Filtering device for wire drawing machine and wire drawing machine
By employing a structure in which multiple screen changers are connected in sequence and an automated screen replacement technology in the plastic drawing machine, the problems of melt pressure fluctuation and inconvenient screen replacement are solved, thereby improving the melt filtration effect and the uniformity of die preparation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- YANFENG PLASTIC MASCH MAIN FACTORY
- Filing Date
- 2025-05-16
- Publication Date
- 2026-05-15
AI Technical Summary
Existing plastic wire drawing machines experience large fluctuations in melt pressure during screen replacement, resulting in uneven film thickness or breakage in the film produced by the die head, and screen replacement is inconvenient.
The system employs a structure in which multiple screen changers are connected in sequence. Each screen changer is equipped with a strip filter with an increasingly larger mesh size. The strip filter is automatically replaced through a winding assembly. Combined with the control of pressure sensors and the hot melt section, the system ensures the stability of melt filtration effect and flow control.
This technology enables multiple filtrations of the melt, reduces melt pressure fluctuations, ensures the uniformity of the membranes prepared by the die head, simplifies the filter replacement process, and reduces equipment costs and complexity.
Smart Images
Figure CN224240311U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to wire drawing equipment, and in particular to a filter device for a wire drawing machine and a wire drawing machine. Background Technology
[0002] After the plastic drawing machine transfers the molten plastic to the die head, it is extruded and drawn into fibers. Because the plastic raw material contains a lot of impurities, the impurities need to be filtered when the molten plastic is transferred. When the molten plastic passes through the filter screen, the impurities in the molten plastic are blocked by the filter screen to prevent the impurities from being transferred to the die head with the molten plastic and affecting the drawing. After the filter screen has been used for a long time, a large amount of impurities adhere to the filter screen, clogging some of the filter pores, which makes the filtration effect of the filter screen worse, and the filter screen needs to be replaced.
[0003] Currently, existing plastic wire drawing machines typically use large disc-shaped or cylindrical filters to hold the filter screen. When the filter screen needs to be replaced, the wire drawing machine must be stopped, the screen changer cover opened, and the filter screen inside the screen changer replaced. This is very inconvenient. Furthermore, before and after screen replacement, the pressure of the plastic melt transmitted in the wire drawing machine fluctuates greatly. The melt with different pressures impacts the die head, resulting in uneven film thickness or breakage in the film produced by the die head. Utility Model Content
[0004] The purpose of this invention is to provide a filter device for a wire drawing machine to solve the problem of large fluctuations in internal melt pressure during the wire drawing machine screen changing process.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: a filtering device for a wire drawing machine, comprising at least two screen changers with melt flow channels, and further comprising a strip filter and a winding assembly corresponding to each screen changer. The strip filter is inserted into the screen changer to filter the melt passing through the melt flow channel. The winding assembly is located on one side of the screen changer for winding the strip filter. The strip filter is moved away from the winding assembly to replace the strip filter in the screen changer. The melt flow channels of the multiple screen changers are connected in sequence, and the mesh size of the strip filter installed on each screen changer gradually increases along the flow direction of the melt flow channel.
[0006] By adopting the above technical solution, this utility model has the following advantages:
[0007] This invention connects multiple screen changers in sequence, allowing the filtration device for the wire drawing machine to filter the flowing melt multiple times through the strip filters within the multiple screen changers, thereby improving the filtration effect of the melt. By setting the mesh size of the strip filters in the multiple screen changers to gradually increase along the melt flow direction, the particle size of the impurities screened by each screen changer gradually decreases during multiple filtrations of the melt, further improving the filtration effect. After a period of use, the strip filter in the screen changer will accumulate a large amount of impurities, resulting in a decrease in its filtration efficiency and an increase in the melt pressure upstream of the strip filter in the melt flow channel. At this point, the strip filter needs to be replaced. By setting the strip filter to pass through the screen changer, when the strip filter is pulled away from the winding assembly, the part of the strip filter with a large amount of impurities can be removed from the melt flow channel of the screen changer, and the clean strip filter wound on the winding assembly can enter the melt flow channel of the screen changer, thus realizing the replacement of the strip filter on the screen changer. It is simple, convenient, and easy to operate. During the use of the screen changer, as more and more impurities adhere to the strip filter, the melt speed decreases as it passes through the filter. This causes the melt pressure upstream of the filter to gradually increase to a higher value, while the pressure downstream decreases. When a new strip filter is installed, the melt passes through quickly, causing a sudden pressure drop upstream and a sudden pressure increase downstream. Therefore, without a metering pump downstream of the screen changer to control melt flow, the large pressure fluctuations downstream of the strip filter will lead to significant pressure fluctuations in the melt entering the downstream die of the wire drawing machine's filter device. This results in uneven diaphragm thickness produced by the die. Even with a metering pump upstream of the die, excessive pressure fluctuations will affect the accuracy of the metering pump and reduce its flow control effectiveness. Therefore, reducing the pressure fluctuations downstream of the strip filter can improve the metering pump's ability to control the flow entering the die. Furthermore, since the upstream screen changer has the highest usage rate for its strip filter, the replacement frequency of the strip filter in the upstream screen changer is higher, and the pressure fluctuation is greater when the strip filter is replaced. By setting up the filter device for the wire drawing machine in a structure where multiple screen changers are connected in sequence, the strip filter of the downstream screen changer can intercept the melt to a certain extent when the strip filter of the upstream screen changer is being replaced. This greatly suppresses the pressure fluctuation of the melt in the filter device for the wire drawing machine during screen replacement, avoids large pressure fluctuations in the melt flowing into the die head during screen replacement, and ensures that the film prepared by the die head is more uniform.
