Lightweight gilding buffer mechanism

Abstract

The application discloses a kind of light gilding buffer mechanism, including rack and the input roller group being arranged on rack, gilding mechanism, output roller group, first floating roller is equipped below input roller group, second floating roller is equipped below output roller group;Input roller group includes the first, second input roller of same horizontal plane, and first floating roller is located directly below them;Output roller group includes the first, second output roller of same horizontal plane and corresponding upper pressure roller, and second floating roller is located directly below them;First floating roller is made of lightweight alloy material with lower density than steel material.The application replaces traditional solid metal load roller by lightweight alloy floating roller, cooperates double-roller segmented buffer layout, significantly reduces the load weight of buffer mechanism, reduces the demand of forward tension and equipment energy consumption, improves tension dynamic response speed, reduces paper damage and mechanical wear, guarantees the stability and precision of gilding processing, and is suitable for various web label gilding equipment.

Description

Technical Field

[0001] This invention relates to the field of label printing and hot stamping equipment technology, and in particular to a lightweight hot stamping buffer mechanism, which is mainly used in the hot stamping process of roll paper labels, packaging paper and other substrates. It is used to achieve tension buffering and constant tension control matching during the continuous paper conveying process, which can effectively reduce the load on the traction mechanism, improve the dynamic response speed of tension, and ensure the accuracy and stability of hot stamping processing. Background Technology

[0002] Hot stamping is one of the core surface finishing technologies in the packaging and printing industry. It involves transferring electroplated aluminum foil onto the substrate surface through heating and pressure, creating a metallic graphic effect. It is widely used in food packaging, tobacco and alcohol labels, and daily chemical product packaging. With the downstream market's increasing demands for precision and production efficiency in hot stamping products, high-speed rotary hot stamping equipment has become the mainstream development direction in the industry. Constant tension control during paper feeding is the core technical aspect that determines the registration accuracy and product yield of hot stamping.

[0003] In the paper conveying system of hot stamping equipment, the buffer mechanism is a key component for achieving tension stability. Its core function is to absorb tension fluctuations during paper conveying, providing buffer margin for the closed-loop control of the unwinding and traction mechanisms, and preventing paper stretching, breakage, or misalignment of the hot stamping pattern caused by sudden tension changes. Currently, the most widely used type in the industry is the gravity-loaded buffer mechanism, which uses the weight of a solid metal load roller to act on the paper, forming a stable reverse tension reference. This, combined with the speed adjustment of the unwinding and traction mechanisms, achieves constant tension control.

[0004] Authorization announcement number CN219546260U discloses a hot stamping film conveying buffer mechanism for a hot stamping machine. This mechanism uses a connecting plate, spring, and pressure plate structure to press and limit the hot stamping film, thus solving the problem of film conveying deviation. However, this solution is a passive limiting buffer, relying solely on spring force to press the film surface, which cannot form a stable gravity-based tension reference. The tension control accuracy is significantly affected by spring fatigue and temperature changes. Furthermore, this structure can only limit the lateral deviation of the film and cannot absorb longitudinal tension impacts. Under conditions of high-speed start-stop and speed switching, its buffering capacity is severely insufficient, making it unsuitable for the high-precision tension control requirements of paper hot stamping.

[0005] CN103921543A discloses a floating adjustable rotary hot stamping device, which sets a floating hot stamping roller between the hot stamping foil feeding mechanism and the hot stamping roller for tension buffering of electroplated aluminum foil. However, the floating roller in this solution is only designed for hot stamping foil and does not include structural design for buffering the conveying of the printing paper; moreover, its floating roller adopts a conventional solid steel roller body, which relies on guide rail slide and intermediate transmission components for drive. The roller body itself is heavy and has a high moment of inertia. When the paper tension fluctuates instantaneously, the displacement response of the floating roller is lagging and cannot quickly offset the tension impact; at the same time, the large roller body weight directly increases the load on the traction mechanism, resulting in an increase in the overall power consumption of the equipment.

