A punch structure for a plastic film thermal punching machine and the plastic film thermal punching machine.

Abstract

This invention provides a punch structure for a plastic film hot punching machine and the machine itself, relating to the technical field of plastic film hot punching machines. The punch structure includes a punch body, an ejector pin assembly, and a heat-insulating sleeve. The ejector pin assembly is housed within the punch body and includes an ejector plate, an ejector tube, a liquid delivery tube, and a drive component. The ejector plate, ejector tube, and drive component are connected sequentially. The drive component drives the ejector tube to move axially along the punch body. The ejector plate lifts the waste material after punching the plastic film to allow it to fall off. A cooling channel is formed within the ejector plate. The ejector tube is a hollow structure with liquid passage holes. The liquid delivery tube passes through the ejector tube and communicates with the cooling channel. The heat-insulating sleeve is fitted over the ejector tube and passes through the punch body. This invention effectively solves the problem of molten material adhesion during hot punching by integrating the cooling channel within the ejector plate and using the heat-insulating sleeve to block heat conduction in the punch.

Description

Technical Field

[0001] This invention relates to the field of hot punching machines for plastic films, and specifically to a punch structure for a hot punching machine for plastic films and the hot punching machine itself. Background Technology

[0002] Currently, thermal perforation technology for plastic films primarily achieves perforation by piercing and melting the plastic film with heated needle components. Because the edges of the perforations are smooth and burr-free after heat shrinkage, this method is widely used in the processing of packaging materials for food, clothing, and leather products. Common thermal perforation devices typically include a needle roller and a support roller that works in conjunction with it. The needle roller surface is equipped with several needle components, and heat is conducted to these needle components through an internal heating element, causing them to melt and penetrate the plastic film instantly upon contact, forming a perforation.

[0003] However, existing hot punching devices still have the following shortcomings in practical use: After the hot needle penetrates the plastic film, the molten plastic easily adheres to the surface of the needle component. If the adhesion is significant, it can tear the film when the needle component withdraws, causing problems such as punching tears, film thinning and elongation, and reduced strength, seriously affecting product quality. At the same time, the adhered waste material gradually accumulates on the needle component, not only contaminating the mold surface but also increasing subsequent punching resistance, worsening hole diameter consistency, and even clogging the needle component. To address this, some solutions attempt to set up auxiliary demolding structures near the needle component to physically separate the waste material, or to arrange cooling functions in different parts of the mold to reduce temperature. However, these auxiliary structures are generally set up independently of the needle component. The ejection component itself gradually increases in temperature due to heat radiation and heat conduction during repeated operation, and is still prone to secondary adhesion with the molten waste material. The ejection effect decreases with the extension of working time, resulting in insufficient reliability in long-term operation and difficulty in meeting the needs of continuous production. Summary of the Invention

[0004] In order to solve the problems in the related technology, the present invention provides a punch structure plastic film hot punching machine for use in plastic film hot punching machine.

[0005] To achieve the above objectives, the technical solution adopted by the present invention includes: According to a first aspect of the present invention, a punch structure for a plastic film thermal punching machine is provided, comprising: The punch body is formed into a tubular structure; A ejector assembly is installed inside the punch body. The ejector assembly includes an ejector plate, a ejector tube, a liquid inlet tube, and a drive component. The ejector plate, the ejector tube, and the drive component are connected in sequence. The drive component is used to drive the ejector tube to move axially along the punch body. The ejector plate is used to lift the waste material after the plastic film is punched so that it falls off. A cooling channel is formed inside the ejector plate. The ejector tube is formed into a hollow structure and a liquid passage hole is opened on the side wall of the ejector tube near the drive component. One end of the liquid inlet tube passes through the ejector tube and communicates with the cooling channel. The other end of the liquid inlet tube passes through the liquid passage hole and exits the ejector tube. A heat insulation sleeve is fitted over the top pipe and passes through the punch body.

[0006] Optionally, the punch body includes an installation part, a heating part, and a punching part connected in sequence. The installation part is used to be detachably installed in the plastic film hot punching machine and connected to the corresponding drive device. The heating part is used to be heated by the heating element. The punching part is used to perform hot punching on the plastic film. The perforated portion includes a reduced-diameter section and a perforated section connected to each other. The reduced-diameter section includes a first end and a second end disposed opposite to each other. The radial dimension of the first end is greater than the radial dimension of the second end. Furthermore, the radial dimension of the reduced-diameter section gradually decreases in the direction from the first end to the second end. The perforated section is connected to the second section, and the radial dimension of the perforated section is the same as the radial dimension of the second end.

[0007] Optionally, the end of the perforated section away from the reduced diameter section is formed into an annular cutting edge, and the cutting edge angle is between 15° and 30°.

[0008] Optionally, the heat insulation sleeve includes a cylindrical body and an installation ring connected to each other. The cylindrical body is sleeved outside the top pipe and passes through the heating part and the perforated part. The installation ring is installed in the installation part and is located between the liquid passage hole and the top plate.

[0009] Optionally, the driving component is configured as a pneumatic driving device, and the ejector pin assembly further includes a plurality of reset components spaced circumferentially along the punch body. The plurality of reset components are disposed between the driving component and the mounting ring, and one end of the reset component is connected to the mounting portion and the other end is connected to the ejector pin, so as to automatically reset the ejector pin when the pneumatic driving device is depressurized.

[0010] Optionally, the mounting portion includes a mounting body, a first ring body, and a second ring body. A through-hole is formed in the mounting body for the top pipe to pass through, and the liquid passage hole is located in the through-hole. The first ring body is mounted in the through-hole near the heating portion and is used to mount the mounting ring. The second ring body is mounted in the through-hole away from the heating portion and is used to mount the reset member.