[0008] Furthermore, the strip filter threaded on the screen changer includes at least two layers of filter screen, and the winding assembly includes a winding shaft, with each layer of filter screen wound on the same winding shaft; or, the strip filter threaded on the screen changer includes at least two layers of filter screen, and the winding assembly includes at least two winding shafts, with each layer of filter screen wound on a different winding shaft.
[0009] Using the aforementioned technical solution, if each layer of filter screen is wound on the same winding shaft, a single winding shaft winding assembly can simplify the structure of the winding assembly. When the strip filter screen moves to replace the screen changer, only the same winding shaft needs to be pulled to rotate. If each layer of filter screen is wound on different winding shafts, when the strip filter screen on the screen changer is pulled to be replaced, each layer of filter screen overlaps at the position entering the screen changer and moves into the screen changer. Through the overlap of multiple layers of filter screens, the filtration effect of the strip filter screen on fine particles is improved. At the same time, because each layer of filter screen is wound on different winding shafts, the moving distance is the same, avoiding wrinkles in one or more layers of the strip filter screen entering the screen changer, resulting in a smoother surface and ensuring stable filtration of impurities in the melt by the strip filter screen.
[0010] Furthermore, the winding assembly also includes a storage bin arranged around the winding shaft to accommodate the strip filter screen, and the side of the storage bin facing the screen changer has an outlet for the strip filter screen to pass through.
[0011] Using the aforementioned technical solution, the strip filter extends into the screen changer through the discharge port, allowing the storage tank to protect and limit the periphery of the strip filter.
[0012] Furthermore, the melt flow channel is provided with a porous mesh pad that divides the melt flow channel into an upstream cavity and a downstream cavity. The strip filter is located in the upstream cavity and is attached to the porous mesh pad. The screen changer is provided with a pressure sensor for detecting the melt pressure in the upstream cavity.
[0013] Using the aforementioned technical solution, after a period of use, some pores of the strip filter on the screen changer gradually become clogged with impurities. The melt pressure in the upstream chamber gradually rises to the critical pressure requiring replacement of the strip filter. At this point, the pressure sensor detects that the pressure value has reached the critical pressure value set by the controller, allowing for timely replacement of the strip filter on the screen changer. The pressure sensor monitors the filtration effect of the strip filter in real time, ensuring stable filtration of the melt by the screen changer. When the controller receives the pressure value detected by the pressure sensor, it can also control the rotation speed of the extrusion screw of the wire drawing machine based on the pressure value. By adjusting the feeding speed of the extrusion screw, the pressure of the melt in the upstream chamber can be regulated. During screen replacement, the strip filter adheres tightly to the porous mesh pad, which supports the strip filter, preventing excessive pressure in the upstream chamber from causing the strip filter to bend towards the downstream chamber, thus ensuring smooth screen replacement.
[0014] Furthermore, the screen changer has a hot melt section that can be heated and melted. The screen changer is equipped with a heating element for heating the hot melt section and a cooling element for cooling the hot melt section. When the hot melt section is heated and melted, the strip filter screen can move relative to the screen changer; when the hot melt section is cooled and solidified, the strip filter screen is fixed on the screen changer.
