Improved Screw and Barrel Device for Injection Molding Machine

Abstract

The present invention provides an improved injection molding machine screw barrel device, which includes a feeding screw, a barrel, and multiple heating mechanisms. An outlet hole communicating with the inner hole is opened on the proximal end face of the barrel, and a feed inlet communicating with the inner hole is opened on the side wall of the distal end of the barrel. The feeding screw extends into the inner hole of the barrel, and the multiple heating mechanisms are coated on the outer wall of the barrel. An exhaust hole is opened at the top of the outer side wall of the barrel, and a surplus material groove is opened on the inner hole side wall of the barrel corresponding to the position of the exhaust hole. The exhaust hole penetrates through the side wall of the barrel and the surplus material groove and communicates with the inner hole of the barrel. The longest side of the projection pattern of the surplus material groove on the barrel end face is an arc. When the feeding screw extrudes the molten plastic raw material to the area near the exhaust hole, the plastic raw material will enter the surplus material groove. The surplus material groove increases the space that the plastic raw material can occupy when moving here, avoiding directly extruding the molten plastic raw material into the exhaust hole, achieving the purpose of exhaust, and not causing the overflow of the molten plastic raw material.

Description

Technical Field

[0001] The present invention relates to the technical field of injection molding processing, and particularly relates to an injection molding machine screw barrel device. Background Art

[0002] In the plastic injection process, for plastic raw materials with high water absorption, such as ABS, nylon, plexiglass, PET, etc., it is necessary to dry them before injection molding, otherwise a large number of bubbles will be trapped in the injection molded products, resulting in adverse consequences such as unqualified product quality. However, using special equipment to dry plastic raw materials not only increases the process but also prolongs the production time. For example, PET plastic needs to be continuously dried for 5 - 6 hours at 160 °C, which not only reduces the production efficiency of the enterprise but also increases the production cost of the enterprise.

[0003] The Chinese utility model patent "Injection Molding Machine Screw Barrel and Injection Molding Machine" with the application number 201621223208.0 discloses an injection molding machine screw barrel including a feeding screw, a barrel, a feeding hopper, an exhaust device, and a heating device. The feeding screw includes a plastic melting and pushing section, a plastic control and pushing section, a plastic storage and pushing section, and a plastic acceleration section arranged in sequence along the feeding direction of the plastic raw material. The feeding hopper is arranged above the plastic melting and pushing section. The exhaust device includes an exhaust passage arranged above the plastic control and pushing section, a sealing plate for sealing the exhaust passage, an exhaust hole opened on the sealing plate, and a connecting conduit arranged between the exhaust device and the feeding hopper. One end of the connecting conduit is fixedly connected to the exhaust hole, and the other end is fixedly connected to the side wall of the feeding hopper. The heating device is wrapped around the outer walls of the barrel and the connecting conduit. The injection molding machine screw barrel provided by the present invention is used to discharge the gas generated inside the barrel.

[0004] However, the above - mentioned patented technology has the following disadvantages:

[0005] 1. In this patent, the exhaust hole is directly communicated with the inner hole of the barrel. In actual use, the feeding screw will directly squeeze the molten plastic raw material into the exhaust hole. The structure of the above - mentioned exhaust device causes the connecting conduit to be inevitably blocked by the raw material, and it is simply impossible to achieve the purpose of exhausting gas. Moreover, even without the exhaust device described in the above patent, it will also cause the molten plastic raw material to overflow, losing the purpose of opening the exhaust hole.

[0006] 2. Only relying on the conventional feeding screw to perform the extrusion and exhaust work cannot fully extrude the air in the plastic raw material. If the drying process is not set at the feeding place, it will also cause a large number of bubbles to be trapped in the injection molded products, resulting in unqualified product quality. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide an improved injection molding machine screw barrel device with a reasonable structure and convenient maintenance, which can prevent plastic raw materials from entering the exhaust holes.

[0008] To solve the above technical problem, the present invention provides an improved injection molding machine screw barrel device;

[0009] It includes a feeding screw, a barrel, and multiple heating mechanisms. An outlet hole communicating with its inner hole is opened on the proximal end face of the barrel, an inlet port communicating with its inner hole is opened on the distal side wall of the barrel, the feeding screw extends into the inner hole of the barrel, threads are provided on the side wall of the feeding screw, and multiple heating mechanisms are covered on the outer wall of the barrel;

[0010] An exhaust hole is opened on the top of the outer side wall of the barrel, a surplus material groove is opened on the inner hole side wall of the barrel corresponding to the position of the exhaust hole, the exhaust hole penetrates through the barrel side wall and the surplus material groove and communicates with the inner hole of the barrel. The longest side of the projection pattern of the surplus material groove on the barrel end face is an arc, the highest point of this arc side intersects with the projection line of the exhaust hole axis on the barrel end face, and the lowest point of this arc side intersects with the projection circle of the inner hole side wall of the barrel on the barrel end face.