[0006] Authorization announcement number CN111572212B discloses a floating roller mechanism for digital label printing machines, which achieves tension adjustment of the floating roller through a lever structure, counterweight balance block, and cylinder. This solution adjusts the tension by using additional counterweight and cylinder thrust, but the structure is complex and difficult to debug. Moreover, the floating roller itself still uses a conventional steel roller body, which has a large self-weight, and the inertia problem is not solved. At the same time, this solution only sets up a single floating roller structure, which cannot independently buffer the paper tension before and after the hot stamping process. The tension fluctuations generated during the hot stamping pressure will be transmitted in reverse to the unwinding side, causing tension coupling interference between the front and rear sides and affecting the stability of hot stamping registration.

[0007] In addition to the solutions disclosed in the aforementioned patent documents, traditional hot stamping buffer mechanisms in the industry generally adopt methods such as... Figure 1 The solid metal load roller structure shown: The paper conveying line passes through the load roller G3. The load roller relies on its own gravity G3 and the constant reverse tension F1 provided by the unwinding mechanism to provide the reverse force required for tension buffering. The traction mechanism provides a constant positive tension F3. In order to ensure that the paper is continuously conveyed under constant tension, the mechanical condition must be met: F3>F1+G3.

[0008] That is, the forward tension F3 must be greater than the sum of the reverse tension F1 and the weight of the load roller G3. Because traditional load rollers are generally made of solid carbon steel or stainless steel, resulting in a large roller weight, this technical solution suffers from the following significant technical drawbacks: Excessive positive tension requirement and high mechanical load: The self-weight of solid metal load rollers can typically reach tens of kilograms. To overcome this gravity load, the traction mechanism needs to provide greater positive tension, which directly increases the mechanical load on components such as traction motors, transmission gears, and bearings. Long-term operation can easily cause component fatigue damage and shorten the service life of the equipment.

[0009] The equipment has high energy consumption and high operating costs: According to the power calculation formula P=F・v, under the premise of constant conveying speed v, the larger the positive tensile force F3, the higher the output power requirement of the drive motor. For industrial production equipment that operates continuously for a long time, a large tensile load will cause significant energy waste, increase production and operating costs, and does not meet the requirements of green manufacturing development.

[0010] Slow tension response and low control accuracy: According to the formula of moment of inertia and Newton's laws of motion, the greater the mass of the load roller, the greater its moment of inertia and linear motion inertia. When the paper tension fluctuates instantaneously (such as when the equipment starts or stops, speeds change, or hot stamping pressure is applied), the floating roller cannot quickly follow the tension change to adjust its displacement, resulting in a lag in the response of the tension closed-loop control and poor dynamic accuracy of constant tension control, which ultimately affects the registration accuracy of the hot stamping pattern.

[0011] Paper is susceptible to impact damage: When tension changes abruptly, the heavier load rollers generate a large inertial impact force that acts directly on the paper. For substrates with low tensile strength, such as thin label paper and specialty paper, excessive inertial impact can easily cause the paper to stretch and deform, and in severe cases, even break, resulting in production interruption and material waste.

[0012] Severe mechanical wear and short maintenance cycles: The heavy load will accelerate the wear rate of the bearings at both ends of the floating roller, the guide rail slider, and the transmission components. The equipment needs to be frequently lubricated and replaced with vulnerable parts, which increases maintenance costs and downtime, and reduces the overall operating efficiency of the equipment.

[0013] Therefore, how to effectively reduce the load weight of the buffer mechanism, reduce the power consumption of the traction mechanism, improve the response speed of tension fluctuation, and reduce paper damage and mechanical wear while ensuring constant tension control and buffering capacity has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0014] To address the shortcomings of existing technologies, the purpose of this invention is to provide a lightweight hot stamping buffer mechanism. By improving the traditional solid metal load roller to a lightweight alloy floating roller structure and optimizing the segmented layout of the dual floating rollers before and after hot stamping, the load weight of the buffer mechanism is significantly reduced while ensuring constant tension control. This reduces the positive tension requirement and equipment energy consumption, improves the dynamic tension response speed, and reduces paper damage and mechanical wear. This solves the technical problems of heavy load rollers, slow response, high energy consumption, and easy paper damage in existing technologies.

[0015] The above-mentioned objective of this invention is achieved through the following technical solutions: A lightweight hot stamping buffer mechanism includes a frame and an input roller group, a hot stamping mechanism, and an output roller group disposed on the frame. A first floating roller is disposed below the input roller group, and a second floating roller is disposed below the output roller group.