[0015] Using the aforementioned technical solution, when it is necessary to move the strip filter to replace the strip filter in the screen changer, the heating element operates to heat and melt the hot-melt part, while the cooling element does not operate, so as to move the strip filter and avoid the hot-melt part from obstructing the movement and replacement of the strip filter. When the strip filter is moved into place and the replacement of the strip filter in the screen changer is completed, the heating element stops operating, and the cooling element operates to cool and solidify the hot-melt part, so that both ends of the strip filter are fixed on the screen changer to tension the strip filter. When the melt passes through the strip filter, the filter will not pull the strip filter outside the screen changer into the screen changer, avoiding large deformation of the strip filter in the melt flow channel or entering other structures and affecting the operation of other structures, ensuring that the strip filter stably filters the melt in the melt flow channel.
[0016] Furthermore, the screen changer is also equipped with a temperature sensor for detecting the temperature of the hot melt section.
[0017] Using the aforementioned technical solution, when it is necessary to replace the strip filter, the temperature sensor can monitor the temperature of the hot-melt section. When the hot-melt section reaches a set temperature with a high degree of melting, the strip filter is moved. This avoids the strip filter being affected by a low degree of melting in the hot-melt section, making the movement of the strip filter smoother and facilitating the quick replacement of the strip filter by the filter changer.
[0018] Furthermore, the screen changer has an inlet and an outlet for the strip filter to pass through. The inlet is located between the outlet and the winding assembly, and the width of the outlet is greater than the width of the inlet.
[0019] Using the aforementioned technical solution, when the strip filter needs to be moved for replacement, only the hot melt section needs to be melted. Because the width of the outlet is greater than the width of the inlet, the portion of the melt flowing in the melt channel will flow out of the melt channel through the outlet. Then, the friction between the melt and the strip filter will drive the strip filter on the screen changer to move away from the winding assembly, so that the part of the strip filter with a large number of impurities is removed from the melt channel, thus realizing the replacement of the strip filter on the screen changer. There is no need to set up a screen changing component for pulling the strip filter, nor is it necessary to stop the wire drawing machine. The automatic screen changing of the screen changer can be realized during the melt flow process, reducing the space occupied by the filter device of the wire drawing machine and reducing the cost of the wire drawing machine.
[0020] Furthermore, a screen changing assembly is provided on the side of the screen changer away from the winding assembly. The screen changing assembly includes a screen changing roller, a clamping roller, and a screen changing motor connected to the screen changing roller. The screen changing roller and the clamping roller together clamp the strip filter screen. Driven by the screen changing motor, the screen changing roller rotates and pulls the strip filter screen away from the screen changer to replace the strip filter screen on the screen changer.
[0021] Using the aforementioned technical solution, when the strip filter inside the screen changer needs to be moved for replacement, the screen changing motor drives the screen changing roller to rotate a set number of times. As the screen changing roller rotates, it pulls the strip filter away from the screen changer, so that the part of the strip filter with a large amount of impurities is just pulled out of the screen changer, and the unused part of the strip filter enters the screen changer. This achieves the replacement of the strip filter inside the screen changer without manual screen changing, and the moving distance of the strip filter is accurate and reliable under the control of the screen changing motor.
[0022] Furthermore, there are two screen changers: a first screen changer and a second screen changer located downstream of the first screen changer. The mesh size of the strip filter installed on the first screen changer ranges from 40 to 150 mesh, and the mesh size of the strip filter installed on the second screen changer ranges from 100 to 300 mesh.
[0023] By adopting the aforementioned technical solution, by setting the mesh size of the strip filter installed on the first screen changer to a range of 40 to 150 mesh, coarse filtration can be performed, allowing large particles of impurities in the melt to be filtered out by the strip filter of the first screen changer. By setting the mesh size of the strip filter installed on the second screen changer to a range of 100 to 300 mesh, fine filtration can be performed, allowing smaller particles of impurities that the first screen changer fails to filter to be blocked when the melt passes through the strip filter on the second screen changer. By setting two screen changers, relatively fine filtration can be achieved, simplifying the overall structural complexity of the filtration device and reducing the manufacturing difficulty and cost of the filtration device.
