An extrusion device for a polytetrafluoroethylene rod and an extrusion process thereof

Abstract

The application relates to the field of extrusion technology, in particular to an extrusion device for a polytetrafluoroethylene rod and an extrusion process thereof, which comprises a machine box, an extrusion cylinder, a shaping pipe installed on the extrusion cylinder, a plunger slidingly embedded in the extrusion cylinder, a second top rod installed on the plunger, an extrusion mechanism arranged on the machine box and capable of driving the plunger to slide, a feeding cylinder installed on the machine box, an opening and closing groove arranged on the feeding cylinder, a sliding plate slidingly embedded on the opening and closing groove, a notch arranged on the sliding plate, an opening and closing mechanism arranged on the machine box and capable of driving the sliding plate to slide and the notch to slide, a rotating rod rotatably installed in the second top rod, a fixed block installed on the rotating rod, a scraper installed on the fixed block, and a cleaning mechanism arranged on the machine box and capable of being driven by the extrusion mechanism to drive the scraper to rotate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of extrusion, in particular to an extrusion device for polytetrafluoroethylene rod and an extrusion process thereof. BACKGROUND

[0002] Polytetrafluoroethylene rod is a kind of polymer material suitable for processing various gaskets, seals and lubricating materials working in corrosive media. This material has high corrosion resistance, high mechanical properties, and is resistant to high temperature, and can be used stably in a wide temperature range from -200°C to 260°C. These characteristics of polytetrafluoroethylene rod make it perform well in many industrial applications, such as chemical industry, food processing, medicine, electronics and machinery manufacturing industries. It is often used to make liners and coatings for pipes, valves, pumps and pipe fittings, as well as lubricated bearings, piston rings, oil seals and sealing rings. Polytetrafluoroethylene rod is a rod material formed by molding, paste extrusion or plunger extrusion process of polytetrafluoroethylene resin (may contain recycled polytetrafluoroethylene resin).

[0003] Common extrusion devices include plunger extruders and screw extruders. Because polytetrafluoroethylene has a high melting point and high melt viscosity, the melting point of polytetrafluoroethylene (PTFE) is as high as 327°C, and it has extremely high viscosity in the molten state, which makes it difficult to process in conventional thermoplastic molding processes, so screw extruders are not suitable for processing polytetrafluoroethylene rods.

[0004] Plunger extruders are used to discharge materials from the barrel through the die by plunger, and usually use hydraulic systems as power source. When using plunger extruders to extrude polytetrafluoroethylene rods, due to the high viscosity of polytetrafluoroethylene, there will be residual polytetrafluoroethylene on the plunger after extrusion, and the amount of residual material will gradually increase over time, reducing the space in the barrel and affecting the extrusion effect. The residual polytetrafluoroethylene makes the surface of the plunger not smooth, further affecting the extrusion effect. SUMMARY

[0005] The purpose of the present application is to provide an extrusion device for polytetrafluoroethylene rod and an extrusion process thereof to solve the problems raised in the background.

[0006] To achieve the above purpose, the present application provides the following technical scheme:

[0007] An extrusion device for polytetrafluoroethylene rod, comprising a machine box; and an extrusion barrel mounted on the machine box; a shaping tube is mounted on one end of the extrusion barrel;

[0008] A plunger is slidably fitted in the extrusion barrel, and a second ejector rod is mounted on the plunger;

[0009] The extrusion mechanism on the case can drive the second top rod to move towards or away from the shaping tube, so as to drive the plunger to slide in the extrusion cylinder to move towards or away from the shaping tube.

[0010] The feeding cylinder is installed on the case, and the opening and closing groove is formed in the feeding cylinder.

[0011] The opening and closing mechanism is arranged on the case, and the extrusion mechanism can drive the opening and closing mechanism to act, so as to drive the sliding plate to slide in the opening and closing groove, and drive the slot to slide.

[0012] The second top rod is rotatably installed in the second top rod, and the fixed block rotatably embedded with the plunger is installed on the rotating rod.

[0013] The cleaning mechanism is arranged on the case, and the extrusion mechanism can drive the cleaning mechanism to act, so as to drive the rotating rod to rotate, and drive the scraper to rotate through the fixed block.

[0014] As a further scheme of the application, the extrusion mechanism comprises a hydraulic cylinder installed on the case, a piston slidably embedded in the hydraulic cylinder, a first top rod rotatably installed on the piston, and a transmission plate fixedly connected with the second top rod and rotatably installed on the first top rod.

[0015] As a further scheme of the application, the opening and closing mechanism comprises a fixed sleeve installed on the extrusion cylinder, a sliding rod slidably embedded in the fixed sleeve, a spring fixedly connected with the sliding rod and installed on one side of the fixed sleeve close to the transmission plate, a connecting rod installed on the other side of the sliding rod, a protruding column installed on the connecting rod, and a matching groove slidably embedded with the protruding column and formed in the sliding plate; the second top rod is provided with a third top rod capable of abutting against the sliding rod.

