Screw backflow prevention sealing structure of injection molding machine

Abstract

The utility model relates to injection molding machine technical field especially injection molding machine's screw anti -back flow sealing structure, including base, the upper end one side of base is fixed with the installation of material cylinder through support, the material cylinder is horizontal structure, one end of material cylinder is provided with injection molding nozzle, material cylinder is fixedly installed with the end away from injection molding nozzle and has the sealing plate, the inside of sealing plate is fixed with bearing and penetrates, the inner ring wall of bearing is fixed with the shaft rod no.

Description

Technical Field

[0001] This utility model relates to the field of injection molding machine technology, and in particular to a screw anti-backflow sealing structure for injection molding machines. Background Technology

[0002] An injection molding machine, also known as an injection molding machine, is a type of mechanical equipment used for the production of plastic products. Its working principle involves heating thermoplastic or thermosetting materials and injecting them into a mold, then cooling and solidifying them to form the desired shape.

[0003] Horizontal barrel injection molding machines, also known as horizontal injection molding machines, are a common type of injection molding machine. Their main characteristic is that the injection system and mold clamping system are arranged horizontally. According to authorization announcement number "CN210453625U", a multi-functional injection molding machine barrel is disclosed, comprising: an injection molding machine barrel with an inlet on one end circumferential surface and an outlet and connector on the other end surface; an integral barrel, fitted onto the injection molding machine barrel, with a connector on one end surface and a sealed connection to the injection molding machine barrel on the other end surface; at least one dividing ring rib inside the integral barrel, contacting the injection molding machine barrel; each dividing ring rib having an air passage hole and a mounting hole; an air outlet pipe and an air inlet pipe respectively connected to the upper and lower ends of the integral barrel; a heating rod, installed in the mounting holes of two adjacent dividing ring ribs and in contact with the injection molding machine barrel; and a fan, with a fan installed on the air outlet pipe. This utility model provides a multi-functional injection molding machine barrel with a simple structure and easy disassembly, integrating heating and heat dissipation functions into one unit.

[0004] Currently, when a horizontal injection molding machine is performing injection molding, the raw material needs to be fed into the horizontal barrel. Then, through the heating of the barrel and the feeding, the granular raw material is melted into a fluid material for transportation. However, because the injection end gradually narrows in the discharge area, the spiral blades of the spiral feeder cannot perfectly fit into the barrel, causing the material being injected by the spiral to be affected by the pressure and resulting in backflow. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned shortcomings in the existing technology by proposing a screw anti-backflow sealing structure for injection molding machines.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a screw anti-backflow sealing structure for an injection molding machine, comprising a base, wherein a material cylinder is fixedly mounted on one side of the upper end of the base via a bracket, the material cylinder is a horizontal structure, an injection nozzle is provided at one end of the material cylinder, and a sealing plate is fixedly mounted at the end of the material cylinder away from the injection nozzle; A bearing is fixedly installed inside the sealing plate. A shaft is fixedly inserted through the inner ring wall of the bearing. An annular plate is fixedly sleeved on the inner wall of the injection nozzle. The shaft passes through the interior of the annular plate, and a gap is provided between the outer ring wall of the shaft and the inner ring wall of the annular plate for material discharge. The surface of the annular plate is also provided with several limiting sleeves. The limiting sleeves are slidably connected to limiting rods. An anti-detachment block is fixedly installed at the end of the limiting rods near the material cylinder. A backstop plate for preventing backflow is installed at the ends of several limiting rods away from the material cylinder.

[0007] The connection between the barrel and the injection nozzle is provided by several fastening bolts, and the ends of the fastening bolts are threaded with nuts, which are tightly fitted to the end face of the injection nozzle.

[0008] A hopper is fixed through and above the end of the material cylinder near the sealing plate.

[0009] The shaft is located on the inner surface of the cylinder and a spiral blade is fixedly wound around it. The outer spiral surface of the spiral blade slides and fits tightly against the inner wall of the cylinder. A motor is installed at the outer end of the shaft, and a rotating shaft for driving is installed inside the motor. The connection between the rotating shaft and the shaft is fixedly connected by a coupling.