[0024] This utility model also provides a wire drawing machine, including an extrusion tube, an extrusion screw and a die head, and a filtering device for the above-mentioned wire drawing machine. The melt flow channels of multiple screen changers are connected in sequence to form a filtering channel. The extrusion tube is connected to the feed end of the filtering channel, and the die head is connected to the discharge end of the filtering channel. Attached Figure Description
[0025] The present invention will be further described below with reference to the accompanying drawings:
[0026] Figure 1 This is a top view of the filter device for the wire drawing machine in Embodiment 1;
[0027] Figure 2 This is a side view of the filter device for the wire drawing machine in Embodiment 1;
[0028] Figure 3 This is an assembly diagram of the screen changer, strip filter, and winding assembly in Example 1;
[0029] Figure 4 This is a schematic diagram of the internal structure of the network switcher in Example 1;
[0030] Figure 5 This is an assembly diagram of the screen changer, strip filter, and winding assembly in Example 2;
[0031] Figure 6 This is an assembly diagram of the screen changer, strip filter, and winding assembly in Example 3;
[0032] Figure 7 This is a top view of the wire drawing machine in Example 4;
[0033] Figure 8 This is a side view of the wire drawing machine in Example 4. Detailed Implementation
[0034] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.
[0035] The terms "first," "second," etc. (if present) in the specification and claims of this utility model are used to distinguish similar objects, not to describe a specific order or sequence. Even if "second" is used before a technical feature for distinction, it does not necessarily imply the presence of "first." It should be understood that in this utility model, "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. It should be understood that in this utility model, "multiple" refers to two or more. "And / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, X and / or Y can represent: X alone, X and Y simultaneously, and Y alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "Containing X, Y, and Z," "Containing X, Y, and Z" means that all three X, Y, and Z are included; "Containing X, Y, or Z" means that one of X, Y, and Z is included; "Containing X, Y, and / or Z" means that any one, two, or three of X, Y, and Z are included.
[0036] The technical solution of this utility model will be described in detail below with specific embodiments. The following specific embodiments can be selected to be combined or substituted with each other according to the actual situation, and the same or similar concepts or processes may not be described again in some embodiments.
[0037] Example 1:
[0038] like Figures 1 to 4 As shown, this utility model provides a filtering device for a wire drawing machine, including multiple (two or more) screen changers 300. Each screen changer 300 has a melt flow channel 310 for the melt to pass through. It also includes a strip filter 400 and a winding assembly 500. The strip filter 400 and the winding assembly 500 are arranged in a one-to-one correspondence with each screen changer 300; that is, each screen changer 300 is equipped with a corresponding strip filter 400 and a winding assembly 500. The winding assembly 500 is located on one side of the screen changer 300 for winding the strip filter 400. One end of the strip filter 400 is wound onto the winding assembly 500, and the other end passes through the screen changer 300. The strip filter 400 is inserted through the screen changer... The portion within 300 separates the melt flow channel 310, allowing the strip filter 400 to filter the melt flowing through the melt flow channel 310. Multiple screen changers 300 are fixedly connected so that the melt flow channels 310 of the multiple screen changers 300 are sequentially connected. When the melt flows in the filter device for the wire drawing machine, it passes through the strip filter 400 in each screen changer 300 sequentially for filtration, improving the filtration effect. The strip filter 400 installed on each screen changer 300 has a different mesh size. Along the flow direction of the melt flow channel 310, the mesh size of the strip filter 400 installed on each screen changer 300 gradually increases, so that each screen changer 300 can filter impurities of different sizes. When the strip filter 400 needs to be replaced, simply move the strip filter 400 away from the winding assembly 500. This will allow the portion of the strip filter 400 within the melt flow channel 310 to be removed from the screen changer 300, while the portion of the strip filter 400 wound on the winding assembly 500 will enter the screen changer 300, thus replacing the strip filter 400 within the screen changer 300.
