Insulation piercing connector and forming process

Abstract

The application relates to an insulation piercing connector and a forming process, and relates to the technical field of insulation piercing connectors. The process comprises the following steps: providing a blade belt and a gasket belt; synchronously feeding the blade belt and the gasket belt into a co-extrusion die head and compounding with molten plastic, continuously extruding a first plastic body, so that the blade belt is exposed on the blade edge side and the rest is embedded in the plastic body, and the gasket belt is completely embedded in the plastic body; cutting to a fixed length; stamping and forming piercing teeth and bolt holes; and covering exposed end faces with plastic elastic second plastic bodies at both ends. The product comprises the first plastic body, the embedded piercing blade, the completely embedded gasket and the second plastic body covering the end faces. The traditional discrete injection molding is reconstructed into a continuous co-extrusion integrated process, the production efficiency is doubled, the positioning precision of the embedded part is high, and the double end face sealing guarantees long-term electrical reliability.

Description

Technical Field

[0001] This application relates to the field of insulating puncture clamp technology, and in particular to an insulating puncture clamp and its molding process. Background Technology

[0002] Insulating piercing clamps are widely used power connection devices in low-voltage distribution networks to achieve conductive connections between main and branch lines without stripping the cable insulation. A typical structure includes an insulating housing, a metal piercing blade embedded within the housing, metal spacers to reinforce the housing structure, and a torque bolt for applying the piercing force. In use, the cable is placed between the upper and lower housings, and tightening the torque bolt forces the piercing blade into the cable insulation and into contact with the internal conductor, thus completing the electrical connection.

[0003] In related technologies, the manufacturing of insulating piercing clamps generally adopts a discrete model of "insert injection molding + assembly". The typical process is as follows: First, independent metal piercing blades and metal gaskets are manufactured separately through stamping; second, these metal inserts are placed one by one into the designated positions of the injection mold by manual or automated equipment; then, the mold is closed and molten plastic is injected into the mold cavity to cover the inserts and form a shell; finally, the injection-molded upper and lower shells are assembled with torque bolts, seals and other components to form the finished product.

[0004] However, injection molding is an intermittent production process, and the placement of inserts relies on manual labor or complex automated equipment, resulting in low production efficiency, poor material utilization, a large amount of semi-finished materials, and high inventory management costs. Summary of the Invention

[0005] In order to improve production efficiency, increase material utilization, and reduce inventory management costs, the purpose of this application is to provide an insulating piercing clamp and its forming process.

[0006] Firstly, the manufacturing process for the insulation piercing clamp provided in this application adopts the following technical solution: A manufacturing process for an insulating piercing clamp includes the following steps: S1. Providing multiple metal strips, including at least one blade strip and at least one pad strip, wherein the pad strip is located on the side of the corresponding blade strip away from the cable contact surface; S2. Simultaneously feeding the blade strip and the pad strip into a co-extrusion die, compounding them with molten plastic within the die, and continuously extruding a first plastic body, exposing the cutting edge side of the blade strip, embedding the remaining portion into the first plastic body, and completely embedding the pad strip into the first plastic body; S3. Cutting the extruded continuous profile to a fixed length into housing units; S4. Punching teeth and bolt holes are stamped onto the housing units; S5. Coating both ends of the housing units along the extrusion direction with an elastic second plastic body, covering the exposed end faces of the blade strip and the pad strip after cutting.

[0007] By adopting the above technical solution, the traditional intermittent, discrete process of "independent stamping of metal inserts → manual placement → injection molding and coating" is reconstructed into a continuous, integrated process of "online synchronous co-extrusion of multi-metal strips → post-stamping functionalization → end-coating and sealing." The blade strip and spacer strip converge synchronously with the molten plastic in the co-extrusion die in continuous roll form. The position of the metal insert is rigidly constrained by the die channel, fundamentally eliminating the positional errors of manual insert placement and the micro-displacement caused by melt impact. The blade strip achieves exposed cutting edges during co-extrusion, and the spacer strip completely covers the insert, significantly shortening the process chain and achieving highly efficient continuous production.

[0008] Optionally, in S4, the piercing teeth are formed by stamping after the blade strip is embedded in the first plastic body.