[0011] Optionally, the radial dimension of the ejector plate is smaller than the inner diameter of the punch body and larger than the outer diameter of the heat insulation sleeve, and the end of the punch body away from the drive member protrudes from the end of the heat insulation sleeve away from the drive member, with a height difference of 1 mm to 5 mm between the two.

[0012] Optionally, the ejector plate includes a first plate and a second plate connected coaxially, the radial dimension of the first plate is larger than the radial dimension of the second plate, the first plate is connected to the ejector tube, a plurality of air jet holes are provided on the surface of the first plate away from the ejector tube, and an air jet channel communicating with the air jet holes is formed in the first plate. The ejector assembly also includes an air supply tube, on which an air passage hole is formed opposite to the liquid passage hole. One end of the air supply tube passes through the top tube and communicates with the jet flow channel, and the other end of the air supply tube passes through the air passage hole and exits the top tube. The cooling channels are formed within the second plate.

[0013] Optionally, a plurality of the jet holes are arranged at circumferential intervals along the punch body, and the jet direction of the plurality of the jet holes is inclined toward the axial direction of the punch body.

[0014] According to a second aspect of the present invention, a hot punching machine for plastic film is also provided, comprising a driving device, a heating element, and a punch structure for a hot punching machine for plastic film as described in any of the technical solutions of the first aspect of the present invention, wherein the driving device is connected to the mounting portion for driving the punch body to perform hot punching of plastic film, and the heating element is mounted on the heating portion for heating the heating portion.

[0015] Beneficial effects: 1. First, by integrating the cooling channel into the inside of the ejector plate, the ejector plate is in a low-temperature state when performing the ejection action. This can accelerate the cooling and solidification of the molten waste at the moment of contact, reduce the adhesion force, and at the same time use physical pushing force to peel the waste off the punch surface. This can achieve the dual synergistic effect of "cooling and reducing adhesion" and "physical ejection", thereby overcoming the defects of the separate setting of the cooling structure and ejection structure in the prior art and the lack of functional coordination, and systematically improving the problem of molten material adhesion.

[0016] Secondly, the ejector pin assembly of the present invention is integrally inserted into the tubular punch body, which allows the ejection action to be performed along the punch axis. It can intervene instantly when the punch retracts, and eject the waste material before it has been fully cooled and solidified. At the same time, the liquid delivery pipe is inserted into the ejector tube and led out through the liquid passage hole. The pipeline routing does not occupy external space, and the axial movement of the ejector tube does not interfere with the fixed routing of the liquid delivery pipe, ensuring the continuous and stable supply of coolant and the smooth execution of the ejection action.

[0017] Third, the present invention divides the punch body into an installation part, a heating part, and a punching part. The punching part is further composed of a reduced diameter section and a constant diameter punching section. The gradient structure of the reduced diameter section can reduce puncture resistance and narrow the melting range. The constant diameter punching section ensures that the hole diameter is uniquely determined by the outer diameter of the punching section, which can guarantee the consistency of the hole diameter and the neatness of the hole edge. The functional partitioning can also optimize the heat conduction path, facilitate the decoupling of heating and installation functions, and enable quick replacement and maintenance of the punch.

[0018] Fourth, the heat insulation sleeve of the present invention is sleeved outside the top tube and inserted into the punch body, forming a physical thermal barrier layer between the punch body and the ejector pin assembly. This can effectively reduce the conduction of high temperature from the punch to the top tube and the ejector plate, making the cooling effect of the cooling channel on the ejector plate less susceptible to interference from the high temperature environment of the punch, and allowing the low temperature state of the ejector plate to be maintained continuously during long-term continuous operation.

[0019] Fifth, the present invention uses a pneumatic drive device to push the jacking pipe and the ejector plate out, which has a fast response speed and sensitive action; the reset component makes the jacking pipe automatically retract after the air pressure is removed, which can realize the simple logic of "single signal control", and multiple reset components are set at intervals along the circumference to make the reset force evenly distributed, which can avoid the jacking pipe from deflecting or getting stuck, and ensure the long-term stability and reliability of the ejection action.

[0020] Sixth, the mounting body of the present invention has a cavity that provides space for the jacking pipe and pipeline to pass through. The first ring provides a precise positioning reference for the mounting ring of the heat insulation sleeve, and the second ring provides a stable mounting base for the reset component. Each ring is relatively independent, so that each auxiliary component of the jacking pin assembly has a clear positioning reference, ensuring assembly accuracy and consistency, and facilitating the processing and individual replacement of each component.

[0021] Seventh, the jet holes and jet channels provided on the first plate of the present invention enable the ejector plate to spray airflow to assist in the stripping of waste material while physically ejecting; the jetting function and the cooling function are arranged in layers in space and do not interfere with each other, and the ejector plate after cooling makes the sprayed airflow have a certain low temperature, which further accelerates the cooling and solidification of waste material; the jet holes are distributed circumferentially and inclined axially, so that the airflow forms a composite flow field with both pushing and stripping effects in the circumference of the waste material, thereby effectively improving the thoroughness of demolding and the adaptability to film materials of different thicknesses.

[0022] 2. Other beneficial effects or advantages of the present invention will be described in detail in the specific embodiments. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of 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.

[0024] in: Figure 1 This is a three-dimensional structural schematic diagram of the punch structure for a plastic film thermal punching machine provided in an exemplary embodiment of the present invention. Figure 2 This is a three-dimensional structural schematic diagram from another perspective of the punch structure for a plastic film thermal punching machine provided in an exemplary embodiment of the present invention. Figure 3 This is a three-dimensional structural diagram of a punch body provided in an exemplary embodiment of the present invention; Figure 4 This is a partial cross-sectional structural diagram of the punch body provided in an exemplary embodiment of the present invention; Figure 5 This is a schematic diagram of the assembly structure of the ejector pin assembly and the heat insulation sleeve provided in an exemplary embodiment of the present invention; Figure 6 This is a three-dimensional structural diagram of a pin assembly provided in an exemplary embodiment of the present invention.

