The discharging and pelletizing mechanism and system of a three-screw extruder

Abstract

The present invention discloses a discharging and pelletizing mechanism and system for a three-screw extruder, which relates to the technical field of extrusion pelletizing machines and includes an extrusion barrel. One end of the extrusion barrel is connected to a transmission box, and the other end is connected to a heating and melting barrel. One end of the transmission box away from the extrusion barrel is connected to an extrusion motor. A feed hopper is fixedly connected to the top surface of the extrusion barrel near the transmission box. A discharging mechanism is connected to one end of the heating and melting barrel away from the extrusion barrel. A lead screw adjustment mechanism is installed on one side of the discharging mechanism away from the heating and melting barrel. An automatic pelletizing mechanism is installed on one side of the lead screw adjustment mechanism and is coaxially arranged with the extrusion barrel. Since the discharging mechanism adjusts the position of the automatic pelletizing mechanism through the lead screw adjustment mechanism based on the internal pressure value, there is no need for manual adjustment, that is, the automatic pelletizing mechanism makes an adaptive adjustment according to the internal pressure value of the discharging mechanism, ensuring the accurate position of the automatic pelletizing mechanism and cutting out plastic pellets with uniform size.

Description

Technical Field

[0001] The present invention relates to the technical field of extrusion pelletizing machines, and particularly relates to a discharging and pelletizing mechanism and system for a three-screw extruder. Background Art

[0002] The discharging and pelletizing mechanism of a screw extruder refers to a device specifically used for producing plastic pellets, which can realize the recycling and reuse of plastics;

[0003] Existing discharging and pelletizing mechanisms of screw extruders, such as a plastic particle granulator with stable feeding disclosed in a Chinese patent with the authorization announcement number CN116604726B and a separation and recycling granulator for waste plastics output by screwing disclosed in a Chinese patent with the authorization announcement number CN110126119B. When producing plastic pellets, the distance between the pelletizing device and the plastic extrusion device in such equipment is fixed. When the speed of the plastic changes during extrusion, the pelletizing device cannot be adjusted in time, resulting in uneven sizes of the plastic pellets produced by the pelletizing device and affecting the uniformity of the plastic pellets. Summary of the Invention

[0004] In order to overcome the above technical problems, the purpose of the present invention is to provide a discharging and pelletizing mechanism and system for a three-screw extruder, so as to solve the problem in the prior art that the distance between the pelletizing device and the plastic extrusion device in the discharging and pelletizing mechanism of the screw extruder is fixed, and when the extrusion speed of the plastic extrusion device changes, due to the fixed position of the pelletizing device, the sizes of the plastic pellets produced by the pelletizing device are uneven.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] In a first aspect of the present invention, a discharging and pelletizing mechanism and system for a three-screw extruder are provided, including an extrusion barrel, one end of which is connected to a transmission box, and the other end is connected to a heating and melting barrel. The end of the transmission box away from the extrusion barrel is connected to an extrusion motor. At the top surface of the extrusion barrel near the transmission box, a feeding hopper is fixedly connected. At the end of the heating and melting barrel away from the extrusion barrel, a discharging mechanism is connected. On one side of the discharging mechanism away from the heating and melting barrel, a lead screw adjustment mechanism is installed. On one side of the lead screw adjustment mechanism, an automatic pelletizing mechanism is installed and is coaxially arranged with the extrusion barrel. The discharging mechanism adjusts the position of the automatic pelletizing mechanism through the lead screw adjustment mechanism based on the internal pressure value.

[0007] As a further solution of the present invention: The discharging mechanism includes a discharging box. One end of the discharging box away from the heating and melting barrel is connected to a discharging die. One end of the discharging die away from the discharging box is connected to a discharging hopper. One end of the discharging hopper away from the discharging die is connected to a coaxial seat. On one side of the discharging box near the lead screw adjustment mechanism, a pressure adjustment mechanism is fixedly connected. At the center position of the bottom of the discharging hopper, a linkage rod is provided.

[0008] As a further solution of the present invention: a discharge chute penetrates through the interior of the discharge box, a pressure groove is formed in the middle position on the side of the discharge chute, and the discharge chute is matched with the discharge die.

[0009] As a further solution of the present invention: the pressure regulating mechanism includes a mechanism main body, an air pressure groove is formed in the side of the mechanism main body close to the pressure groove, a pressure piston is arranged in the air pressure groove, a hydraulic piston is synchronously connected to the side of the pressure piston away from the pressure groove, a hydraulic cavity is formed in the interior of the mechanism main body close to the hydraulic piston, the other end of the hydraulic cavity is plugged with a hydraulic regulating rod, and a pressure regulating block is fixedly connected to the outer end of the hydraulic regulating rod.

