Deep hole electrochemical machining gun drill, composite machining device and machining method

Abstract

The application discloses a deep hole electrochemical machining gun drill, a composite machining device and a machining method, relates to the technical field of metal deep hole machining, and comprises a gun drill body and a blocky cathode. The interior of the gun drill body is provided with an electrolyte channel and a conductive channel which extend along the axial direction and penetrate through the axial two ends. The electrolyte channel is used for conveying electrolyte to the drilling end. The conductive channel is used for mounting a conductive component, and the hole wall is subjected to insulation treatment. The outer peripheral wall of the gun drill body is provided with a chip removal channel which extends from the drilling end to the tail handle end along the axial direction. The chip removal channel is connected with an electrolyte tank through a pipeline and is used for removing the cutting chips generated in the drilling machining and the electrolyte serving as the cutting removal medium. The electrolyte channel, the conductive channel and the chip removal channel are not communicated with each other. The blocky cathode is made of a conductive material and is installed at the rear part of the cutting edge. The blocky cathode can be electrically connected with a power supply through the conductive component. The cutting force is reduced, the surface quality of the hole wall is improved, the problem of excessively high temperature rise in the deep hole machining is solved, and the service life of the drill bit is prolonged.

Description

Technical Field

[0001] This invention relates to the field of deep hole machining technology, specifically to an electrochemical and gun drilling composite machining device and method, belonging to the field of metal cutting and electrochemical composite machining technology. It is particularly suitable for deep hole machining of difficult-to-machine materials such as nickel-based high-temperature alloys and titanium alloys, and can be applied to the deep hole machining production of precision aerospace components. Background Technology

[0002] Deep holes are a typical and indispensable structural feature in precision aerospace components. These deep holes are characterized by high aspect ratios, high machining accuracy requirements, and stringent surface quality requirements. Moreover, the materials being machined are often difficult-to-machine materials such as titanium alloys and nickel-based high-temperature alloys. Traditional gun drilling deep hole machining processes rely solely on mechanical cutting to remove material. When machining difficult materials, this results in high cutting forces and severe temperature rise, which can easily lead to drill deformation and breakage, rapid tool wear, and high machining costs. At the same time, the enclosed deep hole machining environment makes it difficult for heat to dissipate, which can easily cause thermal damage to the workpiece and work hardening of the hole wall. Furthermore, the surface roughness of the hole wall after mechanical cutting is relatively high. In short, traditional single gun drilling mechanical cutting is no longer sufficient to meet the high precision requirements of the aerospace field.

[0003] Therefore, there is an urgent need for a deep hole electrochemical machining gun drill, a composite machining device and machining method to solve the problems of high cutting force, severe temperature rise and poor surface quality in deep hole machining of difficult-to-machine materials, so as to meet the deep hole machining requirements of aerospace precision components. Summary of the Invention

[0004] The purpose of this invention is to provide a deep-hole electrochemical machining gun drill, a composite machining device, and a machining method to solve the problems existing in the prior art. Through combined drilling and electrolytic machining, the machining area is activated and the hole wall is electrolytically polished simultaneously with mechanical drilling, effectively reducing the cutting load and improving the surface finish of the workpiece's inner hole. At the same time, the circulating electrolyte effectively removes the heat generated during deep-hole machining, improving the problems of poor heat dissipation, severe heat accumulation, and excessive temperature rise in traditional deep-hole machining, thus extending the service life of the drill bit.

[0005] To achieve the above objectives, the present invention provides the following solution: A deep-hole electrochemical machining gun drill includes a drill body with a drilling end and a shank end at its axial ends. The drill body has an electrolyte channel and a conductive channel extending axially and penetrating both the drilling end and the shank end. The electrolyte channel and the conductive channel are not interconnected. The electrolyte channel supplies electrolyte to the drilling end, and the conductive channel is used to mount conductive components, with its wall insulated. The outer peripheral wall of the drill body has a chip removal channel extending axially from the drilling end to the shank end. The chip removal channel is connected to an electrolyte tank via a pipe for discharging chips generated during drilling and the electrolyte serving as the cutting medium. A block cathode, made of conductive material, is mounted on the rear of the cutting edge of the drilling end and is electrically connected to a power source via the conductive components.