[0009] By adopting the above technical solution, the aluminum strip with the blade embedded in the plastic body during stamping obtains stable back support from the plastic body. The deviation of the tooth bending angle can be controlled within ±2°, and the forming accuracy is far superior to that of pre-stamping on a thin aluminum strip. The tooth parameters can be flexibly adjusted by changing the stamping die without modifying the expensive co-extrusion die head, resulting in high process flexibility. At the same time, the stamping stroke can simultaneously remove the extremely thin flash left on the blade edge during co-extrusion, completing tooth forming and final cleaning of the functional surface in one process.

[0010] Optionally, in S2, the spacer strip is completely covered by plastic during extrusion, and the spacer strip is located on both sides of the bolt hole axis and does not extend into the bolt hole area; in S4, the bolt hole is formed by stamping in the pure plastic area between the two sets of spacer strips.

[0011] By adopting the above technical solution, "structural enhancement" and "processing convenience" are spatially separated in the design. The spacer strip, as the internal skeleton, is fully embedded in the plastic body to enhance structural strength, while the bolt hole area is a pure plastic structure. Punching only requires cutting the plastic layer, without needing to avoid or cut the metal layer. This results in a long punch life, high punching quality, and a simple and reliable process.

[0012] Optionally, in S2, an independent guide channel corresponding to each metal strip is provided in the co-extrusion die head, and a follow-up positioning pin is provided at the entrance of the channel, so as to achieve dynamic and precise positioning by using the positioning holes pre-punched on the metal strip.

[0013] By adopting the above technical solution, the spatial orientation and relative position of each metal strip are guaranteed by the rigidity of the mold, and the relative position deviation of the four metal strips can be controlled within ±0.1mm. The follow-up positioning pin moves synchronously with the mechanical lock of the metal strip during positioning, and the positioning action is not affected by the speed fluctuation of the production line. The uniformity of the insulation partition thickness is guaranteed, and electrical safety and reliability are ensured.

[0014] Optionally, prior to S5, the method also includes: coating both ends of the housing with a hydrophobic penetrating liquid, allowing it to penetrate into the micro-gaps of the metal-plastic interface to form a waterproof layer.

[0015] By employing the above technical solution, the low-viscosity permeating liquid actively penetrates into the micron-level interface gaps formed by the difference in thermal shrinkage rates between metal and plastic through capillary action and solidifies, thus blocking the moisture penetration path from the inside. The internal waterproof dam formed by the permeating liquid, together with the subsequent plastic-coated second plastic body, constitutes a dual sealing system of "internal blocking and external sealing," fundamentally ensuring long-term electrical insulation reliability.

[0016] Optionally, in S5, the second plastic body integrally forms a cross-sectional covering surface and a blade covering surface during the encapsulation process. The cross-sectional covering surface covers the exposed metal and plastic end faces at both ends of the housing, and the blade covering surface wraps around the outer surface of the strip block assembly for embedding the blade, and opens at the corresponding piercing tooth position for the piercing tooth to extend.

[0017] By adopting the above technical solution, a single plastic coating process simultaneously achieves three functions: end face sealing, metal end face insulation protection, and blade holder outline coverage. This reduces the number of independent sealing rings, end caps, and other parts, simplifying the assembly process. The openings on the covered surface precisely define the exposed area of ​​the piercing teeth, ensuring piercing functionality while maximizing the protection of the rest of the blade.

[0018] Optionally, in S2, the first plastic body is integrally formed into a strip block group composed of multiple spaced strip blocks during co-extrusion; in S5, the blade covering surface is formed into an insert that is embedded in the gap between adjacent strip blocks during plastic coating.

[0019] By adopting the above technical solution, the insert fills the gaps in the strip block assembly, and after cooling, forms multiple physical locking points, firmly fixing the second plastic body to the first plastic body. The bonding strength far exceeds that of simple surface bonding. Under thermal cycling or mechanical vibration, the physical interlocking structure can effectively resist peeling tendencies, while providing lateral support to the strip blocks and enhancing the overall rigidity of the tool holder.

[0020] Optionally, in S5, the second plastic body is a TPE elastomer or silicone rubber.

[0021] By adopting the above technical solutions, materials can be flexibly selected according to product positioning and application scenarios. TPE has moderate hardness, good processability, low injection molding temperature, and high cost performance, making it suitable for conventional applications; silicone rubber has excellent high and low temperature resistance and low compression set, making it suitable for extreme climatic conditions. Both solutions can meet the requirements for sealing and insulation protection.