[0039] This invention connects multiple screen changers 300 in sequence, allowing the filtration device for the wire drawing machine to filter the flowing melt multiple times through the strip filter screens 400 within the multiple screen changers 300, thereby improving the filtration effect of the melt. By setting the mesh size of the strip filter screens 400 of the multiple screen changers 300 to gradually increase along the melt flow direction, the particle size of the impurities screened by each screen changer 300 gradually decreases during multiple filtrations of the melt, further improving the filtration effect. After the strip filter 400 in the screen changer 300 has been used for a period of time, a large amount of impurities will adhere to it, which will reduce the filtration effect of the strip filter 400 and increase the melt pressure upstream of the strip filter 400 in the melt flow channel 310. At this time, the strip filter 400 needs to be replaced. By setting the strip filter 400 to be inserted into the screen changer 300, when the strip filter 400 is pulled away from the winding assembly 500, the part of the strip filter 400 with a large amount of impurities can be removed from the melt flow channel 310 of the screen changer 300, and the clean strip filter 400 wound on the winding assembly 500 can enter the melt flow channel 310 of the screen changer 300, realizing the replacement of the strip filter 400 in the screen changer 300. It is simple, convenient and easy to operate. During the use of the screen changer 300, as more and more impurities adhere to the strip filter 400, the speed of the molten material passing through the strip filter 400 slows down. This causes the molten material pressure upstream of the strip filter 400 to gradually increase to a higher pressure value, while the molten material pressure downstream of the strip filter 400 gradually decreases to a lower pressure value. When a new strip filter 400 is installed, the molten material can pass through the strip filter 400 quickly, causing a sudden decrease in pressure upstream of the strip filter 400 and a sudden increase in pressure downstream of the strip filter 400. Therefore, when there is no metering pump downstream of the screen changer to control the melt flow rate, pressure fluctuations downstream of the strip filter 400 will cause large pressure fluctuations in the melt entering the downstream die of the wire drawing machine's filter device, resulting in uneven film thickness prepared by the die. Even if there is a metering pump upstream of the die downstream of the screen changer, excessive pressure fluctuations will still affect the accuracy of the metering pump and reduce its flow control effect. Therefore, reducing the pressure fluctuations downstream of the strip filter can work in conjunction with the metering pump, making the metering pump have a better flow control effect on the melt entering the die.Furthermore, since the upstream screen changer 300 and strip filter 400 have the highest usage rate, the replacement frequency of the upstream screen changer 300 and strip filter 400 is higher, and the pressure fluctuation is greater when the strip filter 400 is replaced. By setting the filter device for the wire drawing machine in a structure in which multiple screen changers 300 are connected in sequence, the strip filter 400 of the downstream screen changer 300 can intercept the melt to a certain extent when the strip filter 400 of the upstream screen changer 300 is replaced. This greatly suppresses the pressure fluctuation of the melt in the filter device for the wire drawing machine during screen replacement, avoids large pressure fluctuations in the melt flowing into the die head during screen replacement, and ensures that the film prepared by the die head is more uniform.
[0040] like Figure 3 As shown, each strip filter 400 mounted on the screen changer 300 has a multi-layer structure. Each strip filter 400 includes at least two or more overlapping filter layers 410. The winding assembly 500 includes multiple winding shafts 510, the number of which is the same as the number of filter layers 410. Each filter layer 410 is wound on a different winding shaft 510. When the strip filter 400 on the screen changer 300 is pulled for replacement, each filter layer 410... After being stacked at the position of entering the screen changer 300, the strip filter 400 moves into the screen changer 300. Through the stacking of multiple layers of filter screens 410, the filtration effect of the strip filter 400 on fine particles is improved. At the same time, because each layer of filter screen 410 is wound on a different winding shaft 510, the moving distance is the same, which avoids wrinkles in one or more layers of filter screen 410 entering the screen changer 300, making it more flat and ensuring stable filtration of impurities in the melt by the strip filter 400. To protect and limit the periphery of the strip filter 400, the winding assembly 500 also includes a storage tank 520, which is arranged around the winding shaft 510 to accommodate the strip filter 400. The strip filter 400 is placed in the storage tank 520, and a discharge port 521 is provided on the side of the storage tank 520 facing the screen changer 300. The strip filter 400 extends into the screen changer 300 through the discharge port 521.
[0041] In this embodiment, a porous mesh pad 390 is provided in the melt flow channel, which divides the melt flow channel 310 into an upstream cavity 311 and a downstream cavity 312. The upstream cavity 311 is located upstream of the porous mesh pad 390, and the downstream cavity 312 is located downstream of the porous mesh pad 390. A strip filter 400 is located in the upstream cavity 311 and is attached to the porous mesh pad 390. The melt flows from the upstream cavity 311 through the strip filter 400 and the porous mesh pad 390 into the downstream cavity 312. A pressure sensor 320 is provided on the screen changer 300, which is used to detect the melt pressure in the upstream cavity 311. After a period of use, some of the filter pores of the strip filter 400 on the screen changer 300 gradually become clogged with impurities. The melt pressure in the upstream chamber 311 gradually rises to the critical pressure at which the strip filter 400 needs to be replaced. At this point, the pressure sensor 320 detects that the pressure value has reached the critical pressure value set by the controller, so that the strip filter 400 on the screen changer 300 can be replaced in time. The pressure sensor 320 monitors the filtration effect of the strip filter 400 in real time to ensure stable filtration of the melt by the screen changer 300. When the controller obtains the pressure value detected by the pressure sensor 320, it can also control the rotation speed of the extrusion screw of the wire drawing machine according to the pressure value. By adjusting the feeding speed of the extrusion screw, the pressure of the melt in the upstream chamber 311 can be regulated. The porous mesh pad 390 can support the strip filter 400. When the screen changer 300 changes the screen, the strip filter 400 is tightly attached to the porous mesh pad 390 to prevent the strip filter 400 from bending into the downstream cavity 312 due to excessive pressure in the upstream cavity 311. This ensures that the strip filter 400 can pass smoothly through the screen changer 300 for screen changing.
