The cutting process begins as a result of the contact of the laser ray and the used auxiliary gas like oxygen, nitrogen or dry air with the metal surface. The shape of the related part, which is to be processed with the help of axes having micron precision, is drawn to the processing surface and the cutting process is realized. The fiber laser cutting machine transfers the laser ray to the metal surface, which is to be cut, by means of fiber cables. Diodes generate laser ray without needing gas. The joined diode modules and the modules are joined by means of fiber cables and the resonator is formed.

The most important points in laser cutting process are focusing, centering and guiding of laser ray. The operator, who executes the cutting process, has to take the light to the center after each nozzle change. Different applications are realized for centering of the laser ray generated in the resonator, and frequently a transparent band adhered to the nozzle is used. After laser shot is realized for short duration and at low cutting gas pressure, the band is removed and the location of the hole, formed by laser shot and which exists in the nozzle, is examined with the help of lens, and adjustment is realized by means of adjustment screws if said hole is not at the center. This method leads to time loss and leads to non-effective usage of the labor. On the other hand, since this process depends on operator’s competence and eye precision, erroneous adjustment risk increases. In order to eliminate these problems and in order to realize centering adjustment automatically, various studies have been realized and new systems have been developed. One of these studies is the invention which is the subject of the patent application with number TR201819177 and with title “Laser Cutting Machine Having Centering Unit”. The invention relates to a laser cutting machine having a mirror for providing cutting of a quadrangular profile and which moves rotationally and which compresses and holds said quadrangular profile, at least one support arm which supports lifting of the quadrangular profile held by said mirror, a second mirror which provides fixation of the quadrangular profile, put forward by the mirror, at the part where cutting will be realized, and at least one cutting head which realizes cutting process. As an improvement, in order to provide center adjustment of the quadrangular profile, at least one sensor is provided, at least one processor is provided where the center dimension detected by said sensor is transferred, and at least one control unit is provided which adjusts the position of said cutting head in accordance with the information transferred from said processor.

Another study is the invention which is the subject of the patent application with number TR201721028 and with title “Automatic Nozzle Centering System”. The invention relates to automatic nozzle centering system which provides automatic centering of the nozzle positioned at the laser cutting head. As the improvement, in order to determine the position of said laser cutting head, at least one image sensor is provided which senses the laser light sent from said laser cutting head, at least one processor system is provided which sends commands for providing advancing of said nozzle in accordance with the determined distance by calculating the distance of the laser light image, obtained from said image sensor, with respect to the center point, and at least one movement unit which provides advancing of said nozzle to the center point by means of the command received from said processor system.

Another study is the invention which is the subject of the patent application with number EP1561538 A1 and with title “Device for adjusting centering and focusing of a laser ray in a laser processing machine: Laser cutting head with such a device”. While the laser cutting head is at a test position, an alignment unit is used which is arranged in the dispersion direction of the beam for realizing the adjustments. The alignment unit comprises various components. The infrared transformation screen records the projection of the beam on an image plane at a specific focus distance with respect to the cutting nozzle. The auxiliary infrared light, which exists in the laser cutting head, exits the nozzle and reaches the image sensor camera system. Centering is realized with the help of the user in accordance with the auxiliary infrared light coming from the camera system. During this process step, a housing- like ring is used for correct centering. Additionally, ceramic infrared converter screen with thickness of 3 mm and with dimensions of 50x50 mm is used for focusing the coming auxiliary light and making it visible. Moreover, there is the protective box mechanism for protecting the system. This system is a centering system developed for C02 sourced laser systems. In this system, the most important disadvantages are that various intermediate elements like protective box, centering ring and focusing screen are used. Besides, since housing is used for nozzle centering, the heated nozzle contacts this housing and may damage the nozzle frame and the housing. Besides, each time the cutting head is positioned to the centering part, because of millimetrical shifts on the system in accordance with the precision degrees of the used motors, impacts may occur. Auxiliary infrared light is used instead of original cutting laser light for light centering. In this auxiliary light which is taken as reference, millimetrical shift occurs in time in the direction of the operation of the machine, and it never takes the place of the main cutting laser light. The auxiliary light focusing system provided on the system may lose bending and focusing characteristics in time. Moreover, since the image is taken through the screen, shifts may occur on the frame screen in case of nozzle changes having different dimensions.

In the present applications, usage of auxiliary elements for the centering process increases maintenance-repair need and increases machine cost. As a result, the presence of a need for the centralizer mechanism which eliminates the disadvantages present in the present art and the insufficiency of the present solutions made it necessary to make an improvement in the related technical field.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to a centralizer mechanism which provides adjustment in an automatic manner without needing any apparatus, housing or holder while the laser light, produced for cutting metal and similar materials in fiber laser cutting machines, is passing through the nozzle of the processing head having adjustment mechanism, for meeting the abovementioned requirements and for eliminating the abovementioned disadvantages and for bringing new advantages to the related technical field.