[0022] Optionally, in S4, by changing the punches with different cross-sectional shapes, an upper housing with arc-shaped or square bolt holes and a lower housing with strip-shaped bolt holes can be manufactured on the same production line.

[0023] By adopting the above technical solution, the housings are identical first plastic bodies before plastic coating. The difference between the upper and lower housings is achieved only through the punch configuration of the stamping die. The two production lines can share most of the molds and process parameters, significantly reducing industrial investment. The strip bolt holes on the lower housing provide installation and adjustment margins, facilitating the alignment of the upper and lower housings and adapting to cables of different diameters.

[0024] Secondly, this application provides an insulating piercing clamp, manufactured by any of the above-mentioned production processes, and adopts the following technical solution: An insulating piercing clamp includes: a first plastic body, which is an integrally formed insulating structural component; a piercing blade, embedded in the first plastic body, with its cutting edge exposed and its root and both sides covered by the first plastic body, and piercing teeth stamped on the piercing blade; a pad strip, completely embedded inside the first plastic body, located on the side of the piercing blade away from the cable contact surface; and a second plastic body, covering both ends of the first plastic body along the extrusion direction, covering the exposed end faces of the piercing blade and the pad strip.

[0025] By adopting the above technical solution, the piercing blade and the spacer strip are simultaneously embedded into the first plastic body during co-extrusion. The metal-plastic interface is bonded by both chemical bonding with adhesive resin and mechanical locking with anchoring holes, resulting in high bonding strength and preventing delamination over long-term use. The spacer strip, acting as a reinforcing skeleton, is completely embedded inside the plastic body, occupying no external space and resulting in a simple shell shape. The second plastic body covers both exposed end faces, and together with the interface passivation and waterproof layer, a double seal ensures long-term electrical safety. The upper and lower shells are symmetrical in height, and the single-part design halves the mold input, requiring only flipping and pairing during assembly.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. The traditional intermittent discrete process is reconstructed into a continuous integrated process, which greatly improves production efficiency. The metal strip is continuously fed at a speed of 1.2m / min, and the theoretical output is 5-10 times that of the traditional injection molding process. The material utilization rate can reach more than 92%.

[0027] 2. The blade strip and the pad strip are dynamically and precisely positioned in the co-extrusion die through independent guide channels and follow-up positioning pins, with a position deviation of ≤±0.1mm, which in principle ensures the uniformity of the insulation wall thickness and the reliability of electrical isolation.

[0028] 3. The piercing teeth are formed by post-stamping after the blade is embedded in the plastic body. The plastic body provides stable back support, resulting in high precision and consistency in tooth formation. Furthermore, the tooth profile parameters can be flexibly adjusted by changing the stamping die, making the process highly flexible.

[0029] 4. The pad strip is completely enclosed inside the first plastic body as a reinforcing skeleton. At the same time, it is located on both sides of the bolt hole axis and does not extend into the bolt hole area, so that the bolt hole stamping area is a pure plastic structure, which takes into account both structural strength and processing convenience.

[0030] 5. The combination of the interface passivation waterproof layer formed by the hydrophobic penetrating liquid and the three-dimensional encapsulation structure of the elastic second plastic body constitutes a dual sealing system of "internal interface passivation + external elastic encapsulation", which in principle completely blocks the penetration path of moisture along the metal-plastic interface.

[0031] 6. The upper and lower shells have the same structure before the second plastic body is coated. They are distinguished only by the configuration of the punch cross-section shape and the presence or absence of the clamping joint in the coating mold. The highly symmetrical design greatly reduces equipment investment and management costs.

[0032] 7. The piercing blade and the gasket are embedded into the first plastic body simultaneously during co-extrusion. The interface is combined with chemical bonding and mechanical locking, resulting in high bonding strength. The gasket is completely built-in, and the shell has a simple shape. The second plastic body wraps around the end face in three dimensions, and together with the interface passivation waterproof layer, it forms a double seal, ensuring long-term electrical safety and reliability. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this application; Figure 2 This is a schematic diagram of the structure of Embodiment 1 of this application; Figure 3 This is a process flow diagram of Embodiment 2 of this application.

