A rubber extruder

Abstract

The present invention provides a rubber extruder, belonging to the technical field of rubber extrusion machinery. The rubber extruder comprises a barrel, a feed port, and a discharge port. A fast screw and a slow screw are arranged in the barrel. The fast screw and the slow screw are divided into a feeding section, a plasticizing section, and a conveying section. The feeding section and the conveying section are respectively provided with conveying threads with opposite spiral directions and meshing with each other. The number of spirals in the feeding section of the fast screw is less than that in the feeding section of the slow screw, and the number of spirals in the conveying section of the fast screw is less than that in the conveying section of the slow screw. The plasticizing section is provided with a dumbbell-shaped plasticizing element; the plasticizing element is arranged in a spiral shape in the length direction of the screw; the feeding device above the barrel feeds through a pair of counter-rotating feeding gears. The present invention makes innovative improvements to the feeding method of the rubber extruder and the structures of each section of the extrusion screw to improve the feeding capacity, extrusion output, and plasticizing effect within the extrusion glue temperature range permitted by the process.

Description

[Technical field]

[0001] The invention relates to the technical field of rubber extrusion machinery, in particular to a rubber extruder. [Background technology]

[0002] Most of the existing cold-feed rubber extruders use single-screw extruders, and a small number use twin-screw extruders. In the single-screw rubber cold-feed pin barrel extruder, the rubber material fed into the extruder is stirred, mixed, heated, plasticized, etc. under the joint action of the screw, barrel, and pins, and finally extruded through the die at a certain extrusion temperature. In this process, the extrusion capacity, extrusion temperature, and plasticizing capacity are interrelated "devil's triangle" relationships. It is almost impossible to ensure that all three are optimal at the same time.

[0003] The process goal of the cold feed extruder is to achieve the highest extrusion output and the best plasticizing effect under the premise of controllable extrusion rubber temperature. The basic structural type of the cold feed extruder is to install an integral screw into a pin barrel with an inner diameter slightly larger than the outer diameter of the screw. The main extrusion processing area of ​​the rubber is formed between the inner surface of the barrel and the outer surface of the screw. The material properties of the rubber change section by section during the extrusion process. According to the changing characteristics of the rubber state, it can be divided into three areas along the extrusion direction: solid conveying, plasticizing and melting, and melt conveying. They are also called the feeding section, plasticizing section and extrusion section of the extruder. Different functional sections have different screw rib structure designs and pin arrangement types. The rubber in the feeding section is in a highly elastic state, the rubber in the plasticizing section changes from a highly elastic state to a viscous flow state, and the rubber in the extrusion section is in a viscous flow state. In order to facilitate analysis and research, extrusion output, plasticizing effect and extrusion glue temperature are defined as the three elements of extrusion performance; feeding, plasticizing and extrusion are defined as the three elements of extrusion function, and the current extrusion mechanism that uses the same set of barrel and screw component combination to synchronously realize the three functional elements of "feeding, plasticizing and extrusion" is vividly summarized as a "1-1-1" three-stage synchronous extrusion mechanism.

[0004] Current extrusion theory research and production practice have proved that the three elements of extrusion performance cannot reach the ideal high-efficiency value area at the same time. If the extrusion output is to be increased, the plasticizing effect must be reduced, and the extrusion glue temperature will increase; if the plasticizing effect is to be improved, the extrusion glue temperature and extrusion output need to be reduced at the same time. The three show a "devil's triangle" phenomenon of mutual restraint. Therefore, in extrusion production practice, only the extrusion glue temperature range permitted by the process can be chosen to achieve a balance between extrusion output and plasticizing effect.

[0005] The improvement of extrusion output and plasticizing effect can be achieved from two aspects: feeding and plasticizing. Most of the existing cold-feed rubber extruders use a feeding roller to force the rubber into the extruder through the reverse rotation of the feeding roller and the screw. However, the feeding capacity of the feeding roller is unstable, which is reflected in its process capacity C P The feeding capacity and plasticizing capacity are not good enough, which leads to the stability and uniformity of the extruded product quality not meeting the high quality consistency requirements of high-end radial tires. In addition, the production efficiency of forced feeding by the feeding roller is not very high, the number of parts is large, the mechanical structure to prevent rubber leakage is complex, and the matching accuracy requirements are high. After the parts are worn, the rubber is easy to penetrate into the bearing and cause bearing damage, which leads to a high failure rate of the feeding device. Therefore, the industry has been seeking a more advanced feeding method.