In the light of the known state of the art, the object of the present invention is to provide elimination of the need for various intermediate elements like protective box, centering ring and focusing screen, used in the present systems, thanks to the developed centralizer mechanism. The object of the present invention is to provide a structure which is simple and which protects the system by being used only during centering thanks to the springy sliding mechanism developed instead of the circular ring and protective equipment.

Another object of the present invention is to provide centering of the main cutting laser light since cutting light is used which is energized at a level which can be sensed only by the camera system and which is sent by the fiber laser cutting head for light centering.

Another object of the present invention is to provide transfer of cutting laser light and nozzle image, with reduced energy, directly to the receiver screen thanks to the image processing technology used with nitrogen and oxygen structure, which forms air, instead of the focusing lens which exists in the present system.

Another object of the present invention is to provide elimination of millimetrical shifts and impacts which may occur each time the cutting head mechanism will make centering thanks to assembling of two motors on the cutting head, which adjust the laser light adjustment screws, provided on the cutting head, automatically in the orthogonal and horizontal axis in the direction of feedback of image processing algorithm.

Another object of the present invention is to provide centering of light by adjusting through an interface automatically or by the user in the direction of orthogonal and horizontal axis thanks to the motor box which axially adjusts light and comprising two motors and used in the centralizer mechanism.

The structural and characteristic properties and all advantages of the present invention will be understood in a more clear manner by means of the below mentioned figures and the detailed description written by making reference to these figures, therefore, evaluation shall be made by taking into consideration these figures and the detailed description.

BRIEF DESCRIPTION OF THE FIGURES

In order to understand the embodiment of the present invention and the advantages together with additional elements, they shall be evaluated together with the figures whose description is given below.

In Figure 1 , the schematic general view of the mounted form of the centralizer mechanism on the laser cutting machine is given. In Figure 2, the schematic general view of the dismantled form of the light axial adjustment motor is given.

In Figure 3, the schematic general view of the dismantled form of the laser cutting head is given.

In Figure 4, the schematic general view of the mounted form of the adjustment motor and the laser head is given.

In Figure 5, the schematic general view of the dismantled form of the light centralizer system is given.

In Figure 6, the dismantled schematic general view of the centralizer mechanism is given.

In Figure 7a, the schematic general view of the user screen centering image is given.

In Figure 7b, another schematic general view of the user screen centering image is given.

REFERENCE NUMBERS

100. Centralizer mechanism

110. Light axial adjustment motor box

111. Motor shaft

112. Motor cable

120. Laser cutting head

121. Nozzle

122. Adjustment bolt

123. Slide counterpart

130. Light centralizer system

131 . Spring

132. Slide

133. Camera

134. Light source

135. Assembly housing

140. User screen

141 . Fiber cutting light source view

142. Position area where the fiber light source must exist 143. Nozzle diameter M. Fiber laser cutting machine

DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the subject matter centralizer mechanism (100), which provides adjustment automatically without needing any apparatus, housing or holder while passing through the nozzle (121) of the processing head having adjustment mechanism of laser light produced for cutting metal and similar materials in the fiber laser cutting machines (M), is explained with references to examples without forming any restrictive effect only in order to make the subject more understandable.

The centralizer mechanism (100) used in the fiber laser cutting machine (M) and shown in Figure 1 realizes centering process by utilizing image processing technology thanks to oxygen and nitrogen mixture structure in air without needing any light focusing material or lens between the image sensing camera (133) and laser cutting light with voltage reduced to 1-2 mV level such that the contactless automatic focusing automatic laser light centralizer system (130) can be seen by the sensing camera (133) system. Besides, the distance between the nozzle (121) and the sheet material to be processed is changing for the products with different thickness. The problem of adjusting this distance before beginning each process has been solved by said centralizer mechanism (100) by means of automatic focusing process realized by the camera (133) at fixed distance. In said centralizer mechanism (100), when light centering command is given by the user, the laser cutting head

(120) equipment, where the adjustment motors are connected which exist in the light axial adjustment box (110), are moved thanks to the linear movement equipment and the process is realized by moving towards the light centralizer system (130).

The light axial adjustment motor box (110) shown in Figure 2 has two sensitive step motors used for adjusting through the user screen (140) automatically or by the user in the direction of X and Y axes for centering light. On said light axial adjustment motor box (110), there are two alien ended motor shafts (111) which belong to the two adjustment motors and there are motor cables (112) having cable outlets which belong to these two adjustment motors.

The fiber cutting light is emitted in the laser cutting head (120) shown in Figure 3 and which fulfills cutting function of the sheet metal workpiece. Said cutting light exits the nozzle (121) positioned at the lower part of the laser cutting head (120). At the upper part of said nozzle

(121), the slide counterpart (123) has been positioned which contacts the slide (132) provided at the light centralizer system (130). There are two adjustment bolts (122), where the cutting light is adjusted in the direction of X and Y axis, on said laser cutting head (120).

In the subject matter centralizer mechanism (100), the laser cutting head (120) shown in Figure 4 has been assembled to the light axial adjustment motor box (110).