[0010] As a further solution of the present invention: a high-pressure cavity is formed in the interior of the mechanism main body, and the high-pressure cavity is communicated with the air pressure groove.

[0011] As a further solution of the present invention: one end of the linkage rod is installed inside the discharge box through a bearing, the other end of the linkage rod is installed inside the coaxial seat through a bearing, and transmission gears are fixedly connected to both ends of the linkage rod.

[0012] As a further solution of the present invention: the automatic granulation mechanism includes a granulation motor, the output shaft of the granulation motor passes through the center position of the coaxial seat and is connected with a granulation cutter, a track slider is fixedly connected to one side of the granulation motor, a ball nut is fixedly connected to the middle position of the side of the track slider, and the track slider is matched with the limit track.

[0013] As a further solution of the present invention: the output shaft of the granulation motor is meshed with the transmission gear at one end of the linkage rod close to the coaxial seat through a gear;

[0014] The discharge die includes a die main body, an impeller cavity is formed on one side of the die main body, movable impeller blades are arranged in the impeller cavity, a water inlet pipe is connected to the bottom of the die main body, a water outlet pipe is formed on the top of the die main body, a cooling cavity is formed in the interior of the die main body, one end of the cooling cavity is connected to the impeller cavity, the other end of the cooling cavity is connected to the water outlet pipe, and one end of the linkage rod close to the discharge box is meshed with a driving gear through the transmission gear at the end position.

[0015] The first aspect of the present invention is to provide a discharge and granulation system for a screw extruder, which is realized based on a discharge and granulation mechanism of a three-screw extruder and includes:

[0016] A control module, which is loaded on the extrusion barrel;

[0017] A temperature sensor, which is loaded on the heating and melting barrel, and the temperature sensor collects the temperature data of the material in the heating and melting barrel in real time and transmits the temperature data to the control module;

[0018] A pressure sensor is mounted on the discharging mechanism. The pressure sensor collects the pressure data of the material in the discharging mechanism in real time and transmits the pressure data to the control module;

[0019] An infrared sensor is mounted on the discharging mechanism. The infrared sensor collects the extrusion speed data of the material in the discharging mechanism in real time and transmits the extrusion speed data to the control module;

[0020] The control module generates a change curve of the extrusion speed data based on the temperature data, the pressure data, and the rotational speed value of the extrusion motor, and controls the rotational speed value of the extrusion motor based on the change curve of the extrusion speed data.

[0021] As a further solution of the present invention: The control module generates a change curve of the rotational speed value of the pelletizing motor based on the temperature data, the pressure data, and the extrusion speed data.

[0022] Advantages of the present invention:

[0023] In the present invention, the automatic pelletizing mechanism is installed on one side of the lead screw adjustment mechanism. The position of the automatic pelletizing mechanism can be adjusted through the lead screw adjustment mechanism. When the internal pressure value of the discharging mechanism increases, it will inevitably cause the extrusion speed of the plastic in the discharging mechanism to increase. Since the discharging mechanism adjusts the position of the automatic pelletizing mechanism through the lead screw adjustment mechanism based on the internal pressure value, there is no need for manual adjustment, that is, the automatic pelletizing mechanism is adaptively adjusted according to the internal pressure value of the discharging mechanism, ensuring the accurate position of the automatic pelletizing mechanism and cutting out plastic particles with uniform size. The discharging die utilizes the redundant power of the pelletizing motor to realize the circulation of cooling water, eliminating the need for an additional power source, reducing the energy consumption required for cooling the discharging die, and indirectly reducing the cost of producing plastic by the discharging and pelletizing mechanism of this three-screw extruder. Description of the Drawings

[0024] The present invention will be further described below with reference to the drawings.

[0025] Figure 1 is a schematic structural diagram of the discharging and pelletizing mechanism of a three-screw extruder according to the present invention;

[0026] Figure 2 is a front view of the discharging and pelletizing mechanism of a three-screw extruder according to the present invention;

[0027] Figure 3 is a top view of the discharging and pelletizing mechanism of a three-screw extruder according to the present invention;

[0028] Figure 4 is a schematic structure of the discharging mechanism in the present invention Figure 1 ;

[0029] Figure 5 is a cross-sectional view of the discharging mechanism in the present invention;

[0030] Figure 6 is a schematic structural diagram of the lead screw adjustment mechanism in the present invention;

[0031] Figure 7 is a schematic structural diagram of the automatic granulation mechanism in the present invention;

[0032] Figure 8 is a schematic structure of the discharging mechanism in the present invention Figure 2 ;

[0033] Figure 9 is a schematic structural diagram of the discharging box in the present invention;

[0034] Figure 10 is a schematic diagram of the internal structure of the discharging die in the present invention;

[0035] Figure 11 is a cross-sectional view of the discharging die in the present invention;

[0036] Figure 12 is a schematic structural diagram of the impeller blade in the present invention.

