Cylindrical workpiece traceless electroplating clamping device and electroplating process method

Abstract

The invention belongs to the technical field of electroplating production, and relates to a cylindrical workpiece traceless electroplating clamping device and an electroplating process method. In the initial stage of electroplating, the clamping device is matched with the cylindrical workpiece in a specific contact mode, it is guaranteed that the workpiece is stably in place, and the cylindrical workpiece is immersed into a preset position below the electroplating liquid level through the clamping device. The electroplating process is smoothly started, the clamping device changes the contact point position at proper time along with the step-by-step advancing of the electroplating reaction, the surface area of the workpiece which is shielded previously is ingeniously released gradually, it is ensured that the surface of each inch of the cylindrical workpiece can make full contact with an electroplating solution without any hindrance, and full coverage of an electroplating film layer is achieved; and the electroplating effect consistency of the cylindrical workpiece is effectively guaranteed, the thickness uniformity of a plating layer is improved, and the comprehensive corrosion-resistant and wear-resistant effects are achieved.

Description

Technical Field

[0001] This invention belongs to the field of electroplating production technology, and relates to a non-marking electroplating clamping device and electroplating process method for cylindrical workpieces. Background Technology

[0002] Electroplating, a widely used surface treatment technology for metal workpieces, is based on the principle of electrolysis. It uses electric current to reduce metal ions, which then deposit on the surface of a conductive object, forming a metal layer with special properties. This technology plays a crucial role in industrial production, effectively enhancing several key properties of metal workpieces. These include significantly improving corrosion resistance, allowing the workpiece to maintain its good condition even in harsh chemical environments; enhancing wear resistance, extending the workpiece's service life; and optimizing fatigue resistance, ensuring stability and reliability under repeated stress conditions.

[0003] From a process flow perspective, electroplating typically encompasses three closely interconnected stages: pretreatment, electroplating, and post-treatment. The pretreatment stage primarily focuses on removing impurities such as oil and rust from the workpiece surface, laying a solid foundation for subsequent electroplating steps and ensuring a tight adhesion of the plating layer. The electroplating stage is the core of the entire process, achieving the orderly deposition of metal ions through precise control of parameters such as current and plating solution composition. The post-treatment stage emphasizes operations such as passivation and sealing of the plating layer to further optimize its performance. Among the many types of electroplating, cadmium plating, copper plating, nickel plating, chromium plating, and zinc plating are quite common. Different types of plating, based on the specific application requirements of the workpiece, impart different characteristics to suit diverse application scenarios.

[0004] However, ensuring electroplating quality faces numerous challenges in practice. Two key aspects are paramount: First, it is crucial to guarantee a uniform coating thickness. Uneven coating thickness not only affects the smoothness of the workpiece's appearance but can also lead to inconsistent performance in different areas, weakening overall reliability. Second, every effort must be made to ensure a strong bond between the coating and the substrate, eliminating the risk of peeling. Once the coating peels off, the workpiece will quickly lose the protective properties provided by the electroplating, significantly shortening its effective service life.

[0005] Especially for cylindrical workpieces, the implementation of the electroplating process becomes significantly more difficult due to their unique structural characteristics, and the control of electroplating quality becomes even more challenging. Currently, when electroplating cylindrical workpieces, clamping fixtures or copper wires are commonly used to fix the workpiece in place. The fixture and the cylindrical workpiece are immersed in the electroplating solution in a fixed position. As a result, the area of ​​the cylindrical workpiece surface covered by the clamping fixture cannot fully contact the electroplating solution, preventing plating formation in that area and affecting the uniformity of the plating. Even if measures are taken to minimize the contact area between the cylindrical workpiece and the clamping fixture, contact marks are still unavoidable on the workpiece surface. These marks not only detract from the appearance quality of the electroplated product but also negatively impact its corrosion resistance and wear resistance, making it difficult for the workpiece to achieve its expected performance.

