Method for removing oxide layer on surface of ground wire and controller

Abstract

The invention provides a method for removing a surface oxide layer of a ground wire. The method comprises the following steps: determining a laser and a ground wire corresponding to a to-be-removed surface oxide layer; a laser is driven to emit pulse laser by adopting a first specified light spot coverage rate and energy density to perform surface oxide layer removal on the ground wire until the proportion of a non-removed area is smaller than or equal to a first percentage; then, a laser is driven to emit continuous laser by adopting a preset process parameter combination to carry out surface oxide layer removal on the ground wire until the proportion of a non-removed area is smaller than or equal to a second percentage; and finally, driving the laser to emit pulse laser by adopting a second specified light spot coverage rate and an energy density to carry out surface oxide layer removal on the ground wire until the proportion of an unremoved clean area is less than or equal to a third percentage. According to the invention, the problems of time consumption, labor consumption and incomplete cleaning caused by a traditional cleaning mode of a steel brush, abrasive paper and gasoline can be solved, and the wire breaking probability of the ground wire is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of electric power maintenance, and in particular to a method for removing an oxide layer on the surface of a ground wire and a controller. Background Art

[0002] In the construction of overhead power transmission lines, the connection between two adjacent conductors is achieved by driving the clamp head up and down through a hydraulic drive device to crimp the sleeves on the two conductors together. However, the quality of conductor crimping is an important part of overhead line construction, which directly affects the stability of safe operation of the power grid. Therefore, when crimping the conductor, it is necessary to clean the attachments and oxide layer on the surface of the conductor to reduce the contact resistance between the conductor and the joint tube and the tension tube, thereby avoiding the problem of excessive energy consumption in line operation caused by excessive contact resistance of the joint tube, and improving the stability and continuity of power supply.

[0003] At present, the ground wire is cleaned by steel brush, sandpaper or gasoline to remove the surface attachments and oxide layer. For example, for the old ground wire in operation, the black attachments on the surface are cleaned with a fine steel wire brush until the aluminum strand and the steel core surface show metallic luster; for another example, when the ground wire is free of oil stains, it is wiped clean with cotton yarn; for another example, before the ground wire connection construction, the surface of the connection part, the inner wall of the connection pipe, and the surface of the wire that the connection pipe may contact when inserting the pipe are cleaned with gasoline.

[0004] However, the above-mentioned traditional cleaning methods of steel brush, sandpaper and gasoline are time-consuming and labor-intensive, and the cleaning is not thorough enough, which easily causes the probability of the ground wire being broken. Summary of the invention

[0005] The technical problem to be solved by the embodiments of the present invention is to provide a method and a controller for removing the oxide layer on the surface of the ground wire, which can solve the problems of time-consuming, labor-intensive and incomplete cleaning caused by traditional cleaning methods such as steel brushes, sandpaper and gasoline, and reduce the probability of ground wire breakage.

[0006] In order to solve the above technical problems, an embodiment of the present invention provides a method for removing an oxide layer on the surface of a ground wire, the method comprising the following steps:

[0007] Determine the ground wire of the laser and its corresponding surface oxide layer to be removed;

[0008] The laser is driven to emit pulsed laser with a first specified spot coverage and a first specified energy density to remove the surface oxide layer of the ground wire, until the proportion of the area of ​​the ground wire where the surface oxide layer has not been removed is less than or equal to a preset first percentage;

[0009] If it is detected that the proportion of the area where the surface oxide layer has not been removed is less than or equal to the first percentage value, the laser is driven to emit continuous laser using a predetermined process parameter combination to remove the surface oxide layer from the ground wire until the proportion of the area where the surface oxide layer has not been removed is less than or equal to a preset second percentage;

[0010] If it is detected that the proportion of the area where the surface oxide layer has not been removed is less than or equal to the second percentage constant, the laser is driven to emit pulsed laser using a second specified spot coverage and a second specified energy density to remove the surface oxide layer of the ground wire until the proportion of the area where the surface oxide layer has not been removed is less than or equal to a preset third percentage;

[0011] Among them, the second percentage is smaller than the first percentage and larger than the third percentage; the second specified light spot coverage is smaller than the first specified light spot coverage; and the second specified energy density is smaller than the first specified energy density.

[0012] The process parameter combination includes a laser power of 75W / cm 2 , the pulse repetition frequency is 0.4 MHz, the spot overlap rate and the scanning track overlap rate are both 35%, and the number of cycle scans is 15 times.

