Servo injection molding machine with rapid preheating function

Abstract

The invention relates to the technical field of injection molding machines, in particular to a servo injection molding machine with a rapid preheating function. Comprising a rack; the injection molding module is horizontally and fixedly arranged on the rack, and the injection molding module is provided with a material guide pipe capable of conveying molten materials and a pushing rod capable of continuously pushing the materials; the material supply module is vertically arranged on the injection molding module, and the material supply end of the material supply module communicates with a material inlet of the material guide pipe; the heating module is coaxially and fixedly arranged outside the material guide pipe and is arranged close to a material outlet of the material guide pipe; the preheating module is coaxially and fixedly arranged outside the material guide pipe and is close to a material inlet of the material guide pipe, and the preheating module is provided with an air supply pipe capable of continuously leading in a heat source towards the material inlet of the material guide pipe; according to the dehumidification and preheating device, materials can be efficiently dehumidified and efficiently preheated, the dehumidification effect is good, and the preheating efficiency is high.

Description

Technical Field

[0001] This invention relates to the field of injection molding machine technology, specifically to a servo injection molding machine with rapid preheating function. Background Technology

[0002] In injection molding, the pre-drying and rapid melting of plastic granules are crucial for ensuring melt quality and molding stability. Traditional servo injection molding machines typically rely on a separate hot air dryer to pre-dry the plastic granules, and then the heating coils in the injection molding machine barrel and the screw shears work together to melt and plasticize the granules. However, existing drying systems generally suffer from low drying efficiency, poor heat utilization, and difficulty in accurately controlling the moisture content of the granules. Especially in the processing of highly hygroscopic engineering plastics (such as PA, PET, PC, etc.), if the residual moisture in the granules is not fully evaporated, it can easily lead to air streaks, silver streaks, poor welds, and a decline in mechanical properties in the finished product.

[0003] On the other hand, traditional feed tube heating methods mainly rely on the conductive heating of the heating coil and the frictional shear heat generated by the screw movement. The heating rate is limited by the thermal inertia of the heating element and the thickness of the barrel wall, resulting in a slow response in the initial melting stage and poor plasticizing temperature stability. In low-temperature environments or under frequent start-stop conditions, the problem of uneven heat distribution between barrel sections becomes more prominent. Particles cannot be softened quickly in the front section of the barrel, resulting in a long plasticizing initiation time and insufficient plasticizing volume, affecting the stability of injection filling. In addition, most existing heating systems cannot adjust the heating power in real time according to changes in feed rate, particle type, moisture content, and screw speed, making the preheating and melting processes lack adaptability and energy optimization capabilities. Summary of the Invention

[0004] To address the aforementioned issues, a servo injection molding machine with rapid preheating function is provided. By proposing an injection molding machine that can not only quickly dehumidify the material but also efficiently preheat it, the technical problems of long plasticization initiation time and inability to efficiently soften the material during injection molding of existing injection molding machines are solved.

[0005] To address the problems of existing technologies, this invention provides a servo injection molding machine with rapid preheating function. This servo injection molding machine, used for rapid preheating of materials, includes: a frame; an injection module, horizontally fixed on the frame, the injection module having a guide tube for conveying molten material and a push rod for continuously pushing the material; a feeding module, vertically mounted on the injection module with its feeding end connected to the inlet of the guide tube; a heating module, coaxially fixed outside the guide tube and near its outlet; and a preheating module, coaxially fixed outside the guide tube and near its inlet, the preheating module having an air supply pipe for continuously introducing heat towards the inlet of the guide tube.

[0006] Preferably, the feed pipe is further provided with a preheating chamber capable of efficiently preheating the material and a first through hole radially penetrating the outer wall of the preheating chamber to input a heat source toward the preheating chamber; the first through hole is provided in multiple sets along the circumferential direction of the axis of the preheating chamber.

[0007] Preferably, the feed pipe is further provided with a first feed section and a second feed section for conveying materials; the preheating chamber is coaxially fixed between the first feed section and the second feed section; the diameter of the preheating chamber is larger than that of the first feed section and the second feed section.

[0008] Preferably, the push rod consists of a first spiral drive section, a connecting section, and a second spiral drive section that are coaxially and fixedly connected in sequence; both the first spiral drive section and the second spiral drive section are clearance-fitted with the inner wall of the guide tube; the diameter of the connecting section is larger than that of the first spiral drive section and is clearance-fitted with the preheating chamber.

[0009] Preferably, the diameter of the connecting section is larger than that of the first spiral drive section and the outer wall of the connecting section fits into the inner wall of the preheating chamber; the connecting section and the preheating chamber together form an annular cavity capable of preheating the material.