[0034] Explanation of reference numerals in the attached drawings: 1. First plastic body; 2. Piercing blade; 3. Pad strip; 4. Second plastic body; 5. Strip block assembly; 6. Clip strip assembly; 7. Clip connector; 8. Torque bolt. Detailed Implementation

[0035] The following is in conjunction with the appendix Figure 1 -Appendix Figure 3 This application will be described in further detail below. Example

[0036] This embodiment provides an insulating puncture clamp product, referencing... Figure 1 , Figure 2 The insulating piercing clamp consists of an upper housing and a lower housing. Before the second plastic coating, the upper and lower housings have the same structure, distinguished only by the configuration of the punch cross-section shape in the subsequent stamping process and the presence or absence of a clamping joint in the coating mold. During assembly, the lower housing is rotated 180° relative to the upper housing and then connected by torque bolts.

[0037] Each housing comprises a first plastic body, two sets of piercing blades, two sets of pads, and a second plastic body.

[0038] The first plastic body is made of glass fiber reinforced PA66 material and is a one-piece molded main structural component. Two sets of symmetrically arranged strip-shaped blocks are integrally formed on the first plastic body, both sets located on the side of the first plastic body facing the cable. A gap is left between adjacent strip-shaped blocks; this gap allows for the insertion of inserts during the subsequent encapsulation of the second plastic body, enhancing the bonding strength. Bolt holes for torque bolts are provided on the first plastic body; these bolt holes are through-holes penetrating the first plastic body and are located between the two sets of strip-shaped blocks. Specifically, the bolt holes on the upper shell have a circular or square cross-section; the bolt holes on the lower shell have a strip-shaped cross-section.

[0039] Two sets of snap-fit ​​strips are integrally formed on the side of the first plastic body away from the cable. The two sets of snap-fit ​​strips are symmetrically arranged on the two edges of the first plastic body away from the cable. Each set of snap-fit ​​strips consists of multiple snap-fit ​​strips arranged at intervals, and a slot is formed between adjacent snap-fit ​​strips. This slot is used to cooperate with the second plastic body to form a mechanical lock to enhance the connectivity of the second plastic body.

[0040] The piercing blade is made of 6061-T6 aluminum alloy with a thickness of 1.5-2.0 mm. One piercing blade is embedded within each set of strip blocks, extending along the length of the first plastic body. Two sets of piercing teeth are stamped onto the piercing blade, with the tips facing the cable contact surface and fully exposed. The root and sides of the piercing blade are covered by the first plastic body, while the cutting edge is exposed, occupying 40%-50% of the blade's cross-section. Multiple anchoring holes are provided in the area where the piercing blade is embedded within the corresponding strip block set; these holes are filled with the plastic material of the first plastic body, forming a mechanical locking mechanism.

[0041] The spacer strip is made of cold-rolled steel sheet, 2-3mm thick, with a passivated and rust-proof surface. Two sets are arranged symmetrically, positioned below the corresponding piercing blades (away from the cable contact surface), and separated from the blades by a plastic insulating partition. The spacer strip is completely embedded within the first plastic body, entirely covered by it on all sides, with its two ends exposed along its length. The spacer strip is located on both sides of the bolt hole axis, not extending into the bolt hole area. Multiple anchoring holes are provided on the spacer strip, filled with the plastic material of the first plastic body, forming a mechanical locking mechanism.

[0042] The second plastic body is made of TPE elastomer with a Shore A hardness of 60-70. The second plastic body partially covers the first plastic body and includes two integrally formed cross-sectional covering surfaces, two blade covering surfaces, and two snap-fit ​​surfaces. The two cross-sectional covering surfaces respectively cover the two exposed end faces of the first plastic body, the piercing blade, and the padding strip along their length. The two blade covering surfaces cover the outer surfaces of the blade and the strip block assembly for inserting the blade, connecting the two cross-sectional covering surfaces. Each blade covering surface has an integrally formed insert that extends into the space between adjacent strip blocks within the strip block assembly. The two snap-fit ​​surfaces are located in the snap-fit ​​grooves of the snap-fit ​​strip assembly, connecting the two cross-sectional covering surfaces. Each blade covering surface has an opening at the piercing tooth for the piercing tooth to extend from, and the second plastic body forms an arc shape at the piercing tooth to mate with the cable.

[0043] In addition, a snap-fit ​​connector is integrally formed on the outer surface of the second plastic body covering the upper housing, which is used to connect the end cap.