[0016] As a further scheme of the application, the matching groove comprises a first horizontal groove, a first inclined groove, a second horizontal groove and a second inclined groove; the two ends of the second inclined groove are respectively communicated with the first horizontal groove and one end of the second horizontal groove; one end of the first inclined groove is communicated with the other end of the second horizontal groove, and the other end of the first inclined groove is communicated with the first horizontal groove; a limiting rod is rotatably installed on the sliding plate, and a limiting column matched with the limiting rod is installed on the sliding plate.

[0017] As a further scheme of the present application: the cleaning mechanism comprises a protruding column mounted on the hydraulic cylinder, a spiral groove is formed on the first top rod and slidably embedded with the protruding column; a large belt wheel is mounted on the first top rod, a small belt wheel is rotatably mounted on the force transmission plate, and the large belt wheel and the small belt wheel are connected by a belt; a ratchet wheel is mounted on the small belt wheel; a matching wheel is mounted on the rotating rod, and a plurality of ratchets matched with the ratchet wheel are rotatably mounted on the matching wheel.

[0018] As a further scheme of the present application: the scraper is obliquely arranged, and the scraper is in contact with the plunger.

[0019] As a further scheme of the present application: the aperture of the shaping tube is much smaller than the diameter of the extrusion cylinder, and the shaping tube is relatively long.

[0020] An extrusion process, comprising the extrusion device of the polytetrafluoroethylene rod as described above, the steps are as follows:

[0021] First step: connecting the feeding cylinder with the raw material storage bin; connecting the hydraulic cylinder with the hydraulic system; starting the hydraulic system;

[0022] Second step: the hydraulic system injects hydraulic liquid into the hydraulic cylinder to drive the extrusion mechanism to move, the extrusion mechanism drives the plunger to move away from the shaping tube through the second top rod, and in the moving away process, the opening and closing mechanism drives the sliding plate to slide outward in the opening and closing groove to drive the slot to be opened, so as to connect the feeding cylinder with the extrusion cylinder, and the raw material flows into the extrusion cylinder;

[0023] Third step: the hydraulic system extracts the hydraulic liquid in the hydraulic cylinder to drive the extrusion mechanism to move, the extrusion mechanism drives the plunger to move close to the shaping tube through the second top rod, so as to extrude the raw material in the extrusion cylinder, and the shaping tube can cool and shape the polytetrafluoroethylene to form a polytetrafluoroethylene rod;

[0024] Fourth step: the hydraulic system injects hydraulic liquid into the hydraulic cylinder to drive the extrusion mechanism to move, the extrusion mechanism drives the plunger to move away from the shaping tube through the second top rod, and in the moving away process, the cleaning mechanism drives the scraper to rotate through the rotating rod to clean the polytetrafluoroethylene adhered on the plunger, and drives the opening and closing mechanism to move again to extrude the next polytetrafluoroethylene rod.

[0025] Compared with the prior art, the beneficial effects of the present application are that the extrusion mechanism drives the plunger away from the shaping pipe through the second top rod; and drives the cleaning mechanism and the opening and closing mechanism to act simultaneously, drives the scraper to rotate through the cleaning mechanism to scrape off the residual tetrafluoroethylene in the last polytetrafluoroethylene rod extrusion process, so as to prevent the sticky polytetrafluoroethylene on the plunger from increasing under the long-time extrusion process, and affect the quality of the extruded product, effectively improve the production efficiency; and in this process, the opening and closing mechanism will first keep the position of the sliding plate unchanged (the sliding plate blocks the position of the feeding cylinder and the extrusion cylinder), after the cleaning mechanism works for a period of time, the opening and closing mechanism drives the sliding plate to slide, so as to guide the feeding cylinder and the extrusion cylinder through the slot, so that the raw material enters the extrusion cylinder, and after a certain amount of raw material is injected into the extrusion cylinder, the sliding plate is driven to slide reversely to block the feeding cylinder and the extrusion cylinder; so as to effectively improve the cleaning efficiency of the cleaning mechanism (prevent the newly injected raw material from sticking to the plunger when the scraper scrapes off the polytetrafluoroethylene in the last polytetrafluoroethylene rod extrusion process), and improve the production efficiency and the extrusion quality. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 Structure schematic view of an embodiment of the polytetrafluoroethylene rod extrusion device.

[0027] Figure 2 Structure schematic view of another view of an embodiment of the polytetrafluoroethylene rod extrusion device.

[0028] Figure 3 Structure schematic view of a cross-sectional view of an embodiment of the polytetrafluoroethylene rod extrusion device.

[0029] Figure 4 Structure schematic view of Figure 3 Structure schematic view of A in the middle.

[0030] Figure 5 Structure schematic view of the opening and closing mechanism in an embodiment of the polytetrafluoroethylene rod extrusion device.