[0011] After adopting such a structure, a surplus material groove is arranged on the inner hole side wall of the barrel. In actual use, when the feeding screw extrudes the molten plastic raw materials to the area near the exhaust hole, the plastic raw materials will enter the surplus material groove. Compared with the original space only between the feeding screw and the inner wall of the barrel, the surplus material groove increases the space that the plastic raw materials can occupy when moving here, avoiding directly extruding the molten plastic raw materials into the exhaust hole, achieving the purpose of exhaust, and not causing the overflow of the molten plastic raw materials.

[0012] As a preference of this improved injection molding machine screw barrel device, the barrel includes a first barrel body and a second barrel body. The first barrel body is on the proximal side of the second barrel body. An outlet hole communicating with its inner hole is opened on the proximal end face of the first barrel body. The surplus material groove is in the first barrel body. An inlet port communicating with its inner hole is opened on the distal side wall of the second barrel body. A first flange is provided on the distal end face of the first barrel body, a second flange is provided on the proximal end face of the second barrel body, the first flange of the first barrel body and the second flange of the second barrel body are fixedly connected by bolts, and the inner hole of the first barrel body communicates with the inner hole of the second barrel body.

[0013] After adopting such a structure, the barrel is composed of a first barrel body and a second barrel body, which can facilitate the processing of the surplus material groove, and the cooperation of the first flange and the second flange can ensure the overall stability of the barrel.

[0014] This improved injection molding machine screw barrel device does not need to dry the plastic raw materials for 4 - 5 hours before feeding, reducing the adverse working condition that when using a vacuum pump for steam treatment, the plastic raw materials block the pump body due to the excessive suction of the vacuum pump.

[0015] As a preference of the screw barrel device of the improved injection molding machine, an extrusion section is provided in the middle of the side wall of the feeding screw, and a plurality of extrusion bumps extend outward from the side wall of the feeding screw within the extrusion section;

[0016] After the feeding screw is matched with the barrel, the extrusion section is in the area between the exhaust hole of the barrel and the feeding port of the barrel, and the extrusion section of the feeding screw is close to the exhaust hole of the barrel.

[0017] After adopting such a structure, after entering the extrusion section, a plurality of extrusion bumps on the side wall of the feeding screw disperse the plastic raw material, and finally the air in the plastic raw material is fully separated.

[0018] As a preference of the screw barrel device of the improved injection molding machine, a transition section is further provided on the side wall of the feeding screw. The transition section is close to the extrusion section and is in the area between the extrusion section and the feeding port of the barrel. The outer wall diameter of the feeding screw at the distal end of the transition section is smaller than the outer wall diameter of the feeding screw at the proximal end of the transition section, and the outer wall diameter of the feeding screw gradually increases along the direction from the distal end to the proximal end of the transition section.

[0019] After adopting such a structure, after entering the transition section, since the outer wall diameter of the feeding screw gradually increases along the direction from the distal end to the proximal end of the transition section, by reducing the space between the side wall of the feeding screw and the inner wall of the barrel, the air in the plastic raw material is further discharged.

[0020] As a preference of the screw barrel device of the improved injection molding machine, a first feeding section and a second feeding section are further provided on the side wall of the feeding screw. The second feeding section and the first feeding section are successively in the area between the transition section and the distal end of the feeding screw. The thread pitch of the side wall of the feeding screw within the first feeding section is greater than the thread pitch of the side wall of the feeding screw within the second feeding section;

[0021] After the feeding screw is matched with the barrel, the feeding port of the barrel is aligned with the feeding screw in the first feeding section.

[0022] After adopting such a structure, the plastic raw material passes through the first feeding section and the second feeding section in sequence. The plastic raw material in the first feeding section is normally transported by the feeding screw towards the discharge port of the barrel. After entering the second feeding section, since the thread pitch of the side wall of the feeding screw within the first feeding section is greater than the thread pitch of the side wall of the feeding screw within the second feeding section, by changing the thread pitch on the feeding screw, the second feeding section starts to initially extrude the plastic raw material, so that the air in the plastic raw material is initially discharged. Description of the Drawings

[0023] Figure 1 is the front view of the embodiment of the screw barrel device of the improved injection molding machine.