[0013] Among them, the first percentage is 10%; the second percentage is 5%; and the third percentage is 1%.

[0014] The first specified spot coverage is that the spot diameter is between 6 mm and 7 mm, and the first specified energy density is 1.1 J / cm 2 The second specified spot coverage is that the spot diameter is between 5mm-6mm, and the first specified energy density is 0.8J / cm 2 .

[0015] The embodiment of the present invention further provides a controller, including:

[0016] A target object determination unit, used to determine the laser and its corresponding ground wire of the surface oxide layer to be removed;

[0017] A high-density mode oxide layer removal unit, used to drive the laser to emit pulsed laser using a first specified spot coverage and a first specified energy density to remove the surface oxide layer of the ground wire, until the proportion of the area on the ground wire where the surface oxide layer has not been removed is less than or equal to a preset first percentage;

[0018] The medium-density mode oxide layer removal unit is used to drive the laser to emit continuous laser with a predetermined process parameter combination to remove the surface oxide layer of the ground wire if it is detected that the proportion of the area where the surface oxide layer is not removed is less than or equal to the first percentage constant value, until the proportion of the area where the surface oxide layer is not removed is less than or equal to the preset second percentage;

[0019] A low-density mode oxide layer removal unit is used to drive the laser to emit pulsed laser with a second specified spot coverage and a second specified energy density to remove the surface oxide layer of the ground wire if it is detected that the proportion of the area where the surface oxide layer has not been removed is less than or equal to the second percentage constant, so as to remove the surface oxide layer of the ground wire until the proportion of the area where the surface oxide layer has not been removed is less than or equal to a preset third percentage;

[0020] Among them, the second percentage is smaller than the first percentage and larger than the third percentage; the second specified light spot coverage is smaller than the first specified light spot coverage; and the second specified energy density is smaller than the first specified energy density.

[0021] The process parameter combination includes a laser power of 75W / cm 2 , the pulse repetition frequency is 0.4 MHz, the spot overlap rate and the scanning track overlap rate are both 35%, and the number of cycle scans is 15 times.

[0022] Among them, the first percentage is 10%; the second percentage is 5%; and the third percentage is 1%.

[0023] The first specified spot coverage is that the spot diameter is between 6 mm and 7 mm, and the first specified energy density is 1.1 J / cm 2 The second specified spot coverage is that the spot diameter is between 5mm-6mm, and the first specified energy density is 0.8J / cm 2 .

[0024] Implementing the embodiments of the present invention has the following beneficial effects:

[0025] The present invention first uses a laser with a first specified spot coverage and a first specified energy density (i.e., high spot coverage and high energy density) to remove most of the rust layer, and then uses the best process parameter combination obtained by a single factor experiment to remove most of the remaining oxide layer. Finally, a second specified spot coverage and a second specified energy density (i.e., low spot coverage and low energy density) are used to perform a final polishing rust removal strategy on the surface of the ground wire. This strategy can not only obtain a more detailed surface morphology, but also improve the efficiency of removing the oxide layer, thereby solving the problems of time-consuming, labor-intensive and incomplete cleaning caused by traditional cleaning methods such as steel brushes, sandpaper and gasoline, and reducing the probability of ground wire breakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0027] Figure 1 A flow chart of a method for removing an oxide layer on the surface of a ground wire provided by an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the structure of a controller provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] like Figure 1 As shown in the figure, a method for removing the oxide layer on the surface of the ground wire is proposed in an embodiment of the present invention, which is implemented on a controller. The method includes the following steps:

[0031] Step S1, determining a laser and a ground wire corresponding to the surface oxide layer to be removed;

[0032] Step S2, driving the laser to emit pulsed laser with a first specified spot coverage and a first specified energy density to remove the surface oxide layer of the ground wire, until the proportion of the area on the ground wire where the surface oxide layer has not been removed is less than or equal to a preset first percentage;

[0033] Step S3, if it is detected that the proportion of the area where the surface oxide layer has not been removed is less than or equal to the first percentage value, the laser is driven to emit continuous laser using a predetermined process parameter combination to remove the surface oxide layer of the ground wire until the proportion of the area where the surface oxide layer has not been removed is less than or equal to a preset second percentage; wherein the second percentage is less than the first percentage;

[0034] Step S4, if it is detected that the proportion of the area where the surface oxide layer has not been removed is less than or equal to the second percentage value, the laser is driven to emit pulsed laser using a second specified spot coverage and a second specified energy density to remove the surface oxide layer of the ground wire, until the proportion of the area where the surface oxide layer has not been removed is less than or equal to a preset third percentage;

[0035] Among them, the second percentage is smaller than the first percentage and larger than the third percentage; the second specified light spot coverage is smaller than the first specified light spot coverage; and the second specified energy density is smaller than the first specified energy density.