[0031] Figure 6 Structure schematic view of Figure 5 Structure schematic view of an exploded view.

[0032] Figure 7 Structure schematic view of Figure 6 Structure schematic view of B in the middle.

[0033] Figure 8 Structure schematic view of the extrusion mechanism in an embodiment of the polytetrafluoroethylene rod extrusion device.

[0034] Figure 9 Structure schematic view of Figure 8 Structure schematic view of C in the middle.

[0035] Figure 10 Structure schematic view ofFigure 8 A structural diagram from the perspective of an explosion.

[0036] Figure 11 This is a schematic diagram of the structure of the second push rod and the rotating rod in one embodiment of the extrusion device for polytetrafluoroethylene rods.

[0037] In the diagram: 1. Chassis;

[0038] 2. Extrusion cylinder;

[0039] 3. Hydraulic cylinder; 301. Protruding column;

[0040] 4. Piston;

[0041] 5. First push rod; 501. Spiral groove;

[0042] 6. Force transmission plate;

[0043] 7. Second push rod; 701. Third push rod;

[0044] 8. Plunger;

[0045] 9. Feed cylinder; 901. Opening and closing groove;

[0046] 10. Fixing sleeve;

[0047] 11. Slide rod; 1101. Connecting rod; 1102. Protruding post;

[0048] 12. Spring;

[0049] 13. Slide plate; 1301. Groove; 1302. First transverse groove; 1303. First inclined groove; 1304. Second transverse groove; 1305. Second inclined groove; 1306. Limiting rod; 1307. Limiting post;

[0050] 14. Large pulley;

[0051] 15. Small pulley; 1501. Ratchet;

[0052] 16. Belt;

[0053] 17. Rotating rod; 1701. Matching wheel; 1702. Racket tooth; 1703. Fixing block; 1704. Scraper;

[0054] 18. Shaped tubes. Detailed Implementation

[0055] Clearly, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort shall fall within the protection scope of the present application.

[0056] In addition, the elements in the present application are referred to as "fixed to" or "disposed on" another element, which can be directly on another element or can have a middle element. When an element is considered to be "connected" to another element, it can be directly connected to another element or can have a middle element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0057] Please refer to Figures 1-11 In the embodiments of the present application, an extrusion device of a polytetrafluoroethylene rod and an extrusion process thereof include a machine box 1, and an extrusion cylinder 2 mounted on the machine box 1; a shaping pipe 18 is mounted on one end of the extrusion cylinder 2;

[0058] A plunger 8 is slidingly fitted in the extrusion cylinder 2, and a second ejector rod 7 is mounted on the plunger 8;

[0059] An extrusion mechanism is provided on the machine box 1, and the action of the extrusion mechanism can drive the second ejector rod 7 to move towards or away from the shaping pipe 18, so as to drive the plunger 8 to slide towards or away from the shaping pipe 18 in the extrusion cylinder 2;

[0060] A feeding cylinder 9 is mounted on the machine box 1; an opening and closing groove 901 is formed on the feeding cylinder 9; a sliding plate 13 is slidingly fitted on the opening and closing groove 901, and a slot 1301 is formed on the sliding plate 13;

[0061] An opening and closing mechanism is provided on the machine box 1, and the action of the extrusion mechanism can drive the action of the opening and closing mechanism, thereby driving the sliding plate 13 to slide in the opening and closing groove 901, so as to drive the slot 1301 to slide;

[0062] A rotating rod 17 is rotatably mounted in the second ejector rod 7, a fixed block 1703 rotatably fitted with the plunger 8 is mounted on the rotating rod 17, and a scraper 1704 is mounted on the fixed block 1703;

[0063] A cleaning mechanism is provided on the machine box 1, and the action of the extrusion mechanism can drive the action of the cleaning mechanism, so as to drive the rotating rod 17 to rotate, thereby driving the scraper 1704 to rotate through the fixed block 1703.

[0064] In use, the feeding barrel 9 is connected with the raw material storage bin, the hydraulic cylinder 3 is connected with the hydraulic system, the hydraulic system is started, the hydraulic system injects hydraulic liquid into the hydraulic cylinder 3 to drive the extrusion mechanism to move, the extrusion mechanism drives the plunger 8 to move away from the shaping pipe 18 through the second jack 7, in the moving away process, the opening and closing mechanism drives the sliding plate 13 to slide outward in the opening and closing groove 901 to drive the notch 1301 to slide, so as to connect the feeding barrel 9 and the extrusion barrel 2, and make the raw material flow into the extrusion barrel 2; after the required amount of raw material is injected into the extrusion barrel 2, the opening and closing mechanism drives the sliding plate 13 to slide inward in the opening and closing groove 901 to block the feeding barrel 9 and the extrusion barrel 2.