[0037] Explanation of reference numerals: 1, extrusion barrel; 2, feed hopper; 3, transmission box; 4, extrusion motor; 5, heating and melting barrel; 6, discharging mechanism; 61, discharging box; 611, discharging groove; 612, pressure groove; 62, discharging die; 621, die body; 622, impeller cavity; 623, water inlet pipe; 624, water outlet pipe; 625, positioning block; 626, cooling cavity; 627, impeller blade; 628, driving gear; 63, discharging hopper; 64, coaxial seat; 65, pressure regulating mechanism; 650, mechanism main body; 651, air pressure groove; 652, pressure piston; 653, high-pressure cavity; 654, synchronous connecting rod; 655, hydraulic piston; 656, hydraulic cavity; 657, hydraulic regulating rod; 658, limiting sliding groove; 659, pressure regulating block; 66, linkage rod; 7, lead screw adjustment mechanism; 71, horizontal moving beam; 72, limiting track; 73, adjusting lead screw; 74, turntable; 8, automatic granulation mechanism; 81, granulation motor; 82, granulation cutter; 83, support spring; 84, track slider; 85, ball nut. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] Embodiment 1

[0040] As Figures 1-7 shown, the present invention discloses a discharging and pelletizing mechanism of a three-screw extruder, which includes an extrusion barrel 1, one end of which is connected to a transmission box 3, and the other end is connected to a heating and melting barrel 5. One end of the transmission box 3 far from the extrusion barrel 1 is connected to an extrusion motor 4. It should be noted that a screw is arranged inside the extrusion barrel 1, and the number of screws can be one, two or three. The present invention preferably adopts three screws, that is, a three-screw extruder, which is specifically adaptively selected by those skilled in the art according to the specifications of the extrusion barrel 1. The output shaft of the extrusion motor 4 is connected to the input end of the transmission box 3 through a coupling. The transmission box 3 converts the rotation speed of the extrusion motor 4 into a torque force, and the output end of the transmission box 3 is power-connected to the screw inside the extrusion barrel 1. When the extrusion motor 4 is turned on, the output shaft of the extrusion motor 4 transmits power to the transmission box 3 through the coupling, and the transmission box 3 then transmits the power to the screw, causing the screw to rotate inside the extrusion barrel 1. A feed hopper 2 is fixedly connected to the top surface of one end of the extrusion barrel 1 close to the transmission box 3. Plastic raw materials can be conveyed into the extrusion barrel 1 through the feed hopper 2, and then the extrusion barrel 1 can convey the plastic to the heating and melting barrel 5. The outside of the heating and melting barrel 5 can be heated by an electric heating method to melt the plastic inside. One end of the heating and melting barrel 5 far from the extrusion barrel 1 is connected to a discharging mechanism 6. The discharging mechanism 6 extrudes the molten plastic inside the heating and melting barrel 5 into strip-shaped or cylindrical plastics through a mold and directly cuts them into plastic particles of uniform size. A lead screw adjusting mechanism 7 is installed on one side of the discharging mechanism 6 far from the heating and melting barrel 5, and an automatic pelletizing mechanism 8 is installed on one side of the lead screw adjusting mechanism 7 and is coaxially arranged with the extrusion barrel 1. The discharging mechanism 6 adjusts the position of the automatic pelletizing mechanism 8 through the lead screw adjusting mechanism 7 based on the internal pressure value. It should be noted that since the automatic pelletizing mechanism 8 is installed on one side of the lead screw adjusting mechanism 7, the position of the automatic pelletizing mechanism 8 can be adjusted through the lead screw adjusting mechanism 7. When the internal pressure value in the discharging mechanism 6 increases, it will inevitably lead to an increase in the extrusion speed of the plastic in the discharging mechanism 6. At this time, to ensure that the automatic pelletizing mechanism 8 can cut out plastic particles of uniform size, not only the cutting speed of the automatic pelletizing mechanism 8 for cutting the plastic needs to be increased according to the internal pressure value of the discharging mechanism 6, but also the distance between the discharging mechanism 6 and the automatic pelletizing mechanism 8 needs to be increased to ensure that the automatic pelletizing mechanism 8 can cut out plastic particles of uniform size. Since the discharging mechanism 6 adjusts the position of the automatic pelletizing mechanism 8 through the lead screw adjusting mechanism 7 based on the internal pressure value without manual adjustment, that is, the automatic pelletizing mechanism 8 is adaptively adjusted according to the internal pressure value of the discharging mechanism 6, ensuring the accurate position of the automatic pelletizing mechanism 8 and cutting out plastic particles of uniform size.