[0036] The specific process is as follows: in step S1, a driving laser is selected by a controller, and a ground wire corresponding to the surface oxide layer to be removed of the laser is further determined.

[0037] In step S2, the controller modulates the laser to adopt a first specified spot coverage (such as a spot diameter between 6 mm and 7 mm) and a first specified energy density (such as 1.1 J / cm 2 ) emits a pulsed laser, and aims the modulated laser at the ground wire to remove the surface oxide layer, until the proportion of the area on the ground wire where the surface oxide layer has not been removed is less than or equal to a preset first percentage (such as 10%). It should be noted that the first specified spot coverage and the first specified energy density used by the laser are high spot coverage and high specified energy density. Although the rust layer will be completely removed, it may also cause secondary oxidation on the surface of the workpiece and cause over-cleaning. Therefore, the pulsed laser with high spot coverage and high specified energy density can be used to remove most of the rust layer and allow a certain degree of secondary oxidation, so the final finishing cleaning cannot be achieved, and subsequent steps are required for detailed cleaning to improve the efficiency of surface oxide layer removal.

[0038] It is understandable that the area on the ground wire where the surface oxide layer has been cleanly removed and the area where the surface oxide layer has not been cleanly removed can be obtained by scanning with a laser front-end galvanometer and judged and fed back to the controller, or can be obtained by other scanning equipment and fed back to the controller.

[0039] In step S3, different process parameters (laser spot overlap rate and scanning track overlap rate, laser average power, number of cycle scans, laser repetition frequency, etc.) when laser is used to remove the oxide layer on the surface of the ground wire have different influences on the test results after rust removal.

[0040] Therefore, after the oxide layer on the surface of the ground wire is mostly removed in step S2, the laser is modulated by the controller to adopt a combination of process parameters including a laser power of 75 W / cm 2 The pulse repetition frequency is 0.4MHz, the spot overlap rate and the scanning track overlap rate are both 35%, and the number of cyclic scanning is 15 times to emit continuous laser to remove the surface oxide layer of the alignment ground wire until the proportion of the area on the ground wire where the surface oxide layer has not been removed is less than or equal to a preset second percentage (such as 5%), so as to further enhance the efficiency of removing the surface oxide layer.

[0041] It should be noted that in the laser rust removal process, in order to ensure that the oxide layer is evenly removed, its surface is required to be evenly covered by the light spot. In order to evenly and efficiently remove the rust layer without causing insufficient cleaning or secondary oxidation, it is necessary to select a suitable laser spot overlap rate (the overlap rate of two adjacent laser spots on the same laser scanning track) and a laser scanning track overlap rate (the overlap rate of two adjacent laser scanning tracks on the circumferential surface of the grinding wheel) so that the pulse spot is evenly distributed on the workpiece surface. At this time, the laser spot overlap rate and the laser scanning track overlap rate are both selected between 30% and 40%.

[0042] Laser power density directly determines the removal effect and efficiency of the oxide layer through the laser energy deposited on the oxide layer. A low power density will result in incomplete rust removal. To remove all the rust layers, multiple layer removals are required, resulting in low rust removal efficiency. Although a high power density will completely remove the rust layer, it may also cause secondary oxidation on the workpiece surface, resulting in over-cleaning. At this time, when the average laser power is 75W / cm 2 When the rust layer on the workpiece surface can be completely removed without damaging the base material or causing secondary oxidation, the surface is bright and has no obvious protrusions. However, the average power density is less than or greater than this power density 75W / cm 2 When the rust is removed, it may cause incomplete rust removal or secondary oxidation on the workpiece surface.