[0010] Preferably, the inner wall of the push rod is further provided with an axially formed heat dissipation channel that can lead the heat source out of the push rod and a second through hole that is radially formed on the outer wall of the connecting section to guide the heat source into the heat dissipation channel.

[0011] Preferably, the preheating module further includes a heat-absorbing ring capable of efficiently absorbing the heat energy generated on the heating module and an axial flow fan capable of continuously guiding the heat energy on the heat-absorbing ring toward the air supply pipe; the axial flow fan is coaxially fixed outside the heating module and connected to the air supply pipe; the heat-absorbing ring is coaxially fixed outside the heating module and connected to the axial flow fan.

[0012] Preferably, the feeding module is a feeding bin; the feeding bin is vertically fixed on the guide pipe.

[0013] The advantages of this invention compared to the prior art are: 1. This invention achieves optimized processing of injection molding granules from conveying, dehumidifying, heating to melting by constructing a synergistic preheating system consisting of a feeding module, a double-helix section of the push rod, an annular preheating chamber, a high-efficiency hot air circulation, and a heat absorption ring for heat energy reuse.

[0014] 2. The present invention enables materials to undergo comprehensive, uniform, and efficient pre-drying and heating before entering the melting section by forming a closed convection zone through an annular preheating chamber and forced convection hot air.

[0015] 3. This invention achieves stable material conveying and segmented plasticizing through a double-helix drive section, which significantly reduces the heating load of the melting section and significantly improves the initial plasticizing quality; the heat absorption ring structure can fully recover the heat overflowing from the heating module and deliver it to the air supply pipe by the axial flow fan, realizing the recycling of the heat source, reducing energy waste and effectively enhancing the preheating capacity. Attached Figure Description

[0016] Figure 1 This is a 3D view of a servo injection molding machine with rapid preheating function.

[0017] Figure 2 Side view of a servo injection molding machine with rapid preheating function Figure 1 .

[0018] Figure 3 Side view of a servo injection molding machine with rapid preheating function Figure 2 .

[0019] Figure 4 yes Figure 3 Sectional view at point AA.

[0020] Figure 5 yes Figure 4 A magnified view of section B.

[0021] Figure 6 This is an exploded 3D view of a servo injection molding machine with rapid preheating function, excluding the frame.

[0022] Figure 7 This is a top view of a servo injection molding machine with rapid preheating function.

[0023] Figure 8 yes Figure 7 A three-dimensional sectional view of the section at point CC.

[0024] The numbers on the map are: 1. Rack; 2. Injection molding module; 21. Material guide tube; 211. Preheating chamber; 212. First through hole; 213. First material guide section; 214. Second material guide section; 215. Feed pipe; 22. Push rod; 221. First spiral drive section; 222. Connecting section; 223. Second spiral drive section; 224. Heat dissipation channel; 225. Second through hole; 23. Rotary actuator; 3. Material feeding module; 31. Material feeding bin; 4. Heating module; 5. Preheating module; 51. Air supply duct; 52. Axial flow fan; 53. Heat absorption ring. Detailed Implementation

[0025] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0026] See Figures 1 to 8 The image shows a servo injection molding machine with rapid preheating function for rapidly preheating materials. It includes: a frame 1; an injection module 2, horizontally fixed on the frame 1, the injection module 2 having a guide pipe 21 for conveying molten material and a push rod 22 for continuously pushing the material; a feeding module 3, vertically mounted on the injection module 2 with its feeding end connected to the inlet of the guide pipe 21; a heating module 4, coaxially fixed outside the guide pipe 21 and near its outlet; and a preheating module 5, coaxially fixed outside the guide pipe 21 and near its inlet, the preheating module 5 having an air supply pipe 51 for continuously introducing heat towards the inlet of the guide pipe 21.

[0027] When preheating the injection molding granules to be molten, the feeding module 3 is first activated to continuously and stably convey the granules to the inlet of the guide pipe 21. After the material enters the guide pipe 21, the pusher rod 22, located inside the guide pipe 21, continuously pushes the granules axially, causing them to move towards the feed end of the guide pipe 21 at a controlled speed. Simultaneously, the preheating module 5 is activated and draws in the hot air released by the heating module 4, introducing this heat source into the air supply pipe 51 through an internal circulation structure. The high-temperature airflow conveyed through the air supply pipe 51 finally enters the feed inlet area of ​​the guide pipe 21, where it comes into full contact with the material to be molten.