[0016] The input roller assembly includes a first input roller and a second input roller located on the same horizontal plane. The paper passes over the first input roller and the first floating roller in sequence, and then passes over the second input roller. The first floating roller is positioned directly below the first input roller and the second input roller. This arrangement ensures that the gravity of the first floating roller acts perpendicularly on the paper, forming a stable input-side tension reference, while the floating space below provides sufficient buffering margin for tension fluctuations.

[0017] The output roller assembly includes a first output roller and a second output roller located on the same horizontal plane. A third pressure roller is positioned directly above the first output roller, and a fourth pressure roller is positioned directly above the second output roller. A second floating roller is positioned directly below the first and second output rollers. The pressure rollers, in conjunction with the output rollers, clamp and pull the paper, ensuring stable tension on the output side. The second floating roller provides secondary buffering for the tension of the paper after hot stamping, eliminating tension fluctuations caused by the hot stamping process.

[0018] The hot stamping mechanism is located between the input roller group and the output roller group and is used to perform hot stamping on the paper.

[0019] The first floating roller is made of a lightweight alloy material with a density much lower than that of steel, and is used to replace the traditional solid metal load roller.

[0020] Furthermore, the frame is equipped with sensors to detect the position signals of the first floating roller and / or the second floating roller, and to feed the displacement data back to the control system to realize closed-loop constant tension control of the unwinding and traction mechanism.

[0021] Furthermore, the gravity of the first floating roller is defined as GQ, the gravity of the second floating roller as G2, the constant reverse tension provided by the unwinding mechanism as F1, and the constant forward tension provided by the traction mechanism as F3. The mechanical parameters satisfy the relationship: F3 > F1 + G2 + GQ > F1. This mechanical condition ensures that the paper can be continuously conveyed by forward traction, and also ensures that the gravity of the floating rollers can effectively act on the paper, forming a stable tension buffer reference.

[0022] Furthermore, the lightweight alloy material is any one of 6061 aluminum alloy, AZ31 magnesium alloy, and TC4 titanium alloy, which combines high strength, low density, good rigidity, and machinability.

[0023] Furthermore, the first floating roller has a hollow thin-walled roller structure with a roller wall thickness of 1.5mm-3mm. While ensuring the rigidity and roundness accuracy of the roller, the self-weight of the roller is further reduced, and the lightweight effect is improved.

[0024] Furthermore, vertically extending guide rails are provided at both ends of the frame corresponding to the first floating roller and the second floating roller. Sliding sliders are installed at both ends of the roller shafts of the first floating roller and the second floating roller. The sliding sliders slide in cooperation with the guide rails on the corresponding sides to ensure that the floating rollers rise and fall smoothly in the vertical direction and avoid lateral deviation that affects the paper feeding accuracy.

[0025] Furthermore, the sensor is a laser displacement sensor or a wire displacement sensor, which is correspondingly set above or to the side of the stroke of the first floating roller and / or the second floating roller, with a sampling frequency of not less than 1kHz, and can collect the vertical displacement data of the floating roller in real time, providing a high-precision feedback signal for closed-loop control.

[0026] Furthermore, the hot stamping mechanism includes a hot stamping roller and an impression roller arranged opposite each other. The hot stamping roller is equipped with an electric heating tube and a temperature sensor, which can accurately control the hot stamping temperature. The paper passes through the gap between the hot stamping roller and the impression roller, and the electroplated aluminum transfer hot stamping process is completed under heating and pressure conditions.

[0027] Furthermore, both ends of the roller shafts of the third and fourth pressure rollers are connected to a pneumatic pressure adjustment mechanism. This mechanism includes an adjusting screw and a cylinder assembly with adjustable pressure, used to adjust the pressure of the corresponding pressure roller on the output roller. This adapts to the feeding needs of paper of different thicknesses and materials.

[0028] Furthermore, transition guide rollers are provided between the input roller group and the hot stamping mechanism, and between the hot stamping mechanism and the output roller group, to adjust the paper's conveying path and entry angle, ensuring that the paper smoothly enters and leaves the hot stamping mechanism, and avoiding additional tension fluctuations caused by sudden changes in paper angle.