[0041] Example 2

[0042] As Figures 4-7As shown in the figure, the discharging mechanism 6 includes a discharging box 61. One end of the discharging box 61 away from the heating and melting cylinder 5 is connected with a discharging die 62. One end of the discharging die 62 away from the discharging box 61 is connected with a discharging hopper 63. One end of the discharging hopper 63 away from the discharging die 62 is connected with a coaxial seat 64. One side of the discharging box 61 close to the lead screw adjusting mechanism 7 is fixedly connected with a pressure adjusting mechanism 65. It should be noted that one end of the discharging box 61 is directly and hermetically connected to one end of the heating and melting cylinder 5 away from the extrusion cylinder 1. In this way, the heating and melting cylinder 5 can directly transport the molten plastic inside to the inside of the discharging box 61. The molten plastic entering the inside of the discharging box 61 will form strip-shaped or cylindrical plastic after passing through the discharging die 62. The specifications and types of the discharging die 62 are adaptively selected by those skilled in the art according to the specific plastic specifications and the plastic application fields. Therefore, the discharging die 62 and the discharging box 61 are detachably connected to ensure that technicians can select discharging dies 62 with different hole shapes or hole diameters according to the plastic specifications, improving the adaptability of the discharging mechanism 6. When the plastic extruded from the discharging die 62 is cut off, the formed plastic particles will automatically fall into the discharging hopper 63. An aggregate groove can be opened at the bottom of the discharging hopper 63 to collect the plastic particles, or an arc-shaped cover can be set at the top of the discharging hopper 63 to prevent the plastic particles from bouncing outside the discharging hopper 63.

[0043] A discharging groove 611 runs through the inside of the discharging box 61. A pressure groove 612 is opened at the middle position on the side of the discharging groove 611. The discharging groove 611 is matched with the discharging die 62. The molten plastic inside the heating and melting cylinder 5 directly enters the discharging groove 611, and then enters the discharging die 62 from one end of the discharging groove 611. Since the pressure groove 612 is opened at the middle position on the side of the discharging groove 611, the molten plastic inside the discharging groove 611 will directly act on the pressure groove 612.

[0044] As Figure 4 and Figure 5As shown in the figure, the pressure regulating mechanism 65 includes a mechanism main body 650, which can be fixed to the side of the discharge box 61. The connection between the mechanism main body 650 and the discharge box 61 can be fixed by welding or by bolts, and specific selection is made by those skilled in the art according to the specifications of the mechanism main body 650. An air pressure groove 651 is provided at a position on the side of the mechanism main body 650 close to the pressure groove 612. A pressure piston 652 is arranged in the air pressure groove 651. Since the air pressure groove 651 corresponds to the pressure groove 612 and the pressure piston 652 is arranged in the air pressure groove 651, the molten plastic in the pressure groove 612 will directly act on the side of the pressure piston 652, causing the pressure piston 652 to be subjected to the pressure of the molten plastic. A hydraulic piston 655 is synchronously connected to the side of the pressure piston 652 away from the pressure groove 612. A synchronous connecting rod 654 is fixedly connected between the pressure piston 652 and the hydraulic piston 655. When the pressure piston 652 is subjected to the pressure of the molten plastic, the pressure piston 652 will move towards the inner end of the air pressure groove 651. When the pressure piston 652 moves, it will also drive the hydraulic piston 655 to move synchronously through the synchronous connecting rod 654. A hydraulic cavity 656 is provided inside the mechanism main body 650 at a position close to the hydraulic piston 655. When the hydraulic piston 655 moves, the hydraulic piston 655 will compress the hydraulic oil inside the hydraulic cavity 656. The other end of the hydraulic cavity 656 is inserted with a hydraulic regulating rod 657. A pressure regulating block 659 is fixedly connected to the outer end of the hydraulic regulating rod 657. When the hydraulic oil inside the hydraulic cavity 656 is squeezed by the hydraulic piston 655, according to the principle of communicating vessels, the hydraulic regulating rod 657 will also be subjected to the squeezing action of the hydraulic oil inside the hydraulic cavity 656, thereby transmitting the pressure to the pressure regulating block 659 and causing the pressure regulating block 659 to move.