[0006] In view of this, the present invention proposes a new type of rubber extruder, which makes innovative improvements to its feeding method, and the structures of the feeding section, plasticizing section and conveying section of the extrusion screw, so as to achieve an increase in extrusion output and plasticizing effect within the extrusion glue temperature range permitted by the process, so as to reduce the "devil's triangle" contradiction within a feasible range. [Summary of the invention]

[0007] The object of the present invention is to provide a rubber extruder in view of the above-mentioned problems, by making innovative improvements to the structure of its feeding device and the structures of each section of the extrusion screw, so as to improve the feeding capacity, extrusion output and plasticizing effect within the extrusion rubber temperature range permitted by the process, so as to reduce the "devil's triangle" contradiction within a feasible range.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A rubber extruder comprises a barrel, wherein a fast screw and a slow screw are arranged horizontally in parallel in the barrel, both ends of the fast screw and the slow screw are rotatably connected to a bearing seat outside the barrel end through a bearing, and one end of the fast screw and / or one end of the slow screw are driven to rotate by a first power device; the fast screw and the slow screw are both divided into a feeding section, a plasticizing section and a conveying section; the feeding section of the fast screw is aligned with the feeding section of the slow screw, and the feeding section of the fast screw and the feeding section of the slow screw are aligned with each other. The material section is provided with conveying threads with opposite spiral directions and meshing with each other, and the number of spirals in the feeding section of the fast screw is less than that in the feeding section of the slow screw; the plasticizing section of the fast screw is aligned with the plasticizing section of the slow screw and both are provided with plasticizing elements; the conveying section of the fast screw is aligned with the conveying section of the slow screw, and the conveying section of the fast screw and the conveying section of the slow screw are provided with conveying threads with opposite spiral directions and meshing with each other, and the number of spirals in the conveying section of the fast screw is less than that in the conveying section of the slow screw;

[0010] The plasticizing section of the fast screw and the plasticizing section of the slow screw are both cylindrical columnar structures; the plasticizing element includes a mounting portion and a dumbbell portion, the mounting portion is a circular ring arranged at intervals on the outside of the plasticizing section; the dumbbell portion includes a columnar rod and spheres located at both ends of the columnar rod, the middle part of the columnar rod is tilted and fixed on the mounting portion, on the plasticizing section of the fast screw, each mounting portion is provided with a plurality of dumbbell portions, and the dumbbell portions on adjacent mounting portions are staggered, so that when viewed along the length direction of the fast screw, all the dumbbell portions are arranged in a spiral shape; on the plasticizing section of the slow screw, each mounting portion is provided with a plurality of dumbbell portions, and the dumbbell portions on adjacent mounting portions are staggered, so that when viewed along the length direction of the slow screw, all the dumbbell portions are arranged in a spiral shape; the number of dumbbell portions on the fast screw is less than the number of dumbbell portions on the slow screw;

[0011] The top of the barrel is provided with a feed port, and the bottom is provided with a discharge port, wherein the feed port is located above the fast screw feeding section and the slow screw feeding section; and the discharge port is located below the fast screw conveying section and the slow screw conveying section.

[0012] In the present invention, preferably, the feeding section structure of the fast screw is the same as the conveying section structure of the fast screw; the feeding section structure of the slow screw is the same as the conveying section structure of the slow screw; and the ratio of the number of spirals in the feeding section of the fast screw to the number of spirals in the feeding section of the slow screw is 1:2, 1:3 or 1:4.

[0013] In the present invention, preferably, a feeding barrel is further provided above the feed port, a feeding port is provided at the upper end of the feeding barrel, a discharge port is provided at the lower end of the feeding barrel, two feeding gears which can rotate in opposite directions are arranged side by side in the internal cavity of the feeding barrel, the meshing part between the two feeding gears is located directly below the feeding port, and directly above the discharge port and the feeding port, and the two feeding gears rotate in opposite directions to squeeze the rubber material to the bottom and then fall into the meshing part between the fast screw and the slow screw through the feed port; a gear shaft is fixedly sleeved at the inner center of each of the feeding gears, both ends of the gear shaft pass through the upper feeding barrel and are rotatably connected to the feeding gear bearing seat through bearings, the feeding gear bearing seats are arranged on the outer sides of both ends of the upper feeding barrel, one end of the gear shaft passes through the feeding gear bearing seat and is driven to rotate by the second power device.

[0014] In the present invention, preferably, the mounting parts on the fast screw rod and the mounting parts on the slow screw rod are aligned one by one, the number of dumbbell parts on each mounting part on the fast screw rod is the same, the number of dumbbell parts on each mounting part on the slow screw rod is the same, and the ratio of the number of dumbbell parts on each mounting part on the fast screw rod to the number of dumbbell parts on each mounting part on the slow screw rod is 1:2, 1:3 or 1:4.