[0024] Figure 2 is Figure 1 a sectional view of

[0025] Figure 3 is the front view of the feeding screw in the embodiment of the screw barrel device of the improved injection molding machine.

[0026] Figure 4 is Figure 3 an enlarged view of part A of

[0027] Figure 5 is the sectional view of the front view of the barrel in the embodiment of the screw barrel device of the improved injection molding machine.

[0028] Figure 6 is Figure 5 a sectional view along the B-B direction. Detailed implementation manners

[0029] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe the detailed implementation manners of the present invention with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific implementations disclosed below.

[0030] The terms "vertical", "horizontal", "left", "right", and similar expressions used herein are for illustrative purposes only and do not represent the only implementation manner.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art belonging to the technical field of the present invention. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0032] Please refer to FIGS. 1 to 6.

[0033] The screw barrel device of the improved injection molding machine includes a feeding screw 1, a barrel 2, and multiple groups of heating mechanisms 3.

[0034] The barrel 2 includes a first barrel body 23 and a second barrel body 24. The first barrel body 23 is on the proximal side of the second barrel body 24. An outlet hole 21 communicating with its inner hole is provided on the proximal end face of the first barrel body 23. A feed inlet 22 communicating with its inner hole is provided on the distal side wall of the second barrel body 24. A first flange 23a is provided on the distal end face of the first barrel body 23, and a second flange 24a is provided on the proximal end face of the second barrel body 24. The first flange 23a of the first barrel body 23 is fixedly connected to the second flange 24a of the second barrel body 24 by bolts, and the inner hole of the first barrel body 23 communicates with the inner hole of the second barrel body 24.

[0035] An exhaust hole 25 is provided at the top of the outer side wall of the first barrel body 23. A surplus material groove 26 is provided on the inner hole side wall of the first barrel body 23 corresponding to the position of the exhaust hole 25. The exhaust hole 25 penetrates through the side wall of the first barrel body 23 and the surplus material groove 26 and communicates with the inner hole of the first barrel body 23. The longest side of the projection pattern of the surplus material groove 26 on the end face of the first barrel body 23 is an arc. The highest point of this arc side intersects with the projection line of the axis of the exhaust hole 25 on the end face of the first barrel body 23, and the lowest point of this arc side intersects with the projection circle of the inner hole side wall of the barrel 2 on the end face of the first barrel body 23.

[0036] The feeding screw 1 extends into the inner hole of the barrel 2. Threads are provided on the side wall of the feeding screw 1, and multiple heating mechanisms 3 are wrapped on the outer wall of the barrel 2.

[0037] An extrusion section 11 is provided in the middle of the side wall of the feeding screw 1. Threads are not provided on the side wall of the feeding screw 1 within the extrusion section 11, and several extrusion protrusions 11a extend outward from the side wall of the feeding screw 1 within the extrusion section 11.

[0038] A transition section 12 is also provided on the side wall of the feeding screw 1. The transition section 12 is close to the extrusion section 11. The transition section 12 is in the area between the extrusion section 11 and the feed inlet 22 of the barrel 2. The outer wall diameter of the feeding screw 1 at the distal end of the transition section 12 is smaller than the outer wall diameter of the feeding screw 1 at the proximal end of the transition section 12. The outer wall diameter of the feeding screw 1 gradually increases along the direction from the distal end to the proximal end of the transition section 12.

[0039] A first feeding section 14 and a second feeding section 13 are also provided on the side wall of the feeding screw 1. The second feeding section 13 and the first feeding section 14 are successively in the area between the transition section 12 and the distal end of the feeding screw 1. The thread pitch of the threads on the side wall of the feeding screw 1 within the first feeding section 14 is greater than the thread pitch of the threads on the side wall of the feeding screw 1 within the second feeding section 13.

[0040] After the feeding screw 1 is matched with the barrel 2, the extrusion section 11 is in the area between the exhaust hole of the barrel 2 and the feed inlet 22 of the barrel 2, and the extrusion section 11 of the feeding screw 1 is close to the position of the exhaust hole of the barrel 2.

[0041] After the feeding screw 1 is engaged with the barrel 2, the feeding port 22 of the barrel 2 is aligned with the feeding screw 1 in the first feeding section 14, and the second feeding section 13 is in the area between the transition section 12 and the first feeding section 14.

[0042] When the screw barrel device of this improved injection molding machine works, first, the plastic raw material is put into the barrel 2 from the feeding port 22. Subsequently, through the rotation of the feeding screw 1, it is continuously transported from the plastic melting and advancing section to the plastic control and advancing section. The heating mechanism 3 wrapped around the outer wall of the barrel 2 melts the plastic raw material inside the barrel 2 at high temperature, melting the plastic raw material into molten plastic.