[0043] When the number of scans is 4 to 12, the removal depth increases rapidly with the increase of the number of scans. This is because the laser is always removing the oxide layer on the surface of the workpiece without touching the metal substrate. The oxide layer is loose and porous and has a high absorption rate for laser. Most of the laser energy is absorbed by the oxide layer and expands due to heat and flies away from the surface of the workpiece. The resulting metal slag and metal metamorphic layer are thin, which has limited impact on the material removal rate. However, when the number of scans is 16 to 24, the oxide layer has been basically removed, and a large area of ​​the metal substrate is exposed. When the high-energy laser is irradiated, most of the energy generates a thicker and denser metal metamorphic layer, and molten droplets are left to cover the surface of the substrate to form surface defects, which hinders the removal depth of a single scan. As the number of scans continues to increase, the removal depth increases slowly. At this time, the number of scans is selected to be 12 to 16 times.

[0044] In step S4, considering that step S3 does not achieve the final finishing effect of the ground wire, it is necessary to modulate the laser through the controller to adopt a second specified spot coverage (such as a spot diameter between 5 mm and 6 mm) and a second specified energy density (such as 0.8 J / cm 2 ) emits a pulsed laser, and allows the modulated laser to be aimed at the ground wire to remove the surface oxide layer, until the proportion of the area on the ground wire where the surface oxide layer has not been removed is less than or equal to a preset third percentage (such as 1%), so as to achieve the final finishing effect of the ground wire. It should be noted that the second specified spot coverage and the second specified energy density used by the laser are low spot coverage and low specified energy density, and the surface of the ground wire can be finally finished to meet the surface quality requirements of the workpiece.

[0045] At this time, the workpiece after laser rust removal has stronger corrosion resistance than the workpiece polished with sandpaper. This is because the dense metamorphic layer on the surface of the workpiece after laser treatment prevents the metal substrate from contacting the corrosive air, and the metal traces scratched by sandpaper on the metal substrate provide a larger contact area for the water film in the air, accelerating the corrosion rate of the substrate.

[0046] like Figure 2 As shown in the figure, a controller is provided in an embodiment of the present invention, including:

[0047] The target object determination unit 110 is used to determine the laser and its corresponding ground wire of the surface oxide layer to be removed;

[0048] The high-density mode oxide layer removal unit 120 is used to drive the laser to emit pulsed laser with a first specified spot coverage and a first specified energy density to remove the surface oxide layer of the ground wire until the proportion of the area of ​​the ground wire where the surface oxide layer has not been removed is less than or equal to a preset first percentage;

[0049] The medium density mode oxide layer removal unit 130 is used to drive the laser to emit continuous laser with a predetermined process parameter combination to remove the surface oxide layer of the ground wire if it is detected that the proportion of the area where the surface oxide layer is not removed is less than or equal to the first percentage constant value, until the proportion of the area where the surface oxide layer is not removed is less than or equal to the preset second percentage.

[0050] The low-density mode oxide layer removal unit 140 is used to drive the laser to emit pulsed laser with a second specified spot coverage and a second specified energy density to remove the surface oxide layer of the ground wire if it is detected that the proportion of the area where the surface oxide layer is not removed is less than or equal to the second percentage constant value, so as to remove the surface oxide layer of the ground wire until the proportion of the area where the surface oxide layer is not removed is less than or equal to the preset third percentage;

[0051] Among them, the second percentage is smaller than the first percentage and larger than the third percentage; the second specified light spot coverage is smaller than the first specified light spot coverage; and the second specified energy density is smaller than the first specified energy density.

[0052] The process parameter combination includes a laser power of 75W / cm 2 , the pulse repetition frequency is 0.4 MHz, the spot overlap rate and the scanning track overlap rate are both 35%, and the number of cycle scans is 15 times.

[0053] Among them, the first percentage is 10%; the second percentage is 5%; and the third percentage is 1%.

[0054] The first specified spot coverage is that the spot diameter is between 6 mm and 7 mm, and the first specified energy density is 1.1 J / cm 2 The second specified spot coverage is that the spot diameter is between 5mm-6mm, and the first specified energy density is 0.8J / cm 2 .

[0055] Implementing the embodiments of the present invention has the following beneficial effects:

[0056] The present invention first uses a laser with a first specified spot coverage and a first specified energy density (i.e., high spot coverage and high energy density) to remove most of the rust layer, and then uses the best process parameter combination obtained by a single factor experiment to remove most of the remaining oxide layer. Finally, a second specified spot coverage and a second specified energy density (i.e., low spot coverage and low energy density) are used to perform a final polishing rust removal strategy on the surface of the ground wire. This strategy can not only obtain a more detailed surface morphology, but also improve the efficiency of removing the oxide layer, thereby solving the problems of time-consuming, labor-intensive and incomplete cleaning caused by traditional cleaning methods such as steel brushes, sandpaper and gasoline, and reducing the probability of ground wire breakage.