[0015] In the present invention, preferably, the angle between the central axis of the columnar rod and the central axis of the screw where it is located is 8-12°.

[0016] In the present invention, preferably, the diameter of the plasticizing section of the fast screw is equal to the diameter of the plasticizing section of the slow screw; the columnar rod is a cylindrical rod, the diameter of the cylindrical rod is 1 / 9 to 1 / 7 of the working diameter of the outer surface of the plasticizing section, the diameter of the sphere is approximately 1 / 6 to 1 / 4 of the working diameter of the outer surface of the plasticizing section, and the center distance of the spheres at both ends of the same cylindrical rod is 3 / 8 to 5 / 8 of the working diameter of the outer surface of the plasticizing section.

[0017] In the present invention, preferably, the distance between the middle part of the columnar rod and the outer surface of the plasticizing section is 1 / 32 to 3 / 32 of the working diameter of the outer surface of the plasticizing section, the mounting parts are equidistantly distributed on the outer surface of the plasticizing section, and the distance between adjacent mounting parts is 7 / 10 to 1 of the working diameter of the outer surface of the plasticizing section.

[0018] In the present invention, preferably, the length ratios of the feeding section, the plasticizing section and the conveying section on the fast screw and the slow screw are all 4:6-10:3-5.

[0019] In the present invention, preferably, the fast screw and the slow screw are driven to rotate by different power devices respectively, and the spiral structure of the fast screw is a single spiral or a double spiral; the spiral structure of the slow screw is a quadruple spiral, a hexahelix, or an octahelix.

[0020] The present invention also provides a rubber extruder control method. When the rubber extruder is used, the rotation speed of the fast screw is controlled to be 1.1-8.0 times of the rotation speed of the slow screw.

[0021] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0022] 1. In the present invention, the screw includes a feeding section, a plasticizing section and a conveying section arranged in sequence. The outer walls of the feeding section and the conveying section are provided with conveying threads, and their functions focus on conveying the rubber material; the plasticizing section is a cylindrical structure, and its outer wall is provided with a dumbbell-shaped plasticizing element, and its functions focus on stirring, mixing and plasticizing. Such a design allows the plasticizing section to have both the conveying function of the existing technology and increase the plasticizing capacity of the screw.

[0023] 2. The present invention improves the existing pin-type structure into a dumbbell-type structure. The balls at both ends of the dumbbell-type structure can make the shear contact surface larger. The setting direction of the columnar rod changes the shear direction of the original pin mode, and the shapes and sizes of the various parts of the dumbbell-type structure are different. These factors work together to increase the mixing, stirring and shearing effects, thereby improving the plasticizing effect. The dumbbell-shaped structures are staggered on the screw, and the dumbbell part is arranged in a spiral shape from the length direction of the screw. On the one hand, this structure can make the spirally arranged plasticizing device have the plasticizing ability while maintaining the conveying function; on the other hand, the pins of the existing pin-type structure are fixed to the inner wall of the barrel and will not rotate during the working process. The rubber material is sheared and plasticized while flowing; while the dumbbell-shaped structure in the present invention is fixed to the outer wall of the screw, it can rotate with the rotation of the screw, which enhances its stirring and shearing strength on the rubber material, and the shearing effect makes the rubber material in the barrel as a whole be subjected to the force, and the mixing and stirring are more uniform.

[0024] 3. The present invention also arranges two screws in parallel, the number of spirals in the slow screw conveying section is in multiple relationship with the number of spirals in the fast screw conveying section, the number of dumbbell parts on each mounting part on the slow screw plasticizing section is in integer multiple relationship with the number of dumbbell parts on each mounting part on the fast screw plasticizing section, and partial meshing is formed between the dumbbell-shaped structures of the two. When in use, the speeds of the two screws are adjusted to different multiples of rotation speeds. Through the difference in the rotation speeds of the two screws, the shearing efficiency of the threads and the dumbbell parts on the rubber material is adjusted, so that the rubber material inside the barrel is subjected to two different degrees of shearing, thereby achieving the purpose of adjusting and improving the shearing effect of the rubber material, and the plasticizing section can have stronger mixing and stirring capabilities, thereby improving the mixing and plasticizing capabilities of the rubber extruder on the rubber material.