[0006] In view of this, it is urgent to develop a clamping device capable of achieving traceless electroplating, along with a compatible electroplating process. By realizing the technology of this invention, it is expected to comprehensively improve the electroplating quality of cylindrical workpieces, meet increasingly stringent application requirements, and promote the high-quality development of related industries. Summary of the Invention

[0007] The purpose of this invention is: The purpose of this invention is to solve the technical problem of contact marks on the surface of cylindrical workpieces caused by contact between the surface and the clamping fixture during the electroplating process, which affects the anti-corrosion and wear-resistant effect of the workpiece surface. The invention provides a non-marking electroplating clamping device for cylindrical workpieces, which changes the original electroplating process. By introducing an innovative mechanical structure and intelligent control mechanism, the clamping device can flexibly and accurately adjust its contact position with the cylindrical workpiece according to a preset program during the electroplating process, ensuring the quality and uniformity of the plating layer of the electroplated product.

[0008] Specifically, in the initial stage of electroplating, the clamping device engages with the cylindrical workpiece using a specific contact method to ensure stable positioning. The clamping fixture then immerses the cylindrical workpiece in a predetermined position below the electroplating solution. This smoothly initiates the electroplating process. As the electroplating reaction progresses, the clamping device adjusts its contact points in a timely manner, skillfully releasing previously obstructed areas of the workpiece surface step by step. This ensures that every inch of the cylindrical workpiece's surface is in unobstructed contact with the electroplating solution, achieving full coverage of the electroplated film. This effectively guarantees consistent electroplating results for the cylindrical workpiece, improves the uniformity of the coating thickness, and achieves comprehensive corrosion protection and wear resistance.

[0009] The technical solution of the present invention is as follows: According to the first aspect of the present invention, a non-marking electroplating clamping device for cylindrical workpieces is proposed, comprising: a frame, including an upper fixed support (13), a lower fixed support (16) and a fixed support connecting rod (17) connecting the two; a drive system, including a motor support (1) fixed to the top of the fixed support connecting rod (17), and an external drive motor (2) and an internal drive motor (3) fixed to the motor support (1); a transmission mechanism, including an external lead screw (7) driven to rotate by the external drive motor (2) and an internal lead screw (8) driven to rotate by the internal drive motor (3), wherein the internal lead screw (8) is nested in the external lead screw (7) through a bearing (6) and can rotate relative to it; The outer lead screw (7) is fitted with an outer moving ring (9), and the inner lead screw (8) is fitted with an inner moving ring (11). The clamping assembly includes two sets of clamping arm units evenly distributed along the circumference. One end of each clamping arm unit is connected to an end effector (15). The other end of one set of clamping arm units is hinged to the upper fixed support (13), and the middle part is hinged to the outer moving ring (9). The other end of the other set of clamping arm units is hinged to the lower fixed support (16), and the middle part is hinged to the inner moving ring (11). The driving system drives the outer moving ring (9) and / or the inner moving ring (11) to move axially, thereby driving the end effector (15) of the corresponding set of clamping arm units to move radially, so as to achieve internal support at different points of the cylindrical workpiece.

[0010] In one possible embodiment, each clamping arm unit includes two sets of fixed support links (14), an outer lead screw link (10), and an inner lead screw link (12); one end of one set of fixed support links (14) is hinged to the upper fixed support (13), and the other end is hinged to the end effector (15); one end of the outer lead screw link (10) is hinged to the outer moving ring (9), and the other end is hinged to the middle of the set of fixed support links (14); one end of the other set of fixed support links (14) is hinged to the lower fixed support (16), and the other end is hinged to the end effector (15); one section of the inner lead screw link (12) is hinged to the inner moving ring (11), and the other end is hinged to the middle of the set of fixed support links (14).

[0011] In one possible embodiment, the end effector (15) has an embedded resilient power contact piece.

[0012] In one possible embodiment, the surface of the end effector (15) that contacts the workpiece is provided with an anti-slip elastic layer.

[0013] In one possible embodiment, a conductive line is also included, which extends from the power contact of the end effector (15) through the interior of the fixed support link (14), the lower fixed support (16), and the fixed support connecting rod (17) to the external electroplating power source.