[0057] It is worth noting that in the above-mentioned device embodiment, the various device modules included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be realized; in addition, the specific names of the various functional modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0058] A person skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, such as ROM / RAM, disk, CD-ROM, etc.

[0059] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for removing an oxide layer on the surface of a ground wire, characterized in that: The method comprises the following steps: Determine the ground wire of the laser and its corresponding surface oxide layer to be removed; The laser is driven to emit pulsed laser with a first specified spot coverage and a first specified energy density to remove the surface oxide layer of the ground wire, until the proportion of the area of ​​the ground wire where the surface oxide layer has not been removed is less than or equal to a preset first percentage; If it is detected that the proportion of the area where the surface oxide layer has not been removed is less than or equal to the first percentage value, the laser is driven to emit continuous laser using a predetermined process parameter combination to remove the surface oxide layer from the ground wire until the proportion of the area where the surface oxide layer has not been removed is less than or equal to a preset second percentage; If it is detected that the proportion of the area where the surface oxide layer has not been removed is less than or equal to the second percentage constant, the laser is driven to emit pulsed laser using a second specified spot coverage and a second specified energy density to remove the surface oxide layer of the ground wire until the proportion of the area where the surface oxide layer has not been removed is less than or equal to a preset third percentage; Among them, the second percentage is smaller than the first percentage and larger than the third percentage; the second specified light spot coverage is smaller than the first specified light spot coverage; and the second specified energy density is smaller than the first specified energy density.

2. The method for removing the oxide layer on the surface of the ground wire according to claim 1, characterized in that: The process parameter combination includes a laser power of 75W / cm 2 , the pulse repetition frequency is 0.4 MHz, the spot overlap rate and the scanning track overlap rate are both 35%, and the number of cycle scans is 15 times.

3. The method for removing the oxide layer on the surface of the ground wire according to claim 1, characterized in that: The first percentage is 10%; the second percentage is 5%; and the third percentage is 1%.

4. The method for removing the oxide layer on the surface of the ground wire according to claim 1, characterized in that: The first specified spot coverage is that the spot diameter is between 6 mm and 7 mm, and the first specified energy density is 1.1 J / cm 2 The second specified spot coverage is that the spot diameter is between 5mm-6mm, and the first specified energy density is 0.8J / cm 2 .

5. A controller, characterized in that: include: A target object determination unit, used to determine the laser and its corresponding ground wire of the surface oxide layer to be removed; A high-density mode oxide layer removal unit, used to drive the laser to emit pulsed laser using a first specified spot coverage and a first specified energy density to remove the surface oxide layer of the ground wire, until the proportion of the area on the ground wire where the surface oxide layer has not been removed is less than or equal to a preset first percentage; The medium-density mode oxide layer removal unit is used to drive the laser to emit continuous laser with a predetermined process parameter combination to remove the surface oxide layer of the ground wire if it is detected that the proportion of the area where the surface oxide layer is not removed is less than or equal to the first percentage constant value, until the proportion of the area where the surface oxide layer is not removed is less than or equal to the preset second percentage; A low-density mode oxide layer removal unit is used to drive the laser to emit pulsed laser with a second specified spot coverage and a second specified energy density to remove the surface oxide layer of the ground wire if it is detected that the proportion of the area where the surface oxide layer has not been removed is less than or equal to the second percentage constant, so as to remove the surface oxide layer of the ground wire until the proportion of the area where the surface oxide layer has not been removed is less than or equal to a preset third percentage; Among them, the second percentage is smaller than the first percentage and larger than the third percentage; the second specified light spot coverage is smaller than the first specified light spot coverage; and the second specified energy density is smaller than the first specified energy density.

6. The controller according to claim 5, characterized in that The process parameter combination includes a laser power of 75W / cm 2 , the pulse repetition frequency is 0.4 MHz, the spot overlap rate and the scanning track overlap rate are both 35%, and the number of cycle scans is 15 times.

7. The controller according to claim 5, characterized in that The first percentage is 10%; the second percentage is 5%; and the third percentage is 1%.

8. The controller according to claim 5, characterized in that The first specified spot coverage is that the spot diameter is between 6 mm and 7 mm, and the first specified energy density is 1.1 J / cm 2 The second specified spot coverage is that the spot diameter is between 5mm-6mm, and the first specified energy density is 0.8J / cm 2 .

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