[0006] In an exemplary embodiment, the entire wall surface of the conductive channel is pre-treated with insulation, and a first insulating layer is provided outside the pre-treated wall surface to achieve insulation isolation between the conductive channel and the conductive component.

[0007] In an exemplary embodiment, a second insulating layer is provided at the position where the block cathode contacts the blade, and the second insulating layer completely covers the contact area between the block cathode and the blade, thereby achieving insulation and isolation between the block cathode and the blade.

[0008] In an exemplary embodiment, both the first insulating layer and the second insulating layer are insulating adhesive layers formed after coating with insulating and corrosion-resistant adhesive.

[0009] In one exemplary embodiment, the end of the chip removal channel is closed and connected to the electrolyte tank via a recovery pipeline; or the end of the chip removal channel extends to the tail shank end, and the portion of the chip removal channel located at the tail shank end is connected to the electrolyte tank via a recovery pipeline; the chip removal channel is a V-shaped groove.

[0010] In one exemplary embodiment, the outer contour of the block cathode is located inside the cutting contour of the blade.

[0011] A deep-hole electrochemical and gun drilling composite machining device includes a deep-hole electrochemical machining gun drill mounted on a machine tool spindle; a tooling clamping assembly for clamping and fixing the workpiece; a power supply assembly with its positive terminal connected to the workpiece, the conductive component extending to the outside of the tailstock end and connected to the negative terminal of the power supply; an electrolyte circulation assembly including an electrolyte tank connected to an electrolyte channel via a delivery pump and a supply pipeline, the electrolyte tank being connected to a chip removal channel via a recovery pipeline; and a control assembly electrically connected to a drive assembly that drives the gun drill to rotate, the power supply assembly, and the delivery pump, to achieve synchronous control of cutting parameters, electrolysis parameters, and electrolyte circulation parameters.

[0012] In an exemplary embodiment, the electrolyte circulation assembly further includes a cooler, a heater, and a filter. The electrolyte tank includes a turbid liquid tank and a clean liquid tank. The filter is provided between the turbid liquid tank and the clean liquid tank. The cooler is provided inside the turbid liquid tank or on the recovery pipeline connecting the turbid liquid tank and the chip removal channel. The heater is provided inside the clean liquid tank or on the supply pipeline connecting the clean liquid tank and the electrolyte channel.

[0013] In an exemplary embodiment, the electrolyte in the electrolyte tank is a 10% sodium nitrate neutral electrolyte, which has the dual functions of an electrolytic machining conductive medium and a mechanical cutting fluid.

[0014] A deep-hole electrochemical and gun-drilling composite machining method, applicable to the aforementioned deep-hole electrochemical and gun-drilling composite machining device, includes the following steps: S1. Installing the deep-hole electrochemical machining gun drill onto the machine tool spindle, and the tooling clamping assembly clamping and fixing the workpiece to be machined in the machining position; S2. Activating the control assembly, setting cutting parameters, electrolysis parameters, and electrolyte circulation parameters, and activating the drive assembly, the power supply assembly, and the delivery pump to achieve electrochemical and gun-drilling composite machining; S3. After machining is completed, turning off the drive assembly, the power supply assembly, and the delivery pump, and removing the workpiece.

[0015] The present invention achieves the following technical effects compared to the prior art: This invention enables integrated drilling and electrolytic machining, improving the efficiency of deep hole machining. By opening electrolyte and conductive channels inside the gun drill body, and setting a block cathode at the rear of the cutting edge of the gun drill body, and electrically connecting the block cathode to the conductive components in the conductive channels, the workpiece activation and hole wall electrolytic polishing can be completed simultaneously while the gun drill is mechanically cutting, achieving integrated cutting, activation, and polishing. Furthermore, the control components can synchronously adjust cutting parameters, electrolytic parameters, and electrolyte circulation parameters, ensuring that each machining process is carried out in tandem, significantly improving the efficiency of deep hole machining.