[0029] In summary, compared with the prior art, the present invention has at least one of the following beneficial technical effects: Significantly reduced load weight and mechanical load: This invention replaces the traditional solid steel load roller with a first floating roller made of lightweight alloy material. Combined with a hollow thin-walled structure design, the weight of the first floating roller can be reduced by 60%-75%. Taking a commonly used 320mm wide label hot stamping machine as an example, the traditional solid steel roller weighs approximately 18kg. With the 6061 aluminum alloy hollow thin-walled structure, the roller weight can be reduced to approximately 4.5kg, significantly reducing the overall load on the buffer mechanism and directly lowering the mechanical load on the traction mechanism and transmission components.

[0030] Reducing the forward tension requirement and achieving energy saving and consumption reduction: Due to the significant reduction in the self-weight of the first floating roller, the forward tension F3 required for constant tension control is significantly reduced. According to the mechanical condition F3>F1+G2+GQ, under the same reverse tension F1, the forward tension requirement can be reduced by more than 30%. Correspondingly, the output power of the traction motor is reduced simultaneously, which can reduce equipment operating energy consumption by 20%-30%, effectively reducing production and operating costs, and conforming to the green and low-carbon manufacturing concept.

[0031] Improving dynamic response speed and enhancing constant tension control accuracy: The lightweight floating roller has a small mass and low inertia. According to Newton's second law F=ma, under the same tension change force, the first floating roller can obtain a greater acceleration, enabling it to quickly follow paper tension fluctuations and adjust its displacement. The response speed is more than 50% faster than that of traditional steel load rollers. The tension fluctuation amplitude under high-speed conditions can be controlled within ±1.5%, significantly improving the dynamic accuracy of constant tension control and providing a reliable guarantee for high-precision hot stamping registration.

[0032] Reduce paper impact damage and improve product yield: The inertial force of the lightweight floating roller is greatly reduced. In scenarios of sudden tension changes such as equipment start-up and shutdown, speed switching, and hot stamping pressure, the impact load on the paper is significantly reduced. This can effectively avoid the stretching deformation and breakage of thin and easily stretchable paper, reduce paper scrap rate, and improve production continuity and product yield.

[0033] Reduce mechanical wear and extend equipment maintenance cycle: The lower load weight significantly reduces the wear rate of components such as bearings at both ends of the first floating roller, guide rail sliders, and transmission gears. The service life of vulnerable parts can be extended by 1.5-2 times, reducing the frequency and cost of equipment maintenance, reducing downtime for maintenance, and improving the overall operating efficiency of the equipment.

[0034] Dual-roller segmented buffer for more stable hot stamping tension: This invention sets independent floating roller buffer structures on the input and output sides of the hot stamping mechanism, which can independently control the paper tension before and after hot stamping in segments. This avoids the tension fluctuations generated during the hot stamping pressure process from being transmitted back to the unwinding side, eliminates the coupling interference between the front and rear tensions, makes the paper tension at the hot stamping process more stable, and further improves the consistency of hot stamping quality. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the paper transport circuit principle of a traditional hot stamping buffer mechanism in the prior art; Figure 2 This is a schematic diagram of the overall structure of the lightweight hot stamping buffer mechanism of the present invention.

[0036] Reference numerals: 1. Frame; 2. Input roller group; 21. First input roller; 22. Second input roller; 3. First floating roller; 4. Hot stamping mechanism; 41. Hot stamping roller; 42. Imprinting roller; 5. Output roller group; 51. First output roller; 52. Second output roller; 53. Third pressing roller; 54. Fourth pressing roller; 6. Second floating roller; 7. Sensor; G3. Gravity of conventional load roller; F1. Reverse tension; F3. Forward tension; GQ. Gravity of first floating roller; G2. Gravity of second floating roller. Detailed Implementation

[0037] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0038] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Example

[0040] like Figure 2 As shown, this embodiment provides a lightweight hot stamping buffer mechanism, including a frame 1. The frame 1 is welded from steel profiles and has an anti-rust coating to provide stable installation support for the entire mechanism. An input roller group 2, a hot stamping mechanism 4, and an output roller group 5 are sequentially arranged on the frame 1 along the paper feeding direction. A first floating roller 3 is arranged below the input roller group 2, and a second floating roller 6 is arranged below the output roller group 5. Both floating rollers are vertically and buoyantly mounted on the frame 1.