[0010] Among them, the first shaft is located inside the injection nozzle and a second shaft is fixedly installed on one end face. The surface of the second shaft is fixedly wound with a second spiral blade. The outer spiral surface of the second spiral blade is slidably and tightly attached to the outlet position of the injection nozzle.

[0011] The outer wall of the barrel is wrapped with a heat-conducting sleeve, and several heating tubes are embedded and fixed in the inner wall of the heat-conducting sleeve. The barrel, injection nozzle and heat-conducting sleeve are all made of stainless steel.

[0012] The heat-conducting sleeve is wrapped and fixed with a heat-insulating sleeve. The lower end of the outer ring wall of the heat-insulating sleeve is fixed to the upper end of the base by a bracket. The heat-insulating sleeve is made of ceramic material.

[0013] The design scheme proposed in this utility model has the following beneficial effects in application: 1. This solution effectively prevents material backflow through the design of the backstop plate, thereby improving injection molding stability. When material backflow occurs inside the injection nozzle, the backflow pressure will push the backstop plate to move in the opposite direction, so that it covers the discharge gap between the annular plate and the shaft, thereby blocking the backflow channel. This automatic response anti-backflow mechanism does not require additional power and can be triggered by the material's own pressure, which simplifies the structure and improves reliability. 2. As described in 1, the sliding fit between the limit rod and the limit sleeve ensures the accurate movement trajectory of the backstop plate, the anti-detachment block design avoids the risk of parts falling off, and the overall anti-backflow function effectively maintains the unidirectional flow of the injection molding process while ensuring normal material discharge. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 For the present utility model Figure 2 Enlarged view of point A; Figure 4 This is a schematic diagram of the internal side structure of this utility model.

[0015] In the diagram: 1. Base; 11. Barrel; 12. Injection nozzle; 13. Sealing plate; 14. Bearing; 15. Shaft 1; 16. Ring plate; 17. Limiting sleeve; 18. Limiting rod; 19. Anti-detachment block; 101. Fastening bolt; 102. Nut; 2. Hopper; 21. Motor; 22. Spiral blade 1; 3. Shaft 2; 31. Spiral blade 2; 4. Heat-conducting sleeve; 41. Heating element; 42. Heat insulation sleeve. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Example

[0017] Reference Figures 1-4 A screw anti-backflow sealing structure for an injection molding machine includes a base 1. A material cylinder 11 is fixedly mounted on one side of the upper end of the base 1 via a bracket. The material cylinder 11 has a horizontal structure. An injection nozzle 12 is provided at one end of the material cylinder 11. A sealing plate 13 is fixedly mounted at the end of the material cylinder 11 away from the injection nozzle 12. The material cylinder 11 can convey and melt materials, and the injection nozzle 12 can gather materials and inject them out. A bearing 14 is fixedly installed inside the sealing plate 13. A shaft 15 is fixedly inserted through the inner ring wall of the bearing 14. An annular plate 16 is fixedly sleeved on the inner wall of the injection nozzle 12. The shaft 15 is installed through the interior of the annular plate 16. The outer ring wall of the shaft 15 and the inner ring wall of the annular plate 16 are provided with a gap for material discharge. The gap between the annular plate 16 and the shaft 15 can serve as the discharge port for molten material, which can stably enter the interior of the injection nozzle 12. The bearing 14 is a sealed type, which can ensure the stable rotation of the shaft 15 while also ensuring the sealing effect of the rotation position. Several limiting sleeves 17 are also fixedly distributed on the surface of the annular plate 16. Limiting rods 18 are slidably connected inside the limiting sleeves 17. An anti-detachment block 19 is fixedly installed at the end of the limiting rod 18 near the material cylinder 11. A backflow prevention plate 110 is installed at the end of the several limiting rods 18 away from the material cylinder 11. When backflow of material inside the injection nozzle 12 occurs, the backflow pressure will push the backflow prevention plate 110 to move in the opposite direction. By sliding the limiting rods 18 inside the limiting sleeves 17, the backflow prevention plate 110 can slide on the surface of the shaft 15 and cover the annular plate 16, sealing the discharge gap formed between the shaft 15 and the annular plate 16, thereby achieving the backflow prevention effect.