[0025] 4. When setting the size ratio of each part of the screw, the present invention can achieve a balance between a more compact layout, lower material cost, better plasticizing effect and higher output by designing parameters such as the cylindrical rod diameter, the sphere diameter, the sphere center distance, the distance between the columnar rod and the plasticizing section, and the spacing of the mounting parts.

[0026] 5. The feeding device of the present invention improves the feeding method of the existing cold-feed rubber extruder, and improves the existing feeding method of the feeding roller and the feeding screw to a double-gear feeding method, and then the feeding is carried out by the feeding screw. The gear feeding is a stable conveying method, and its conveying capacity is very stable, which is reflected in its process capacity C PThe value is very good, therefore, gear feeding can improve the feeding stability and uniformity of the extruder. When used in conjunction with the extrusion screw in the present invention, the feeding speed can also be adjusted in accordance with the plasticizing capacity to adapt to the improvement of the plasticizing capacity, thereby improving the extrusion stability, uniformity and output of the present invention and meeting the technical requirements of high-quality radial tire production for higher extrusion stability and uniformity.

Brief Description of the Drawings

[0027] Figure 1 It is a schematic diagram of the planar structure of a rubber extruder provided by the present invention;

[0028] Figure 2 yes Figure 1 Cross-sectional view along AA direction;

[0029] Figure 3 yes Figure 1 Cross-sectional view along direction BB;

[0030] Figure 4 yes Figure 1 Cross-sectional view along CC direction;

[0031] Figure 5 It is a three-dimensional structural schematic diagram of a rubber extruder provided by the present invention;

[0032] Figure 6 It is a schematic diagram of the planar structure of the fast screw in the present invention;

[0033] Figure 7 It is a schematic diagram of the structure of two screw rods used in pairs;

[0034] Figure 8 yes Figure 7 Cross-sectional view in the middle DD direction;

[0035] Fig. 9 yes Figure 7 Cross-sectional view in the EE direction;

[0036] Fig.10 It is a cross-sectional view in the FF direction in 7.

[0037] Among them, 1-fast screw, 101-feeding section, 102-plasticizing section, 1021-installation part, 1022-columnar rod, 1023-sphere, 103-conveying section, 2-slow screw, 201-feeding section, 202-plasticizing section, 2021-installation part, 2022-columnar rod, 2023-sphere, 203-conveying section, 3-feeding end bearing seat, 4-barrel, 401-feeding port, 402-discharging port, 5-discharging end bearing seat, 6-bearing one, 7-bearing two, 8-bearing three, 9-feeding barrel, 901-feeding port, 902-discharging port, 10-feeding gear, 11-feeding gear bearing seat, 12-gear shaft, 13-anti-rubber leakage device. [Specific implementation method]

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The drawings are only for illustrative purposes and represent only schematic diagrams, not physical drawings, and cannot be understood as limitations on this patent. In order to better illustrate the specific implementation methods of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. It is understandable to those skilled in the art that some well-known structures, parts and their descriptions in the drawings may be omitted. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it 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 it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] The present invention aims to improve the feeding capacity, output and plasticizing effect by making innovative improvements to the feeding method of the rubber extruder and the structure of each section of the extrusion screw. The following are the specific introductions one by one. Figure 1-10A rubber extruder comprises a barrel 4, in which a fast screw 1 and a slow screw 2 are arranged horizontally in parallel. Both ends of the fast screw 1 and the slow screw 2 are rotatably connected to the bearing seat outside the end of the barrel 4 through bearings, and one end of the fast screw 1 and / or one end of the slow screw 2 is driven to rotate by a first power device, that is, the fast screw 1 and the slow screw 2 can be driven to rotate by the same power device, and the rotational motion of one of the screws is transmitted to the other screw through gear transmission or sprocket transmission. The rotation speed of the two screws is the same, but a more preferred way is that the fast screw 1 and the slow screw 2 are driven to rotate by different power devices so that the rotation speeds of the two are different. The generally used speed of the fast screw 1 is twice, three times or four times that of the slow screw 2, or it can be a multiple between 1.1-8.0. The fast screw 1 and the slow screw 2 are both divided into a feeding section (101, 201), a plasticizing section (102, 202) and a conveying section (103, 203). The two screws are integrally formed, and the structural characteristics of each part are different. The feeding section 101 of the fast screw 1 and the feeding section 201 of the slow screw 2 are aligned side by side. The feeding section 101 of the fast screw 1 and the feeding section 201 of the slow screw 2 are provided with conveying threads with opposite spiral directions and meshing with each other, and the fast screw 1 and the slow screw 2 are respectively provided with a feeding section 101 and a conveying section 201 of the slow screw 2. The number of spirals in the feeding section 101 of the fast screw 1 is less than the number of spirals in the feeding section 201 of the slow screw 2. Preferably, the ratio of the number of spirals in the feeding section 101 of the fast screw 1 to the number of spirals in the feeding section 201 of the slow screw 2 is 1:2, 1:3 or 1:4; specifically, the spiral structure of the feeding section 101 of the fast screw 1 is preferably a single spiral or a double spiral; the spiral structure of the feeding section 201 of the slow screw 2 is a quadruple spiral, a hexahelical spiral, or an octahelical spiral. Through the above arrangement, during production, the conveying capacity of the two screws can be adjusted to be the same by adjusting the rotation speed. At the same time, the difference in spirals and rotation speeds generates two different pushing forces on the rubber material, so that the rubber material inside the barrel is subjected to two different degrees of force, thereby achieving the purpose of adjusting and improving the conveying capacity of the rubber material and enhancing plasticization.

