Laser and electrochemical composite processing system and method for deep hole internal annular recess structure

Abstract

This invention discloses a laser-electrochemical composite machining system and method for creating annular recessed structures inside deep holes, belonging to the field of composite machining in special processing technology. It combines electrochemical jet machining technology with laser beam defocusing technology to process various types of recessed structures inside deep holes. Specifically, an electrochemical reaction system is constructed using an electrolyte flow, a tool cathode, and a workpiece. By controlling the feed motion of the tool cathode, the machining of annular recessed structures of different shapes can be achieved. Simultaneously, laser beam defocusing is achieved through optical elements and a glass tube coated with a total internal reflection coating, removing the oxide layer that hinders electrochemical machining. This invention, by cleverly combining and separately controlling electrochemical and laser machining, can achieve efficient and high-quality machining of various complex recessed structures inside deep holes.

Description

Technical Field

[0001] This invention relates to the field of composite processing in special processing technology, and in particular to a laser and electrochemical composite processing system and method for a deep hole internal annular recess structure. Background Technology

[0002] In the aerospace field, to improve the cooling efficiency of engine blades, researchers have designed special deep-hole structures such as recessed bamboo-shaped holes. Machining these special deep-hole structures has become a challenge in traditional machining methods, which has spurred the development of special irregular-shaped hole machining technology. The materials used in the aerospace field are mostly difficult to machine. For the special recessed structures in these difficult-to-machine materials, traditional machining techniques struggle to achieve efficient and high-quality machining. Laser machining and electrochemical machining, as specialized machining technologies widely used in the aerospace field, each have unique advantages in machining deep holes. However, both of these methods have shortcomings when machining the special recessed structures of deep, small holes. Laser machining offers high efficiency and precision, but the recessed structure makes it difficult for the laser beam to reach the machined area, and the machined surface often has a heat-affected zone and a recast layer, resulting in poor surface quality. While electrochemical machining is more adaptable and avoids machining heat defects, it generates an oxide layer during the process, which hinders the further electrochemical reaction, thus severely reducing the efficiency of electrochemical machining. How to effectively overcome the problems of poor accessibility of traditional cutting, poor quality of laser processing, and low efficiency of electrochemical processing, and achieve efficient and high-quality processing of irregular structures in deep hole structures is an important issue in the processing of advanced aerospace parts. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a laser and electrochemical composite machining system and method for deep hole internal annular recessed structures. By employing laser and metal tube jet electrolytic machining tools, it achieves efficient and high-quality machining of various special internal recessed structures in deep holes.

[0004] The present invention achieves the above-mentioned technical objectives through the following technical means.

[0005] A laser-metal tube jet electrolytic machining tool includes a tool cathode and a glass tube; the glass tube has a hollow structure, and the tool cathode has a double-layer hollow structure, with the inner wall of the tool cathode fitted onto the outer wall of the glass tube; a defocused laser is conducted by total internal reflection through the inner wall of the glass tube and then irradiates the surface to be machined parallel to the glass tube; an electrolyte flows between the inner and outer walls of the tool cathode, and the electrolyte flows through a small hole at the bottom of the tool cathode and is ejected onto the surface to be machined parallel to the tool cathode.

[0006] In the above scheme, the inner and outer sidewalls of one end of the tool cathode form a conical structure; the tool cathode is made of stainless steel, and the sidewall of the tool cathode is coated with an insulating layer.

[0007] In the above scheme, one end of the glass tube has a tapered structure; the sidewall of the glass tube is coated with a total reflection coating.

[0008] Laser and metal tube jet electrolytic machining tools are used for machining the internal recessed structures of deep holes.

[0009] A laser-electrochemical composite machining system for a deep hole with an internal annular recess structure includes a laser-metal tube jet electrolytic machining tool, a laser machining system, an electrochemical machining system, and a movement control system. The laser machining system emits a laser beam and defocuses it before entering the laser-metal tube jet electrolytic machining tool. The electrochemical machining system provides electrolyte to the laser-metal tube jet electrolytic machining tool and discharges the electrolyte from the bottom of the deep hole. The movement control system drives the movement of the cathode clamp, which holds the laser-metal tube jet electrolytic machining tool.

[0010] In the above scheme, the laser processing system includes a laser, an optical fiber, a laser head, and optical elements; the laser is connected to the laser head via an optical fiber, and an optical element is disposed below the laser head; by adjusting the optical element, the focal position of the laser beam is changed, so that the laser beam defocuses before entering the laser-metal tube jet electrolytic processing tool.