[0025] Explanation of the labels in the attached drawings: 100- Punch structure for a plastic film thermal punching machine; 101- Heating element; 1- Punch body; 11- Mounting part; 111- Mounting body; 1111- Receiving cavity; 112- First ring body; 113- Second ring body; 12- Heating part; 13- Punching part; 131- Diameter reduction section; 132- Punching section; 2- Ejector pin assembly; 21- Ejector plate; 211- First plate body; 2111- Air jet hole; 212- Second plate body; 22- Top tube; 221- Liquid passage hole; 222- Air passage hole; 23- Liquid delivery pipe; 24- Driving component; 25- Reset component; 26- Air delivery pipe; 3- Heat insulation sleeve; 31- Cylinder body; 32- Mounting ring. Detailed Implementation

[0026] 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 some embodiments of the present invention, but not all embodiments.

[0027] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0028] To facilitate a clearer and more accurate understanding of the technical solutions of this invention by those skilled in the art, the existing related technologies and their technical problems will be described in more detail below.

[0029] Thermal perforation technology for plastic films is an important process in the processing of packaging materials, composite materials, and agricultural mulch films. Taking composite concrete curing films as an example, the surface film needs to have good isolation properties, while the bottom film needs to have good water permeability, which requires perforation processing on the film. Thermal perforation has significant advantages over manual perforation, laser perforation, and purely mechanical perforation: manual perforation is difficult to control precisely in terms of position and size, is labor-intensive, inefficient, and unsuitable for large-scale production; laser perforation equipment has a complex structure, high cost, and occupies a large space; purely mechanical perforation tools are prone to damage, resulting in uneven perforation and low hole penetration, and can only process thinner film materials. Therefore, thermal perforation technology has become the most widely used perforation method at present.

[0030] A typical plastic film thermal perforation device includes a needle roller, a rubber roller, and a film support roller. The needle roller has a hollow roller structure with several needle components radially arranged on its surface. A heating element (such as a heating tube) is installed inside the roller to conduct heat to each needle component. The rubber roller and needle roller are arranged opposite each other, and the plastic film passes between them. The heated needle components on the needle roller complete the perforation through thermal melting upon contact with the plastic film. The device has an unwinding device and a rewinding device at the front and rear, respectively, to achieve continuous production. Some improved designs have an array of threaded holes on the surface of the needle roller. The needle components are sealed to the roller via threaded sections. By installing needle components on threaded holes with different spacing, the perforation density can be adjusted. Additionally, some designs employ a stamping structure with an upper and lower die. The upper die is driven by a cylinder for lifting, and the lower die contains an electric heating element electrically connected to a power source to achieve thermal melting perforation.

[0031] However, existing thermal drilling technology faces a significant technical challenge in practical applications—molten material adhesion. During the penetration of the plastic film by the hot needle, the high temperature on the needle surface (typically far exceeding the plastic's melting point) causes the plastic in the contact area with the needle tip to melt instantaneously. When the needle withdraws from the film, the molten plastic solidifies upon cooling and adheres to the needle surface, forming a layer of solidified plastic residue. If the adhesion is strong, the needle withdrawal can also tear the film, causing drilling tears, film thinning and elongation, and reduced strength—all quality problems. More seriously, with each drilling attempt, the adhesive gradually accumulates on the needle surface, altering not only the effective dimensions and surface finish of the needle but also leading to poorer hole diameter consistency, increased drilling resistance, and even clogging of the needle, severely impacting the long-term stable operation of the equipment.

[0032] In view of this, the present invention provides a novel solution, namely, a punch structure for a plastic film thermal punching machine and the machine itself. The technical concept of the present invention lies in integrating the cooling and ejection functions into the same ejector assembly, and achieving thermal isolation between the ejector assembly and the heating punch. Specifically, by inserting the ejector assembly into the hollow punch body, the ejector plate simultaneously serves as the working end of the cooling medium and the physical ejection end of the waste material; the coolant is directly transported to the cooling channel inside the ejector plate via a delivery pipe inserted within the ejector tube, providing targeted cooling to the ejector plate. Simultaneously, a heat-insulating sleeve fitted outside the ejector tube blocks the heat conduction path from the punch body to the ejector assembly, ensuring that the ejector plate maintains a low temperature throughout the punching process. Therefore, when the punch completes the drilling and begins to retract, the cooled ejector plate extends under the action of the drive component, physically pushing the cooled and solidified molten waste with significantly reduced adhesion away from the end of the punch. This allows the anti-adhesion effect to be effectively exerted at the critical point where the waste detaches from the punch, thereby achieving a synergistic cooperation between the ejection function and the cooling function in the structure, and systematically improving the problem of molten material adhesion during the hot drilling process.

[0033] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] like Figures 1 to 6As shown, according to a first aspect of the present invention, a punch structure 100 for a plastic film thermal punching machine is provided, comprising a punch body 1, a pin assembly 2, and a heat insulation sleeve 3. The punch body 1 is formed into a tubular structure; the ejector pin assembly 2 is inserted into the punch body 1. The ejector pin assembly 2 includes an ejector plate 21, an ejector tube 22, a liquid delivery tube 23, and a drive member 24. The ejector plate 21, the ejector tube 22, and the drive member 24 are connected in sequence. The drive member 24 is used to drive the ejector tube 22 to move axially along the punch body 1. The ejector plate 21 is used to lift the waste material after the plastic film is punched so that it falls off. A cooling channel is formed inside the ejector plate 21. The ejector tube 22 is formed into a hollow structure and a liquid passage hole 221 is opened on the side wall of the ejector tube 22 near the drive member 24. One end of the liquid delivery tube 23 is inserted into the ejector tube 22 and communicates with the cooling channel. The other end of the liquid delivery tube 23 passes through the liquid passage hole 221 and exits the ejector tube 22. The heat insulation sleeve 3 is sleeved on the outside of the ejector tube 22 and inserted into the punch body 1.