[0065] Then the hydraulic system extracts the hydraulic liquid in the hydraulic cylinder 3 to drive the extrusion mechanism to move, the extrusion mechanism drives the plunger 8 to move close to the shaping pipe 18 through the second jack 7, to extrude the raw material in the extrusion barrel 2, and the shaping pipe 18 can cool and shape the polytetrafluoroethylene to form a polytetrafluoroethylene rod; and in this process, the extrusion mechanism drives the opening and closing mechanism to move, so that the opening and closing mechanism resets and keeps blocking.

[0066] The hydraulic system injects hydraulic liquid into the hydraulic cylinder 3 to drive the extrusion mechanism to move, the extrusion mechanism drives the plunger 8 to move away from the shaping pipe 18 through the second jack 7, in the moving away process, the cleaning mechanism drives the scraper 1704 to rotate through the rotating rod 17 to clean the polytetrafluoroethylene adhered to the plunger 8, and drives the opening and closing mechanism to move again to extrude the next polytetrafluoroethylene rod, and the clamping mechanism moves to connect the feeding barrel 9 and the extrusion barrel 2.

[0067] The extrusion mechanism drives the plunger 8 to move away from the shaping pipe 18 through the second jack 7, and drives the cleaning mechanism and the opening and closing mechanism to move at the same time, the cleaning mechanism drives the scraper 1704 to rotate to remove the residual polytetrafluoroethylene in the extrusion process of the last polytetrafluoroethylene rod, to prevent the polytetrafluoroethylene adhered to the plunger 8 from increasing in the long-term extrusion process, and affect the quality of the extruded product, effectively improving the production efficiency; and in this process, the opening and closing mechanism keeps the position of the sliding plate 13 unchanged (the sliding plate 13 blocks the feeding barrel 9 and the extrusion barrel 2), after the cleaning mechanism works for a period of time, the opening and closing mechanism drives the sliding plate 13 to slide to connect the feeding barrel 9 and the extrusion barrel 2 through the notch 1301, so that the raw material enters the extrusion barrel 2, and after a certain amount of raw material is injected into the extrusion barrel 2, the sliding plate 13 is driven to slide reversely to block the feeding barrel 9 and the extrusion barrel 2; in this way, the cleaning efficiency of the cleaning mechanism can be effectively improved (to prevent the newly injected raw material from adhering to the plunger 8 when the scraper 1704 removes the polytetrafluoroethylene adhered to the plunger 8 in the extrusion process of the last polytetrafluoroethylene rod), and the production efficiency and the extrusion quality are improved.

[0068] Another embodiment of the present application, the extrusion mechanism comprises a hydraulic cylinder 3 mounted on the chassis 1, the hydraulic cylinder 3 in slidingly fitted with a piston 4, the piston 4 on the first top bar 5 is rotatably mounted, the first top bar 5 on the fixed connection with the second top bar 7 force plate 6 is rotatably mounted.

[0069] In use, the embodiment of all features described in this application, when the hydraulic system into the hydraulic cylinder 3 injection of hydraulic fluid, with the increase of the injection amount of hydraulic fluid, the hydraulic fluid will continue to extrude the piston 4, make it in the hydraulic cylinder 3 to the force plate 6 direction sliding, the sliding distance is directly related to the injection amount of hydraulic fluid; the piston 4 sliding, will drive the first top bar 5 synchronous displacement, thus through the force plate 6 drive the second top bar 7 synchronous displacement, to drive the plunger 8 gradually sliding away from the shaping tube 18, thus providing space for the injection of raw materials; at the same time, the opening and closing mechanism will act, so that the feeding cylinder 9 and extrusion cylinder 2 conduction, so as to be able to inject raw materials into the extrusion cylinder 2.

[0070] After the hydraulic system will be extracted from the hydraulic cylinder 3 in the hydraulic fluid, with the continuous decrease of the hydraulic fluid, the piston 4 will gradually move away from the force plate 6 thus drive the plunger 8 to the shaping tube 18 close to, in order to extrude the raw materials in the extrusion cylinder 2, and through the shaping tube 18 extrusion.

[0071] Extrusion mechanism can be relatively simple for polytetrafluoroethylene rod extrusion process to provide extrusion force, effectively improve the production efficiency.

[0072] Another embodiment of the present application, the opening and closing mechanism comprises a fixed sleeve 10 mounted on the extrusion cylinder 2, the fixed sleeve 10 in slidingly fitted with a slide bar 11, the fixed sleeve 10 close to the one side of the force plate 6 is installed with the spring 12 fixedly connected with the slide bar 11, the other side of the slide bar 11 is installed with connecting rod 1101, the connecting rod 1101 is installed with the convex column 1102, the slide plate 13 is provided with the matching groove which is slidingly fitted with the convex column 1102; the second top bar 7 is installed with the third top bar 701 which can be in contact with the slide bar 11.