[0028] Hot air output from the air supply duct 51 forms a stable high-temperature drying air curtain at the inlet of the feed pipe 21, allowing the injection molding granules in this area to be fully dehydrated and rapidly preheated before entering the melting section, significantly reducing residual moisture in the granules and increasing the surface and core temperatures of the granules. Subsequently, the preheated and dried material is further conveyed by the push rod 22 into the discharge area of ​​the feed pipe 21, where it is directly heated by the heating module 4, rapidly reaching the melting temperature and transforming into injectable melt. Finally, the molten material is driven by the push rod 22 and fed into the plasticizing and injection system of the injection molding machine for the next process.

[0029] The heating module 4 is existing technology and will not be described in detail here.

[0030] The injection molding module 2 also includes a rotary driver 23 that can continuously drive the push rod 22 to rotate.

[0031] Through a collaborative process of "hot air pre-drying + conveyor preheating + rapid melting in the discharge zone", continuous, rapid and deep preheating and efficient dehumidification of injection molding granules are achieved, which greatly shortens the melt preparation time and improves the stability of melt quality.

[0032] See Figure 6 As shown: The feed pipe 21 is also provided with a preheating chamber 211 that can efficiently preheat the material and a first through hole 212 that is radially opened through the outer wall of the preheating chamber 211 and can input a heat source toward the preheating chamber 211; the first through hole 212 is opened in multiple sets along the circumferential direction of the axis of the preheating chamber 211.

[0033] As the material is continuously conveyed from the inlet to the outlet of the feed pipe 21 under the drive of the push rod 22, the material at the inlet end of the feed pipe 21 is temporarily stored in the preheating chamber 211. In the preheating chamber 211, the high-temperature airflow continuously output from the air supply pipe 51 directly contacts the granular material, forming a locally stable hot air field, and continuously and uniformly drying the granules entering the chamber. With the help of the forced convection effect of this heat source, the residual moisture inside and on the surface of the material can be quickly evaporated and discharged; at the same time, the overall temperature of the material is raised to the preheating temperature zone suitable for plasticization in a short time, so that the granules that were originally in a low temperature or cooled state can be fully heated. After being treated in the preheating chamber 211, the material with significantly reduced moisture content and uniform temperature is pushed to the subsequent heating module 4 for melting, thereby ensuring a more stable heat load in the melting section and improving the initial conditions for material plasticization.

[0034] By establishing a high-efficiency preheating chamber 211 during the conveying process, rapid dehumidification and uniform heating of the material are achieved, significantly improving the plasticizing efficiency and melt quality stability in the subsequent melting stage.

[0035] See Figure 5 and Figure 6 As shown: The feed pipe 21 is also provided with a first feed section 213 and a second feed section 214 for conveying materials; the preheating chamber 211 is coaxially fixed between the first feed section 213 and the second feed section 214; the diameter of the preheating chamber 211 is larger than that of the first feed section 213 and the second feed section 214.

[0036] The first guide section 213 and the second guide section 214 have the same diameter. The side wall of the first guide section 213 is also radially fixed with a feed pipe 215 that can guide the material into its interior.

[0037] The feeding module 3 maintains fluid communication with the feed pipe 215. When the feeding module 3 starts to convey material to the feed pipe 21, the material to be melted in the feeding module 3 is first introduced into the first guide section 213 of the feed pipe 21 via the feed pipe 215. After entering the first guide section 213, the material is stably pushed forward along the direction of the feed pipe 21 under the continuous axial thrust of the push rod 22, and passes through the preheating chamber 211 and the second guide section 214 in sequence according to the set rhythm. The push rod 22 maintains a continuous and controllable transmission speed throughout the conveying process, so that the material stays in each section for the corresponding time according to the process requirements, and completes preheating, dehumidification and initial heating in sequence, ultimately realizing the continuous, orderly and uninterrupted conveying of material in the feed pipe 21.

[0038] Through the coordinated operation of the feeding module 3, the feed pipe 215 and the multi-section guiding structure, stable and continuous material conveying is achieved, providing a reliable prerequisite for subsequent efficient preheating and rapid melting and improving the overall plasticization consistency.

[0039] See Figure 5 and Figure 6 As shown: The push rod 22 is composed of a first spiral drive section 221, a connecting section 222, and a second spiral drive section 223 that are coaxially and fixedly connected in sequence; the first spiral drive section 221 and the second spiral drive section 223 are both clearance-fitted with the inner wall of the guide tube 21; the diameter of the connecting section 222 is larger than that of the first spiral drive section 221 and is clearance-fitted with the preheating chamber 211.

