Patent Application
20250214121
This application is related to application number DE 10 1023 136 881.8, filed Dec. 29, 2023 in Germany, the complete disclosure of which is incorporated herein and to which priority is claimed.
The present invention relates to a method for cleaning the surface of a metallic rod material extending in a longitudinal direction, in which the rod material is moved in the longitudinal direction through a cleaning station. Furthermore, the invention relates to a cleaning station designed for carrying out such a method and to a screw manufacturing plant comprising a rod material cutting-to-length station, at least one rod material forming station and such a cleaning station.
Screws are manufactured from metallic rod material with a circular cross-section, which is usually cold-formed beforehand to increase its strength. Before the rod material is cut to length and the actual screw shape is subsequently formed, which is usually achieved by hot or cold forming, it is advisable to remove any impurities present on the surface of the rod material, such as black scale, oxides, oils, greases, emulsions, stearates and the like, which have remained on the surface during the production of the rod material. Various methods are used for surface cleaning, in which the surface of the rod material is cleaned in a cleaning station chemically, ultrasonically, using a high-pressure fluid, mechanically or in another form. In this context, reference is made by way of example to DE 10 2011 017 360 A1, which briefly summarizes known cleaning processes in the introductory section.
Based on this prior art, it is an object of the present invention to provide an alternative method for the surface cleaning of a rod material extending in a longitudinal direction, in which the rod material is moved in the longitudinal direction through a cleaning station, as well as a corresponding cleaning station and a corresponding screw manufacturing plant.
To solve this object, the present invention provides a method for cleaning the surface of a metallic rod material extending in a longitudinal direction, in which the rod material is moved in the longitudinal direction through a cleaning station, characterized in that in the cleaning station at least one laser beam is directed onto the surface of the rod material to be cleaned, which laser beam removes impurities present on the surface. It has been found that the surface cleaning of rod material by means of laser radiation is very effective, as proper cleaning results are achieved even at very high movement speeds of the rod material compared to known cleaning methods. In addition, cleaning rod material using laser radiation is very environmentally friendly, as no cleaning agents or chemical substances are used. In addition, cleaning rod material using laser radiation requires significantly less space, especially compared to the chemical cleaning methods typically used, and the rod material can be processed immediately after cleaning.
According to one embodiment of the method according to the invention, at least three, preferably at least four laser beams are directed onto the surface to be cleaned, distributed over the circumference of the rod material. Depending on the diameter of the rod material, the entire circumference of the rod material can be covered with at least three such laser beams.
Advantageously, the at least one laser beam is directed onto the rod material in a direction which has a direction vector pointing against the direction of movement of the rod material. Particularly good cleaning results are achieved when the laser beam or laser beams are aligned in this way.
The angle drawn by the laser beam(s) and the rod material is preferably in the range of 70 to 90°.
Preferably, removed impurities are evacuated.
According to one embodiment of the present invention, the degree of contamination of the rod material is detected before cleaning and the parameters of the laser irradiation are controlled as a function of the detected degree of contamination. In this way, an optimum cleaning result can be achieved.
The cleaning result is preferably recorded for quality control and/or for readjusting the parameters of the laser irradiation.
According to one embodiment of the present invention, the method is carried out as a machining step of a screw manufacturing process, in particular before forming and subsequent cutting to length of the rod material.
Furthermore, the present invention provides a cleaning station with a laser irradiation device, characterized in that it is designed to carry out a method according to the invention.
According to one embodiment of the present invention, the laser irradiation device has a processing chamber with a rod material inlet and a rod material outlet, at least one laser optic being positioned inside the processing chamber, preferably several laser optics are positioned inside the processing chamber, which can be aligned in such a way that it/they can apply laser radiation to the entire circumference of a rod material moved through the processing chamber in the longitudinal direction of the rod material. In this way, a simple design is achieved that can be easily adapted to different wire geometries.
The at least one laser optic or the several laser optics can preferably be moved in such a way that at least the distance and angle of the laser beam or laser beams emitted by it/them to the rod material moving through the processing chamber can be changed.
Both pulsed and continuously emitting laser sources can be used as laser sources. The wavelength can vary depending on the material and/or the dimensions of the rod material and/or the type of contamination to be removed.
Optionally, the laser irradiation device can have a sensor device and a control system which are designed and set up in such a way that the sensor device detects the degree of contamination before cleaning and the control system regulates at least one parameter of the laser irradiation as a function of the detected degree of contamination.
Preferably, the laser irradiation device has a sensor device and a control unit which are designed and set up in such a way that the sensor device detects the cleaning result, whereby the detected cleaning result is used for quality control and/or for readjusting the parameters of the laser irradiation.
Advantageously, the laser processing device has an evacuation device to properly remove the ablated material from the processing site.
In addition, the present invention provides a screw manufacturing plant comprising a rod material forming and cutting-to-length station, wherein the screw manufacturing plant has a cleaning station according to the present invention, which is arranged ahead, preferably immediately ahead, the rod material forming and cutting-to-length station.
Further features and advantages of the present invention will become clear from the following description with reference to the accompanying drawing. Therein
Both pulsed and continuously emitting laser sources can be used as laser sources. The wavelength can vary depending on the material and/or the dimensions of the rod material and/or the type of contamination to be removed.
Optionally, the laser irradiation device 7 can have a sensor device 14 and a controller 17, which are designed and set up in such a way that the sensor device 14 detects the degree of contamination before cleaning and the controller 17 regulates at least one parameter of the laser irradiation depending on the detected degree of contamination. Alternatively or additionally, the sensor device 14 and the control unit 17 can be designed and set up in such a way that the sensor device 14 detects the cleaning result, whereby the detected cleaning result is used for quality control and/or for readjusting the parameters of the laser irradiation. For this purpose, the sensor device 14 can, for example, be equipped with one or more cameras which are directed at the surface of the rod material in front of and/or behind the processing location. Based on the image data, the surface quality of the rod material is then evaluated, in particular in real time, using image recognition software.
During operation of the cleaning station 1, the rod material 2 is continuously moved in the direction of the arrow 4 through the processing chamber 3 and cleaned using the laser irradiation device 7.
Finally, it should be noted that the embodiments described above serve only as examples and are not to be understood as limiting. Rather, changes and/or modifications are possible without departing from the scope of protection defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102023136881.8 | Dec 2023 | DE | national |