[0016] This invention can effectively reduce cutting force and cutting temperature rise: the workpiece metal layer to be cut is activated by electrochemical dissolution, thereby reducing the cutting force; the continuously circulating electrolyte continuously flushes the processing area to remove cutting heat and electrolytic heat, stabilizing the cutting temperature within a safe range, solving the problem of poor heat dissipation and heat accumulation during deep hole processing, and reducing tool wear and workpiece thermal damage.

[0017] This invention improves the surface quality of the hole wall: Insulation layers are provided on the entire inner wall of the conductive channel and the entire area where the block cathode contacts the cutting edge to shield stray electric fields and prevent edge electric field concentration and tip discharge; a constant and uniform inter-electrode gap is maintained between the workpiece and the block cathode through the tooling clamping assembly and the machine tool spindle, ensuring a uniform distribution of electric field strength; the coaxiality of the workpiece and the block cathode is adjusted to eliminate the electric field imbalance caused by eccentricity; the electrolyte flow field is regulated uniformly and stably through the control assembly to ensure matching of power supply and electrical parameters. These measures form a uniform electrolytic electric field. Under the action of this uniform electrolytic electric field, microscopic protrusions on the hole wall can be preferentially etched away due to higher current density, achieving hole wall smoothing and deburring, significantly reducing the surface roughness of the hole wall, and meeting the surface quality requirements of precision aerospace components.

[0018] This invention is easy to modify and highly adaptable: it only adds a block cathode to the non-cutting area of ​​the gun drill body, and opens a conductive channel behind the block cathode. It directly utilizes the original internal cooling hole channel and chip removal channel of the gun drill body, without making any changes to the core cutting structure such as the cutting edge. The modified gun drill completely retains the mechanical cutting function of the traditional gun drill, and only achieves auxiliary efficiency through composite electrolytic machining. It does not have any adverse effects on the cutting accuracy, chip removal efficiency, tool life and machining continuity of the original gun drill. It can be directly adapted to existing gun drill deep hole machining equipment, with low modification difficulty, low modification cost and high adaptability. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the axial side structure of a deep hole electrochemical machining gun drill disclosed in a specific embodiment of the present invention. Figure 2 This is a right-side structural schematic diagram of a deep-hole electrochemical machining gun drill disclosed in a specific embodiment of the present invention. Figure 3 for Figure 2Schematic diagram of the cross-sectional structure at point AA; Figure 4 This is a schematic diagram of the deep hole electrochemical and gun drilling composite processing device disclosed in a specific embodiment of the present invention.

[0021] The components include: 1. Gun drill body; 110. Electrolyte channel; 120. Conductive channel; 130. Chip removal channel; 2. Block cathode; 3. Workpiece to be processed; 4. Tooling clamping assembly; 5. Power supply assembly; 6. Electrolyte circulation assembly; 610. Turbid liquid tank; 620. Clean liquid tank; 630. Cooler; 640. Heater; 650. Filter; 660. Recovery pipeline; 670. Supply pipeline; 7. Control assembly. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Example 1: Please refer to Figures 1 to 3 This embodiment provides a deep hole electrochemical machining gun drill, including a gun drill body 1 and a block cathode 2.