[0040] When the push rod 22 rotates continuously along its axis under the drive of the rotary driver 23, the first spiral drive section 221 at its front end first contacts the material introduced by the feeding module 3, and applies axial propulsion force to the material using the conveying thrust of the spiral blades, so that the material stably enters the guiding area between the connecting section 222 and the preheating chamber 211. As the material is continuously pushed by the first spiral drive section 221, it enters the preheating chamber 211 and undergoes forced convection drying and preheating in the high-temperature airflow environment formed by the preheating module 5, causing the residual moisture inside and on the surface of the particles to evaporate rapidly, while simultaneously gradually raising the overall temperature of the material to a suitable preheating temperature zone for melting.

[0041] As the push rod 22 continues to rotate, the axial extrusion force generated by the first spiral drive section 221 gradually conveys the preheated material deeper into the feed pipe 21, forcing the material into the second spiral drive section 223. The pitch, depth, and compaction ratio of the second spiral drive section 223 are optimized according to the plasticizing characteristics of the melting section, enabling it to apply higher conveying pressure and shear stress to the material entering this section. Thus, under the heat provided by the heating module 4, the material quickly completes the melting transformation. Finally, under the continuous spiral thrust output by the second spiral drive section 223, the molten material is directionally conveyed from the outlet of the feed pipe 21 into the plasticizing system of the injection molding machine, entering the subsequent injection process.

[0042] Through the synergistic effect of the dual-helix drive section's partitioned conveying and the preheating chamber 211, the material is processed continuously and efficiently from cold drying and preheating to rapid melting, significantly improving the melting speed and plasticizing stability.

[0043] See Figure 5 As shown: the diameter of the connecting section 222 is larger than that of the first spiral drive section 221 and its outer wall fits into the inner wall of the preheating chamber 211; the connecting section 222 and the preheating chamber 211 enclose an annular cavity that can preheat the material.

[0044] By configuring the connecting section 222 to fit snugly against the inner wall of the preheating chamber 211, an annular cavity is formed to preheat the material. This annular cavity is used to surround and heat the material after it is pushed into the preheating chamber 211 from the first spiral drive section 221. Through the structural arrangement of this annular cavity, the high-temperature airflow from the air supply pipe 51 can be evenly distributed along the inner wall of the preheating chamber 211 and fully fill the entire annular cavity, so that the material in the cavity is continuously subjected to hot air from all directions, achieving comprehensive and uniform preheating of the material. At the same time, the annular cavity structure reduces heat loss and increases the contact area between the hot air and the material, thereby improving the thermal convection efficiency and ensuring that the material entering the melting section has more stable and uniform initial temperature conditions.

[0045] By constructing an annular preheating chamber that is fully coupled with hot air, the material is preheated in an all-round, uniform and efficient manner before entering the melting section, which greatly improves the overall plasticizing efficiency and melt quality stability.

[0046] See Figure 6 and Figure 8 As shown: The inner wall of the push rod 22 is also provided with a heat dissipation channel 224 that can lead the heat source out of the push rod 22 and a second through hole 225 that is opened radially on the outer wall of the connecting section 222 to guide the heat source into the heat dissipation channel 224.

[0047] When preheating the material in the preheating chamber 211 (i.e., the annular cavity), the high-temperature airflow from the preheating module 5 first enters the annular cavity through the first through-hole 212, and fully contacts the material circumferentially within the cavity. Forced convection continuously heats and dehumidifies the material. As hot air is continuously input into the annular cavity, the airflow carries evaporated moisture through the material accumulation layer towards the second through-hole 225 at the other end, and finally enters the heat dissipation channel 224 connected to it. Guided by the heat dissipation channel 224, the hot and humid airflow is promptly discharged, achieving circulation and renewal of the hot air within the cavity, ensuring a stable high-temperature, low-humidity preheating environment in the annular cavity. This continuously circulating heat source not only quickly removes moisture from the inside and surface of the material but also provides a uniform and sufficient preheating temperature to the material in a short time, providing excellent initial conditions for efficient plasticization in the subsequent melting section.

[0048] By constructing a continuous circulating hot air path of "air inlet through the first through hole 212 - convection in the annular cavity - exhaust through the second through hole 225", rapid dehumidification and uniform preheating of materials are achieved, significantly improving preheating efficiency and plasticizing stability.

[0049] See Figure 7 As shown: The preheating module 5 also includes a heat-absorbing ring 53 that can efficiently absorb the heat energy generated on the heating module 4 and an axial flow fan 52 that can continuously guide the heat energy on the heat-absorbing ring 53 toward the air supply pipe 51; the axial flow fan 52 is coaxially fixedly disposed outside the heating module 4 and connected to the air supply pipe 51; the heat-absorbing ring 53 is coaxially fixedly disposed outside the heating module 4 and connected to the axial flow fan 52.