[0011] In the above scheme, the electrochemical machining system includes a rubber hose, a storage tank, a fine filter, a coarse filter, a supply pump, and a suction pump. One end of the rubber hose extends to the bottom of the deep hole in the workpiece, and the other end is connected to the suction pump through a pipe. The suction pump transports the extracted electrolyte through the pipe to the fine filter for filtration and then back to the storage tank. The electrolyte in the storage tank is filtered through the coarse filter via a pipeline and then pumped into the laser and metal tube jet electrochemical machining tool by the supply pump. The electrolyte pumping rate is adjusted by a regulating valve.

[0012] In the above scheme, the motion control system includes a computer, a cathode fixture, an XY-axis worktable, and a Z-axis worktable; the cathode fixture is mounted on the Z-axis worktable, and a workpiece is placed on the XY-axis worktable; the computer is used to control the operation of the XY-axis worktable and the Z-axis worktable; the cathode fixture integrates optical elements, a laser head, and an electrolyte flow channel.

[0013] The processing method of the laser-electrochemical hybrid machining system for the annular recessed structure inside deep holes includes machining the inner surface of large-diameter deep holes and machining the inner surface of small-diameter deep holes. Specifically,

[0014] When machining the inner surface of a large-diameter deep hole, the laser-metal jet electrochemical machining tool is tilted to one side of the workpiece. On the side closer to the tool cathode, electrochemical machining proceeds normally. However, on the side farther from the tool cathode, the electrolyte flow, after being ejected a certain distance from the cathode, reaches the workpiece surface in droplet form. The continuous electrolyte flow transforms into droplets, preventing the formation of an electrochemical pathway, and thus electrochemical machining stops. After machining on one side, the laser-metal jet electrochemical machining tool can be tilted to the other side of the workpiece, thereby achieving the machining of the inner surface of a large-diameter deep hole.

[0015] When machining the inner surface of a small-diameter deep hole, the laser and the metal tube jet electrolytic machining tool are positioned in the center to achieve machining of the inner surface of the deep hole.

[0016] In the above scheme, the diameter of the tool cathode is slightly smaller than that of the small-diameter deep hole, and the diameter of the tool cathode is much smaller than that of the large-diameter deep hole. The electrolyte flow velocity is 20-30 m / s, and the laser power is 10-20 W, which is a nanosecond laser.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. This invention employs a combination of electrochemical and laser beam defocusing to process deep micro-hole recessed structures. The laser beam defocusing process removes the oxide layer that hinders electrochemical processing, while the electrochemical processing technology is used to process various recessed structures. At the same time, the heat and products generated by the laser processing are removed by the subsequent low-temperature electrolyte flow.

[0019] 2. Due to the characteristics of the laser beam, the energy density is low at locations far from the laser focal point, which will not cause additional damage to the already processed area of ​​the workpiece, thus facilitating high-quality processing of deep small hole recessed structures.

[0020] 3. By controlling the laser processing parameters, the feed rate of the tool electrode, and the electrochemical processing parameters, structures with different concave contours can be obtained, thus improving the processing flexibility of deep small hole concave structures.

[0021] 4. In this invention, the electrolyte retained inside the deep hole during processing can be quickly recovered and discharged by a pump, avoiding excessive electrolyte residue in the hole that would affect the processing of the hole structure. The recovered electrolyte can be recycled through a circulating filtration system.

[0022] 5. In this invention, an electrochemical reaction system is formed by an electrolyte flow, a tool cathode, and a workpiece. By controlling the feed motion of the tool cathode, the processing of annular concave structures of different shapes can be achieved. At the same time, laser beam defocusing processing is achieved through optical elements and a glass tube coated with a total reflection coating to remove the oxide layer that hinders electrochemical processing.

[0023] 6. This invention, by cleverly combining and separately controlling electrochemical processing and laser processing, can achieve efficient and high-quality processing of various complex internal concave structures in deep holes. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the laser and electrochemical composite processing device for the annular recessed structure inside the deep hole involved in the present invention.

[0025] Figure 2 A schematic diagram illustrating the machining principle of a small-diameter deep hole recessed structure;

[0026] Figure 3 A schematic diagram illustrating the machining principle of a large-diameter deep concave structure;

[0027] Figure 4 Schematic diagrams showing different styles of deep concave hole structures.