[0041] The input roller group 2 includes a first input roller 21 and a second input roller 22. The roller shafts of both input rollers are horizontally mounted on the frame 1 via bearing seats, and their central axes are located in the same horizontal plane, with the roller surfaces at the same height. The first input roller 21 is located on the paper entry side and is connected to the upstream unwinding mechanism; the second input roller 22 is located near the hot stamping mechanism 4 and is used to guide the paper to the hot stamping process.

[0042] The first floating roller 3 is positioned directly below the first input roller 21 and the second input roller 22, meaning that the projection of the central axis of the first floating roller 3 onto the horizontal plane lies on the perpendicular bisector of the line connecting the centers of the first input roller 21 and the second input roller 22. The paper's path is as follows: after being drawn from the unwinding mechanism, it descends past the lower surface of the first input roller 21, then extends vertically downwards, past the lower surface of the first floating roller 3, and then extends vertically upwards, past the upper surface of the second input roller 22, before being conveyed to the hot stamping mechanism 4.

[0043] The winding path ensures that the gravity of the first floating roller 3 acts perpendicularly to the paper, resulting in high force transmission efficiency and the formation of a stable input-side tension reference. At the same time, sufficient floating stroke space is reserved below the first floating roller 3. When the paper tension decreases, the floating roller moves downward to release the stored material; when the paper tension increases, the floating roller moves upward to absorb the tension increment, achieving passive tension buffering.

[0044] The first floating roller 3 includes a roller body and a roller shaft. The roller body is made of 6061 aluminum alloy with a density of approximately 2.7 g / cm³, far lower than that of carbon steel (7.85 g / cm³). The roller body has a hollow, thin-walled structure. In this embodiment, the outer diameter of the roller body is 80 mm, and the wall thickness is 2 mm. Three annular reinforcing ribs are evenly arranged along the axial direction inside the roller body to minimize the roller body's weight while ensuring radial rigidity and roundness accuracy. The roller shaft is made of stainless steel and is interference-fitted at both ends of the roller body for connection with sliding components. Actual calculations show that the overall weight (GQ) of this first floating roller 3 is approximately 4.2 kg, while the weight of a solid steel load roller of the same specification is approximately 16 kg, achieving a weight reduction effect of 73.75%.

[0045] Vertically extending guide rails are installed on both sides of the frame 1, corresponding to the two ends of the first floating roller 3. These guide rails are high-precision linear guides, offering low running resistance and high guiding accuracy. A sliding slider is installed at each end of the first floating roller 3's shaft. These sliders slide in conjunction with the corresponding guide rails, restricting the first floating roller 3 to float only vertically, preventing lateral shifts or swaying, and ensuring the straightness and stability of the paper feed. The sliders and guide rails employ a maintenance-free, self-lubricating design, reducing daily maintenance workload.

[0046] A sensor 7 is installed on the frame 1 above the stroke of the first floating roller 3. In this embodiment, the sensor 7 is a laser displacement sensor with a sampling frequency of 2kHz and a measurement accuracy of 0.01mm. The detection end of the sensor 7 is vertically downward aligned with the end of the roller shaft of the first floating roller 3, which can collect the vertical displacement data of the first floating roller 3 in real time and transmit the signal to the PLC control system of the equipment. The control system adjusts the unwinding speed of the unwinding mechanism in real time according to the displacement deviation of the floating roller, so that the first floating roller 3 is always kept near the equilibrium position, realizing constant tension closed-loop control of the paper on the input side.

[0047] The hot stamping mechanism 4, located between the input roller group 2 and the output roller group 5, is the core component for hot stamping processing. In this embodiment, the hot stamping mechanism 4 includes a hot stamping roller 41 and an impression roller 42 arranged vertically opposite each other. The hot stamping roller 41 is located above, and multiple electric heating tubes are evenly arranged axially inside the roller body. It also has a built-in platinum resistance temperature sensor, which can accurately control the roller surface temperature within ±1℃ to meet the hot stamping temperature requirements of different electroplated aluminum materials. The impression roller 42 is located below, and its surface is covered with a high-temperature resistant silicone layer to provide elastic imprinting force and ensure uniform hot stamping pressure.