[0044] The first plastic body has a hydrophobic, penetrating liquid-coated interfacial passivation and waterproof layer at both ends, which penetrates into the micro-gaps of the metal-plastic interface. The second plastic body wraps around the end face area from the outside, forming a double-sealing system together with the waterproof layer.

[0045] Within the same housing, the space between the roots of the left and right piercing blades embedded in the first plastic body, as well as the space between the roots of the piercing blades and the corresponding spacers, is completely filled and isolated by the material of the first plastic body, with a minimum plastic partition thickness of 3.0 mm. The exposed cutting edges of the left and right piercing blades are insulated from each other by the spatial electrical clearance provided by the strip block assembly and the creepage distance along the surface of the strip block assembly, with the electrical clearance being no less than 3.0 mm.

[0046] The upper and lower housings are connected by torque bolts. The torque bolts pass through bolt holes in both housings, with the bolt head contacting the bottom surface of the first plastic body of the upper housing. The threaded end of the bolt passes through the first plastic body of the lower housing and is threadedly connected to a fastening nut. A washer is fitted between the fastening nut and the first plastic body of the lower housing. A helical spring is fitted onto the smooth portion of the torque bolt, with both ends of the helical spring abutting against the upper and lower housings respectively. Example

[0047] This embodiment provides a continuous manufacturing method for an insulating piercing clamp, referring to... Figure 3 This is used to manufacture insulating piercing clamps as described in Example 1. The upper and lower housings follow the exact same process path, including the following stages: metal strip preparation → co-extrusion of four metal strips (first plastic body) → cooling, shaping and length cutting → stamping → plastic coating of the second plastic body → assembly and packaging.

[0048] I. Metal Strip Preparation Stage This stage involves preparing four metal strips: two aluminum alloy blade strips and two steel pad strips.

[0049] 1. Preparation of aluminum alloy strip for blades 6061-T6 aluminum alloy strip with a thickness of 1.5-2.0mm is selected. The aluminum strip is fed into a precision punch press in a flat state, and the multi-station progressive die is used to complete the blanking of the blade outline, the array of anchor holes, and the positioning holes. The anchor holes are filled with plastic during co-extrusion to form a mechanical lock. A process allowance is reserved on the edge of the aluminum strip for the stamping piercing teeth.

[0050] 2. Preparation of pad steel strip Cold-rolled steel sheet with a thickness of 2.0-3.0mm is selected, and the surface is passivated for rust prevention. The steel strip is fed into another precision punch press to punch out the shape of the spacer strip, the array of anchor holes, and the positioning holes. The spacer strip is smaller than the cutting blade and does not extend into the subsequent bolt hole area. The spacer strip is completely embedded inside the first plastic body, serving as a structural reinforcement skeleton.

[0051] 3. Metal strip surface treatment and preheating The four metal strips were roughened by online sandblasting (Ra=25-35μm) and then preheated to 180±10℃ by medium frequency induction heating.

[0052] 2. Four-stage co-extrusion molding of metal strips (forming the first plastic body) Four preheated metal strips are simultaneously fed into the co-extrusion die. The die contains four independent guide channels: the left and right blade aluminum strip channels keep the aluminum strips vertical with the cutting edge facing the cable contact surface; the left and right spacer steel strip channels are located below the blades, in a horizontal position, with the spacers positioned on either side of the future bolt hole axis. Each channel entrance is equipped with a follow-up positioning pin, utilizing pre-punched positioning holes on the metal strips to achieve dynamic and precise positioning (deviation ≤ ±0.1mm).

[0053] Three extruders supply the bonding resin (PP-g-MAH, 0.15mm thickness) and the base plastic (PA66-GF30) respectively. Extrusion temperatures: bonding resin 185-220℃, PA66 240-265℃, die 260℃. Metal strip feed speed 1.2m / min.

[0054] The following plastic structure is integrally formed in a co-extrusion mold: Strip block assembly: Through mold cavity design, two sets of symmetrical raised strip structures are formed on one side of the cable contact surface for embedding piercing blades. A gap is left between adjacent strip blocks, which allows for the insertion of inserts during the subsequent second plastic body encapsulation, enhancing the bonding force.

[0055] Clip-on strip assembly and slots: Multiple clip-on strips are formed at intervals on both edges of the side away from the cable, and slots are formed between adjacent clip-on strips for engaging with the second plastic body.