[0028] Figure label:

[0029] 1-Fiber optic cable; 2-Laser head; 3-Cathode clamp; 4-Optical element; 5-Laser beam; 6-Electrolyte flow channel; 7-Tool cathode; 8-Glass tube; 9-Rubber hose; 10-Adjustable power supply; 11-XY axis stage; 12-Base; 13-Reservoir tank; 14-Pipeline; 15-Fine filter; 16-Coarse filter; 17-Supply pump; 18-First motor; 19-Computer; 20-Regulating valve; 21-Column; 22-Z axis stage; 23-Laser; 24-Second motor; 25-Liquid pump; 26-Workpiece; 27-Electrolyte flow; 28-Electrochemical products; 29-Ablation products; 30-Total reflection coating; 31-Insulation layer. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0033] The laser-electrochemical composite machining device for deep hole internal annular recessed structures comprises a tool cathode 7, an electrolyte flow 27, and a workpiece 26 forming an electrochemical reaction system. The movement of the cathode fixture 3 is adjusted by a computer 19, thereby controlling the feed rate of the tool cathode 7 to achieve machining of different internal recessed structures. Adjusting the optical element 4 changes the focal position of the laser beam 5, thus controlling the laser beam defocusing process. This facilitates the realization of electrochemical and laser beam defocusing composite machining, improving machining flexibility and enabling high-quality machining of various internal recessed structures within deep holes.

[0034] The tool cathode 7 is a hollow structure made of stainless steel, with an outer surface coated with an insulating layer 31, which is an epoxy resin insulating layer. Epoxy resin has advantages such as strong adhesion and good chemical stability, thus improving the stability of the processing. The glass tube 8 is coated with a total reflection coating 30, enabling total reflection of the laser beam 5 within the glass tube 8. This facilitates the combination of electrochemical processing and laser beam defocusing, thereby ensuring processing accuracy. The cathode fixture 3 is mounted on the Z-axis worktable 22, controlling the movement of the tool cathode 7 in the Z direction and ensuring the accuracy of its feed motion. The workpiece 26 is mounted on the XY-axis worktable 11. By controlling the movement of the XY-axis worktable 11, the movement of the workpiece 26 in the XY direction can be controlled, improving the adaptability of the processing system. The tool cathode 7 is connected to the negative terminal of the adjustable power supply 10, and the workpiece 26 is connected to the positive terminal of the adjustable power supply 10.

[0035] The electrochemical machining system enables the supply and recovery of electrolyte. A rubber hose 9 and a pump 25 are connected. The remaining electrolyte after machining is recovered into a storage tank 13 via a coarse filter 16. The coarse filter 16 also performs preliminary filtration of the ablation products 29, ensuring minimal impurities enter the storage tank 13. The supply pump 17 supplies the electrolyte from the storage tank 13 to the tool cathode 7, forming an electrolyte flow 27. During this process, a fine filter 15 further filters the electrolyte, ensuring the electrolyte flow 27 is free of impurities, thus guaranteeing the stability and quality of the machining process. The flow rate and pressure of the electrolyte flow 27 are regulated by a computer 19 via a control valve 20, ensuring the machining system can meet the machining requirements of different deep small hole recesses, improving machining flexibility and guaranteeing machining quality.

[0036] When machining a single-sided concave structure in a deep hole with a large diameter, the tool cathode 7 is biased towards one side of the workpiece 26. Electrochemical machining can proceed normally on the side closer to the tool cathode 7. However, on the side farther from the tool cathode 7, the electrolyte flow 27, after being ejected a certain distance from the tool cathode 7, reaches the surface of the workpiece 26 in the form of droplets. The continuous electrolyte flow 27 transforms into droplets, preventing the formation of an electrochemical pathway and halting the electrochemical machining. Therefore, a single-sided concave structure in a deep hole can be machined. After machining one side, the tool cathode 7 can be biased towards the other side of the workpiece 26, thus achieving the machining of the inner surface of a large-diameter deep hole. Specifically, the diameter of the tool cathode 7 is slightly smaller than that of a small-diameter deep hole, and much smaller than that of a large-diameter deep hole; the flow velocity of the electrolyte flow 27 is 20-30 m / s; and the laser power is 10-20 W, which is a nanosecond laser.

[0037] Combined with appendix Figure 1As shown, the computer 19 adjusts the Z-axis stage 22 and the XY-axis stage 11, thereby controlling the positions of the tool cathode 7 and the workpiece 26 to reach the initial machining position. The electrochemical machining system supplies electrolyte; once the electrolyte flow 27 stabilizes, the adjustable power supply 10 and the laser 23 are connected for electrochemical and laser beam defocusing composite machining. During machining, the feed motion of the tool cathode 7, the pressure and flow rate adjustment of the electrolyte flow 27, the adjustment of the optical element 4, the adjustment of the laser 23 output parameters, and the output voltage of the adjustable power supply 10 are all precisely controlled by the computer 19 without manual intervention, ensuring machining accuracy and quality. The optical element 4 is a focusing lens.