[0045] As Figure 5As shown, a high-pressure chamber 653 is provided inside the mechanism body 650. The high-pressure chamber 653 is communicated with the air pressure groove 651. Since the high-pressure chamber 653 is communicated with the air pressure groove 651, the high air pressure in the high-pressure chamber 653 will directly act inside the air pressure groove 651, causing the side of the pressure piston 652 away from the pressure groove 612 to be affected by the high air pressure. High-pressure inert gas can be filled inside the high-pressure chamber 653. For example, it can be nitrogen. To ensure that the high-pressure inert gas inside the high-pressure chamber 653 is not affected by the high temperature of the molten plastic, a heat insulation layer should be provided around the high-pressure chamber 653. Those skilled in the art set the preset pressure of the high-pressure inert gas inside the high-pressure chamber 653 according to the preset pressure inside the heating and melting cylinder 5. That is, when the molten plastic inside the heating and melting cylinder 5 is under the standard pressure, the pressures on both sides of the pressure piston 652 will be in an equilibrium state, and the pressure piston 652 will not move inside the air pressure groove 651. When the molten plastic inside the heating and melting cylinder 5 is greater than or less than the standard pressure, the pressure piston 652 will move inside the air pressure groove 651. When the molten plastic is greater than the standard pressure, the pressure piston 652 moves towards the inside of the air pressure groove 651. When the molten plastic is less than the standard pressure, the pressure piston 652 moves towards the outside of the air pressure groove 651.

[0046] As Figure 6 shown, the lead screw adjustment mechanism 7 includes a horizontal moving beam 71. A limit track 72 is provided inside the horizontal moving beam 71. A lead screw 73 is installed at the center position inside the horizontal moving beam 71 through a bearing. One end of the lead screw 73 is fixedly connected to a turntable 74. On-site workers can rotate the turntable 74 to rotate the lead screw 73, enabling the lead screw 73 to be manually rotated.

[0047] A fastening bolt is provided on the outer side of the horizontal moving beam 71 near the lead screw 73. When it is necessary to fix the position of the lead screw 73, the fastening bolt can be rotated so that the inner end of the fastening bolt presses against the side of the lead screw 73, and the position of the lead screw 73 is fixed by friction to prevent the lead screw 73 from rotating.

[0048] As Figure 6 and Figure 7As shown in the figure, the automatic granulation mechanism 8 includes a granulation motor 81. The output shaft of the granulation motor 81 passes through the center position of the coaxial seat 64 and is connected with a granulation cutter 82. One side of the granulation motor 81 is fixedly connected with an orbital slider 84. The middle position of the side surface of the orbital slider 84 is fixedly connected with a ball nut 85. The orbital slider 84 is matched with the limit track 72, and the ball nut 85 is matched with the adjusting lead screw 73. It should be noted that since the orbital slider 84 is matched with the limit track 72 and the ball nut 85 is matched with the adjusting lead screw 73, when the rotating adjusting lead screw 73 cooperates with the ball nut 85, the orbital slider 84 can slide on the limit track 72, thereby controlling the position of the granulation motor 81. A support spring 83 is nested on the side surface of the output shaft of the granulation motor 81. One end of the support spring 83 supports on the granulation cutter 82, and the other end of the support spring 83 supports on the inner side surface of the coaxial seat 64. The output shaft of the granulation motor 81 and the output shaft of the extrusion motor 4 are on the same central axis. When the granulation motor 81 is turned on, the power of the granulation motor 81 can be transmitted to the granulation cutter 82 through the output shaft, so that the granulation cutter 82 rotates at a high speed. The granulation cutter 82 rotating at a high speed can cut off the plastic conveyed by the discharge die 62 to form plastic particles.

[0049] As Figures 1-7 shown, a limit chute 658 matching the horizontal moving beam 71 is opened at a position on the side surface of the mechanism main body 650 close to the horizontal moving beam 71. The pressure adjusting block 659 is fixedly connected to the end surface of the horizontal moving beam 71. It should be noted that since the limit chute 658 is matched with the horizontal moving beam 71 and the pressure adjusting block 659 is fixedly connected to the end surface of the horizontal moving beam 71, when the pressure adjusting block 659 moves, it can drive the horizontal moving beam 71 to move synchronously. Since the granulation motor 81 is installed on the horizontal moving beam 71 through the orbital slider 84 and the ball nut 85, the moving horizontal moving beam 71 will drive the granulation motor 81 through the orbital slider 84 and the ball nut 85, thereby realizing the movement of the granulation motor 81. The moving granulation motor 81 will also drive the granulation cutter 82 to move through the transmission shaft, so that the distance between the granulation cutter 82 and the discharge die 62 can be automatically adjusted to ensure that the granulation cutter 82 can cut out plastic particles with uniform size.