[0073] In use, the embodiment of all features described in this application, in the initial state, the plunger 8 is located in the minimum distance position with the shaping tube 18, at this time, the third top bar 701 is in contact with the slide bar 11, the spring 12 is in the compressed state (the slide bar 11 is installed with a baffle on the one end close to the third top bar 701, the spring 12 is fixedly connected with the baffle).

[0074] In the process that the second ejector rod 7 drives the plunger 8 to move away from the shaping tube 18, the third ejector rod 701 moves synchronously; under the elastic force of the spring 12, the sliding rod 11 is driven to slide in the fixed sleeve 10 towards the third ejector rod 701, so as to drive the convex column 1102 to slide in the matching groove, thereby driving the sliding plate 13 to slide outwards in the opening and closing groove 901, so that the slot 1301 can be connected to the feeding cylinder 9 and the extrusion cylinder 2, and then the position of the sliding plate 13 is kept unchanged to keep the connection state; after the raw material is injected into the extrusion cylinder 2, the sliding plate 13 is driven to slide inwards in the opening and closing groove 901 through the sliding cooperation of the convex column 1102 and the matching groove, so as to block the feeding cylinder 9 and the extrusion cylinder 2 through the sliding plate 13; in this process, the third ejector rod 701 and the sliding rod 11 always keep in contact, and then the third ejector rod 701 is separated from the sliding rod 11.

[0075] In the process that the second ejector rod 7 drives the plunger 8 to move away from the shaping tube 18, the third ejector rod 701 moves synchronously; under the elastic force of the spring 12, the sliding rod 11 is driven to slide in the fixed sleeve 10 towards the third ejector rod 701, so as to drive the convex column 1102 to slide in the matching groove, thereby driving the sliding plate 13 to slide outwards in the opening and closing groove 901, so that the slot 1301 can be connected to the feeding cylinder 9 and the extrusion cylinder 2, and then the position of the sliding plate 13 is kept unchanged to keep the connection state; after the raw material is injected into the extrusion cylinder 2, the sliding plate 13 is driven to slide inwards in the opening and closing groove 901 through the sliding cooperation of the convex column 1102 and the matching groove, so as to block the feeding cylinder 9 and the extrusion cylinder 2 through the sliding plate 13; in this process, the third ejector rod 701 and the sliding rod 11 always keep in contact, and then the third ejector rod 701 is separated from the sliding rod 11.

[0076] In another embodiment of the present application, the matching groove comprises a first horizontal groove 1302, a first inclined groove 1303, a second horizontal groove 1304 and a second inclined groove 1305; the two ends of the second inclined groove 1305 are communicated with the first horizontal groove 1302 and one end of the second horizontal groove 1304 respectively; one end of the first inclined groove 1303 is communicated with the other end of the second horizontal groove 1304, and the other end of the first inclined groove 1303 is communicated with the first horizontal groove 1302; a limiting rod 1306 is rotatably installed on the sliding plate 13, and a limiting column 1307 matched with the limiting rod 1306 is installed on the sliding plate 13.

[0077] In use, the initial position, the convex column 1102 is located at the first horizontal groove 1302 near the end of the shaping tube 18; when the third top rod 701 gradually moves away from the fixed sleeve 10, the connecting rod 1101 drives the convex column 1102 to move away from the shaping tube 18 under the elastic force of the spring 12, at this time, the convex column 1102 will slide in the first horizontal groove 1302 (the position of the sliding plate 13 remains unchanged), slide to the connection between the first horizontal groove 1302 and the first inclined groove 1303, and then the convex column 1102 will enter the first inclined groove 1303 from the first horizontal groove 1302 and slide in the first inclined groove 1303 to the second horizontal groove 1304 (at this time, under the extrusion of the inner wall of the first inclined groove 1303 and the convex column 1102, the sliding plate 13 will slide outwards in the opening and closing groove 901 to drive the slot 1301 to slide synchronously, and the slot 1301 will gradually guide the feeding cylinder 9 and the extrusion cylinder 2 to be in communication); when the convex column 1102 slides to the communication position between the first inclined groove 1303 and the second horizontal groove 1304, the feeding cylinder 9 and the extrusion cylinder 2 have the maximum communication area, and then the convex column 1102 will enter the second horizontal groove 1304 from the first inclined groove 1303 and slide in the second horizontal groove 1304 to the second inclined groove 1305 (in this process, the position of the sliding plate 13 remains unchanged, and the position of the slot 1301 is changed so that the feeding cylinder 9 and the extrusion cylinder 2 are always in communication); when the convex column 1102 slides to the position between the second horizontal groove 1304 and the second inclined groove 1305, the convex column 1102 will enter the second inclined groove 1305 and then slide in the second inclined groove 1305 to the first horizontal groove 1302 (under the extrusion of the inner wall of the second inclined groove 1305 and the convex column 1102, the sliding plate 13 will slide inwards in the opening and closing groove 901, thereby driving the slot 1301 to change position to gradually reduce the communication area of the feeding cylinder 9 and the extrusion cylinder 2); when the convex column 1102 reaches the communication position between the second inclined groove 1305 and the first horizontal groove 1302, the communication area is zero (i.e., the sliding plate 13 blocks the feeding cylinder 9 and the extrusion cylinder 2). Then the third top rod 701 is separated from the sliding rod 11, the connecting rod 1101 is in contact with the fixed sleeve 10, so that the sliding rod 11 is not in sliding, and the convex column 1102 is located at the communication position between the second inclined groove 1305 and the first horizontal groove 1302.