[0041] The plasticizing section 102 of the fast screw 1 and the plasticizing section 202 of the slow screw 2 are aligned side by side and both are provided with plasticizing elements.

[0042] The conveying section 103 of the fast screw 1 is aligned side by side with the conveying section 203 of the slow screw 2. The conveying section 103 of the fast screw 1 and the conveying section 203 of the slow screw 2 are provided with conveying threads with opposite spiral directions and meshing with each other, and the number of spirals of the conveying section 103 of the fast screw 1 is less than the number of spirals of the conveying section 203 of the slow screw 2. Preferably, the ratio of the number of spirals of the conveying section 103 of the fast screw 1 to the number of spirals of the conveying section 203 of the slow screw 2 is 1:2, 1:3 or 1:4; specifically, it is preferred that the spiral structure of the conveying section 103 of the fast screw 1 is a single spiral or a double spiral; the spiral structure of the conveying section 203 of the slow screw 2 is a quadruple spiral, a hexahelix, or an octahelix. The structure of the feeding section 101 of the fast screw 1 can be completely identical to or different from the structure of the conveying section 103 of the fast screw 1; the structure of the feeding section 201 of the slow screw 2 can be completely identical to or different from the structure of the conveying section 203 of the slow screw 2.

[0043] The fast screw 1 and the slow screw 2 can be installed in a specific manner that one end of the fast screw 1 and the slow screw 2 near the feeding section (101, 201) is rotatably installed in the feed end bearing seat 3 through bearing two 7 and bearing three 8, and the end protrudes outside the feed end bearing seat 30, and the outer surface of the protruding part is provided with a spline groove so as to be connected to an external first power device to drive rotation (the power device is not shown), and the feed end bearing seat 3 can be fixed to the outer wall of one end of the barrel 4 by bolts. The other end of the fast screw 1 and the slow screw 2 near the conveying section (103, 203) is rotatably connected to the discharge end bearing seat 5 through bearing one 6.

[0044] The following describes the structural improvement of the plasticizing section (102, 202), see Figure 6-10The plasticizing section 102 of the fast screw 1 and the plasticizing section 202 of the slow screw 2 are both cylindrical columnar structures; the plasticizing element includes a mounting portion (1021, 2021) and a dumbbell portion, the mounting portion (1021, 2021) is a circular ring arranged at intervals on the outside of the plasticizing section (102, 202), and can be fixed to the outer wall of the plasticizing section (102, 202) by welding; the dumbbell portion includes a columnar rod (1023, 2023) and spheres (1023, 2023) located at both ends of the columnar rod (1023, 2023), the middle part of the columnar rod (1023, 2023) is obliquely fixed on the mounting portion (1021, 2021), preferably fixed by welding, and preferably the angle between the central axis of the columnar rod (1023, 2023) and the central axis of the screw where it is located is 8-12°, more preferably 10°. On the plasticizing section 102 of the fast screw 1, each mounting portion (1021, 2021) is provided with a plurality of dumbbell portions, and the dumbbell portions on adjacent mounting portions (1021, 2021) are installed in a staggered manner, so that when viewed along the length direction of the fast screw 1, all the dumbbell portions are arranged in a spiral shape; on the plasticizing section 202 of the slow screw 2, each mounting portion (1021, 2021) is provided with a plurality of dumbbell portions, and the dumbbell portions on adjacent mounting portions (1021, 2021) are installed in a staggered manner, so that when viewed along the length direction of the slow screw 2, all the dumbbell portions are arranged in a spiral shape. The fast screw rod 1 is arranged in a spiral shape; the number of dumbbell parts on the fast screw rod 1 is less than that on the slow screw rod 2. Preferably, the mounting part 1021 on the fast screw rod 1 and the mounting part 2021 on the slow screw rod 2 are aligned one by one, the number of dumbbell parts on each mounting part 1021 on the fast screw rod 1 is the same, the number of dumbbell parts on each mounting part 2021 on the slow screw rod 2 is the same, and the ratio of the number of dumbbell parts on each mounting part 1021 on the fast screw rod 1 to the number of dumbbell parts on each mounting part 2021 on the slow screw rod 2 is 1:2, 1:3 or 1:4. The present invention improves the existing pin type into a dumbbell type structure, the spheres (1023, 2023) at both ends can make the shear contact surface larger, the setting direction of the columnar rod (1023, 2023) changes the shear direction of the original mode, and the shapes and sizes of the various parts of the dumbbell type structure are different. These factors work together to increase the mixing, stirring and shearing effects, thereby improving the plasticizing effect. The columnar rods (1023, 2023) are tilted so that the multiple dumbbell parts are arranged in a spiral shape along the length of the screw rod, so that the plasticizing section of the present invention can not only convey materials but also help plasticize the rubber material.