[0018] Several fastening bolts 101 are distributed through the connection between the barrel 11 and the injection nozzle 12. The ends of the fastening bolts 101 are threaded with nuts 102. The nuts 102 are tightly attached to the end face of the injection nozzle 12. By using the fastening bolts 101 distributed at multiple points to be threaded with the corresponding nuts 102, the barrel 11 and the injection nozzle 12 can be stably closed and disassembled for cleaning.

[0019] Among them, a hopper 2 is fixedly installed above the end of the material cylinder 11 near the sealing plate 13. The hopper 2 can stably feed easy-to-inject materials into the interior of the material cylinder 11.

[0020] The shaft 15 is located on the inner surface of the material cylinder 11 and a spiral blade 22 is fixedly wound around it. The outer spiral surface of the spiral blade 22 is slidably and tightly attached to the inner wall of the material cylinder 11. A motor 21 is provided at the outer end of the shaft 15. The motor 21 has a rotating shaft for driving inside. The connection between the rotating shaft and the shaft 15 is fixedly and transmitted through a coupling. After the motor 21 is powered on, the rotating shaft rotates and drives the shaft 15 to rotate, thereby enabling the spiral blade 22 to rotate and realize spiral feeding in the material cylinder 11.

[0021] Among them, shaft 15 is located inside the injection nozzle 12 and one end face is fixedly installed with shaft 22. Helical blade 21 is fixedly wound on the surface of shaft 22. The outer helical surface of helical blade 22 is slidably and tightly attached to the discharge port of injection nozzle 12. After the material is melted, it is fed into the inside of injection nozzle 12 through helical blade 22. Then, shaft 15 drives shaft 22 to rotate synchronously, so that helical blade 22 feeds material outward spirally at the discharge position of injection nozzle 12, thereby ensuring stable feeding during injection molding.

[0022] The outer wall of the barrel 11 is wrapped with a heat-conducting sleeve 4. Several electric heating tubes 41 are embedded and fixed in the inner wall of the heat-conducting sleeve 4. The barrel 11, injection nozzle 12 and heat-conducting sleeve 4 are all made of stainless steel. Several electric heating tubes 41 are connected to the same external temperature control panel through end connecting wires. The temperature of multiple electric heating tubes 41 can be controlled simultaneously so that they can generate heat. Through the heat conduction effect of the heat-conducting sleeve 4, the barrel 11 can be heated, thereby allowing the material to be heated and melted.

[0023] The heat-conducting sleeve 4 is wrapped and fixed with a heat-insulating sleeve 42. The lower end of the outer ring wall of the heat-insulating sleeve 42 is fixed to the upper end of the base 1 by a bracket. The heat-insulating sleeve 42 is made of ceramic material. The heat-insulating sleeve 42 can insulate the position of the heat-conducting sleeve 4, so as to reduce heat transfer when it is mounted on the base 1.

[0024] In practice In this design, the barrel 11 is driven by the motor 21 to rotate the shaft 15. The spiral blades 22 on the surface of the shaft 15 are tightly attached to the inner wall of the barrel 11 to form a spiral propulsion structure. When the material enters the barrel 11 from the hopper 2, the rotation of the spiral blades 22 transports the material towards the injection nozzle 12. During this process, the heat-conducting sleeve 4 surrounding the barrel 11 heats up through the internal electric heating tube 41 and evenly transfers the heat to the barrel 11, causing the material to gradually melt during the transport process. The ceramic heat insulation sleeve 42 on the outer layer of the heat-conducting sleeve 4 effectively reduces heat loss and ensures that the heat energy is concentrated inside the barrel 11. The molten material continues to be pushed by the spiral blades 22 and enters the injection nozzle 12 through the gap between the shaft 15 and the annular plate 16. The shaft 3 and the spiral blades 31 on its surface rotate further, stably extruding the molten material from the outlet of the injection nozzle 12 to complete the injection feeding. When material backflow occurs inside the injection nozzle 12, the backflow pressure pushes the stop plate 110 to slide axially along the shaft 15. The limiting rod 18 moves synchronously within the limiting sleeve 17, so that the stop plate 110 covers the discharge gap between the annular plate 16 and the shaft 15. The anti-detachment block 19 limits the displacement range of the limiting rod 18 to prevent detachment. The closing action of the stop plate 110 blocks the material backflow channel, achieving dynamic sealing. The bearing 14 adopts a sealing structure to ensure that there is no leakage at the connection between the shaft 15 and the sealing plate 13 when the shaft 15 rotates. The gap design between the annular plate 16 and the shaft 15 allows for normal material discharge and can respond quickly through the mechanical structure during backflow, providing double protection for the unidirectional flow of the injection molding process.