[0042] In this embodiment, the screen changer 300 is provided with a heat-fusion section 330, which is located on both sides of the screen changer 300. That is, the heat-fusion section 330 is located at the front and rear ends of the strip filter 400 inside the screen changer 300. The strip filter 400 is set through the heat-fusion section 330. The heat-fusion section 330 can be repeatedly heated to melt or cooled to solidify. The screen changer 300 is also provided with a heating element 340 and a cooling element 350. The heating element 340 is used to heat the heat-fusion section 330. After the heat-fusion section 330 is heated, it melts, allowing the strip filter 400 to move relative to the heat-fusion section 330. The cooling element 350 is used to cool the heat-fusion section 330. After the heat-fusion section 330 is cooled, it solidifies. The solidified heat-fusion section 330 fixes the two ends of the strip filter 400 inside the screen changer 300 to the screen changer 300, so as to achieve the fixation and tension of the strip filter 400 on the screen changer 300.
[0043] When the pressure sensor 320 detects that the pressure value in the upstream cavity 311 is too high, requiring the strip filter 400 to be moved to replace the strip filter 400 in the screen changer 300, the heating element 340 operates to heat and melt the heat-melting part 330. At this time, the cooling element 350 does not operate, so as to move the strip filter 400 and prevent the heat-melting part 330 from obstructing the movement and replacement of the strip filter 400. When the strip filter 400 has moved into place and the replacement of the strip filter 400 in the screen changer 300 is completed, the heating element 340 stops operating. The cooling element 350 operates to cool and solidify the hot-melt section 330, fixing both ends of the strip filter 400 to the screen changer 300 to tension the strip filter 400. When the melt passes through the strip filter 400, the filter will not pull the strip filter 400 outside the screen changer 300 into the screen changer 300, preventing significant deformation of the strip filter 400 within the melt flow channel 310 or its entry into other structures and affecting their operation. This ensures stable filtration of the melt within the melt flow channel 310 by the strip filter 400. Preferably, the heating element 340 is a heating rod, and the cooling element 350 is a cooling water channel on the screen changer 300, through which cooling water is circulated to rapidly cool the hot-melt section 330.
[0044] In this embodiment, the screen changer 300 is also equipped with a temperature sensor 360. The temperature sensor 360 is used to detect the temperature of the hot melt section 330 in real time and feed it back to the controller. When it is necessary to replace the strip filter 400, the temperature sensor 360 can monitor the temperature of the hot melt section 330. When the hot melt section 330 reaches a set temperature with a high degree of melting, the strip filter 400 is moved. This avoids the strip filter 400 being affected by a low degree of melting of the hot melt section 330, making the movement of the strip filter 400 smoother and facilitating the screen changer 300 to quickly replace the strip filter 400.
[0045] In this embodiment, a screen changing assembly 600 is provided on the side of the screen changer 300 away from the winding assembly 500. That is, the screen changing assembly 600 and the winding assembly 500 are respectively arranged on both sides of the screen changer 300. The screen changing assembly 600 includes a screen changing roller 610, a clamping roller 620 and a screen changing motor 630. The rotating shafts of the screen changing roller 610 and the clamping roller 620 are arranged in parallel so that the outer periphery of the screen changing roller 610 and the clamping roller 620 jointly clamp the strip filter screen 400 extending from the screen changing assembly 600. The output shaft of the screen changing motor 630 is connected to the screen changing roller 610 to drive the screen changing roller 610 to rotate. When the strip filter 400 inside the screen changer 300 needs to be moved for replacement, the screen changing motor 630 drives the screen changing roller 610 to rotate a set number of times. As the screen changing roller 610 rotates, it pulls the strip filter 400 away from the screen changer 300, so that the part of the strip filter 400 with a large amount of impurities is just pulled out of the screen changer 300, and the clean (i.e., unused) part of the strip filter 400 enters the screen changer 300. This achieves the replacement of the strip filter 400 inside the screen changer 300 without manual screen changing, and the moving distance of the strip filter 400 is precise and reliable under the control of the screen changing motor 630.