[0035] Through the above technical solution, firstly, in this invention, a cooling channel is formed inside the ejector plate 21. One end of the liquid delivery pipe 23 passes through the hollow ejector tube 22 and communicates with the cooling channel, while the other end passes through the liquid passage hole 221 on the side wall of the ejector tube 22 to connect to an external coolant source. With this structure, coolant can be directly delivered to the cooling channel inside the ejector plate 21 via the liquid delivery pipe 23, directly exchanging heat with the ejector plate 21 to achieve targeted and efficient cooling of the ejector plate 21. Thus, the ejector plate 21, as the actuator that directly contacts and ejects the waste material, can maintain a low temperature before or during each drilling action. When the ejector plate 21 extends and contacts the molten waste material under the action of the drive member 24, the low-temperature ejector plate 21 can quickly absorb the heat from the waste material, accelerating the cooling and solidification of the molten material, thereby significantly reducing the adhesion of the waste material to the ejector plate 21 and the punch surface. Meanwhile, since the coolant acts directly on the ejector plate 21 rather than other parts of the mold, the cooling efficiency is high and the temperature drop is concentrated, which can avoid the dissipation of cooling energy in the conduction path.

[0036] Secondly, in this invention, the heat insulation sleeve 3 is fitted over the top tube 22 and passes through the inside of the punch body 1, forming a physical thermal barrier layer between the punch body 1 and the ejector pin assembly 2. The punch body 1 is at a high temperature during operation, while the ejector pin assembly 2 passes inside the punch body 1. Without heat insulation, the heat from the punch would be continuously transferred to the top tube 22 and the ejector plate 21 through contact and radiation, causing the temperature of the ejector plate 21 to passively rise, thereby weakening the cooling effect of the cooling channel on the ejector plate 21. The heat insulation sleeve 3 effectively reduces the conduction of heat from the punch body 1 to the top tube 22 and the ejector plate 21, making the cooling effect of the cooling channel on the ejector plate 21 less susceptible to interference from the high temperature of the punch, and allowing the low temperature of the ejector plate 21 to be maintained continuously during long-term operation.

[0037] Third, in this invention, the ejector plate 21 simultaneously performs two functions: firstly, it serves as the terminal for the cooling medium, with internal cooling channels to receive direct cooling from the coolant; secondly, it acts as a physical ejection element for the waste material, extending under the action of the drive member 24 to eject the waste. The ejector plate 21 is kept at a low temperature due to the cooling channels and performs the ejection action due to the drive member 24, achieving a high degree of temporal and spatial uniformity between the two functions. When the punch completes drilling and begins to retract, the cooled ejector plate 21 extends immediately. At this time, the ejector plate 21's own temperature is lower than the viscous flow temperature of the plastic, and its contact with the waste not only avoids new adhesion but also accelerates the cooling and solidification of the waste, thus enabling the physical ejection action to be completed with minimal waste adhesion. Compared to existing solutions where the cooling and ejection structures are separate, this structure allows the cooling effect to take effect directly at the moment of ejection, rather than cooling occurring only after ejection is complete.

[0038] Fourth, in this invention, the punch body 1 is formed as a tubular structure, and the ejector pin assembly 2 is entirely inserted inside the tubular structure. The ejector plate 21, the top tube 22, and the drive member 24 are connected sequentially along the axial direction. The infusion tube 23 is inserted inside the top tube 22 and led out through the side wall liquid passage hole 221. The routing of the pipeline does not occupy additional space outside the punch body 1. Thus, the ejector plate 21 is located inside the front end of the punch body 1, and the ejection action is performed along the punch axial direction. After the punch has completed penetration, the drive member 24 can drive the top tube 22 to move the ejector plate 21 forward along the axial direction, extending from the front end of the punch body 1 to push away the waste. Since the ejector pin assembly 2 is coaxially arranged with the punch body 1, the path of the ejector plate 21 directly corresponds to the location of the waste. The ejection action can intervene immediately at the moment the punch retracts, physically stripping the molten waste before it has fully cooled and solidified on the surface of the punch. This coaxial, integrated layout ensures precise spatial and timely ejection action, effectively avoiding action lag or coordination deviation caused by separate ejection structure and punch.

[0039] Fifth, in this invention, one end of the infusion pipe 23 passes through the top pipe 22 and communicates with the cooling channel, while the other end exits through the liquid passage hole 221 on the side wall of the top pipe 22 (it is understood that the size of the liquid passage hole 221 can be larger than that of the infusion pipe 23; for example, the liquid passage hole 221 can be set as an oblong hole to facilitate the movement of the infusion pipe 23). This structure creates a cooperative relationship between the infusion pipe 23 and the top pipe 22 that allows relative movement. That is, when the top pipe 22 moves axially under the action of the driving member 24, the infusion pipe 23 can remain fixed or move along with it. And since the infusion pipe 23 exits through the liquid passage hole 221, its routing does not restrict the axial travel of the top pipe 22. In other words, the coolant delivery channel (infusion pipe 23) and the actuator of the ejection action (top pipe 22) are structurally independent but compactly integrated. The axial movement of the top pipe 22 will not pull or bend the infusion pipe 23, and the presence of the infusion pipe 23 will not hinder the movement of the top pipe 22. Therefore, the stroke of the ejection action is not limited by the cooling pipe layout, and the ejection plate 21 can extend a sufficient distance to effectively eject the waste when needed. At the same time, the supply of coolant remains continuous and stable, and the coordinated operation of the two functions is not interrupted due to motion coordination issues.