[0045] A feed port 401 is provided at the top of the barrel 4, and a discharge port 402 is provided at the bottom. The feed port 401 is located above the feeding section of the fast screw 1 and the feeding section of the slow screw 2, specifically above the meshing point of the feeding section of the fast screw 1 and the feeding section of the slow screw 2; the discharge port 402 is located below the conveying section of the fast screw 1 and the conveying section of the slow screw 2, specifically below the meshing point of the conveying section of the fast screw 1 and the conveying section of the slow screw 2.

[0046] The present invention also relates to an improvement in the feeding method. The specific structure is that a feeding barrel 9 is additionally provided above the feeding port 401. The upper end of the feeding barrel 9 is provided with a feeding port 901, and the lower end of the feeding barrel 9 is provided with a discharge port 902. Two feeding gears 10 that can rotate in opposite directions are arranged side by side in the internal cavity of the feeding barrel 9. The meshing part between the two feeding gears 10 is located directly below the feeding port 901 and directly above the discharge port 902 and the feeding port 402. When the two feeding gears 10 rotate in opposite directions, After the rubber material is squeezed to the bottom, it falls into the meshing part between the fast screw 1 and the slow screw 2 through the feed port 401; a gear shaft 12 is fixedly sleeved on the inner center of each feeding gear 10, and both ends of the gear shaft 12 pass through the upper feeding barrel 9 and are rotatably connected to the feeding gear bearing seat 11 through bearings. The feeding gear bearing seat 11 is arranged on the outer side of both ends of the upper feeding barrel 9, and one end of the gear shaft 12 passes through the feeding gear bearing seat 11 and is driven to rotate by the second power device (the second power device is not shown). Preferably, the central axis of the gear shaft 12 is parallel to the central axis of the fast screw 1 and the central axis of the slow screw 2. Feeding by gears can improve the feeding stability and uniformity of the extruder, and the feeding speed can also be adjusted to follow the plasticizing capacity to adapt to the improvement of the plasticizing capacity.

[0047] In the present invention, the feeding gear 10 can be a spur gear or a helical gear, and the specific tooth shape can be a standard gear or a non-standard gear. The power device can be a separate set of reduction motors, and can also be shared with the driving device of the fast screw or the slow screw, that is, the rotational motion of the screw is transmitted to the feeding gear 10 through gear transmission or sprocket transmission, which is also a conventional setting in the art.

[0048] In the present invention, the center distance between the feeding gears 10 is adjustable to adapt to the change in the thickness of the rubber sheet fed into the cold feed rubber extruder. The distance adjustment device of the feeding gear can be designed as a manual adjustment mode or an automatic electric distance adjustment mode. Those skilled in the art can make additional improvements on the above technical solution.