[0014] In one possible embodiment, the outer moving ring (9) and the inner moving ring (11) are provided with balls or threaded sleeves that engage with the corresponding lead screw threads.

[0015] In one possible embodiment, the output ends of the external drive motor (2) and the internal drive motor (3) are respectively connected to the external drive wheel (4) and the internal drive wheel (5), and the external drive wheel (4) and the internal drive wheel (5) drive the external lead screw (7) and the internal lead screw (8) to rotate respectively.

[0016] In one possible embodiment, the component in the device that comes into contact with the electroplating solution has a base material that is a hard, corrosion-resistant material or a metal material with a surface coated with a corrosion-resistant coating.

[0017] According to a second aspect of the present invention, a method for traceless electroplating of cylindrical workpieces is provided, employing the aforementioned traceless electroplating clamping device for cylindrical workpieces, the electroplating method comprising: Step 1: Both sets of clamping arm units in the clamping assembly are in the retracted state. The production line hanger moves the clamping device above the workpiece and extends into the workpiece. Step 2: Both sets of clamping arm units in the clamping assembly are extended outward to lift the workpiece, which is then moved sequentially by the production line rack to above the pretreatment, electroplating bath and posttreatment areas. Step 3: The production line hanger immerses the clamping device and the workpiece together in the electroplating solution, ensuring that the workpiece is completely immersed; Step 4: As the electroplating process proceeds, the clamping assembly controls the end effectors of each clamping arm unit to periodically contact and separate from the inner wall of the workpiece according to a set cycle. During this process, it can be ensured that all positions of the workpiece can be in uniform contact with the electroplating solution. Step 5: After electroplating is completed, both sets of clamping arm units in the clamping assembly are pushed outward, so that the end effector is pushed outward and contacts the inner wall of the workpiece. The production line hanger rises up, so that the workpiece is removed from the electroplating solution and the solution on the surface of the workpiece is drained above the electroplating solution tank.

[0018] The advantages of this invention are: 1. This invention discloses a traceless electroplating clamping device and electroplating process for cylindrical workpieces. Unlike traditional static contact clamping fixtures, the clamping device of this invention has dynamic adjustment capabilities, allowing it to change its contact position with the cylindrical workpiece in real time according to the electroplating process. This breaks the limitations of previous fixed clamping modes and fundamentally solves the problem of contact marks on the workpiece surface caused by clamping. It proposes a revolutionary electroplating process method, constructing a complete electroplating process innovation around the dynamic clamping device. Compared with existing cylindrical workpiece electroplating processes, it no longer simply and mechanically fixes the workpiece for electroplating, but optimizes the electroplating effect by precisely controlling the state changes of the clamping device.

[0019] 2. This invention addresses the problem at its source: preventing marks from forming on the surface of cylindrical workpieces due to contact with clamping fixtures. This ensures a smooth, mark-free surface after electroplating. By dynamically adjusting the clamping device, the entire workpiece is continuously and completely in contact with the plating solution, guaranteeing a complete and uniform electroplating film. This significantly improves the product's appearance quality, effectively ensuring the uniformity and consistency of the plating layer, and endowing the workpiece with excellent corrosion resistance and wear resistance.

[0020] 3. The cylindrical workpiece non-marking electroplating clamping device disclosed in this invention patent adopts fully automated adjustment and is used in conjunction with an automated electroplating production line to realize fully automated electroplating of products. No manual intervention is required during the electroplating process, reducing labor intensity, improving electroplating efficiency, and effectively reducing physical harm caused by long-term human contact with solutions. It meets the national requirements for automation, intelligence and greening of new quality productivity in industrial production. Attached Figure Description