[0078] When the third top rod 701 approaches the fixed sleeve 10, it will first collide with the sliding rod 11, then drive the sliding rod 11 to move synchronously, thereby driving the protruding column 1102 to slide in the first horizontal groove 1302, and the sliding direction is from the position where the second inclined groove 1305 and the first horizontal groove 1302 are communicated to the other end of the first horizontal groove 1302 (in this process, the position of the sliding plate 13 remains unchanged, and the feeding barrel 9 and the extrusion barrel 2 are in the blocking state); during the sliding process of the protruding column 1102, it will collide with the limiting rod 1306 and drive the limiting rod 1306 to rotate and separate from the limiting column 1307, and after the protruding column 1102 passes through the position where the first inclined groove 1303 and the first horizontal groove 1302 are communicated, the limiting rod 1306 separates from the protruding column 1102, and under the action of the torsional spring, the limiting rod 1306 will reset to collide with the limiting column 1307; when the protruding column 1102 slides to the other end of the first horizontal groove 1302, the distance between the plunger 8 and the shaping tube 18 is the smallest.

[0079] The extrusion mechanism drives the plunger 8 to move away from the shaping tube 18 through the second top rod 7; and the cleaning mechanism and the opening and closing mechanism are driven to move simultaneously, the scraper 1704 is driven to rotate through the cleaning mechanism to scrape off the residual tetrafluoroethylene in the last polytetrafluoroethylene rod extrusion process, so as to prevent the polytetrafluoroethylene adhered to the plunger 8 from increasing over time under the long-time extrusion process, thereby affecting the quality of the extruded product, and effectively improving the production efficiency; and in this process, the opening and closing mechanism first keeps the position of the sliding plate 13 unchanged (the sliding plate 13 blocks the position of the feeding barrel 9 and the extrusion barrel 2), after the cleaning mechanism works for a period of time, the opening and closing mechanism drives the sliding plate 13 to slide to open the feeding barrel 9 and the extrusion barrel 2 through the slot 1301, so that the raw material enters the extrusion barrel 2, and after a certain amount of raw material is injected into the extrusion barrel 2, the sliding plate 13 is driven to slide reversely to block the feeding barrel 9 and the extrusion barrel 2; in this way, the cleaning efficiency of the cleaning mechanism can be effectively improved (to prevent the newly injected raw material from adhering to the plunger 8 when the scraper 1704 scrapes off the polytetrafluoroethylene adhered in the last polytetrafluoroethylene rod extrusion process), and the production efficiency and the extrusion quality are improved.

[0080] In another embodiment of the present application, the cleaning mechanism comprises a protruding column 301 mounted on the hydraulic cylinder 3, and a spiral groove 501 is formed on the first top rod 5 and slidably embedded with the protruding column 301; a large pulley 14 is mounted on the first top rod 5, a small pulley 15 is rotatably mounted on the transmission plate 6, and the large pulley 14 and the small pulley 15 are connected through a belt 16; a thorn wheel 1501 is mounted on the small pulley 15; a matching wheel 1701 is mounted on the rotating rod 17, and a plurality of ratchets 1702 matched with the thorn wheel 1501 are rotatably mounted on the matching wheel 1701.

[0081] In use, the piston 4 drives the first top rod 5 to move towards the transmission plate 6, the convex column 301 slides with the spiral groove 501, thereby driving the first top rod 5 to rotate, thereby driving the large pulley 14 to rotate, and driving the small pulley 15 to rotate on the transmission plate 6 through the belt 16, the small pulley 15 drives the ratchet wheel 1501 to rotate, and drives the matching wheel 1701 to rotate through the mutual resistance of the ratchet teeth 1702, thereby driving the rotating rod 17 to rotate, thereby driving the scraper 1704 to rotate through the fixed block 1703, and scraping the polytetrafluoroethylene remaining on the plunger 8 through the rotating scraper 1704.

[0082] Since the second top rod 7 moves synchronously with the third top rod 701, in the process of rotating the scraper 1704, the slide rod 11 drives the convex column 1102 to slide with the matching groove under the driving of the spring 12, and the convex column 1102 slides in the first horizontal groove 1302 first, so as to avoid that the newly added raw material affects the cleaning effect in the scraping process of the scraper 1704.

[0083] The cleaning mechanism can effectively reduce the influence of the residual raw material on the extrusion process, thereby improving the production efficiency and production quality.