[0040] To facilitate a clearer and more accurate understanding of the technical solutions of this invention by those skilled in the art, the working process / working principle of the above technical solutions are explained below.

[0041] In the above technical solution, the punch structure's workflow can be divided into four stages: initial standby, punching and penetration, ejection and demolding, and reset standby. Specifically: I. Initial standby state.

[0042] Before the drilling action begins, the punch structure is in standby mode; Position of ejector assembly 2: When the driving component 24 (such as a cylinder) is not applying driving force, the ejector tube 22 is in the retracted position under the action of the reset component 25 (such as a spring). The ejector plate 21 connected to the ejector tube 22 is located inside the punch body 1, and its end face does not protrude from the front end face of the punch body 1 to avoid interfering with the punch's piercing effect on the plastic film during subsequent drilling.

[0043] Coolant circulation: An external coolant source continuously supplies coolant, which flows into the cooling channels inside the ejector plate 21 through the inlet pipe 23. After heat exchange with the ejector plate 21, it flows back to the external cooling system. The coolant maintains continuous flow within the ejector plate 21, ensuring that the ejector plate 21 remains at a preset low temperature throughout the entire standby and operation process.

[0044] Thermal insulation: The thermal insulation sleeve 3, which is sleeved outside the jacking pipe 22 and passes through the punch body 1, forms a thermal barrier between the punch body 1 and the jacking pipe 22, reducing the heat conduction from the high temperature of the punch body 1 to the jacking pipe 22 and the ejector plate 21.

[0045] II. Drilling and Penetration Stage.

[0046] When the punch structure is driven by an external drive device (such as a needle roller rotation drive mechanism or a cylinder) to move toward the plastic film, it enters the punching and penetration stage. Action of punch body 1: Punch body 1 moves forward as a whole (towards the plastic film), and its front end (punching section 132) first contacts and penetrates the plastic film. As the punch body 1 is heated to a temperature higher than the melting point of the plastic by the heating element 101, the plastic in contact with the front end of the punch melts instantly, and the punch body 1 continues to advance forward until it completely penetrates the plastic film, forming the required hole.

[0047] State of ejector assembly 2: Throughout the entire punching process, ejector assembly 2 remains stationary (i.e., ejector plate 21 does not extend; it can be understood that ejector assembly 2 can move with punch body 1 or remain completely stationary). Ejector plate 21 is located in the inner cavity of punch body 1, and its front end does not contact the plastic film, thus it is not subject to mechanical impact or direct heat melting during the punching process.

[0048] Continuous coolant circulation: During the drilling process, the coolant continuously circulates within the cooling channels of the ejector plate 21, continuously carrying away the heat transferred to the ejector plate 21 via heat radiation or heat conduction from the punch body 1, ensuring that the low-temperature state of the ejector plate 21 is not damaged by the high-temperature environment of the punch.

[0049] III. Ejection and demolding stage.

[0050] When the punch body 1 completes penetration and begins to retract, it enters the ejection and demolding stage; Punch retraction action: The external drive device drives the punch body 1 to move axially backward (away from the plastic film), and the front end of the punch gradually exits from the perforation of the plastic film.

[0051] Molten state: During the punch penetration process, the molten plastic that comes into contact with the front end of the punch remains attached to the front end surface of the punch when the punch is withdrawn, and is in a high-temperature molten or semi-molten state.

[0052] Drive unit 24 is activated: At the moment or shortly after the punch body 1 begins to retract (according to timing control), drive unit 24 (such as a pneumatic cylinder) is triggered, applying driving force to the top tube 22, pushing the top tube 22 forward (towards the plastic film) along the axial direction of the punch body 1.

[0053] Coordinated movement of the infusion tube 23: During the forward movement of the jacking pipe 22, the infusion tube 23 remains fixed or relatively stationary (i.e., follows the movement). Since the infusion tube 23 passes through the jacking pipe 22 and exits through the liquid passage 221, the axial movement of the jacking pipe 22 will not pull or bend the infusion tube 23, and the supply of coolant remains continuous and stable.

[0054] Ejector plate 21 extends: The forward movement of the ejector tube 22 drives the ejector plate 21 to move forward synchronously. The ejector plate 21 extends from the front end of the punch body 1, directly contacting and pushing against the molten waste material attached to the front end surface of the punch.

[0055] Synergistic effect of low-temperature ejection: When the ejector plate 21 extends, it is in a low-temperature state due to the continuous flow of coolant in the cooling channel. When the low-temperature ejector plate 21 comes into contact with the high-temperature molten waste, a significant temperature difference is formed between the two. The ejector plate 21 quickly absorbs the heat of the waste, accelerating the cooling and solidification of the waste, and significantly reducing its adhesion. At the same time, the physical thrust applied forward by the ejector plate 21 pushes the cooled and solidified waste away from the front surface of the punch, causing it to fall off the punch.

[0056] IV. Reset and standby phase.

[0057] After the waste material is pushed away, the punch structure enters the reset phase; Drive component 24 cancels driving force: Drive component 24 (pneumatic cylinder) stops supplying air or reverses direction, canceling the driving force on the jacking pipe 22.

[0058] The reset element 25 drives the top tube 22 to retract: The reset element 25 (such as a spring) releases elastic potential energy, driving the top tube 22 to move backward (away from the plastic film) along the axis of the punch body 1, returning to the retracted position. The ejector plate 21 retracts synchronously into the punch body 1, and its front end face is once again lower than the front end face of the punch body 1.

[0059] Preparing for the next drilling cycle: The punch structure returns to its initial standby state, awaiting the start of the next drilling cycle. Throughout the reset process, the coolant remains in circulation to prepare for the next drilling cycle.