[0021] Figure 1 Full view of the device of the present invention; Figure 2 A cross-sectional view of the device of the present invention; Figure 3 This device has three states during use (A. Full support state, B. Half support state, and C. Another type of half support state). Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0024] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] According to a first aspect of the present invention, a non-marking electroplating clamping device for cylindrical workpieces is provided, comprising a motor support 1, an external drive motor 2, an internal drive motor 3, an external drive wheel 4, an internal drive wheel 5, a bearing 6, an external lead screw 7, an internal lead screw 8, an external moving ring 9, an external lead screw connecting rod 10, an internal moving ring 11, an internal lead screw connecting rod 12, an upper fixed support 13, a fixed support connecting rod 14, an end effector 15, a lower fixed support 16, and a fixed support connecting rod 17; The motor support 1 is a support part for the drive motor that provides power to the device. It can support the two motors to prevent relative movement during rotation, ensuring the stable use of the device. The external drive motor 2 and the internal drive motor 3 can provide opposite rotational forces to drive the external drive wheel 4 and the internal drive wheel 5 to transmit power; The outer drive wheel 4 and the inner drive wheel 4 transmit power to the outer lead screw 7 and the inner lead screw 8, causing the outer lead screw 7 and the inner lead screw 8 to rotate relative to each other; The bearing 6 is used to ensure that the cylinder walls remain parallel during relative movement of the outer lead screw 7 and the inner lead screw 8, and serves to lubricate and maintain the relative positions of the outer lead screw 7 and the inner lead screw 8. The outer lead screw 7 and inner lead screw 8 are embedded in the track, and through their coordinated action with the outer moving ring 9 and inner moving ring 11, they control and drive the outer lead screw connecting rod 10 and inner lead screw connecting rod 12 to perform up-and-down reciprocating motion; The outer moving ring 9 and the inner moving ring 11 contain ball bearings and cooperate with the outer lead screw 7 and the inner lead screw 8; under the rotation of the outer lead screw 7 and the inner lead screw 8, the outer moving ring 9 and the inner moving ring 11 move. The outer lead screw connecting rod 10 and the inner lead screw connecting rod 12 are connected between the outer moving ring 9, the inner moving ring 11, and the fixed support connecting rod 14. The movement of the outer moving ring 9 and the inner moving ring 11 drives the outer lead screw connecting rod 10 and the inner lead screw connecting rod 12 to move, thereby driving the fixed support connecting rod 14 to reciprocate. The fixed support connecting rod 14 is connected to the fixed support and the end effector 15, and is driven by the movement of the outer lead screw connecting rod 10 and the inner lead screw connecting rod 12 to realize the reciprocating motion of the end effector 15.

[0026] The upper fixed support 13 and the lower fixed support 16 are rigidly connected to the support connecting rod 17, and their relative positions remain unchanged during the process of the device of the present invention.

[0027] In one possible embodiment, the end effector 15 is the structure in which the device of the present invention contacts the electroplating component, and has an embedded elastic power contact piece that can provide potential to the electroplating component to ensure electroplating quality.

[0028] In one possible embodiment, the end effector 15 has an anti-slip rubber structure to prevent relative sliding of components, which could affect the electroplating quality.

[0029] In one possible embodiment, the base material of the inventive device is a hard material or a metal substrate coated with a corrosion-resistant coating to prevent tooling corrosion or electroplating damage during the electroplating process and to ensure electroplating quality.

[0030] Preferably, the external wiring circuit of the device of the present invention is sequentially introduced from the elastic power contact piece of the end effector 15, through the fixed support connecting rod 14 to embed the wire, into the lower fixed support 16, and then through the fixed support connecting rod 17 to introduce the power supply of the electroplating production line.