The light centralizer system (130) shown in Figure 5 tries to correspond the laser cutting head (120) with the camera (133) by pushing the slide (132) connected to the spring (131). Said spring (131) is compressed when centering will be realized by the laser cutting head (120). The slide (132) made of delrin material and connected to said spring (131) contacts the slide counterpart (123) which exists at the laser cutting head (120). Said camera (133) senses the light source coming through the laser cutting head (120) and having voltage value of 1-2 mV. The circular light source (134) has been positioned, which is formed by little white light LEDs for providing better sensing of light, in a manner encircling said camera (133). There is the assembly housing (135) for the assembly of the camera (143) and the light source (134) at the lateral part of the light centralizer system (130).

In the centralizer mechanism (100) shown in Figure 6, the laser cutting head (120) and the light axial adjustment motor box (110), assembled to each other, correspond onto the light centralizer system (130) positioned at the lowermost part and are adjusted for centering the laser light. The nozzle (121), provided at the lowermost part of said laser cutting head (120), corresponds to the camera (143) positioned at the top part of the light centralizer system (130) and corresponds to the light source (134) around thereof. When the light centralizer command comes at the user side through the computer unit at the fiber laser cutting machine (M), the centralizer mechanism (100) compresses and pushes the slide (132) connected to the spring (131). The laser cutting light having reduced voltage and passing through the nozzle (121) corresponds to the camera (134) as shown in Figure 7a. On the user screen (140) shown in Figure 7a, the fiber cutting light source view (141), which is outside of the position area (142) where the fiber light source must exist in the nozzle diameter (143), moves adjustment bolts (122) by the motor shafts (111) by means of the image processing technology command for centering the laser cutting light, and the centering process is realized automatically. After the centering process, the fiber light source view (141), which is outside of the position area (142) where the fiber light source must exist, is brought into the position area (142) where the fiber light source must exist. Besides, the distance between the nozzle (121) and the sheet material, which is to be processed for products having different thicknesses, is changing. Instead of adjusting this distance before beginning each process, the camera (133) is automatically focused at fixed distance.

Claims

1. A centralizer mechanism (100) for automatically adjusting of laser light, produced for cutting metal and similar materials in fiber laser cutting machines (M), while the laser light is passing through the nozzle (121) of the processing head, wherein

- light axial adjustment motor box (110) is provided which is connected to the laser cutting head (120) and which has at least two sensitive step motors used for adjusting through the user screen (140) automatically or by the user in the direction of X and Y axes for centering the light;

- contactless automatically focused automatic laser light centralizer system (130) is provided which has light axial adjustment motor box (110) and laser cutting head (120) assembled one on the other one and which corresponds and adjusts the laser cutting head (120) with the camera (133) by pushing the slide (132) connected to the spring (131) for centering the laser light;

- a user screen (140) is provided for corresponding the laser cutting light, which passes through the nozzle (121) and having reduced voltage, to the camera (134) as the centralizer mechanism (100) compresses the slide (132) connected to the spring (131) when the light centering command comes on the user side through the computer unit and for bringing the fiber cutting light source view (141), which is outside of the position area (142) where the fiber light source must exist in the nozzle diameter (143), to the position area (142) where the fiber light source must exist.

2. The centralizer mechanism (100) according to claim 1 , wherein image sensing camera (133) is provided which can see the laser cutting light having voltage reduced to 1-2 mV level for realizing the centering process by utilizing image processing technology thanks to the oxygen and nitrogen mixture structure which exist in air.

3. The centralizer mechanism (100) according to claim 1 , wherein automatically focused camera (133) is provided which is positioned at fixed distance for eliminating the need for the adjustment before beginning each process for the different distances between the nozzle (121) and the sheet material to be processed for products having different thicknesses.

4. The centralizer mechanism (100) according to claim 1 , wherein alien ended motor shaft (111) is provided which is positioned on the light axial adjustment motor box (110) and which belongs to the adjustment motor which moves the adjustment bolts

(122) for automatic realizing the centering process.

5. The centralizer mechanism (100) according to claim 1 , wherein motor cables (112) are provided which have cable outlets which belong to two adjustment motors provided in the light axial adjustment motor box (110).

6. The centralizer mechanism (100) according to claim 1 , wherein slide counterpart

(123) is provided which contacts the slide (132) provided at the light centralizer system (130) at the upper part of the nozzle (121).

7. The centralizer mechanism (100) according to claim 1 , wherein spring (131) is provided which is connected to the slide (132) and which is compressed when centering will be made by the laser cutting head (120).

8. The centralizer mechanism (100) according to claim 1 , wherein slide (132) is provided which is connected to the spring (131) and which contacts the slide counterpart (123) provided in the laser cutting head (120).

9. The centralizer mechanism (100) according to claim 1 , wherein slide (132) is provided which is made of delrin material.

10. The centralizer mechanism (100) according to claim 1 , wherein circular light source (134) is provided which is positioned in a manner encircling the camera (133) and which is formed by little white lighted LEDs for sensing the light in a better manner.