[0025] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A screw anti-backflow sealing structure for an injection molding machine, comprising a base (1), characterized in that: The upper side of the base (1) is fixed with a material cylinder (11) by a bracket. The material cylinder (11) is a horizontal structure. One end of the material cylinder (11) is provided with an injection nozzle (12). The end of the material cylinder (11) away from the injection nozzle (12) is fixed with a sealing plate (13). The sealing plate (13) has a bearing (14) fixed inside. The inner ring wall of the bearing (14) is interference-fitted and fixed with a shaft (15). The inner wall of the injection nozzle (12) is fixedly sleeved with an annular plate (16). The shaft (15) is disposed inside the annular plate (16), and the outer ring wall of the shaft (15) and the inner ring wall of the annular plate (16) are provided with a gap for material discharge. The surface of the annular plate (16) is also provided with a number of limiting sleeves (17). The limiting sleeves (17) are slidably connected to the limiting rods (18). The end of the limiting rods (18) near the material cylinder (11) is fixedly installed with an anti-detachment block (19). The ends of the limiting rods (18) away from the material cylinder (11) are jointly installed with a backflow preventer plate (110) for preventing backflow.

2. The anti-backflow sealing structure for the screw of an injection molding machine according to claim 1, characterized in that: Several fastening bolts (101) are distributed through the connection between the barrel (11) and the injection nozzle (12). The ends of the fastening bolts (101) are threaded with nuts (102), and the nuts (102) are tightly attached to the end face of the injection nozzle (12).

3. The anti-backflow sealing structure for the screw of an injection molding machine according to claim 2, characterized in that: A hopper (2) is fixed through and above one end of the material cylinder (11) near the sealing plate (13).

4. The anti-backflow sealing structure for the screw of an injection molding machine according to claim 3, characterized in that: The shaft (15) is located on the inner surface of the cylinder (11) and a spiral blade (22) is fixedly wound around it. The outer spiral surface of the spiral blade (22) is slidably attached to the inner wall of the cylinder (11). A motor (21) is provided at the outer end of the shaft (15). A rotating shaft for driving is provided inside the motor (21), and the connection position between the rotating shaft and the shaft (15) is fixedly connected by a coupling.

5. The anti-backflow sealing structure for the screw of an injection molding machine according to claim 4, characterized in that: The shaft 1 (15) is located inside the injection nozzle (12) and a shaft 2 (3) is fixedly installed on one end face. A spiral blade 2 (31) is fixedly wound on the surface of the shaft 2 (3). The outer spiral surface of the spiral blade 2 (31) is slidably attached to the outlet position of the injection nozzle (12).

6. The anti-backflow sealing structure for the screw of an injection molding machine according to claim 5, characterized in that: The outer wall of the barrel (11) is wrapped with a heat-conducting sleeve (4), and a number of electric heating tubes (41) are embedded and fixed in the inner wall of the heat-conducting sleeve (4). The barrel (11), the injection nozzle (12) and the heat-conducting sleeve (4) are all made of stainless steel.

7. The anti-backflow sealing structure for the screw of an injection molding machine according to claim 6, characterized in that: The surface of the heat-conducting sleeve (4) is wrapped with a heat-insulating sleeve (42). The lower end of the outer ring wall of the heat-insulating sleeve (42) is fixed to the upper end of the base (1) by a bracket. The heat-insulating sleeve (42) is made of ceramic material.

Images