[0031] According to another aspect of the present invention, a method for traceless electroplating of cylindrical workpieces is also provided, wherein the electroplating process is performed using a traceless electroplating clamping device for cylindrical workpieces as described in any of the preceding claims, the method comprising: Step 1: Connect the invention device to the movable bracket in the electroplating production line. At this time, the end effector of the invention device is in the retracted state. The production line bracket moves the invention device above the workpiece and extends into the workpiece. Step 2: Drive the internal motor of the invention device to rotate through the controller, and all end effectors will spread outward to lift the workpiece and move it sequentially above the pretreatment, electroplating bath and posttreatment by the production line rack. Step 3: The production line hanger immerses the invention device and the workpiece together in the electroplating solution, ensuring that the workpiece is completely immersed; Step 4: As the electroplating process proceeds, the invention device controls multiple sets of end effectors to periodically contact and separate from the inner wall of the workpiece according to a set cycle. During this process, it can ensure that all positions of the workpiece can be in uniform contact with the electroplating solution. Step 5: After electroplating is completed, all end effectors are pushed outward to contact the inner wall of the workpiece, and the production line rack is raised to separate the invention device from the workpiece from the electroplating solution, and the solution on the surface of the workpiece is drained above the electroplating tank. Step 6: The production line rack moves the invention device and the workpiece together to the designated storage area. The controller drives the internal motor of the invention device to rotate, and all end effectors retract inward. The workpiece is separated from the invention device, and the entire electroplating process ends.

[0032] Example 1 This invention provides a non-marking electroplating clamping device for cylindrical workpieces. For example... Figures 1-2 As shown, the non-marking electroplating clamping device for cylindrical workpieces provided in this embodiment mainly includes a motor support 1, an external drive motor 2, an internal drive motor 3, an external drive wheel 4, an internal drive wheel 5, a bearing 6, an external lead screw 7, an internal lead screw 8, an external moving ring 9, an external lead screw connecting rod 10, an internal moving ring 11, an internal lead screw connecting rod 12, an upper fixed support 13, a fixed support connecting rod 14, an end effector 15, a lower fixed support 16, and a fixed support connecting rod 17.

[0033] The motor support 1 serves as the base of the device and is used to fix and install the external drive motor 2 and the internal drive motor 3, ensuring that the two maintain a stable relative position during operation.

[0034] The external drive motor 2 and the internal drive motor 3 are preferably servo motors or stepper motors that can rotate in both directions. Their output shafts rotate in opposite directions and drive the external drive wheel 4 and the internal drive wheel 5 connected to them, respectively.

[0035] The outer drive wheel 4 and the inner drive wheel 5 are mounted on the motor output shaft by key connection or interference fit, transmitting power to the outer lead screw 7 and the inner lead screw 8 that mesh or drive with them, driving the outer lead screw 7 and the inner lead screw 8 to generate relative rotational motion.

[0036] Bearing 6 is preferably a thrust bearing or a deep groove ball bearing, installed between the outer lead screw 7 and the inner lead screw 8, to bear axial force and maintain the coaxiality and positional accuracy of the two during relative rotation, while also reducing friction.

[0037] The outer and inner lead screws 7 and 8 have helical tracks machined on their outer circumferential surfaces. The outer moving ring 9 and inner moving ring 11 respectively engage with the tracks of the corresponding lead screws through ball bearings (or have internal threads machined directly on them). When the lead screws rotate, the outer moving ring 9 and inner moving ring 11 generate linear motion along the axial direction of the lead screws.

[0038] One end of the outer lead screw connecting rod 10 is connected to the outer moving ring 9 via a hinge or ball joint, and the other end is hinged to the fixed support connecting rod 14. Similarly, one end of the inner lead screw connecting rod 12 is connected to the inner moving ring 11, and the other end is hinged to the fixed support connecting rod 14. The axial movement of the outer moving ring 9 and the inner moving ring 11 is converted into the pushing and pulling action of the outer lead screw connecting rod 10 and the inner lead screw connecting rod 12, thereby driving the fixed support connecting rod 14 to reciprocate.

[0039] The fixed support link 14 is fixedly connected to the end effector 15 or integrally formed. The reciprocating motion of the fixed support link 14 is directly transmitted to the end effector 15, controlling its radial opening and closing.

[0040] The upper fixed support 13 and the lower fixed support 16 are rigidly connected by the fixed support connecting rod 17 to form the fixed frame of the device, which remains stationary during the operation of the device.