[0060] In one embodiment of the present invention, such as Figures 1 to 4 As shown, the punch body 1 of the present invention may include an installation part 11, a heating part 12 and a punching part 13 connected in sequence. The installation part 11 is used to be detachably installed in the plastic film hot punching machine and connected to the corresponding drive device. The heating part 12 is used to be heated by the heating element 101. The punching part 13 is used to perform hot punching on the plastic film. The perforated portion 13 includes a reduced diameter section 131 and a perforated section 132 connected to each other. The reduced diameter section 131 includes a first end and a second end that are disposed opposite to each other. The radial dimension of the first end is greater than that of the second end. Furthermore, the radial dimension of the reduced diameter section 131 gradually decreases in the direction from the first end to the second end. The perforated section 132 is connected to the second section and the radial dimension of the perforated section 132 is the same as that of the second end.

[0061] In this embodiment, the punch body 1 includes a mounting portion 11, a heating portion 12, and a punching portion 13. Furthermore, the punching portion 13 is designed as a combination of a reduced-diameter section 131 and a constant-diameter punching section 132. This ensures that the constant-diameter structure of the punching section 132 guarantees that the hole diameter is uniquely determined by the outer diameter of the punching section 132, ensuring that the hole diameter produced by different punches is consistent. The gradient structure of the reduced-diameter section 131 can effectively reduce the piercing resistance, making the punch insertion process smoother. The functional partitioning of the mounting portion 11, the heating portion 12, and the punching portion 13 optimizes the heat conduction path on the punch body 1, facilitating the effective heating of the punching section 132 by the heating element 101 while reducing the conduction of heat to the mounting portion 11. Moreover, the functional boundaries of each part are clear, which is beneficial for the processing and manufacturing of the punch body 1 and for quick replacement and maintenance.

[0062] In one embodiment of the present invention, the end of the perforated section 132 away from the diameter reduction section 131 is formed as an annular cutting edge, and the cutting edge angle is between 15° and 30°.

[0063] In existing thermal punching devices, the punch tip is mostly a flat end or a sharp needle tip. A flat end has high puncture resistance but a wide melting range; while a sharp needle tip is easy to penetrate, the contact surface with the plastic film is point-like, resulting in a small initial melting area and insufficient initial puncture. This embodiment sets the end of the punching section 132 away from the diameter reduction section 131 as an annular cutting edge. This changes the contact between the punch tip and the plastic film from surface or point contact to an annular line contact. During puncture, stress is concentrated on the annular line, enabling penetration with less force. Simultaneously, the annular cutting edge structure allows melting to occur along an annular path, facilitating the formation of regular, neat circular hole walls. Furthermore, the cutting edge angle is limited to between 15° and 30°. This angle range ensures sufficient sharpness to reduce puncture resistance while avoiding problems such as insufficient strength, chipping, or wear due to an overly sharp edge, achieving a balance between puncture sharpness and cutting edge durability.

[0064] In one embodiment of the present invention, such as Figure 5 As shown, the heat insulation sleeve 3 of the present invention may include a cylinder body 31 and an installation ring 32 connected to each other. The cylinder body 31 is sleeved on the outside of the top pipe 22 and passes through the heating part 12 and the perforated part 13. The installation ring 32 is installed in the installation part 11 and is located between the liquid passage hole 221 and the top plate 21.

[0065] In this embodiment, the sleeve body 31 is fitted over the top tube 22 and passes through the heating part 12 and the perforated part 13. The mounting ring 32 is installed inside the mounting part 11 and located between the liquid passage hole 221 and the ejector plate 21. In this way, the heat insulation sleeve 3 can form a continuous thermal barrier layer inside the punch body 1, extending from the heating part 12 to the perforated part 13, which can fully isolate the top tube 22 from the high temperature of the punch body 1. The mounting ring 32 is positioned between the liquid passage hole 221 and the ejector plate 21, which can provide a stable installation position for the heat insulation sleeve 3 inside the punch body 1. At the same time, it can also avoid interference with the liquid passage hole 221 and the coolant pipeline, ensuring the stability of the heat insulation effect and the compactness of the structure.

[0066] In addition, it is understood that, in order to further reduce the thermal impact of the heating element 101 on the inside of the jacking pipe 22 (infusion pipe 23 and gas pipe 26), a heat insulation layer may be sprayed on the inner and / or outer walls of the jacking pipe 22.

[0067] In one embodiment of the present invention, such as Figure 1 , Figure 5 and Figure 6 As shown, the driving component 24 of the present invention is configured as a pneumatic driving device, and the ejector pin assembly 2 further includes a plurality of reset components 25 arranged circumferentially along the punch body 1. The plurality of reset components 25 are disposed between the driving component 24 and the mounting ring 32. One end of the reset component 25 is connected to the mounting portion 11, and the other end is connected to the ejector tube 22, so as to automatically reset the ejector tube 22 when the pneumatic driving device is depressurized.

[0068] In this embodiment, the drive unit 24 is configured as a pneumatic drive device, using compressed air as a power source. It has a fast response speed and sensitive action, and can push the jacking tube 22 and the ejector plate 21 to extend in time when the punch retracts. At the same time, a number of reset elements 25 (e.g., springs or elastic bodies) are arranged between the drive unit 24 and the mounting ring 32, distributed circumferentially around the punch body 1. When the air pressure of the pneumatic drive device is removed, the reset elements 25 can automatically retract the jacking tube 22 back to its original position without the need for an additional reverse drive control signal. The combination of pneumatic drive and elastic reset can realize "single signal control" of the ejection action, and the control logic is simple and reliable. The multiple reset elements 25 are arranged circumferentially to ensure that the reset force is evenly distributed around the jacking tube 22, which can prevent the jacking tube 22 from deflecting or jamming due to uneven force during the reset process.