[0056] Encapsulation characteristics: The aluminum strip blade has its back and sides completely covered with plastic, while the edge side is only covered up to the root of the blade, leaving most of the edge exposed (40%-50% of the cross-section). The die exit scraping device removes excess material, leaving only a very thin flash.

[0057] The padding steel strip is completely covered by plastic, with its upper surface, bottom surface, and all sides embedded inside the first plastic body.

[0058] Insulation and isolation: During co-extrusion, the molten plastic completely fills the space between the roots of the left and right blade aluminum strips embedded in the plastic body, as well as the space between the roots of the blade aluminum strips and the spacer steel strip, forming a plastic insulation wall with a minimum thickness of 3.0 mm. The exposed cutting edges of the left and right blades are open spaces, and their insulation relies on sufficient electrical clearance and creepage distance provided by the strip block assembly.

[0059] III. Cooling, Shaping, and Length Cutting Stage The extruded profile is cooled to 50-60℃ using a dry forming die (15-18℃) and a water bath (20-25℃), with a traction tension of 50-80N. After cooling, a PE protective film is applied. A servo flying saw then cuts the profile to a fixed length. After cutting, the two ends of the padding steel strip in the extrusion direction are exposed at the cut surface.

[0060] IV. Stamping Forming Stage 1. Puncture teeth stamping forming The housing unit enters a precision stamping press, where two sets of piercing teeth are stamped into the exposed area of ​​the blade edge. The plastic body provides stable back support. Simultaneously, the stamping process removes burrs from the blade edge, followed by high-pressure cleaning.

[0061] 2. Bolt hole punching The housing unit enters the second stamping machine, where bolt holes penetrating the first plastic body are directly punched into the solid plastic area between the two sets of spacers. The difference in cross-sectional shape between the bolt holes of the upper and lower housings is achieved in this process by changing to punches with different cross-sectional shapes: the upper housing production line uses arc-shaped or square punches, while the lower housing production line uses strip-shaped punches. The stamping direction is from the bottom surface of the housing towards the blade to ensure a flat bottom surface.

[0062] 3. Post-stamping inspection 3D vision inspection of tooth profile, 2D vision inspection of bolt hole shape and position, and initial measurement of insulation resistance (DC1000V).

[0063] V. Second Plastic Body Coating Stage 1. Preprocessing Remove the protective film and clean both ends. Spray a hydrophobic penetrating liquid (viscosity ≤30cps, surface tension ≤28mN / m) onto both ends to penetrate into the micro-cracks at the metal-plastic interface and form a waterproof dam. Preheat both ends of the shell to 80-100℃ and apply a coupling agent.

[0064] 2. Plastic coating molding The housing unit is placed into the encapsulation mold of the vertical injection molding machine. The mold is equipped with an elastic protective pressure block to hold down the piercing teeth. The second plastic body material is TPE elastomer (hardness Shore A 60-70), the barrel temperature is 180-210℃, the mold temperature is 30-50℃, and the injection pressure is 60-80MPa.

[0065] The following structures are precisely formed using plastic coating molds: Cross-section covering surface: precisely covers the exposed metal and plastic end faces at both ends of the shell.

[0066] Blade covering and inserts: These cover the outer surface of the blade holder (strip block assembly) and form "inserts" that embed into the gaps between the strip blocks, creating a strong physical fit. Openings are made at corresponding positions for the piercing teeth to extend out.

[0067] Snap-fit ​​surface: Filled into the slot on the back of the first plastic body to form a mechanical lock.

[0068] Cable contact arc surface: An arc-shaped recess is formed in the piercing tooth area to match the outer periphery of the cable.

[0069] Clip-on connector (upper shell only): The upper shell coating mold has a cavity for forming the "clip-on connector" to connect the end cap. This is a difference in molds between the upper and lower shell production lines during the coating stage.

[0070] VI. Assembly and Packaging Stage Remove the upper and lower housing units, and rotate one 180° so that the tool table faces are opposite each other. Insert the torque bolt, and put on the helical spring, so that the two ends of the spring abut against the upper and lower housings respectively. Screw in the fastening nut and place the washer. The helical spring provides preload force to keep the product in the maximum opening position. After the accessories are sealed, package them together with the pre-assembled kit and put them into storage.