[0025] The gun drill body 1 is a slender rod-shaped structure with a cutting head and a handle at its two axial ends. For ease of description, the end of the gun drill body 1 with the cutting head is called the drilling end, and the end of the gun drill body 1 with the handle is called the tail shank end. The gun drill body 1 has an internal electrolyte channel 110 and a conductive channel 120. The electrolyte channel 110 and conductive channel 120 extend axially along the drill body 1 and pass through the drilling end and the tailstock end, respectively. The electrolyte channel 110 and conductive channel 120 are not interconnected. The electrolyte channel 110 utilizes the internal cooling hole channel of the gun drill body 1 to supply electrolyte to the cutting head at the drilling end. The conductive channel 120 is used to install conductive components. Its entire wall surface undergoes insulation pretreatment, including surface cleaning, surface roughening, shielding of non-insulating areas, priming / coating, and drying / dehumidification. A first insulating layer is formed on the outside of the pretreated hole wall. This first insulating layer is an insulating adhesive layer formed after applying insulating and corrosion-resistant adhesive, achieving insulation isolation between the conductive channel 120 and the conductive components. A gap is maintained between the conductive components and the first insulating layer within the conductive channel 120, with no contact. The apertures of the electrolyte channel 110 and conductive channel 120 can be adjusted as needed.

[0026] The outer peripheral wall of the gun drill body 1 has a chip removal channel 130 extending axially from the drilling end to the tail shank end. The chip removal channel 130, the electrolyte channel 110, and the conductive channel 120 are not interconnected. The chip removal channel 130 is connected to the electrolyte tank through a pipeline and is used to remove the chips generated during drilling and the electrolyte that serves as the cutting discharge medium. The chip removal channel 130 can be a through hole penetrating both the drilling end and the tail shank end, or it can be a blind hole that does not penetrate the tail shank end. The structure of the chip removal channel 130 is not limited to... Figure 1 The V-shaped groove shown can also be a U-shaped groove, a semi-circular groove, a rectangular groove, a trapezoidal groove, or other forms.

[0027] The bulk cathode 2 is a bulk structure made of conductive material, and its shape is not limited to... Figure 1The square shape shown can also be round, elliptical, polygonal, or other shapes. The outer contour of the block cathode 2 does not exceed the cutting contour of the cutting edge to avoid affecting the drilling process. The contact area between the block cathode 2 and the cutting edge is coated with insulating and corrosion-resistant adhesive. The adhesive layer formed after drying is the second insulating layer. The second insulating layer completely fills and seals the contact area between the block cathode 2 and the cutting edge, without gaps or exposed substrate, achieving insulation isolation between the block cathode 2 and the cutting edge. By applying insulating and corrosion-resistant adhesive, both insulation of the contact area between the block cathode 2 and the cutting edge is achieved, and the block cathode 2 is bonded to the rear of the cutting edge. The block cathode 2 is installed at the rear of the cutting edge at the drilling end and is located on the extension line of the conductive channel 120. After installation, the block cathode 2 can achieve a unique electrical connection with one end of the conductive component, that is, the current can only flow unidirectionally from the negative terminal of the power supply through the conductive component to the block cathode 2, making the block cathode 2 negatively charged. All other metal parts are insulated and do not participate in the conduction or electrolytic reaction. The block cathode 2 is fixedly connected to the conductive component.

[0028] Example 2: Please refer to Figure 4 This embodiment provides a deep hole electrochemical and gun drilling composite machining device, including a deep hole electrochemical machining gun drill, a tooling clamping assembly 4, a power supply assembly 5, an electrolyte circulation assembly 6, and a control assembly 7.

[0029] The deep hole electrochemical machining gun drill adopts the structure shown in Example 1, which is mounted on the machine tool spindle and connected to the drive assembly for transmission.

[0030] The tooling clamping assembly 4 is used to clamp the workpiece 3 to be processed and fix the workpiece 3 in the position to be processed. The tooling clamping assembly 4 can be a robot arm, an existing drilling jig, a magnetic chuck jig, etc.

[0031] The positive terminal of the power supply assembly 5 is connected to the workpiece 3 being processed, and the conductive component in the conductive channel 120 can extend to the outside of the tailstock end and be connected to the negative terminal of the power supply.