[0043] During the process of the plastic raw material from the feeding port 22 of the barrel 2 to the exhaust hole, the plastic raw material successively passes through the first feeding section 14, the second feeding section 13, the transition section 12, and the extrusion section 11. The plastic raw material in the first feeding section 14 is normally transported by the feeding screw 1 towards the discharge port of the barrel 2;

[0044] After entering the second feeding section 13, since the thread pitch on the side wall of the feeding screw 1 in the first feeding section 14 is greater than the thread pitch on the side wall of the feeding screw 1 in the second feeding section 13, by changing the thread pitch on the feeding screw 1, the second feeding section 13 starts to preliminarily extrude the plastic raw material, enabling the air in the plastic raw material to be preliminarily discharged;

[0045] After entering the transition section 12, since the outer wall diameter of the feeding screw 1 gradually increases along the direction from the distal end to the proximal end of the transition section 12, by reducing the space between the side wall of the feeding screw 1 and the inner wall of the barrel 2, the air in the plastic raw material is further discharged;

[0046] After entering the extrusion section 11, several extrusion protrusions 11a on the side wall of the feeding screw 1 disperse the plastic raw material, ultimately achieving the purpose of fully separating the air in the plastic raw material, and the air is discharged from the exhaust hole.

[0047] At the same time, the molten plastic raw material inside the barrel 2 continues to be transported forward, and finally the molten plastic raw material is pushed into the molding die and cooled and solidified.

[0048] The above is only one implementation mode of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several variations and improvements can be made, and these should also be regarded as belonging to the protection scope of the present invention.

Claims

1. An improved screw barrel device for an injection molding machine, characterized in that: It includes a feeding screw, a barrel and multiple heating mechanisms. An outlet hole communicating with its inner hole is opened on the proximal end face of the barrel, and a feeding port communicating with its inner hole is opened on the side wall of the distal end of the barrel. The feeding screw extends into the inner hole of the barrel. Threads are provided on the side wall of the feeding screw, and multiple heating mechanisms are covered on the outer wall of the barrel; It is characterized in that: An exhaust hole is opened at the top of the outer side wall of the barrel. A surplus material groove is opened on the side wall of the inner hole of the barrel corresponding to the exhaust hole. The exhaust hole penetrates the side wall of the barrel and the surplus material groove and communicates with the inner hole of the barrel. The longest side of the projection pattern of the surplus material groove on the barrel end face is an arc. The highest point of this arc side intersects with the projection line of the axis of the exhaust hole on the barrel end face, and the lowest point of this arc side intersects with the projection circle of the side wall of the inner hole of the barrel on the barrel end face; The barrel includes a first barrel body and a second barrel body. The first barrel body is on the proximal side of the second barrel body. An outlet hole communicating with its inner hole is opened on the proximal end face of the first barrel body. The surplus material groove is in the first barrel body. A feeding port communicating with its inner hole is opened on the side wall of the distal end of the second barrel body. A first flange is provided on the distal end face of the first barrel body, and a second flange is provided on the proximal end face of the second barrel body. The first flange of the first barrel body and the second flange of the second barrel body are fixedly connected by bolts, and the inner hole of the first barrel body communicates with the inner hole of the second barrel body; First feeding sections and second feeding sections are further provided on the side wall of the feeding screw. The second feeding section and the first feeding section are successively in the area between the transition section and the distal end of the feeding screw. The thread pitch of the threads on the side wall of the feeding screw in the first feeding section is greater than the thread pitch of the threads on the side wall of the feeding screw in the second feeding section; After the feeding screw and the barrel are matched, the feeding port of the barrel is aligned with the feeding screw in the first feeding section.

2. The improved screw barrel device for an injection molding machine according to claim 1, characterized in that: A squeezing section is provided in the middle of the side wall of the feeding screw. A number of squeezing protrusions extend outward from the side wall of the feeding screw in the squeezing section; After the feeding screw and the barrel are matched, the squeezing section is in the area between the exhaust hole of the barrel and the feeding port of the barrel, and the squeezing section of the feeding screw is close to the exhaust hole of the barrel.

3. The improved screw barrel device for an injection molding machine according to claim 2, characterized in that: A transition section is further provided on the side wall of the feeding screw. The transition section is close to the squeezing section and is in the area between the squeezing section and the feeding port of the barrel. The outer wall diameter of the feeding screw at the distal end of the transition section is smaller than the outer wall diameter of the feeding screw at the proximal end of the transition section, and the outer wall diameter of the feeding screw gradually increases along the direction from the distal end to the proximal end of the transition section.

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