[0050] Example 3

[0051] As Figures 1-8As shown in the figure, the present invention discloses a discharging and pelletizing system for a screw extruder. This discharging and pelletizing system is implemented based on the discharging and pelletizing mechanism of a three-screw extruder in Embodiment 1 and Embodiment 2, and includes a control module, a temperature sensor, a pressure sensor, and an infrared sensor. Among them, the control module is installed on the extrusion barrel 1, the temperature sensor is installed on the heating and melting barrel 5. The temperature sensor collects the temperature data of the material in the heating and melting barrel 5 in real time and transmits the temperature data to the control module. The pressure sensor is installed on the discharging mechanism 6. The pressure sensor collects the pressure data of the material in the discharging mechanism 6 in real time and transmits the pressure data to the control module. The infrared sensor is installed on the discharging mechanism 6. The infrared sensor collects the extrusion speed data of the material in the discharging mechanism 6 in real time and transmits the extrusion speed data to the control module. A microprocessor is provided on the extrusion barrel 1, and the control programs of the control module are all loaded on the microprocessor. The number of settings, specifications, and installation positions of the temperature sensor, pressure sensor, and infrared sensor are adaptively selected by those skilled in the art according to the actual on-site conditions of the heating and melting barrel 5 and the discharging mechanism 6.

[0052] The control module generates a change curve of the extrusion speed data based on the temperature data, pressure data, and rotational speed value of the extrusion motor 4, and controls the rotational speed value of the extrusion motor 4 based on the change curve of the extrusion speed data. The temperature data refers to the temperature value of the molten plastic inside the heating and melting barrel 5. The pressure data refers to the pressure value of the molten plastic inside the discharging mechanism 6. The extrusion speed data is the speed at which the plastic is extruded from the end face of the discharging mechanism 6. Usually, the greater the pressure value of the molten plastic inside the discharging mechanism 6, the faster the speed at which the plastic is extruded from the end face of the discharging mechanism 6. To ensure the smoothness of the speed at which the plastic is extruded from the end face of the discharging mechanism 6, it is necessary to appropriately reduce the rotational speed value of the extrusion motor 4 at this time. The reduction amplitude is adaptively adjusted by those skilled in the art. Specifically, different temperature data, pressure data, and rotational speed values of the extrusion motor 4 are collected in advance, and then the change curve of the extrusion speed data is simulated by a computer according to different temperature data, pressure data, and rotational speed values of the extrusion motor 4. Finally, the rotational speed value of the extrusion motor 4 is controlled according to the temperature data, pressure data, and change curve of the extrusion speed data to ensure the smoothness of the speed at which the plastic is extruded from the end face of the discharging mechanism 6.

[0053] The control module generates a change curve of the rotational speed value of the pelletizing motor 81 based on the temperature data, pressure data, and extrusion speed data. Since the adjustment of the rotational speed value of the extrusion motor 4 has hysteresis, that is, when the pressure value of the molten plastic inside the discharging mechanism 6 increases or decreases, the speed at which the plastic is extruded from the end face of the discharging mechanism 6 will inevitably increase or decrease. Therefore, it is necessary to adjust the rotational speed of the pelletizing motor 81 in a timely manner. That is, when the speed at which the plastic is extruded from the end face of the discharging mechanism 6 increases, the rotational speed of the pelletizing motor 81 is increased. When the speed at which the plastic is extruded from the end face of the discharging mechanism 6 decreases, the rotational speed of the pelletizing motor 81 is decreased to ensure that the pelletizing motor 81 produces plastic pellets of uniform size.

