Annular light spot center feeding laser head

Abstract

The utility model relates to laser cladding technical field, a kind of annular light spot center feeding laser head including hollow base body, the top of base body is equipped with optical fiber joint, bottom is equipped with light outlet, mirror group is equipped in base body, mirror group includes prism, focusing mirror, prism is used to form annular light beam, feeding channel is equipped in base body, base body outside is equipped with feeding port, feeding channel includes inclined section and vertical section, inclined section is located in the upside of vertical section, inclined section is connected with the feeding port, vertical section is set up corresponding the light outlet, the upside of the inclined section is equipped with reflector, the cavity wall of base body is equipped with beam combiner, one side of beam combiner is reflective surface, for receiving the light reflected by reflector and downward reflection, the other side is perspective surface, for the light beam from the prism to pass downward. Through the cooperation of the use of the reflector and beam combiner of design, the light beam above feeding channel inclined section can be reflected to beam combiner by reflector, after second reflection, it can be mixed with other light beams downward, can be utilized, improve the energy utilization rate of laser, also meet the requirement that laser beam avoids feeding channel.

Description

Technical Field

[0001] This utility model relates to the field of laser cladding technology, specifically to a circular spot center-feeding laser head. Background Technology

[0002] Laser cladding, also known as laser bonding or laser coating, is a novel surface modification technology. It involves adding a cladding material to the surface of a substrate and then using a high-energy-density laser beam to melt and solidify it together with a thin layer on the substrate surface, forming a metallurgically bonded filler cladding layer. There are two types of cladding processes: pre-placed laser cladding and synchronous laser cladding. In pre-placed laser cladding, the cladding material is placed beforehand at the cladding area on the substrate surface, and then melted by laser beam irradiation. The cladding material is added in powder or filament form. In synchronous laser cladding, powdered or filamentous cladding material is simultaneously fed into the molten pool through a nozzle during the cladding process.

[0003] Traditionally, a side-axis feeding method is used, where the filament feed direction is not coaxial with the laser beam axis, resulting in uneven laser energy distribution. Patent application CN119194441A discloses an extended focal-area laser beam hot filament deposition device. One embodiment employs a lens group including a beam-splitting conical lens, a collimating lens, and a beam-combining conical lens. The beam-splitting conical lens expands the incident laser beam, the collimating lens collimates the laser beam expanded by the beam-splitting conical lens, and the beam-combining conical lens combines the collimated laser beam emitted from the collimating lens to obtain an extended focal-area laser beam. Although the end of the filament is coaxial with the extended focal-area laser beam, there are always points where the filament or powder feeding pipe intersects with the laser, requiring treatment to prevent the laser from melting the pipe. For example, patent CN101148760B discloses a laser processing forming manufacturing process with internal powder feeding and an internal powder feeding nozzle. This process involves coating the upper light-facing surface of the powder feeding pipe with a light-absorbing material to increase the light absorption rate and creating internal cooling channels for cooling. This approach leads to a waste of laser energy and also complicates the structure by adding cooling channels. Utility Model Content

[0004] The purpose of this invention is to provide a circular spot center-feeding laser head to solve the problem of laser beam affecting the arrangement of the feeding pipeline.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A ring-shaped laser head with a central feeder includes a hollow substrate. The top of the substrate has an optical fiber connector, and the bottom has a light outlet. A mirror assembly, including a prism and a focusing lens, is located within the substrate. The prism forms a ring-shaped beam. A feed channel is located within the substrate, and a feed port is located on the outer side of the substrate. The feed channel includes an inclined section and a vertical section. The inclined section is located above the vertical section and is connected to the feed port. The vertical section is positioned corresponding to the light outlet. A reflecting mirror is located above the inclined section. A beam combiner is located on the inner wall of the substrate. One side of the beam combiner is a reflecting surface, used to receive light reflected by the reflecting mirror and reflect it downwards; the other side is a viewing surface, allowing the beam from the prism to pass downwards.

[0007] Furthermore, the lens assembly also includes a collimating lens and a conical lens. The collimating lens is located above the conical lens, and the conical lens is located above the prism. The conical lens is used to split the collimated beam. The focusing lens is located below the prism and is used to focus the beam and form a ring-shaped light spot.

[0008] Furthermore, at least one protective lens is provided below the focusing lens.

[0009] Furthermore, the vertical section passes through the focusing lens and the protective lens, and a nozzle is detachably connected to the lower end of the vertical section.

[0010] Furthermore, the substrate includes a multi-section cylindrical structure, one of which has a connecting block with a connecting hole, the upper part of the vertical section is inserted into the connecting hole, and the other cylindrical structure has an inclined section with an inclined feeding through hole, one end of which is connected to the material hole in the vertical section and the other end is connected to the feed port.