[0032] The electrolyte circulation assembly 6 includes an electrolyte tank, a cooler 630, a heater 640, and a filter 650. The electrolyte tank includes a turbid liquid tank 610 and a clean liquid tank 620. The turbid liquid tank 610 is connected to the chip removal channel 130 via a recovery pipeline 660, and the clean liquid tank 620 is connected to the electrolyte channel 110 via a supply pipeline 670. A filter 650 is installed between the turbid liquid tank 610 and the clean liquid tank 620. The filter 650 uses existing equipment to filter impurities such as chips and electrolytic products from the electrolyte, preventing impurities from clogging the channel or affecting electrolytic processing. The cooler 630 is installed inside the turbid liquid tank 610 or on the recovery pipeline 660, and the heater 640 is installed inside the clean liquid tank 620 or on the supply pipeline 670. A transfer pump is installed inside the clean liquid tank 620. The cooler 630 and the heater 640 are used to precisely control the temperature of the electrolyte, ensuring the conductivity and processing stability of the electrolyte.

[0033] The control component 7 is an industrial computer, which is electrically connected to the drive component, power supply component 5, and delivery pump. The industrial computer has a built-in control program and receives feedback signals from each module. On the one hand, it controls the cutting parameters by adjusting the spindle speed, tool feed rate, and feed amount. On the other hand, it regulates the electrolysis parameters by adjusting the output voltage, current, current density, pulse duty cycle, and other parameters through the power supply component 5. At the same time, it regulates the circulation parameters such as electrolyte flow rate, pressure, and flow velocity by adjusting the operating speed and output pressure of the delivery pump. The three components work together and are synchronized to ensure the stable operation of the deep hole electrolytic drilling process.

[0034] The electrolyte is a 10% sodium nitrate neutral electrolyte, which has the dual functions of an electrolytic machining conductive medium and a mechanical cutting fluid. While realizing the electrolytic circuit between the workpiece 3 and the block cathode 2, the electrolyte directly acts as a cutting fluid to cool and lubricate the cutting area of ​​the gun drill bit. The electrolyte also pushes the chips to be flushed out along the chip discharge channel 130, without the need for an additional cutting fluid delivery structure.

[0035] Working principle: The power supply assembly 5, drive assembly, and delivery pump are activated. The drive assembly rotates the drill body 1 to achieve deep hole cutting. Simultaneously, the workpiece 3 is positively charged, and the block cathode 2 is negatively charged. The delivery pump pumps the electrolyte from the clean electrolyte tank 620 to the drilling end through the electrolyte channel 110, thus establishing an electrolytic circuit between the workpiece 3 and the block cathode 2. This activates the machining area and electropolishes the hole wall during drilling. The electrolyte pushes the chips generated during cutting along the chip removal channel 130 to the turbid electrolyte tank 610, where it is cooled to a suitable temperature by the cooler 630. Then, it passes through the filter 650 to remove impurities such as chips and electrolytic products. The filtered electrolyte flows back to the clean electrolyte tank 620 for recycling.

[0036] Example 3: This embodiment provides a deep hole electrochemical and gun drilling combined machining method, applicable to the deep hole electrochemical and gun drilling combined machining apparatus described in Embodiment 2, and includes the following: S1. Install the deep hole electrochemical machining gun drill onto the machine tool spindle, and clamp the tooling clamping assembly 4 to clamp and fix the workpiece 3 to be processed in the position to be processed; S2. Start control component 7, preset cutting parameters, electrolysis parameters and electrolyte circulation parameters, start drive component, power component 5 and delivery pump, so that gun drill mechanical drilling and electrochemical erosion work together to realize electrolysis and gun drill composite processing.

[0037] S3. After processing is completed, turn off the drive assembly, power supply assembly 5 and the conveying pump, and remove the workpiece.

[0038] In the embodiments of this application, the same reference numerals are used to denote the same component or the same part.

[0039] Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0040] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A deep-hole electrochemical machining gun drill, characterized in that: include The gun drill body has a drilling end and a shank end at its axial ends. Inside the gun drill body, there are an electrolyte channel and a conductive channel extending axially and penetrating both the drilling end and the shank end. The electrolyte channel and the conductive channel are not interconnected. The electrolyte channel is used to supply electrolyte to the drilling end, and the conductive channel is used to install conductive components, and its hole wall is insulated. The outer peripheral wall of the gun drill body has a chip removal channel extending axially from the drilling end to the shank end. The chip removal channel is connected to an electrolyte tank via a pipe and is used to discharge chips generated during drilling and the electrolyte that serves as the cutting discharge medium. And a block cathode, which is made of conductive material and installed at the rear of the cutting edge of the drill end, and the block cathode can be electrically connected to a power source through the conductive component.