[0038] The tool cathode 7 has a double-layer hollow structure, and the inner and outer walls of one end of the tool cathode 7 form a conical structure. An arc-shaped baffle is provided at the conical structure to prevent the electrolyte from flowing directly down between the inner and outer walls. Several small holes are opened at the connection between the arc-shaped baffle and the outer wall, thereby changing the flow direction of the electrolyte so that the electrolyte flows out through the small holes onto the surface to be processed.

[0039] One end of the glass tube 8 is tapered, making the glass tube 8 arrow-shaped from top to bottom. The defocused laser undergoes total internal reflection within the glass tube 8, and its direction of propagation is changed again by the tapered structure of the glass tube 8, so that the defocused laser radiates onto the surface to be processed. The purpose of setting one end of the glass tube 8 to be tapered is to change the direction of propagation of the defocused laser.

[0040] In this embodiment of the invention, the tool cathode 7 and the glass tube 8 have a conical structure at the same end.

[0041] The electrochemical machining system includes a rubber hose 9, a storage tank 13, a fine filter 15, a coarse filter 16, a supply pump 17, and a suction pump 25. One end of the rubber hose 9 extends to the bottom of the deep hole, and the other end is connected to the suction pump 25 via a pipe. The suction pump 25 pumps the extracted electrolyte through the pipe to the fine filter 15 for filtration, and then returns it to the storage tank 13. The electrolyte in the storage tank 13 is filtered through the coarse filter 16 via the pipe 14 and then pumped into the tool cathode 7 by the supply pump 17 through the electrolyte flow channel 6. The electrolyte pumping rate is adjusted by the regulating valve 20. The supply pump 17 and the suction pump 25 are driven by a first motor 18 and a second motor 24.

[0042] Combined with attachment Figure 2 As shown, Figure 2 This illustrates the processing principle of small-diameter deep-hole recessed structures. The laser beam 5 is conducted through the total reflection coating 30 inside the glass tube 8 by total reflection. The laser beam defocusing process can quickly remove the oxide layer that hinders the electrochemical reaction, improving the quality of subsequent electrochemical processing. Electrochemical jet processing can efficiently electrochemically dissolve the laser-treated surface, and different recessed structures can be obtained under the control of various processing parameters. Figure 3 The diagram illustrates the machining principle of a single-sided concave structure for a large-diameter deep hole. When machining a single-sided concave structure in a large-diameter deep hole, the tool cathode 7 is biased towards one side of the workpiece 26. The side closer to the tool cathode 7 has an electrochemical pathway, allowing electrochemical machining to proceed normally. However, on the side farther from the tool cathode 7, the electrolyte flow 27, after being ejected a certain distance from the tool cathode 7, reaches the surface of the workpiece 26 in the form of droplets. At this point, the continuous electrolyte flow 27 transforms into dispersed droplets, preventing the formation of an electrochemical pathway and halting the electrochemical machining. On the inner surface of the workpiece 26 within the tool cathode 7, the laser defocusing is large, and the energy is very low, failing to cause damage to the surface of the workpiece 26.

[0043] Combined with appendix Figure 4 As shown, the internal concave structures of deep micro-holes are diverse, and traditional processing methods are insufficient to meet their processing requirements. By using a computer 19 to control the feed motion of the tool cathode 7 and adjusting the output voltage of the adjustable power supply 10 to control the electrochemical reaction rate, different internal concave structures can be obtained.

[0044] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0045] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A laser and metal tube jet electrolytic machining tool, characterized in that, It includes a tool cathode (7) and a glass tube (8); the glass tube (8) is hollow, the tool cathode (7) is double-layered hollow, and the inner wall of the tool cathode (7) is fitted onto the outer wall of the glass tube (8); the defocused laser is conducted by total internal reflection through the inner wall of the glass tube (8) and then irradiates the surface to be processed that is parallel to the glass tube (8); an electrolyte flows between the inner wall and the outer wall of the tool cathode (7), and the electrolyte flow (27) is sprayed out through the small hole at the bottom of the tool cathode (7) onto the surface to be processed that is parallel to the tool cathode (7).