[0054] Example 4

[0055] As Figures 9-12 shown, a linkage rod 66 is provided at the center of the bottom of the discharge hopper 63. One end of the linkage rod 66 is installed inside the discharge box 61 through a bearing, and the other end of the linkage rod 66 is installed inside the coaxial seat 64 through a bearing. Transmission gears (not shown in the drawings) are fixedly connected to both ends of the linkage rod 66.As Figure 7 、 Figure 8 and Figure 9 shown, the output shaft of the pelletizing motor 81 passes through the coaxial seat 64, and a gear (not shown in the drawings, it should be noted that the installation position of the gear is adaptively changed by those skilled in the art according to the position of the output shaft of the pelletizing motor 81 inside the coaxial seat 64 and the position of the transmission gear on the linkage rod 66 inside the coaxial seat 64, as long as the power of the output shaft of the pelletizing motor 81 can be transmitted to the transmission gear through the gear) is installed inside the coaxial seat 64. At the same time, a gear is also installed at the position of the output shaft of the pelletizing motor 81 corresponding to the coaxial seat 64. The output shaft of the pelletizing motor 81 is meshed with the transmission gear at one end of the linkage rod 66 close to the coaxial seat 64 through the gear. In this way, after the pelletizing motor 81 is turned on, the output shaft of the pelletizing motor 81 can transmit the power to the transmission gear at one end of the linkage rod 66 through the gear, driving the transmission gear to rotate;

[0056] As Figure 8 shown, several groups of dial rods are nested at the side of the linkage rod 66 close to the discharge hopper 63. In this way, when the linkage rod 66 rotates, the linkage rod 66 can drive the nested dial rods on the side to rotate synchronously, and the rotating dial rods can act on the plastic particles accumulated at the discharge hopper 63 to ensure that the discharge hopper 63 is not blocked by the plastic particles;

[0057] As Figure 8 、 Figure 10 、 Figure 11 ​​As shown in the figure, the discharge die 62 includes a die body 621. A positioning block 625 is fixedly connected to the side of the die body 621. Through the cooperation of the positioning block 625 and the discharge box 61, the installation and positioning of the die body 621 are facilitated. An impeller cavity 622 is provided on one side of the die body 621. An active impeller blade 627 is arranged inside the impeller cavity 622. A water inlet pipe 623 is connected to the bottom of the die body 621. The water inlet pipe 623 can be connected to a cold water tank to ensure that the cooling water in the cold water tank can enter the impeller cavity 622 through the water inlet pipe 623. A water outlet pipe 624 is provided at the top of the die body 621. A cooling cavity 626 is also provided inside the die body 621. One end of the cooling cavity 626 is connected to the impeller cavity 622, and the other end of the cooling cavity 626 is connected to the water outlet pipe 624. The position and size of the cooling cavity 626 opened inside the die body 621 are adaptively adjusted by those skilled in the art according to the extrusion channel of the discharge die 62 to ensure that the cooling water can cool the plastic in the extrusion channel;

[0058] As Figure 12 shown in the figure, a driving gear 628 is meshed with the side of the impeller blade 627. It should be noted that the driving gear 628 is installed inside the discharge box 61 through a rotating shaft. After one end of the linkage rod 66 close to the discharge box 61 is inserted into the discharge box 61, it is meshed with the driving gear 628 through a transmission gear at the end position. In this way, when the linkage rod 66 rotates, the rotating linkage rod 66 can drive the driving gear 628 to rotate through the transmission gear, and the rotating driving gear 628 will drive the impeller blade 627 to rotate. As Figure 10 shown in the figure, the rotating impeller blade 627 will squeeze the cooling water into the inside of the cooling cavity 626, realizing the automatic circulation of the cooling water and ensuring the cooling effect of the cooling cavity 626 on the plastic inside the discharge die 62. The driving of the impeller blade 627 utilizes the redundant power of the pelletizing motor 81, eliminating the need for an additional power source, reducing the energy consumption required for cooling the discharge die 62, and indirectly reducing the cost of producing plastic by the discharge and pelletizing mechanism of this three-screw extruder.

[0059] The above has described a specific embodiment of the present invention in detail, but the content described is only the preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. Any equal changes and improvements made according to the scope of the present invention application should still fall within the scope covered by the patent of the present invention.