[0048] The paper passes through the gap between the hot stamping roller 41 and the impression roller 42, while the electroplated aluminum foil passes through the gap simultaneously. Under the combined action of heating and pressure, the metal layer on the electroplated aluminum foil is transferred to the surface of the paper, completing the hot stamping process.

[0049] Transition guide rollers are provided between the input roller group 2 and the hot stamping mechanism 4, and between the hot stamping mechanism 4 and the output roller group 5. The height of the transition guide rollers can be finely adjusted to adjust the angle at which the paper enters and leaves the hot stamping roller gap, ensuring that the paper enters the hot stamping area at a flat angle, avoiding additional tension caused by sudden changes in the paper angle, and ensuring the tension stability of the hot stamping process.

[0050] The output roller group 5 includes a first output roller 51, a second output roller 52, a third pressure roller 53, and a fourth pressure roller 54. The central axes of the first output roller 51 and the second output roller 52 are located in the same horizontal plane and are both horizontally mounted on the frame 1 via bearing seats. The first output roller 51 is located closer to the hot stamping mechanism 4, while the second output roller 52 is located on the paper output side and connected to the downstream traction and winding mechanism.

[0051] The third clamping roller 53 is positioned directly above the first output roller 51, and the fourth clamping roller 54 is positioned directly above the second output roller 52. The roller surfaces of the two clamping rollers are tangentially abutted against the roller surfaces of the corresponding output rollers to form a clamping roller pair, which can form a stable clamping and traction on the paper, prevent the paper from slipping on the roller surface, and ensure the stable transmission of positive tension.

[0052] Both ends of the roller shafts of the third pressure roller 53 and the fourth pressure roller 54 are connected to pneumatic pressure adjustment mechanisms. These mechanisms include an adjusting screw and a cylinder assembly, and the pressure is adjustable. The adjusting screw is threaded onto the mounting base of the frame 1, and its lower end is connected to the end of the roller shaft of the pressure roller via the cylinder assembly. The cylinder assembly is sleeved on the outside of the adjusting screw, with its two ends abutting against a spring seat and the mounting base, respectively. By rotating the adjusting screw, the compression amount of the cylinder assembly can be adjusted, thereby changing the pressure of the pressure rollers on the output rollers to adapt to the feeding needs of paper with different thicknesses and friction coefficients, thus broadening its applicability.

[0053] The second floating roller 6 is located directly below the first output roller 51 and the second output roller 52, and its installation structure is exactly the same as that of the first floating roller 3: the roller body also adopts a hollow thin-walled structure of 6061 aluminum alloy, and both ends are slidably engaged with the guide rails on the frame 1 through sliding sliders, allowing it to float freely in the vertical direction. The paper's path is as follows: after being output from the hot stamping mechanism 4, it passes over the upper roller surface of the first output roller 51, extends vertically downwards past the lower roller surface of the second floating roller 6, then extends vertically upwards past the upper roller surface of the second output roller 52, and is finally pulled out by the traction mechanism.

[0054] The second floating roller 6 is a solid steel load roller, weighing approximately 16 kg. The second floating roller 6 mainly provides secondary buffering for the tension of the paper after hot stamping, absorbing the tension fluctuations on the output side caused by hot stamping pressure and the disengagement of the printing roller, ensuring the stability of the paper tension on the output side, and avoiding tension fluctuations from affecting subsequent processes such as die-cutting and winding.

[0055] A sensor 7 is also installed on the frame 1 at the position corresponding to the second floating roller 6. This sensor is used to detect the displacement signal of the second floating roller 6 in real time and feed it back to the control system to adjust the traction speed of the traction mechanism, thereby achieving constant tension closed-loop control on the output side.