[0069] In one embodiment of the present invention, such as Figure 4As shown, the mounting portion 11 of the present invention may include a mounting body 111, a first ring 112, and a second ring 113. A through-hole accommodating cavity 1111 is formed in the mounting body 111. The accommodating cavity 1111 is used for the top tube 22 to pass through, and the liquid passage hole 221 is located in the accommodating cavity 1111. The first ring 112 is installed at one end of the accommodating cavity 1111 near the heating portion 12 and is used to install the mounting ring 32. The second ring 113 is installed at one end of the accommodating cavity 1111 away from the heating portion 12 and is used to install the reset member 25.

[0070] In this embodiment, a through-hole accommodating cavity 1111 is formed within the mounting body 111 for the top tube 22 to pass through. A liquid passage hole 221 is located within the accommodating cavity 1111, providing space for the coolant pipeline to pass through. A first ring 112 is installed at the end of the accommodating cavity 1111 near the heating part 12 and is used to install the mounting ring 32, ensuring precise fixation of the heat insulation sleeve 3. A second ring 113 is installed at the end of the accommodating cavity 1111 away from the heating part 12 and is used to install the reset member 25, providing a stable mounting base for the reset member 25. With this structure, each auxiliary component of the ejector pin assembly 2 has a clear positioning reference within the mounting part 11, ensuring assembly accuracy and consistency. Furthermore, each ring is relatively independent, facilitating processing and replacement.

[0071] In one embodiment of the present invention, such as Figure 2 and Figure 5 As shown, the radial dimension of the ejector plate 21 of the present invention is smaller than the inner diameter of the punch body 1 and larger than the outer diameter of the heat insulation sleeve 3. Furthermore, the end of the punch body 1 away from the drive member 24 protrudes from the end of the heat insulation sleeve 3 away from the drive member 24, and the height difference between the two is 1 mm to 5 mm.

[0072] This design allows the ejector plate 21 to slide smoothly within the inner cavity of the punch body 1 without interference, and also enables the ejector plate 21 to effectively cover the end of the punch tube 22 and apply ejection force. Simultaneously, the height difference between the punch body 1 and the heat insulation sleeve 3 is 1 mm to 5 mm. This height difference defines the relative position between the ejector plate 21 and the front end of the punch when the ejector plate 21 is retracted, ensuring that the heat insulation sleeve 3 does not protrude beyond the front end of the punch body 1 and interfere with drilling in the standby state. Furthermore, the ejector plate 21 has sufficient stroke to push away waste material when extended. The 1 mm to 5 mm height difference ensures an effective ejection distance while preventing the ejector plate 21 from extending too far and causing excessive compression or damage to the membrane material.

[0073] In one embodiment of the present invention, such as Figure 5 and Figure 6As shown, the ejector plate 21 of the present invention may include a first plate 211 and a second plate 212 coaxially connected. The radial dimension of the first plate 211 is larger than the radial dimension of the second plate 212. The first plate 211 is connected to the ejector tube 22. A plurality of jet holes 2111 are provided on the surface of the first plate 211 away from the ejector tube 22. A jet flow channel communicating with the jet holes 2111 is formed in the first plate 211. The ejector pin assembly 2 also includes an air supply pipe 26. An air passage hole 222 is formed on the ejector tube 22, which is opposite to the liquid passage hole 221. One end of the air supply pipe 26 passes through the ejector tube 22 and communicates with the jet flow channel. The other end of the air supply pipe 26 passes through the air passage hole 222 and exits the ejector tube 22. A cooling flow channel is formed in the second plate 212.

[0074] In this embodiment, the introduction of the jet function allows the ejector plate 21 to spray airflow onto the interface between the waste and the punch while physically ejecting the waste. The impact and purging force of the airflow assists in the removal of the waste. Even in areas where direct contact with the ejector plate 21 is difficult, the airflow can still play a role, making it easier for the waste to detach from the punch surface. The coaxial connection structure between the first plate 211 and the second plate 212 spatially separates the cooling function (second plate 212) and the jet function (first plate 211) into layers, ensuring they do not interfere with each other. After the cooling channel cools the second plate 212, the low temperature is transferred to the first plate 211 through heat conduction, causing the ejected airflow to also carry a certain low temperature, further accelerating the cooling and solidification of the waste and reducing its adhesion. The gas pipe 26 is independently led out through the air passage 222 on the side wall of the top pipe 22, and runs independently from the liquid pipe 23. Both are installed inside the top pipe 22 but do not interfere with each other, preventing the gas pipe and liquid pipe from tangling or colliding inside the top pipe 22. In this way, physical ejection, airflow purging and low-temperature cooling can achieve a triple synergistic effect on the same ejector plate 21, making the demolding effect more reliable, especially suitable for thicker or more viscous plastic film materials.

[0075] In one embodiment of the present invention, a plurality of jet holes 2111 are arranged at circumferential intervals along the punch body 1, and the jet direction of the plurality of jet holes 2111 is inclined toward the axial direction of the punch body 1.

[0076] In this embodiment, the jet holes 2111 are distributed circumferentially, allowing the ejected airflow to cover all circumferential directions of the punch tip. This simultaneously applies a purging force to the entire circumferential edge of the waste material, preventing waste residue from remaining due to areas unaffected by airflow. The jet direction is inclined towards the punch axis, causing the airflow to generate axial and radial components when impacting the waste material. The axial component pushes the waste material along the punch withdrawal direction to assist ejection, while the radial component subjects the waste material to an outward expanding force, helping to "peel" the waste material from the punch surface rather than merely "push" it away, resulting in a better peeling effect. Simultaneously, the inclined jet airflow can form a swirling or diffused flow field around the punch tip, allowing the purging effect to cover a wider area, reducing purging dead zones, and further ensuring complete removal of waste material. This improves the stability of the punching quality and the reliability of continuous mold operation.