Claims

1. A discharging and pelletizing mechanism of a three-screw extruder, characterized in that, Comprising: An extrusion barrel (1), one end of which is connected to a transmission box (3), and the other end is connected to a heating and melting barrel (5). One end of the transmission box (3) far from the extrusion barrel (1) is connected to an extrusion motor (4); A feed hopper (2), which is fixedly connected to the top surface of one end of the extrusion barrel (1) close to the transmission box (3); A discharging mechanism (6), which is connected to one end of the heating and melting barrel (5); A lead screw adjustment mechanism (7), which is installed on one side of the discharging mechanism (6); An automatic granulating mechanism (8), which is installed on one side of the lead screw adjustment mechanism (7) and is coaxially arranged with the extrusion barrel (1); The discharging mechanism (6) adjusts the position of the automatic granulating mechanism (8) through the lead screw adjustment mechanism (7) based on the magnitude of the internal pressure value, and the discharging mechanism (6) utilizes the redundant power of the automatic granulating mechanism (8) to cool the plastic; The discharging mechanism (6) includes a discharging box (61). One end of the discharging box (61) far from the heating and melting barrel (5) is connected to a discharging die (62). One end of the discharging die (62) far from the discharging box (61) is connected to a discharging hopper (63). One end of the discharging hopper (63) far from the discharging die (62) is connected to a coaxial seat (64). One side of the discharging box (61) close to the lead screw adjustment mechanism (7) is fixedly connected to a pressure adjustment mechanism (65). The center position of the bottom of the discharging hopper (63) is provided with a linkage rod (66); An discharging groove (611) runs through the inside of the discharging box (61). A pressure groove (612) is opened at the middle position of the side surface of the discharging groove (611). The discharging groove (611) is matched with the discharging die (62); The pressure adjustment mechanism (65) includes a mechanism main body (650). An air pressure groove (651) is opened at a position on the side surface of the mechanism main body (650) close to the pressure groove (612). A pressure piston (652) is arranged in the air pressure groove (651). One side of the pressure piston (652) far from the pressure groove (612) is synchronously connected to a hydraulic piston (655). A hydraulic cavity (656) is opened at a position in the mechanism main body (650) close to the hydraulic piston (655). The other end of the hydraulic cavity (656) is plugged with a hydraulic adjustment rod (657). A pressure adjustment block (659) is fixedly connected to the outer end of the hydraulic adjustment rod (657); A high-pressure cavity (653) is opened inside the mechanism main body (650), and the high-pressure cavity (653) is communicated with the air pressure groove (651).

2. The discharge pelletizing mechanism of a three-screw extruder according to claim 1, characterized in that, One end of the linkage rod (66) is installed inside the discharging box (61) through a bearing, and the other end of the linkage rod (66) is installed inside the coaxial seat (64) through a bearing. Transmission gears are fixedly connected to both ends of the linkage rod (66).

3. The discharging and pelletizing mechanism of a three-screw extruder according to claim 2, characterized in that, The automatic granulating mechanism (8) includes a granulating motor (81). The output shaft of the granulating motor (81) passes through the center position of the coaxial seat (64) and is connected to a granulating cutter (82). One side of the granulating motor (81) is fixedly connected to a track slider (84). A ball nut (85) is fixedly connected to the middle position of the side surface of the track slider (84). The track slider (84) is matched with a limit track (72).

4. The discharging and pelletizing mechanism of a three-screw extruder according to claim 3, characterized in that, The output shaft of the pelletizing motor (81) is engaged with the transmission gear at one end of the linkage rod (66) close to the coaxial seat (64) through a gear; The discharging die (62) includes a die body (621). An impeller cavity (622) is formed on one side of the die body (621). An active impeller blade (627) is arranged inside the impeller cavity (622). A water inlet pipe (623) is connected to the bottom of the die body (621). A water outlet pipe (624) is formed on the top of the die body (621). A cooling cavity (626) is formed inside the die body (621). One end of the cooling cavity (626) is connected to the impeller cavity (622), and the other end of the cooling cavity (626) is connected to the water outlet pipe (624). One end of the linkage rod (66) close to the discharging box (61) is engaged with a driving gear (628) through the transmission gear at the end position.

5. A discharge and pelletizing system for a screw extruder, which is implemented based on the discharge and pelletizing mechanism of a three-screw extruder according to any one of claims 1-4, and is characterized in that, Comprising: A control module, which is loaded on the extrusion barrel (1); A temperature sensor, which is loaded on the heating and melting barrel (5). The temperature sensor collects the temperature data of the material in the heating and melting barrel (5) in real time and transmits the temperature data to the control module; A pressure sensor, which is loaded on the discharging mechanism (6). The pressure sensor collects the pressure data of the material in the discharging mechanism (6) in real time and transmits the pressure data to the control module; An infrared sensor, which is loaded on the discharging mechanism (6). The infrared sensor collects the extrusion speed data of the material in the discharging mechanism (6) in real time and transmits the extrusion speed data to the control module; The control module generates a change curve of the extrusion speed data based on the temperature data, the pressure data and the rotation speed value of the extrusion motor (4), and controls the rotation speed value of the extrusion motor (4) based on the change curve of the extrusion speed data.

6. The discharging and pelletizing system of a screw extruder according to claim 5, characterized in that, The control module generates a change curve of the rotation speed value of the pelletizing motor (81) based on the temperature data, the pressure data and the extrusion speed data.

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