[0046] In this embodiment, there can be two or more screen changers 300. Preferably, there are two screen changers 300, namely a first screen changer 370 and a second screen changer 380 located downstream of the first screen changer 370. The mesh size of the strip filter 400 installed on the first screen changer 370 ranges from 40 to 150 mesh, which is a coarse filter. The mesh size of the strip filter 400 installed on the second screen changer 380 ranges from 100 to 300 mesh, which is a fine filter. By setting the mesh size of the strip filter 400 installed on the first screen changer 370 to 40 to 150 mesh, large particles of impurities in the melt will be filtered out by the strip filter 400 of the first screen changer 370. By setting the mesh size of the strip filter 400 installed on the second screen changer 380 to 100 to 300 mesh, smaller particles of impurities that the first screen changer 370 fails to filter will be blocked when the melt passes through the strip filter 400 on the second screen changer 380. By setting two screen changers 300, relatively fine filtration can be achieved. Moreover, the length of the strip filter 400 can be made more than 10 meters, allowing for automatic screen changing for more than 10 days without machine downtime. This simplifies the overall structural complexity of the filtration device for wire drawing machines and reduces the manufacturing difficulty and cost of the filtration device for wire drawing machines.
[0047] Example 2:
[0048] like Figure 5As shown, the difference between this embodiment and Embodiment 1 is that in this embodiment, each screen changer 300 is provided with a corresponding winding shaft 510. The multiple layers of filter screens passing through the same screen changer 300 are wound on the same winding shaft 510. That is, the multiple layers of filter screens are stacked to form a strip filter screen 400 installed on the screen changer 300, and all filter screens are wound on the same winding shaft 510. The winding assembly 500 with a single winding shaft 510 can simplify the structure of the winding assembly 500. When the strip filter screen 400 moves to change the screen of the screen changer 300, it is only necessary to pull the same winding shaft 510 to rotate.
[0049] Example 3:
[0050] like Figure 6 As shown, the difference between this embodiment and Embodiment 1 is that in this embodiment, the screen changer 300 has an inlet 391 and an outlet 392 for the strip filter to pass through. The inlet 391 is located between the outlet 392 and the winding assembly 500, and the width of the outlet 392 is greater than the width of the inlet 391. When the strip filter 400 needs to be moved for screen replacement, only the hot melt section needs to be melted. Because the width of the outlet 392 is greater than the width of the inlet 391, part of the melt flowing in the melt channel 310 will flow out of the melt channel 310 through the outlet 392. Then, the friction between the melt and the strip filter 400 will drive the strip filter 400 on the screen changer 300 to move away from the winding assembly 500, so that the part of the strip filter 400 with a large number of impurities will be removed from the melt channel 310, thus realizing the replacement of the strip filter 400 on the screen changer 300. There is no need to set up a screen changing assembly (i.e., screen changing motor and screen changing roller, etc.) for pulling the strip filter 400, nor is it necessary to stop the wire drawing machine. The automatic screen changing of the screen changer 300 can be realized during the melt flow process, reducing the space occupied by the filter device of the wire drawing machine and reducing the cost of the wire drawing machine. Preferably, the width of the inlet 391 is 0.5mm to 1mm greater than the thickness of the strip filter 400, resulting in an inlet gap of no more than 1mm between the two sides of the strip filter 400 and the inner wall of the inlet 391. The width of the outlet 392 is twice the thickness of the strip filter 400. When replacing the strip filter 400, the inlet gap facilitates the strip filter 400 entering the screen changer 300 through the inlet 391. At the same time, because the inlet gap is no more than 1mm and the width of the outlet 392 is twice the thickness of the strip filter 400, it facilitates the outflow of melt. Therefore, the strip filter 400 with a large number of impurities will not retract into the winding assembly 500 through the inlet 391, but will move out of the melt flow channel 310 along with the melt flowing out of the wider outlet 392.