[0084] In the process of moving the piston 4 to drive the first top rod 5 away from the transmission plate 6, the convex column 301 slides with the spiral groove 501, thereby driving the first top rod 5 to rotate, thereby driving the large pulley 14 to rotate, and driving the small pulley 15 to rotate on the transmission plate 6 through the belt 16, the small pulley 15 drives the ratchet wheel 1501 to rotate, at this time the ratchet teeth 1702 do not cooperate with the ratchet wheel 1501, so the rotating rod 17 does not rotate, and the scraper 1704 also does not rotate, so as to avoid that the large pressure in the extrusion cylinder 2 during the extrusion process (the greater the pressure, the greater the load of the rotating scraper 1704) damages the device, thereby improving the service life of the device.

[0085] In another embodiment of the present application, the scraper 1704 is inclined, and the scraper 1704 is in contact with the plunger 8.

[0086] In use, the inclined scraper 1704 can improve the efficiency of scraping the polytetrafluoroethylene, and the scraper 1704 is in contact with the plunger 8, thereby cleaning the plunger 8 to the greatest extent.

[0087] In another embodiment of the present application, the diameter of the shaping pipe 18 is much smaller than the diameter of the extrusion cylinder 2, and the shaping pipe 18 is relatively long.

[0088] In use, the embodiment combining all the features described in the present application is used as an example, the shaping tube 18 has a smaller diameter than the diameter of the extrusion barrel 2, which can improve the extrusion effect and improve the extrusion quality; the longer shaping tube 18 can effectively shape the extruded polytetrafluoroethylene and provide a solidification time.

[0089] An extrusion process, including the extrusion device of the polytetrafluoroethylene rod as described above, has the following steps:

[0090] First step: connecting the feeding barrel 9 with the raw material storage bin; connecting the hydraulic cylinder 3 with the hydraulic system; starting the hydraulic system;

[0091] Second step: the hydraulic system injects hydraulic liquid into the hydraulic cylinder 3 to drive the extrusion mechanism to move, the extrusion mechanism drives the plunger 8 away from the shaping tube 18 through the second jack 7, and in the process of moving away, the opening and closing mechanism drives the sliding plate 13 to slide outward in the opening and closing groove 901 to drive the notch 1301 to slide, thereby connecting the feeding barrel 9 with the extrusion barrel 2, and making the raw material flow into the extrusion barrel 2;

[0092] Third step: the hydraulic system extracts the hydraulic liquid in the hydraulic cylinder 3 to drive the extrusion mechanism to move, the extrusion mechanism drives the plunger 8 to move close to the shaping tube 18 through the second jack 7, to extrude the raw material in the extrusion barrel 2, and the polytetrafluoroethylene is extruded from the shaping tube 18, and the shaping tube 18 can cool and shape the polytetrafluoroethylene to form a polytetrafluoroethylene rod;

[0093] Fourth step: the hydraulic system injects hydraulic liquid into the hydraulic cylinder 3 to drive the extrusion mechanism to move, the extrusion mechanism drives the plunger 8 to move away from the shaping tube 18 through the second jack 7, and in the process of moving away, the cleaning mechanism drives the scraper 1704 to rotate through the rotating rod 17 to clean the polytetrafluoroethylene adhered to the plunger 8, and drives the opening and closing mechanism to move again to extrude the next polytetrafluoroethylene rod.

[0094] It is apparent to those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference signs in the claims should not be construed as limiting the claims to the features to which the reference signs are directed.

[0095] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes every feature described. The specification can include implicit combinations of explicitly mentioned features and / or explicit combinations of implicitely mentioned features. Each embodiment depends on the explicit combinations of features and / or the implicit combinations of features made specifically within that embodiment, and each such embodiment can be combined with every other such embodiment to create further embodiments.