2. The laser and metal tube jet electrolytic machining tool according to claim 1, characterized in that, The inner and outer walls of one end of the tool cathode (7) form a conical structure; the tool cathode (7) is made of stainless steel and the sidewall of the tool cathode (7) is coated with an insulating layer (31).

3. The laser and metal tube jet electrolytic machining tool according to claim 1, characterized in that, One end of the glass tube (8) is tapered; the sidewall of the glass tube (8) is coated with a total reflection coating.

4. The laser and metal tube jet electrolytic machining tool according to any one of claims 1 to 3, characterized in that, Used for machining recessed structures inside deep holes.

5. A laser-electrochemical composite machining system for deep hole internal annular recessed structures, characterized in that, The invention includes the laser and metal tube jet electrolytic machining tool, laser processing system, electrochemical processing system and motion control system as described in any one of claims 1-3; the laser processing system is used to emit a laser beam (5) and defocus the laser beam (5) before it enters the laser and metal tube jet electrolytic machining tool; the electrochemical processing system is used to provide electrolyte to the laser and metal tube jet electrolytic machining tool and discharge the electrolyte at the bottom of the deep hole; the motion control system is used to drive the cathode clamp (3) to move; the cathode clamp (3) holds the laser and metal tube jet electrolytic machining tool.

6. The laser and electrochemical composite processing system for deep hole internal annular recessed structures according to claim 5, characterized in that, The laser processing system includes a laser (23), an optical fiber (1), a laser head (2), and an optical element (4); the laser (23) is connected to the laser head (2) via the optical fiber (1), and the optical element (4) is located below the laser head (2); by adjusting the optical element (4), the focal position of the laser beam (5) is changed, so that the laser beam (5) defocuses before entering the laser and metal tube jet electrolytic processing tool.

7. The laser and electrochemical composite processing system for the annular recessed structure inside a deep hole according to claim 5, characterized in that, The electrochemical machining system includes a rubber hose (9), a storage tank (13), a fine filter (15), a coarse filter (16), a supply pump (17), and a suction pump (25). One end of the rubber hose (9) extends to the bottom of the deep hole of the workpiece, and the other end is connected to the suction pump (25) through a pipe. The suction pump (25) transports the extracted electrolyte through the pipe to the fine filter (15) for filtration and then back to the storage tank (13). The electrolyte in the storage tank (13) is filtered through the coarse filter (16) via the pipe (14) and then pumped into the laser and metal tube jet electrochemical machining tool by the supply pump (17). The electrolyte pumping rate is adjusted by the regulating valve (20).

8. The laser and electrochemical composite processing system for deep hole internal annular recessed structures according to claim 5, characterized in that, The motion control system includes a computer (19), a cathode fixture (3), an XY-axis worktable (11), and a Z-axis worktable (22); the cathode fixture (3) is mounted on the Z-axis worktable (22), and a workpiece (26) is placed on the XY-axis worktable (11); the computer (19) is used to control the operation of the XY-axis worktable (11) and the Z-axis worktable (22); the cathode fixture (3) integrates an optical element (4), a laser head (2), and an electrolyte flow channel (6).

9. The processing method of the laser and electrochemical composite processing system for the annular recessed structure inside a deep hole according to claim 5, characterized in that, This includes machining the inner surface of large-diameter deep holes and machining the inner surface of small-diameter deep holes. Specifically, when machining the inner surface of large-diameter deep holes, the laser and metal tube jet electrolytic machining tool is biased towards one side of the workpiece (26). At this time, the electrochemical machining can proceed normally on the side closer to the tool cathode (7). On the side farther from the tool cathode (7), the electrolyte flow (27) will reach the surface of the workpiece (26) in the form of droplets after being sprayed a certain distance from the tool cathode (7). The continuous electrolyte flow (27) is converted into droplets, the electrochemical path cannot be formed, and the electrochemical machining stops. After machining on one side, the laser and metal tube jet electrolytic machining tool is biased towards the other side of the workpiece (26) to achieve machining of the inner surface of large-diameter deep holes. When machining the inner surface of small-diameter deep holes, the laser and metal tube jet electrolytic machining tool is set in the center to achieve machining of the inner surface of deep holes.

10. The processing method according to claim 9, characterized in that, in, The diameter of the tool cathode (7) is slightly smaller than that of the small-diameter deep hole, and the diameter of the tool cathode (7) is much smaller than that of the large-diameter deep hole. The flow velocity of the electrolyte (27) is 20-30 m / s, and the laser power is 10-20 W, which is a nanosecond laser.

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