[0050] When the heating module 4 directly heats the section of the feed pipe 21 near the discharge port, the heat radiated and conducted outward by the heating module 4 is continuously absorbed by the heat-absorbing ring 53, which is fitted around its outer periphery and arranged coaxially with it. The heat-absorbing ring 53 is made of a high thermal conductivity material, which can efficiently collect the heat energy overflowing from the heating module 4 in a short time and form a stable circumferential heat storage zone. Subsequently, through the forced airflow of the axial flow fan 52, the heat energy absorbed by the heat-absorbing ring 53 is continuously transported to the interior of the air supply pipe 51 in the form of controlled airflow, so that the air supply pipe 51 obtains a continuous and stable heat source input, thereby providing sufficient and uniform high-temperature airflow during the material preheating stage. Through this heat energy recovery and reuse path, the heating energy that was originally easily lost is effectively guided back to the preheating system, realizing the closed-loop utilization of the heat source and ensuring the continuous high-temperature output of the preheating air path.

[0051] The heat recovery and retransmission structure formed by the heat absorption ring 53 and the axial flow fan 52 enables efficient utilization of the heat overflow of the heating module 4, allowing the air supply pipe 51 to continuously and stably obtain a high-temperature air source, thereby significantly improving the material preheating efficiency and the overall system energy efficiency.

[0052] See Figure 6 As shown: The feeding module 3 is specifically a feeding bin 31; the feeding bin 31 is fixedly installed vertically on the guide pipe 21.

[0053] The feeding bin 31 is a hollow rectangular bin with an open top; the feeding bin 31 is used to store materials and continuously feed materials into the feed pipe 21.

[0054] This invention can not only efficiently dehumidify materials but also efficiently preheat them, with good dehumidification effect and high preheating efficiency.

[0055] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. A servo injection molding machine with rapid preheating function, used for rapid preheating of materials, characterized in that, include: frame; The injection molding module is horizontally fixed on the frame. The injection molding module is equipped with a guide tube that can transport molten material and a push rod that can continuously push the material. The feeding module is vertically mounted on the injection molding module and its feeding end is connected to the inlet of the guide tube; The heating module is coaxially fixed outside the feed tube and close to the outlet of the feed tube; The preheating module is coaxially fixed outside the guide pipe and close to the inlet of the guide pipe. The preheating module is provided with an air supply pipe that can continuously introduce heat source towards the inlet of the guide pipe.

2. A servo injection molding machine with rapid preheating function according to claim 1, characterized in that, The feed pipe is also provided with a preheating chamber that can efficiently preheat the material and a first through hole that is radially opened through the outer wall of the preheating chamber and can input a heat source toward the preheating chamber. Multiple sets of the first through holes are formed circumferentially along the axis of the preheating chamber.

3. A servo injection molding machine with rapid preheating function according to claim 2, characterized in that, The feed pipe is also provided with a first feed section and a second feed section capable of conveying materials. The preheating chamber is coaxially fixed between the first and second guide sections; the diameter of the preheating chamber is larger than that of the first and second guide sections.

4. A servo injection molding machine with rapid preheating function according to claim 2, characterized in that, The push rod consists of a first spiral drive section, a connecting section, and a second spiral drive section that are coaxially and fixedly connected in sequence. Both the first spiral drive section and the second spiral drive section are clearance-fitted with the inner wall of the feed tube; The diameter of the connecting section is larger than that of the first spiral drive section and is fitted with a gap in the preheating chamber.

5. A servo injection molding machine with rapid preheating function according to claim 4, characterized in that, The diameter of the connecting section is larger than that of the first spiral drive section, and its outer wall fits into the inner wall of the preheating chamber. The connecting section and the preheating chamber enclose an annular cavity capable of preheating the material.

6. A servo injection molding machine with rapid preheating function according to claim 4, characterized in that, The inner wall of the push rod is also provided with an axial heat dissipation channel that can lead the heat source out of the push rod and a second through hole that is radially opened on the outer wall of the connecting section to guide the heat source into the heat dissipation channel.

7. A servo injection molding machine with rapid preheating function according to claim 1, characterized in that, The preheating module also includes a heat-absorbing ring that can efficiently absorb the heat energy generated on the heating module and an axial flow fan that can continuously guide the heat energy on the heat-absorbing ring toward the air supply duct. The axial flow fan is coaxially fixed outside the heating module and connected to the air supply pipe; The heat absorption ring is coaxially fixed outside the heating module and connected to the axial flow fan.

8. A servo injection molding machine with rapid preheating function according to claim 1, characterized in that, The feeding module is specifically a feeding bin; The feeding bin is fixedly installed vertically on the feed pipe.

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