[0077] According to a second aspect of the present invention, a plastic film hot punching machine (not shown) is also provided, including a driving device (not shown), a heating element 101, and a punch structure 100 for a plastic film hot punching machine according to any one of the technical solutions of the first aspect of the present invention. The driving device is connected to the mounting part 11 to drive the punch body 1 to perform hot punching of the plastic film, and the heating element 101 is mounted on the heating part 12 to heat the heating part 12.

[0078] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A punch structure for a plastic film thermal punching machine, characterized in that, include: The punch body (1) is formed into a tubular structure; The ejector assembly (2) is installed inside the punch body (1). The ejector assembly (2) includes an ejector plate (21), a top tube (22), a liquid inlet tube (23), and a drive member (24). The ejector plate (21), the top tube (22), and the drive member (24) are connected in sequence. The drive member (24) is used to drive the top tube (22) to move along the axial direction of the punch body (1). The ejector plate (21) is used to lift the waste material after the plastic film is punched so that it falls off. A cooling channel is formed inside the ejector plate (21). The top tube (22) is formed into a hollow structure and a liquid passage hole (221) is opened on the side wall of the top tube (22) near the drive member (24). One end of the liquid inlet tube (23) is installed inside the top tube (22) and communicates with the cooling channel. The other end of the liquid inlet tube (23) passes through the liquid passage hole (221) and exits the top tube (22). The heat insulation sleeve (3) is sleeved outside the top pipe (22) and passes through the punch body (1).

2. The punch structure for a plastic film thermal punching machine according to claim 1, characterized in that, The punch body (1) includes an installation part (11), a heating part (12) and a punching part (13) connected in sequence. The installation part (11) is used to be detachably installed in the plastic film hot punching machine and connected to the corresponding drive device. The heating part (12) is used to heat the heating element (101). The punching part (13) is used to hot punch the plastic film. The perforated portion (13) includes a reduced diameter section (131) and a perforated section (132) connected to each other. The reduced diameter section (131) includes a first end and a second end disposed opposite to each other. The radial dimension of the first end is greater than that of the second end. In the direction from the first end to the second end, the radial dimension of the reduced diameter section (131) gradually decreases. The perforated section (132) is connected to the second section and the radial dimension of the perforated section (132) is the same as that of the second end.

3. The punch structure for a plastic film thermal punching machine according to claim 2, characterized in that, The end of the perforated section (132) away from the reduced diameter section (131) is formed into an annular cutting edge, and its cutting edge angle is between 15° and 30°.

4. The punch structure for a plastic film thermal punching machine according to claim 2, characterized in that, The heat insulation sleeve (3) includes a cylindrical body (31) and an installation ring (32) connected to each other. The cylindrical body (31) is sleeved outside the top pipe (22) and passes through the heating part (12) and the perforated part (13). The installation ring (32) is installed in the installation part (11) and is located between the liquid passage hole (221) and the top plate (21).

5. The punch structure for a plastic film thermal punching machine according to claim 4, characterized in that, The drive unit (24) is configured as a pneumatic drive device. The ejector pin assembly (2) also includes a plurality of reset members (25) arranged circumferentially along the punch body (1). The plurality of reset members (25) are arranged between the drive unit (24) and the mounting ring (32). One end of the reset member (25) is connected to the mounting part (11) and the other end is connected to the ejector tube (22) to enable the ejector tube (22) to automatically reset when the pneumatic drive device is depressurized.

6. The punch structure for a plastic film thermal punching machine according to claim 5, characterized in that, The mounting portion (11) includes a mounting body (111), a first ring (112), and a second ring (113). A through-hole (1111) is formed in the mounting body (111), which is used for the top tube (22) to pass through. The liquid passage (221) is located in the cavity (1111). The first ring (112) is mounted on the end of the cavity (1111) near the heating portion (12) and is used to mount the mounting ring (32). The second ring (113) is mounted on the end of the cavity (1111) away from the heating portion (12) and is used to mount the reset member (25).

7. The punch structure for a plastic film thermal punching machine according to claim 1, characterized in that, The radial dimension of the ejector plate (21) is smaller than the inner diameter of the punch body (1) and larger than the outer diameter of the heat insulation sleeve (3). Furthermore, the end of the punch body (1) away from the drive member (24) protrudes from the end of the heat insulation sleeve (3) away from the drive member (24), with a height difference of 1 mm to 5 mm between the two.

8. The punch structure for a plastic film hot punching machine according to any one of claims 1-7, characterized in that, The ejector plate (21) includes a first plate (211) and a second plate (212) coaxially connected. The radial dimension of the first plate (211) is larger than that of the second plate (212). The first plate (211) is connected to the ejector pipe (22). A plurality of jet holes (2111) are provided on the surface of the first plate (211) away from the ejector pipe (22). A jet flow channel communicating with the jet holes (2111) is formed in the first plate (211). The ejector assembly (2) also includes an air supply pipe (26), and an air passage hole (222) is formed on the ejector tube (22) opposite to the liquid passage hole (221). One end of the air supply pipe (26) passes through the ejector tube (22) and communicates with the jet flow channel, and the other end of the air supply pipe (26) passes through the air passage hole (222) and exits the ejector tube (22). The cooling channels are formed within the second plate (212).

9. The punch structure for a plastic film thermal punching machine according to claim 8, characterized in that, A plurality of the jet holes (2111) are arranged circumferentially around the punch body (1), and the jet direction of the plurality of jet holes (2111) is inclined toward the axial direction of the punch body (1).

10. A plastic film thermal punching machine, characterized in that, The device includes a drive unit, a heating element (101), and a punch structure for a plastic film hot punching machine according to any one of claims 1-9. The drive unit is connected to the mounting portion (11) for driving the punch body (1) to perform hot punching of the plastic film, and the heating element (101) is mounted on the heating portion (12) for heating the heating portion (12).

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