Claims

1. An extrusion device of a polytetrafluoroethylene rod, comprising a machine box (1) and an extrusion cylinder (2) mounted on the machine box (1), a shaping tube (18) mounted on one end of the extrusion cylinder (2); characterized in that a plunger (8) slidingly fitted in the extrusion cylinder (2), a second ejector rod (7) mounted on the plunger (8); an extrusion mechanism provided on the machine box (1), the extrusion mechanism being capable of driving the second ejector rod (7) to move towards or away from the shaping tube (18) so as to drive the plunger (8) to slide towards or away from the shaping tube (18) in the extrusion cylinder (2); a feeding cylinder (9) mounted on the machine box (1), an opening and closing groove (901) formed on the feeding cylinder (9), a sliding plate (13) slidingly fitted on the opening and closing groove (901), and a slot (1301) formed on the sliding plate (13); an opening and closing mechanism provided on the machine box (1), the extrusion mechanism being capable of driving the opening and closing mechanism to drive the sliding plate (13) to slide in the opening and closing groove (901) so as to drive the slot (1301) to slide; a rotating rod (17) rotatably mounted in the second ejector rod (7), a fixed block (1703) rotatably fitted on the rotating rod (17) and rotatably fitted on the plunger (8), and a scraper (1704) mounted on the fixed block (1703); a cleaning mechanism provided on the machine box (1), the extrusion mechanism being capable of driving the cleaning mechanism to drive the rotating rod (17) to rotate, so as to drive the scraper (1704) to rotate through the fixed block (1703); the extrusion mechanism comprising a hydraulic cylinder (3) mounted on the machine box (1), a piston (4) slidingly fitted in the hydraulic cylinder (3), a first ejector rod (5) rotatably mounted on the piston (4), and a force transmission plate (6) fixedly connected with the second ejector rod (7) and rotatably mounted on the first ejector rod (5); the opening and closing mechanism comprising a fixed sleeve (10) mounted on the extrusion cylinder (2), a sliding rod (11) slidingly fitted in the fixed sleeve (10), a spring (12) fixedly connected with the sliding rod (11) and mounted on one side of the fixed sleeve (10) close to the force transmission plate (6), a connecting rod (1101) mounted on the other side of the sliding rod (11), a protruding column (1102) mounted on the connecting rod (1101), a matching groove (1301) formed on the sliding plate (13) and slidingly fitted on the protruding column (1102), and a third ejector rod (701) mounted on the second ejector rod (7) and capable of abutting against the sliding rod (11). The matching groove comprises a first horizontal groove (1302), a first inclined groove (1303), a second horizontal groove (1304), and a second inclined groove (1305); the two ends of the second inclined groove (1305) are respectively communicated with the first horizontal groove (1302) and one end of the second horizontal groove (1304); one end of the first inclined groove (1303) is communicated with the other end of the second horizontal groove (1304), and the other end of the first inclined groove (1303) is communicated with the first horizontal groove (1302); a limiting rod (1306) is rotatably installed on the sliding plate (13), and a limiting column (1307) matched with the limiting rod (1306) is installed on the sliding plate (13).

2. An apparatus for extruding a polytetrafluoroethylene rod according to claim 1, wherein The cleaning mechanism comprises a protruding column (301) installed on the hydraulic cylinder (3), and a helical groove (501) slidably embedded with the protruding column (301) is formed in the first top rod (5); a large belt wheel (14) is installed on the first top rod (5), a small belt wheel (15) is rotatably installed on the force transmission plate (6), and the large belt wheel (14) and the small belt wheel (15) are connected through a belt (16); a thorn wheel (1501) is installed on the small belt wheel (15); a matching wheel (1701) is installed on the rotating rod (17), and a plurality of ratchets (1702) matched with the thorn wheel (1501) are rotatably installed on the matching wheel (1701).

3. An apparatus for extruding a polytetrafluoroethylene rod according to claim 2, wherein The scraper (1704) is obliquely arranged, and the scraper (1704) is in contact with the plunger (8).

4. An apparatus for extruding a polytetrafluoroethylene rod as defined in claim 1, wherein The aperture of the shaping tube (18) is much smaller than the diameter of the extrusion cylinder (2), and the shaping tube (18) is relatively long.

5. An extrusion process comprising an extrusion device of a polytetrafluoroethylene rod as claimed in claims 1-4, characterized in that, The method comprises the following steps: In the first step, the feeding cylinder (9) is connected with the raw material storage bin, and the hydraulic cylinder (3) is connected with the hydraulic system; and the hydraulic system is started; In the second step, the hydraulic system injects hydraulic liquid into the hydraulic cylinder (3) to drive the extrusion mechanism to move, the extrusion mechanism drives the plunger (8) to move away from the shaping tube (18) through the second top rod (7), and in the moving away process, the opening and closing mechanism drives the sliding plate (13) to slide outward in the opening and closing groove (901) to drive the groove (1301) to slide, so as to connect the feeding cylinder (9) with the extrusion cylinder (2) and make the raw material flow into the extrusion cylinder (2); In the third step, the hydraulic system extracts the hydraulic liquid in the hydraulic cylinder (3) to drive the extrusion mechanism to move, the extrusion mechanism drives the plunger (8) to move close to the shaping tube (18) through the second top rod (7) to extrude the raw material in the extrusion cylinder (2), and the raw material is extruded out of the shaping tube (18), and the shaping tube (18) can cool and shape the polytetrafluoroethylene to form a polytetrafluoroethylene rod; Fourth step: hydraulic system will inject hydraulic fluid into the hydraulic cylinder (3) to drive the extrusion mechanism, the extrusion mechanism through the second top rod (7) driven plunger (8) away from the shaping tube (18), away from the process, the cleaning mechanism through the rotating rod (17) driven scraper (1704) rotation, in order to clean the plunger (8) on the sticky polytetrafluoroethylene, and drive the opening and closing mechanism to act again, in order to carry on the next polytetrafluoroethylene rod extrusion.

Images