[0011] Furthermore, the reflector and the beam combiner are arranged in parallel.

[0012] Furthermore, the substrate is provided with water channels for cooling water to flow through.

[0013] The beneficial effects of this utility model are:

[0014] To prevent the feed tube from being directly irradiated by a laser, this invention incorporates a reflector and a beam combiner in the laser head. The reflector is tilted to reflect the beam from the upper side of the tilted section of the feed channel, thus blocking the tilted section. The beam reflected by the reflector goes to the lower side of the beam combiner and is reflected downwards again. The upper side of the beam combiner allows the laser beam above to pass through and mix with the reflected beam before being projected downwards. Compared to the existing technology that uses light-absorbing materials to absorb part of the beam to block the feed tube, this embodiment can fully utilize the beam energy. Attached Figure Description

[0015] Figure 1This is an external view of the circular spot center feeding laser head of this utility model;

[0016] Figure 2 This is a partial cross-sectional view of the circular spot center feeding laser head of this utility model;

[0017] Figure 3 This is a schematic diagram of the optical path principle;

[0018] Figure 4 This is a schematic diagram illustrating the principle of using a reflector and a beam combiner together.

[0019] 1. Fiber optic connector; 2. Light outlet; 3. Substrate; 31. Second cylinder; 311. Inclined section; 312. Feeding through hole; 32. First cylinder; 33. Conical cylinder; 41. Feed port; 42. Vertical section; 421. Feed hole; 43. Nozzle; 51. Reflector; 52. Beam combiner; 53. Collimating lens; 54. Conical lens; 55. Prism; 56. Second protective lens; 57. Focusing lens; 58. First protective lens; 6. Laser. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art are within the protection scope of the present utility model.

[0021] Embodiments of this utility model:

[0022] like Figures 1-4 As shown, the annular spot central feeding laser head includes a hollow substrate 3. The top of the substrate 3 has an optical fiber connector 1, and the bottom has a light outlet 2. The substrate 3 contains a lens assembly, including various lenses. The optical fiber connector 1 at the top connects to an optical fiber. The laser 6 is emitted from top to bottom, forming a focused annular spot from the light outlet 2. The principle of the annular spot is similar to existing technologies. A feeding channel is provided inside the substrate 3. Powder or filament is fed into the spot on the workpiece surface through the feeding channel. The focused laser beam 6 melts the powder or filament, completing the cladding of the material. The cladding principle is existing technology and will not be elaborated further.

[0023] The lens assembly includes a collimating lens 53, a conical lens 54, a prism 55, and a focusing lens 57, all coaxially arranged vertically. The laser beam emitted by the laser emitter is a diffused laser beam, which is transformed into a collimated laser beam after being adjusted by the collimating lens 53. The collimating lens 53 is located above the conical lens 54, which is located above the prism 55. The conical lens 54, or conical lens, is used to split the collimated beam, preparing for the next step of forming a ring beam, corresponding to the conical lens in the patent cited in the background art.

[0024] The light beam passing through prism 55 is collimated and forms a ring beam. Focusing lens 57 is located below prism 55 and is used to focus the light beam and form a ring spot.

[0025] The substrate 3 has a feeding channel inside and a feeding port 41 on the outside of the substrate 3. The feeding channel includes an inclined section 311 and a vertical section 42. The inclined section 311 is located above the vertical section 42. The inclined section 311 is connected to the feeding port 41. The vertical section 42 is set corresponding to the light outlet 2 and is located in the dark area.

[0026] The base 3 comprises multiple cylindrical structures, assembled sequentially in the vertical direction using bolts. The separate sections facilitate the installation of lenses at various locations, and cooling water channels are machined within the cylindrical structures. The lowermost part of the base 3 is a conical cylinder 33, which has a conical cavity and a bottom opening forming a light outlet 2. The vertical section 42 of the feeding channel is located at the center of the conical cylinder 33. One of the cylindrical structures, referred to as the first cylinder 32, contains a connecting block. The connecting block has a connecting hole into which the upper part of the vertical section 42 is inserted and connected by a pressure ring and screws. The pressure ring is fixed to the lower side of the connecting block by screws and is used to press the upper part of the vertical section 42. Another cylindrical structure is referred to as the second cylinder 31 body, which has the aforementioned inclined section 311 inside. The inclined section 311 has an inclined feeding through hole 312 inside. One end of the feeding through hole 312 is connected to the material hole 421 in the vertical section 42, and the other end is connected to the feeding port 41.