[0051] Example 4:
[0052] like Figure 7 and Figure 8 As shown, this embodiment provides a wire drawing machine, including an extrusion tube 110, an extrusion screw 120, and a die 210. It also includes the wire drawing machine filtration device described in the previous embodiment. Multiple screen changers 300 have their melt channels sequentially connected to form a filtration channel. The extrusion tube 110 is connected to the feed end of the filtration channel. The extrusion screw 120 passes through the extrusion tube 110 to deliver the melt from the extrusion tube 110 to the filtration channel via rotation. The die 210 is connected to the discharge end of the filtration channel to prepare the received melt into a film. A metering pump 220 can also be connected between the die 210 and the discharge port 521 of the filtration channel. Pressure sensors are provided at the upstream chamber of the melt channel in each screen changer 300 and at both the front and rear ends of the metering pump. The controller can accelerate or decelerate the extrusion screw based on the data detected by the pressure sensors to control the melt flow rate entering the die 210, resulting in a more uniform film formation.
[0053] In addition to the preferred embodiments described above, there are other embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection claimed by this utility model.
Claims
1. A filtering device for a wire drawing machine, characterized in that, The device includes at least two screen changers with melt flow channels, and also includes strip filters and winding assemblies corresponding to each screen changer. The strip filters are inserted into the screen changers to filter the melt passing through the melt flow channels. The winding assemblies are located on one side of the screen changers to wind the strip filters. The strip filters are moved away from the winding assemblies to replace the strip filters in the screen changers. The melt flow channels of the multiple screen changers are connected in sequence, and the mesh size of the strip filters installed on each screen changer gradually increases along the flow direction of the melt flow channels.
2. The filtering device for a wire drawing machine according to claim 1, characterized in that, The strip filter threaded on the screen changer includes at least two layers of filter screen, and the winding assembly includes a winding shaft, with each layer of filter screen wound on the same winding shaft; or, the strip filter threaded on the screen changer includes at least two layers of filter screen, and the winding assembly includes at least two winding shafts, with each layer of filter screen wound on a different winding shaft.
3. A filtering device for a wire drawing machine according to claim 2, characterized in that, The winding assembly also includes a storage tank arranged around the winding shaft to accommodate the strip filter screen, and the storage tank has an outlet on the side facing the screen changer for the strip filter screen to pass through.
4. A filtering device for a wire drawing machine according to claim 1, characterized in that, The melt flow channel is provided with a porous mesh pad that divides the melt flow channel into an upstream cavity and a downstream cavity. The strip filter is located in the upstream cavity and is attached to the porous mesh pad. The screen changer is provided with a pressure sensor for detecting the melt pressure in the upstream cavity.
5. A filter device for a wire drawing machine according to claim 1, characterized in that, The screen changer has a hot melt section that can be heated and melted. The screen changer is provided with a heating element for heating the hot melt section and a cooling element for cooling the hot melt section. When the hot melt section is heated and melted, the strip filter screen can move relative to the screen changer. When the hot melt section is cooled and solidified, the strip filter screen is fixed on the screen changer.
6. A filtering device for a wire drawing machine according to claim 5, characterized in that, The screen switch is also equipped with a temperature sensor for detecting the temperature of the hot melt section.
7. A filter device for a wire drawing machine according to claim 5 or 6, characterized in that, The screen changer has an inlet and an outlet for the strip filter to pass through. The inlet is located between the outlet and the winding assembly, and the width of the outlet is greater than the width of the inlet.
8. A filter device for a wire drawing machine according to claim 1, 5, or 6, characterized in that, The screen changer has a screen changing assembly on the side away from the winding assembly. The screen changing assembly includes a screen changing roller, a clamping roller, and a screen changing motor connected to the screen changing roller. The screen changing roller and the clamping roller together clamp the strip filter screen. The screen changing roller rotates under the drive of the screen changing motor and pulls the strip filter screen away from the screen changer to replace the strip filter screen on the screen changer.
9. A filter device for a wire drawing machine according to claim 1, characterized in that, The screen changer is provided in two parts: a first screen changer and a second screen changer located downstream of the first screen changer. The mesh size of the strip filter installed on the first screen changer ranges from 40 to 150 mesh, and the mesh size of the strip filter installed on the second screen changer ranges from 100 to 300 mesh.
10. A wire drawing machine, comprising an extrusion tube, an extrusion screw, and a die, characterized in that, It also includes a filter device for a wire drawing machine as described in any one of claims 1 to 9, wherein the melt channels of a plurality of screen changers are connected in sequence to form a filter channel, the extrusion tube is connected to the feed end of the filter channel, and the die head is connected to the discharge end of the filter channel.