[0049] When the screw of the present invention is implemented, those skilled in the art can set specific dimensions according to the design specifications. As long as the aforementioned technical features are met, they are within the protection scope of the present invention. However, in order to achieve a balance between a more compact layout, lower material costs, better plasticizing effects, and higher output, the present invention also optimizes parameters. Specifically, the diameter of the plasticizing section 102 of the fast screw 1 is equal to the diameter of the plasticizing section 202 of the slow screw 2; the columnar rod (1023, 2023) can be a cylindrical rod or a square column rod. The specific design is now described using a cylindrical rod. The diameter of the columnar rod (1023, 2023) is 1 / 9 to 1 / 7 of the working diameter of the outer surface of the plasticizing section (102, 202), preferably 1 / 8, and the diameter of the sphere is approximately 1 / 6 to 1 / 4 of the working diameter of the outer surface of the plasticizing section (102, 202), preferably 1 / 5. The distance between the centers of the spheres at the two ends of the same columnar rod (1023, 2023) is 3 / 8 to 5 / 8 of the working diameter of the outer surface of the plasticizing section (102, 202), preferably 1 / 2. The distance between the middle of the columnar rod (1023, 2023) and the outer surface of the plasticizing section (102, 202) is 1 / 32 to 3 / 32 of the working diameter of the outer surface of the plasticizing section (102, 202), preferably 1 / 16. The mounting parts (1021, 2021) are evenly distributed on the outer surface of the plasticizing section (102, 202), and the distance between adjacent mounting parts (1021, 2021) is 7 / 10 to 1 of the working diameter of the outer surface of the plasticizing section (102, 202), preferably 4 / 5. The length ratios of the feeding section, the plasticizing section and the conveying section on the fast screw and the slow screw are 4:6 to 10:3 to 5, preferably 1:2:1. The relationship between the above dimensions is a preferred reference value during design. During specific implementation, those skilled in the art may perform any combination and optimization of the above parameters, all of which are within the protection scope of the present invention.

[0050] Since there are tooth gaps at both ends of the feeding gear 10, the rubber material overflowing from the tooth gaps is likely to damage the bearings, so the present invention preferably provides a rubber material leakage prevention device 13 at both ends of the feeding gear 10, the outer surface of the rubber material leakage prevention device 13 is cylindrical, and the outer surface of the cylinder is provided with multiple rubber return threads, and the spiral directions of the rubber return threads at both ends of the feeding gear 10 are opposite. When the feeding gear 10 rotates, the rubber material can be forced to return to the meshing position of the feeding gear 1 6 and the feeding gear 2 7 to prevent the rubber material from leaking.

[0051] When the rubber extruder of the present invention is used, rubber material is fed in from a feeding port 901, and after being squeezed by the gears, the rubber material falls into the meshing position of the fast screw 1 and the slow screw 2, and is plasticized and conveyed by the feeding section (101, 201), the plasticizing section (102, 202), and the conveying section (103, 203) of the fast screw 1 and the slow screw 2, and then discharged from a discharge port 402. During this process, the rotation speed of the fast screw 1 is controlled to be greater than the rotation speed of the slow screw 2, and the rotation speed of the fast screw 1 is twice, three times, or four times that of the slow screw 2, and can also be 1.1-8.0 times.

[0052] Through the above-mentioned improvements of the present invention, the feeding capacity, extrusion output and plasticizing effect can be improved within the extrusion glue temperature range permitted by the process, and the "devil's triangle" contradiction can be reduced within a feasible range.

[0053] The above description is a detailed description of the preferred feasible embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modified changes completed under the technical spirit suggested by the present invention should fall within the patent scope covered by the present invention.

Claims

1. A rubber extruder, characterized in that: The invention comprises a barrel, wherein a fast screw and a slow screw are arranged horizontally in parallel in the barrel, both ends of the fast screw and the slow screw are rotatably connected to the bearing seat outside the barrel end through bearings, and one end of the fast screw and / or one end of the slow screw are driven to rotate by a first power device; the fast screw and the slow screw are both divided into a feeding section, a plasticizing section and a conveying section; the feeding section of the fast screw is aligned with the feeding section of the slow screw, and the feeding section of the fast screw and the feeding section of the slow screw are provided with There are conveying threads with opposite spiral directions and meshing with each other, and the number of spirals in the feeding section of the fast screw is less than the number of spirals in the feeding section of the slow screw; the plasticizing section of the fast screw is aligned with the plasticizing section of the slow screw and both are provided with plasticizing elements; the conveying section of the fast screw is aligned with the conveying section of the slow screw, and the conveying section of the fast screw and the conveying section of the slow screw are provided with conveying threads with opposite spiral directions and meshing with each other, and the number of spirals in the conveying section of the fast screw is less than the number of spirals in the conveying section of the slow screw; The plasticizing section of the fast screw and the plasticizing section of the slow screw are both cylindrical columnar structures; the plasticizing element includes a mounting portion and a dumbbell portion, the mounting portion is a circular ring arranged at intervals on the outside of the plasticizing section; the dumbbell portion includes a columnar rod and spheres located at both ends of the columnar rod, the middle part of the columnar rod is tilted and fixed on the mounting portion, on the plasticizing section of the fast screw, each mounting portion is provided with a plurality of dumbbell portions, and the dumbbell portions on adjacent mounting portions are staggered, so that when viewed along the length direction of the fast screw, all the dumbbell portions are arranged in a spiral shape; on the plasticizing section of the slow screw, each mounting portion is provided with a plurality of dumbbell portions, and the dumbbell portions on adjacent mounting portions are staggered, so that when viewed along the length direction of the slow screw, all the dumbbell portions are arranged in a spiral shape; the number of dumbbell portions on the fast screw is less than the number of dumbbell portions on the slow screw; The top of the barrel is provided with a feed port, and the bottom is provided with a discharge port, wherein the feed port is located above the fast screw feeding section and the slow screw feeding section; and the discharge port is located below the fast screw conveying section and the slow screw conveying section.