[0041] The end effector 15 is a component that directly contacts the inner wall of the cylindrical workpiece. Its contact surface is fitted with an anti-slip rubber pad and equipped with a flexible power contact piece (such as a copper alloy spring). This power contact piece, through a wire embedded in the fixed support connecting rod 14, passes through the lower fixed support 16 and the fixed support connecting rod 17, and is ultimately connected to an external electroplating power source to apply the current required for electroplating to the workpiece.

[0042] In a preferred embodiment, the components in the device that come into contact with the electroplating solution (such as the end effector 15, the fixed support link 14, etc.) are made of hard corrosion-resistant materials (such as titanium, stainless steel, or engineering plastics such as PP or PVDF), or an anti-corrosion coating (such as a polytetrafluoroethylene coating) is applied to the surface of the metal substrate to prevent electroplating corrosion and avoid contamination of the electroplating solution.

[0043] Example 2 This invention provides a method for a traceless electroplating process for cylindrical workpieces using the above-mentioned device, comprising the following steps: Step S101: Clamp the workpiece.

[0044] Install the clamping device on the movable bracket of the electroplating production line, ensuring that the end effector 15 is in the retracted state. Control the movement of the production line bracket to smoothly insert the device into the inner cavity of the cylindrical workpiece to be electroplated.

[0045] Step S102: Open the workpiece and transfer it.

[0046] The controller starts the external drive motor 2 and the internal drive motor 3, which drive the external lead screw 7 and the internal lead screw 8 to rotate, causing multiple sets of end effectors 15 to expand radially outward in sync until they tightly support the inner wall of the workpiece and lift the workpiece away from the support surface. Subsequently, the production line hanger drives the device and the workpiece to pass over the pretreatment tank, the electroplating tank and the posttreatment tank in sequence.

[0047] Step S103: Immerse in electroplating solution.

[0048] The production line rack is lowered to immerse the clamping device and the workpiece together in the electroplating bath, ensuring that the workpiece is completely submerged below the liquid surface.

[0049] Step S104: Dynamic electroplating process.

[0050] like Figure 3 As shown, during electroplating, the controller periodically controls the drive motor according to a preset program, causing multiple sets of end effectors 15 to perform small-amplitude, periodic contraction and opening movements. During this process, the end effectors 15 intermittently contact and separate from the inner wall of the workpiece, thereby changing the contact point position between the workpiece and the fixture, and disturbing the flow state of the solution near the workpiece. This ensures that all areas of the inner wall of the workpiece receive a uniform supply of metal ions and current distribution, effectively eliminating clamping marks and improving the uniformity of the plating layer.

[0051] Step S105: Discharge from the tank and air dry.

[0052] Once the electroplating time is reached, all end effectors 15 are controlled to tighten the inner wall of the workpiece outwards again. Subsequently, the production line rack rises, lifting the device and the workpiece together out of the liquid surface, and pauses briefly above the electroplating tank to allow the residual electroplating solution on the workpiece surface to dry.

[0053] Step S106: Remove the workpiece.

[0054] The production line rack moves the device and workpiece to the designated unloading area. The controller drives the motor in reverse, causing all end effectors 15 to retract radially inward, disengaging from the inner wall of the workpiece and completing the workpiece unloading. This concludes the entire electroplating process.

Claims

1. A non-marking electroplating clamping device for cylindrical workpieces, characterized in that, include: The frame includes an upper fixed support (13), a lower fixed support (16), and a fixed support connecting rod (17) connecting the two; the drive system includes a motor support (1) fixed to the top of the fixed support connecting rod (17), and an external drive motor (2) and an internal drive motor (3) fixed to the motor support (1); the transmission mechanism includes an external lead screw (7) driven to rotate by the external drive motor (2) and an internal lead screw (8) driven to rotate by the internal drive motor (3), the internal lead screw (8) being nested inside the external lead screw (7) through a bearing (6) and being able to rotate relative to it; an external moving ring (9) is sleeved on the external lead screw (7), and the internal lead screw... An inner moving ring (11) is fitted on the rod (8); the clamping assembly includes two sets of clamping arm units evenly distributed along the circumference; one end of one clamping arm unit is connected to an end effector (15); the other end of one set of clamping arm units is hinged to the upper fixed support (13), and the middle part is hinged to the outer moving ring (9); the other end of the other set of clamping arm units is hinged to the lower fixed support (16), and the middle part is hinged to the inner moving ring (11); the driving system drives the outer moving ring (9) and / or the inner moving ring (11) to move axially, thereby driving the end effector (15) of the corresponding set of clamping arm units to move radially, so as to achieve internal support at different points of the cylindrical workpiece.