[0071] The implementation principle of this embodiment is as follows: This embodiment provides a continuous manufacturing method for insulating piercing clamps. Its core principle is to reconstruct the discrete and intermittent process of "independent stamping of metal inserts → manual placement of inserts → injection molding" in the traditional manufacturing of piercing clamps into a continuous integrated process of "online synchronous co-extrusion of multi-metal strips → post-stamping functionalization → end plastic sealing".

[0072] Unlike traditional processes where pre-stamped individual blades and spacers are placed one by one into the injection mold, this method allows two aluminum alloy blade strips and two steel spacer strips to converge synchronously with the molten plastic in a continuous roll within the co-extrusion die. Under the constraint of independent guide channels and moving positioning pins, the four metal strips pass through the die with a preset spatial posture and precise relative position (deviation ≤ ±0.1mm). Under pressure, the molten plastic fills all the gaps between the metal strips in one go and covers the designated surfaces of each metal strip. After cooling, it forms the first plastic profile with four sets of precisely embedded metal functional components. This "synchronous embedding" principle fundamentally eliminates the positional errors of manual placement of inserts, while utilizing the high temperature and pressure conditions during co-extrusion to achieve high-strength chemical adhesion and mechanical locking at the metal-plastic interface.

[0073] Within the co-extrusion die, differentiated encapsulation strategies are employed to address the varying functional requirements of the blades and spacers. For the piercing blades, the die head flow channel design ensures that the molten plastic only encapsulates the blade root, with 40%-50% of the cross-section exposed on the cutting edge side via an exit scraping device, leaving only a very thin flash. This "high-proportion exposure" strategy eliminates the need to remove the thick sacrificial layer before subsequent piercing tooth stamping, significantly shortening the process chain. For the spacers, a complete encapsulation strategy is used, embedding them entirely within the plastic body, exposing only the two end faces after fixed-length cutting. The design of the spacers being located on both sides of the bolt hole axis and not extending into the bolt hole area ensures that the bolt hole stamping area is a pure plastic structure, simplifying and reliably implementing the punching process.

[0074] The piercing teeth are not pre-formed on the aluminum strip, but rather formed through a precision stamping process after the aluminum strip has been embedded in the plastic body. The core advantage of this "post-stamping" principle is that the plastic body provides stable back support for the stamping, resulting in far superior tooth forming accuracy compared to pre-stamping on a thin aluminum strip. Tooth parameters (number of teeth, tooth shape, angle, etc.) can be flexibly adjusted by changing the stamping die, eliminating the need to modify expensive co-extrusion dies, thus offering high process flexibility. Simultaneously, the stamping stroke removes the extremely thin flash remaining on the cutting edge, achieving tooth forming and final cleaning of the functional surface in a single process. Bolt holes are also formed by stamping at this stage; the difference in cross-sectional shape between the upper and lower housing bolt holes is achieved by changing punches with different cross-sectional shapes.

[0075] After being cut to a fixed length, the blade and spacer strip are exposed at both ends in the extrusion direction. This method involves coating the end faces with a low-viscosity hydrophobic penetrating liquid, which then penetrates into the micron-level gaps at the metal-plastic interface through capillary action and solidifies, forming an internal waterproof dam. Subsequently, a secondary plastic coating process is used to inject elastic second plastic bodies into both ends of the shell, completely covering the exposed end faces from the outside with the cross-sectional covering surface. Inserts on the blade's covering surface are embedded into the gaps of the strip block assembly, and the snap-fit ​​surface fills the grooves, forming multiple mechanical locks. This dual sealing system of "internal interface passivation + external elastic coating" fundamentally blocks the penetration path of moisture along the metal-plastic interface, ensuring long-term electrical insulation reliability.