2. The deep hole electrochemical machining gun drill according to claim 1, characterized in that: The entire wall surface of the conductive channel is pre-insulated, and a first insulating layer is provided outside the pre-insulated wall surface to achieve insulation isolation between the conductive channel and the conductive component.

3. The deep hole electrochemical machining gun drill according to claim 2, characterized in that: A second insulating layer is provided at the position where the block cathode contacts the blade. The second insulating layer completely covers the contact area between the block cathode and the blade, thereby achieving insulation and isolation between the block cathode and the blade.

4. The deep hole electrochemical machining gun drill according to claim 3, characterized in that: Both the first insulating layer and the second insulating layer are insulating adhesive layers formed after coating with insulating and corrosion-resistant adhesive.

5. The deep hole electrochemical machining gun drill according to claim 1, characterized in that: The end of the chip removal channel is closed and connected to the electrolyte tank through a recovery pipeline; or the end of the chip removal channel extends to the tail shank end, and the portion of the chip removal channel located at the tail shank end is connected to the electrolyte tank through a recovery pipeline. The chip removal channel is a V-shaped groove.

6. The deep hole electrochemical machining gun drill according to claim 1, characterized in that: The outer contour of the block cathode is located inside the cutting contour of the blade.

7. A deep-hole electrochemical and gun drilling composite machining device, characterized in that: Includes the deep hole electrochemical machining gun drill as described in any one of claims 1 to 6, which is mounted on the machine tool spindle; Tooling clamping assembly, used to clamp and fix the workpiece being processed; A power supply assembly, the positive terminal of which is connected to the workpiece being processed, and the conductive component extending to the outside of the tailstock end and connected to the negative terminal of the power supply. An electrolyte circulation assembly includes an electrolyte tank, which is connected to an electrolyte channel via a delivery pump and a supply pipeline, and the electrolyte tank is connected to a chip removal channel via a recovery pipeline. The system also includes a control component, which is electrically connected to the drive component that drives the drill to rotate, the power supply component, and the delivery pump, respectively, to achieve synchronous control of cutting parameters, electrolysis parameters, and electrolyte circulation parameters.

8. The deep hole electrochemical and gun drilling composite machining device according to claim 7, characterized in that: The electrolyte circulation assembly further includes a cooler, a heater, and a filter. The electrolyte tank includes a turbid liquid tank and a clean liquid tank. The filter is provided between the turbid liquid tank and the clean liquid tank. The cooler is provided inside the turbid liquid tank or on the recovery pipeline used to connect the turbid liquid tank and the chip removal channel. The heater is provided inside the clean liquid tank or on the supply pipeline used to connect the clean liquid tank and the electrolyte channel.

9. The deep hole electrochemical and gun drilling composite machining device according to claim 7, characterized in that: The electrolyte in the electrolyte tank is a 10% sodium nitrate neutral electrolyte, which has the dual functions of an electrolytic machining conductive medium and a mechanical cutting fluid.

10. A deep-hole electrochemical and gun drilling composite machining method, characterized in that: The deep hole electrochemical and gun drilling composite machining apparatus according to any one of claims 7-9 includes the following: S1. The deep hole electrochemical machining gun drill is installed onto the machine tool spindle, and the tooling clamping assembly clamps and fixes the workpiece to be processed in the processing position; S2. Start the control component, set the cutting parameters, electrolysis parameters and electrolyte circulation parameters, start the drive component, the power supply component and the delivery pump to realize electrochemical and gun drilling composite machining; S3. After processing is completed, turn off the drive assembly, the power supply assembly and the delivery pump, and remove the workpiece.

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