2. The non-marking electroplating clamping device for cylindrical workpieces according to claim 1, characterized in that, The clamping arm unit includes a fixed support link (14), an outer lead screw link (10), and an inner lead screw link (12); one end of one set of fixed support links (14) is hinged to the upper fixed support (13), and the other end is hinged to the end effector (15); one end of the outer lead screw link (10) is hinged to the outer moving ring (9), and the other end is hinged to the middle of the fixed support link (14); one end of another set of fixed support links (14) is hinged to the lower fixed support (16), and the other end is hinged to the end effector (15); one section of the inner lead screw link (12) is hinged to the inner moving ring (11), and the other end is hinged to the middle of the fixed support link (14).

3. The non-marking electroplating clamping device for cylindrical workpieces according to claim 1, characterized in that, The end effector (15) has a flexible power contact piece embedded in it.

4. The non-marking electroplating clamping device for cylindrical workpieces according to claim 1, characterized in that, The end effector (15) has an anti-slip elastic layer on the surface that contacts the workpiece.

5. The non-marking electroplating clamping device for cylindrical workpieces according to claim 2, characterized in that, It also includes conductive lines that extend from the power contact piece of the end effector (15), through the interior of the fixed support link (14), the lower fixed support (16), and the fixed support connecting rod (17), to the external electroplating power source.

6. The non-marking electroplating clamping device for cylindrical workpieces according to claim 1, characterized in that, The outer moving ring (9) and the inner moving ring (11) are provided with balls or threaded sleeves that mate with the corresponding lead screw threads.

7. The non-marking electroplating clamping device for cylindrical workpieces according to claim 1, characterized in that, The output ends of the external drive motor (2) and the internal drive motor (3) are respectively connected to the external drive wheel (4) and the internal drive wheel (5), and the external drive wheel (4) and the internal drive wheel (5) drive the external lead screw (7) and the internal lead screw (8) to rotate respectively.

8. The non-marking electroplating clamping device for cylindrical workpieces according to claim 1, characterized in that, The components in the device that come into contact with the electroplating solution are made of a hard, corrosion-resistant material or a metal material with a corrosion-resistant coating on its surface.

9. A method for traceless electroplating of cylindrical workpieces, characterized in that, The cylindrical part non-marking electroplating clamping device according to any one of claims 1-7, wherein the electroplating process includes: Step 1: Both sets of clamping arm units in the clamping assembly are in the retracted state. The production line hanger moves the clamping device above the workpiece and extends into the workpiece. Step 2: Both sets of clamping arm units in the clamping assembly are extended outward to lift the workpiece, which is then moved sequentially by the production line rack to above the pretreatment, electroplating bath and posttreatment areas. Step 3: The production line hanger immerses the clamping device and the workpiece together in the electroplating solution, ensuring that the workpiece is completely immersed; Step 4: As the electroplating process proceeds, the clamping assembly controls the end effectors of each clamping arm unit to periodically contact and separate from the inner wall of the workpiece according to a set cycle. During this process, it can be ensured that all positions of the workpiece can be in uniform contact with the electroplating solution. Step 5: After electroplating is completed, both sets of clamping arm units in the clamping assembly are pushed outward, so that the end effector is pushed outward and contacts the inner wall of the workpiece. The production line hanger rises up, so that the workpiece is removed from the electroplating solution and the solution on the surface of the workpiece is drained above the electroplating solution tank.

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