[0076] The upper and lower shells manufactured using this method are identical first plastic body structures before the second plastic body is coated. They are distinguished only by the configuration of the punch cross-section shape during the bolt hole stamping process and the presence or absence of a retaining connector in the coating mold. This highly symmetrical design allows two production lines to share most of the molds, process parameters, and equipment, significantly reducing equipment investment and production management complexity for industrialization. During assembly, simply rotating one shell 180° aligns the piercing blades of the two shells, completing the pairing. Example

[0077] This embodiment is basically the same as Embodiment 2, except that the second plastic body material is replaced with silicone rubber (hardness Shore A50) instead of TPE, and the encapsulation mold temperature is adjusted accordingly to 120-150℃. Silicone rubber has better high and low temperature resistance (-60℃ to 200℃) and lower compression set, making it suitable for applications under extreme climatic conditions. Example

[0078] This embodiment is basically the same as Embodiment 2, except that: polyphenylene oxide (PPO) is used instead of PA66-GF30 for the main plastic, and a modified polystyrene system compatible with PPO is used for the adhesive resin. The co-extrusion temperature is adjusted accordingly to 270-285℃. PPO has extremely low water absorption (<0.07%), excellent dimensional stability, and is suitable for harsh operating environments with high temperature and high humidity.

[0079] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A manufacturing process for an insulating piercing clamp, characterized in that, Includes the following steps: S1. Provide multiple metal strips, including at least one blade strip and at least one pad strip, wherein the pad strip is located on the side of the corresponding blade strip away from the cable contact surface; S2. The blade strip and the spacer strip are simultaneously fed into the co-extrusion die head, compounded with the molten plastic in the die head, and the first plastic body is continuously extruded, so that the cutting edge side of the blade strip is exposed and the rest part is embedded in the first plastic body, and the spacer strip is completely embedded in the first plastic body. S3. Cut the extruded continuous profile into shell units of a fixed length; S4. Punch teeth and bolt holes are formed on the housing unit; S5. The housing unit is coated with an elastic second plastic body at both ends along the extrusion direction, covering the exposed end faces of the blade strip and the pad strip after cutting.

2. The manufacturing process of the insulation piercing clamp according to claim 1, characterized in that, In S4, the piercing teeth are formed by stamping after the blade strip is embedded in the first plastic body.

3. The manufacturing process of the insulation piercing clamp according to claim 1, characterized in that, In S2, the pad strip is completely covered by plastic during extrusion, and the pad strip is located on both sides of the bolt hole axis and does not extend into the bolt hole area; in S4, the bolt hole is formed by stamping in the pure plastic area between the two sets of pad strips.

4. The manufacturing process of the insulation piercing clamp according to claim 1, characterized in that, In S2, an independent guide channel corresponding to each metal strip is provided in the co-extrusion die head. The channel entrance is provided with a follow-up positioning pin, and dynamic and precise positioning is achieved by using the pre-punched positioning holes on the metal strip.

5. The manufacturing process of the insulation piercing clamp according to claim 1, characterized in that, Prior to S5, it also included: coating the two end faces of the shell with a hydrophobic penetrating liquid, allowing it to penetrate into the micro-gaps of the metal-plastic interface to form a waterproof layer.

6. The manufacturing process of the insulation piercing clamp according to claim 1, characterized in that, In S5, the second plastic body integrally forms a cross-sectional covering surface and a blade covering surface during the plastic coating process. The cross-sectional covering surface covers the exposed metal and plastic end faces at both ends of the housing. The blade covering surface wraps around the outer surface of the strip block assembly for embedding the blade and opens at the position of the corresponding piercing tooth for the piercing tooth to extend.

7. The manufacturing process of the insulation piercing clamp according to claim 6, characterized in that, In S2, the first plastic body is integrally formed into a strip block group composed of multiple spaced strip blocks during co-extrusion; in S5, the blade covering surface is formed into an insert that is embedded in the gap between adjacent strip blocks during plastic coating.

8. The manufacturing process of the insulation piercing clamp according to claim 1, characterized in that, In S5, the second plastic body is a TPE elastomer or silicone rubber.

9. The manufacturing process of the insulation piercing clamp according to claim 1, characterized in that, In S4, by changing punches with different cross-sectional shapes, upper housings with arc-shaped or square bolt holes and lower housings with strip-shaped bolt holes are manufactured on the same production line.

10. An insulating piercing clamp, manufactured by the production process described in any one of claims 1 to 9, characterized in that, include: The first plastic body is an integrally molded insulating structural component; The piercing blade is embedded in the first plastic body, with its cutting edge exposed and its root and sides covered by the first plastic body. The piercing blade has piercing teeth stamped on it. The pad is completely embedded inside the first plastic body and is located on the side of the piercing blade away from the cable contact surface; The second plastic body covers both ends of the first plastic body along the extrusion direction, covering the exposed end faces of the piercing blade and the pad strip.

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