[0027] The upper side of the inclined section 311 is an inclined plane, on which a reflector 51 is mounted by screws. The reflector 51 is inclined. A beam combiner 52 is provided on the inner wall of the substrate 3. One side of the beam combiner 52 is a reflecting surface, used to receive the light reflected by the reflector 51 and reflect it downwards; the other side is a viewing surface, allowing the light beam from the prism 55 to pass downwards. The reflector 51 and the beam combiner 52 are arranged parallel to each other. A schematic diagram of the working principle of the reflector 51 and the beam combiner 52 on the light beam is shown below. Figure 4 As shown: Both the reflector 51 and the beam combiner 52 are rectangular. The reflector 51 is used to reflect the light beam on the upper side of the inclined section 311 to block the lower side of the inclined section 311. The light beam reflected by the reflector 51 goes to the lower side of the beam combiner 52 and is reflected vertically downward again, mixing with the light beam passing through the beam combiner 52 from above. Compared with the existing technology of absorbing part of the light beam to block the tube, the method of this embodiment can make full use of the light beam energy.

[0028] Due to the obstruction of the reflector 51, the light spot ultimately formed by the focusing lens 57 on the side of the workpiece is an annular light spot with a small notch.

[0029] At least one protective lens is provided below the focusing lens 57. In this embodiment, two protective lenses are provided below the focusing lens 57, referred to as the first protective lens 58. The first protective lens 58 is a high-transmittance lens, mainly serving a protective function to prevent welding slag or unmelted powder generated during the cladding process from entering the space above the first protective lens 58, thus protecting other lenses, such as the focusing lens 57. Because the first protective lens 58 is low in cost, it can be replaced if it breaks after a period of use, resulting in low maintenance costs. A protective lens is provided above the focusing lens 57, referred to as the second protective lens 56.

[0030] The vertical section 42 is a tubular structure that passes through the central hole of the focusing lens 57 and the protective lens. The lower end of the vertical section 42 is detachably connected to a nozzle 43. The nozzle 43 has a through hole that runs vertically through the vertical section 42 and communicates with the inner hole of the vertical section 42. It can be slightly smaller than the inner hole diameter of the vertical section 42. The nozzle 43 is replaceable, and nozzles with different inner diameters can also be replaced according to actual needs.

[0031] The substrate 3 is equipped with water channels for cooling water to flow through. Specifically, water flow holes, including horizontal and vertical holes, are pre-machined in the corresponding cylindrical structures. The horizontal holes are arranged around the central hole of the substrate 3, and the vertical holes are used to connect adjacent cylindrical structures. The vertical holes and the horizontal holes are connected at one point to form the water channels. Inlet and outlet water pipe connectors are connected to the outside of the substrate 3, connecting to the water channels to achieve cooling water circulation. During operation, this cools the substrate 3 portion of the laser head. The cooling water channels are not the core feature of this embodiment; the core lies in the aforementioned beam lens layout and beam processing.

Claims

1. A ring-shaped laser head with a central feed, comprising a hollow substrate, an optical fiber connector at the top of the substrate, a light outlet at the bottom, a mirror assembly within the substrate including a prism and a focusing lens, the prism being used to form a ring-shaped beam, a feed channel within the substrate, and a feed port on the outer side of the substrate, the feed channel including an inclined section and a vertical section, the inclined section being located above the vertical section and connected to the feed port, the vertical section being positioned corresponding to the light outlet, characterized in that: A reflector is provided on the upper side of the inclined section, and a beam combiner is provided on the inner wall of the substrate. One side of the beam combiner is a reflective surface, which is used to receive the light reflected by the reflector and reflect it downwards, and the other side is a transparent surface, which allows the light beam coming out of the prism to pass downwards.

2. The annular spot center-feeding laser head according to claim 1, characterized in that: The lens assembly also includes a collimating lens and a conical lens. The collimating lens is located above the conical lens, and the conical lens is located above the prism. The conical lens is used to split the collimated beam. The focusing lens is located below the prism and is used to focus the beam and form a ring-shaped spot.

3. The annular spot center-feeding laser head according to claim 2, characterized in that: At least one protective lens is provided below the focusing lens.

4. The annular spot center-feeding laser head according to claim 3, characterized in that: The vertical section passes through the focusing lens and the protective lens, and a nozzle is detachably connected to the lower end of the vertical section.

5. The annular spot center-feeding laser head according to claim 2, characterized in that: The base includes multiple cylindrical structures. One cylindrical structure has a connecting block with a connecting hole. The upper part of the vertical section is inserted into the connecting hole. Another cylindrical structure has an inclined section with an inclined feeding through hole. One end of the feeding through hole is connected to the material hole in the vertical section, and the other end is connected to the feed port.

6. The annular spot center-feeding laser head according to claim 1, characterized in that: The reflector and the beam combiner are arranged in parallel.

7. The annular spot center-feeding laser head according to claim 1, characterized in that: The substrate is provided with water channels for cooling water to flow through.

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