[0056] In this embodiment, the constant reverse tension force exerted on the paper by the unwinding mechanism is defined as F1, the constant forward tension force exerted on the paper by the traction mechanism is defined as F3, the weight of the first floating roller is defined as GQ, and the weight of the second floating roller is defined as G2. To ensure stable paper feeding and proper buffering function, each force must meet the following conditions: F3>F1+G2+GQ>F1; Among them, F3>F1+G2+GQ ensures that the positive tension can overcome the reverse tension and the gravity of the two floating rollers, and pull the paper forward continuously; F1+G2+GQ>F1 ensures that the gravity of the floating roller can effectively act on the paper, forming a stable tension reference, so that the floating roller has the ability to buffer tension fluctuations.

[0057] Compared to the mechanical condition F3>F1+G3 in the traditional mechanism, the forward tension F3 required by this invention is significantly reduced because GQ+G2 is much smaller than G3. In this embodiment, the reverse tension F1 is set to 50N, and the weight of the traditional load roller G3 is about 160N. Therefore, the forward tension F3 in the traditional solution needs to be greater than 210N. However, in this solution, GQ+G2 is about 82N, and the forward tension F3 only needs to be greater than 132N. The forward tension requirement is reduced by about 37%, which corresponds to a reduction of about 30% in traction motor power, resulting in significant energy savings.

[0058] During normal operation, the paper is continuously fed under the pull of the traction mechanism. Two floating rollers tension the paper under their own weight, creating a stable tension. When the unwinding speed is slightly faster than the conveying speed, the paper tension decreases, and the floating rollers move downwards under gravity to store excess paper. When the unwinding speed is slightly slower than the conveying speed, the paper tension increases, pulling the floating rollers upwards to release the stored paper, thus passively absorbing tension fluctuations. Simultaneously, sensors monitor the position of the floating rollers in real time, feeding the signal back to the control system to dynamically adjust the unwinding and traction speeds, ensuring the floating rollers remain in a balanced position and achieving high-precision constant tension control.

[0059] Because the first floating roller is made of lightweight alloy material, it has low weight and low inertia. When instantaneous tension fluctuations occur, the floating roller can quickly move up and down to respond without generating large inertial impact forces. This improves the response speed and accuracy of tension control and prevents the paper from deforming and breaking due to excessive impact. At the same time, the lighter load also reduces wear on components such as guide rails and bearings, extending the service life of the equipment. Example

[0060] This embodiment is basically the same in structure as Embodiment 1, except that: in this embodiment, the roller body of the first floating roller 3 is made of AZ31 magnesium alloy, with a density of about 1.8 g / cm³, which is lighter than aluminum alloy. The roller body also adopts a hollow thin-walled structure with a wall thickness of 2.5 mm. According to calculations, the weight of the roller body of the same specification can be reduced to about 3.2 kg, which is more effective in weight reduction. The self-weight is reduced by about 80% compared with the steel roller, and the tension response speed is further improved, making it particularly suitable for applications such as ultra-thin paper and high-speed hot stamping.

[0061] Meanwhile, the sensor 7 in this embodiment is a wire displacement sensor, with the wire end connected to the slider of the floating roller. It has a larger measurement stroke, stronger anti-interference ability, and is suitable for complex industrial environments in factory workshops. Example

[0062] This embodiment has a structure that is basically the same as that of Embodiment 1, except that: in this embodiment, the first floating roller 3 is made of TC4 titanium alloy, with a density of approximately 4.5 g / cm³. Although its density is higher than that of aluminum alloy, its strength and wear resistance are superior, and its specific strength is much higher than that of steel. The roller body wall thickness is 1.5 mm, which balances lightweight design with high rigidity and high wear resistance, making it suitable for industrial production scenarios with high loads and long-term continuous operation. The roller surface has a longer service life and a longer maintenance cycle.

[0063] Meanwhile, in this embodiment, buffer limit blocks are provided at both the upper and lower ends of the guide rail to prevent the floating roller from exceeding the stroke range and causing mechanical collision, thereby improving the safety of equipment operation.

[0064] All three embodiments described above can achieve the technical effects of the present invention. Those skilled in the art can select appropriate floating roller materials and structural parameters according to actual production conditions, paper type, and speed requirements.