2. A rubber extruder according to claim 1, characterized in that: The feeding section structure of the fast screw is the same as the conveying section structure of the fast screw; the feeding section structure of the slow screw is the same as the conveying section structure of the slow screw; and the ratio of the number of spirals in the feeding section of the fast screw to the number of spirals in the feeding section of the slow screw is 1:2, 1:3 or 1:

4.

3. A rubber extruder according to claim 1, characterized in that: A feeding barrel is also provided above the feed port, a feeding port is provided at the upper end of the feeding barrel, a discharge port is provided at the lower end of the feeding barrel, two feeding gears which can rotate in opposite directions are arranged side by side in the internal cavity of the feeding barrel, the meshing part between the two feeding gears is located directly below the feeding port, and directly above the discharge port and the feeding port, and the two feeding gears squeeze the rubber material downwards and then drop it through the feed port to the meshing part between the fast screw and the slow screw; a gear shaft is fixedly sleeved at the inner center of each feeding gear, both ends of the gear shaft pass through the upper feeding barrel and are rotatably connected to the feeding gear bearing seat through bearings, the feeding gear bearing seats are arranged on the outer sides of both ends of the upper feeding barrel, one end of the gear shaft passes through the feeding gear bearing seat and is driven to rotate by the second power device.

4. A rubber extruder according to claim 1, 2 or 3, characterized in that: The mounting parts on the fast screw rod are aligned one by one with the mounting parts on the slow screw rod, the number of dumbbell parts on each mounting part on the fast screw rod is the same, the number of dumbbell parts on each mounting part on the slow screw rod is the same, and the ratio of the number of dumbbell parts on each mounting part on the fast screw rod to the number of dumbbell parts on each mounting part on the slow screw rod is 1:2, 1:3 or 1:

4.

5. A rubber extruder plasticizing device according to claim 1, characterized in that: The angles between the central axis of the columnar rod and the central axis of the screw rod where it is located are both 8-12°.

6. A rubber extruder plasticizing device according to claim 1, characterized in that: The diameter of the plasticizing section of the fast screw is equal to the diameter of the plasticizing section of the slow screw; the columnar rod is a cylindrical rod, the diameter of the cylindrical rod is 1 / 9 to 1 / 7 of the working diameter of the outer surface of the plasticizing section, the diameter of the sphere is 1 / 6 to 1 / 4 of the working diameter of the outer surface of the plasticizing section, and the center distance of the spheres at both ends of the same cylindrical rod is 3 / 8 to 5 / 8 of the working diameter of the outer surface of the plasticizing section.

7. A rubber extruder plasticizing device according to claim 1, characterized in that: The distance between the middle of the columnar rod and the outer surface of the plasticizing section is 1 / 32 to 3 / 32 of the working diameter of the outer surface of the plasticizing section. The mounting parts are evenly distributed on the outer surface of the plasticizing section, and the distance between adjacent mounting parts is 7 / 10 to 1 of the working diameter of the outer surface of the plasticizing section.

8. A rubber extruder plasticizing device according to claim 4, characterized in that: The length ratios of the feeding section, the plasticizing section and the conveying section on the fast screw and the slow screw are all 4:6-10:3-5.

9. A rubber extruder plasticizing device according to claim 1, characterized in that: The fast screw and the slow screw are driven to rotate by different power devices respectively. The spiral structure of the fast screw is a single spiral or a double spiral; the spiral structure of the slow screw is a quadruple spiral, a hexahelix, or an octahelix.

10. A rubber extruder control method, characterized in that: Utilizing the rubber extruder according to any one of claims 1 to 9, the rotation speed of the fast screw is controlled to be 1.1 to 8.0 times the rotation speed of the slow screw.

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