[0065] In summary, this invention replaces the traditional solid steel load roller with a lightweight alloy floating roller, and with the segmented buffer layout of double floating rollers before and after hot stamping, it effectively solves the technical problems of heavy load rollers, high tensile force requirements, slow response speed, high energy consumption, and easy paper damage in the prior art. Under the premise of ensuring constant tension control effect, it realizes the lightweighting of the buffer mechanism and significantly improves the operating performance and economy of hot stamping equipment.

[0066] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A lightweight hot stamping buffer mechanism, comprising a frame (1) and an input roller group (2), a hot stamping mechanism (4), and an output roller group (5) disposed on the frame (1), characterized in that: A first floating roller (3) is provided below the input roller group (2), and a second floating roller (6) is provided below the output roller group (5); The input roller group (2) includes a first input roller (21) and a second input roller (22) located on the same horizontal plane. The paper passes around the first input roller (21), the first floating roller (3) in sequence, and then passes around the second input roller (22). The first floating roller (3) is located directly below the first input roller (21) and the second input roller (22). The output roller group (5) includes a first output roller (51) and a second output roller (52) located on the same horizontal plane. A third pressing roller (53) is arranged directly above the first output roller (51), and a fourth pressing roller (54) is arranged directly above the second output roller (52). The second floating roller (6) is arranged directly below the first output roller (51) and the second output roller (52). The hot stamping mechanism (4) is located between the input roller group (2) and the output roller group (5) and is used to hot stamp the paper. The first floating roller (3) is made of a lightweight alloy material with a density lower than that of steel.

2. The lightweight hot stamping buffer mechanism according to claim 1, characterized in that: A sensor (7) is provided on the frame (1). The sensor (7) is used to detect the position signals of the first floating roller (3) and / or the second floating roller (6) to provide feedback on the tension state of the paper.

3. The lightweight hot stamping buffer mechanism according to claim 1, characterized in that: Define the weight of the first floating roller (3) as GQ, the weight of the second floating roller (6) as G2, the constant reverse tension of the unwinding mechanism on the paper as F1, and the constant forward tension of the traction mechanism on the paper as F3. The forces satisfy the relationship: F3>F1+G2+GQ>F1.

4. The lightweight hot stamping buffer mechanism according to claim 1, characterized in that: The lightweight alloy material is any one of aluminum alloy, magnesium alloy, and titanium alloy.

5. A lightweight hot stamping buffer mechanism according to claim 4, characterized in that: The first floating roller (3) is a hollow thin-walled roller structure with a roller wall thickness of 1.5mm-3mm.

6. The lightweight hot stamping buffer mechanism according to claim 1, characterized in that: Vertically extending guide rails are provided on both ends of the frame (1) corresponding to the first floating roller (3) and the second floating roller (6). Sliding sliders are installed at both ends of the roller shafts of the first floating roller (3) and the second floating roller (6), and the sliding sliders slide in cooperation with the guide rails on the corresponding sides.

7. A lightweight hot stamping buffer mechanism according to claim 2, characterized in that: The sensor (7) is a laser displacement sensor (7) or a wire displacement sensor (7). The sensor (7) is correspondingly set above or to the side of the stroke of the first floating roller (3) and / or the second floating roller (6) to collect the vertical displacement data of the floating roller in real time.

8. The lightweight hot stamping buffer mechanism according to claim 1, characterized in that: The hot stamping mechanism (4) includes a hot stamping roller (41) and an impression roller (42) arranged opposite to each other. The hot stamping roller (41) is equipped with a heating component. The paper passes through the gap between the hot stamping roller (41) and the impression roller (42) to complete the hot stamping process.

9. A lightweight hot stamping buffer mechanism according to claim 1, characterized in that: Both ends of the roller shafts of the third pressing roller (53) and the fourth pressing roller (54) are connected to a pneumatic pressing adjustment mechanism. The pressing adjustment mechanism includes an adjusting screw and a cylinder assembly with adjustable pressure, and is used to adjust the pressing pressure of the corresponding pressing roller on the output roller.

10. A lightweight hot stamping buffer mechanism according to claim 1, characterized in that: Transition guide rollers are provided between the input roller group (2) and the hot stamping mechanism (4), and between the hot stamping mechanism (4) and the output roller group (5), for adjusting the paper's conveying path and entry angle.

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