A dual station simultaneous injection molding machine for a stack molding

Abstract

The application discloses a double-station synchronous injection molding machine for a laminated injection mold, which comprises a middle fixed module, a first sliding module and a second sliding module symmetrically arranged on the two sides of the middle fixed module, a first molding cavity arranged between the first sliding module and the middle module, a second molding cavity arranged between the second sliding module and the middle module, a plurality of mounting grooves formed in the first sliding module and / or the second sliding module, and a push module detachably arranged in the mounting grooves. The push module comprises a sleeve rod embedded in the mounting groove, a push rod slidingly arranged at the front end of the sleeve rod, and a driving rod with one end slidingly arranged in the sleeve rod and the other end slidingly arranged in a driving cavity formed at the rear end of the sleeve rod.

Description

Technical Field

[0001] This invention relates to the field of injection molding equipment technology, specifically a dual-station synchronous injection molding machine for stacked injection molds. Background Technology

[0002] Stacked injection molds, capable of molding multiple products simultaneously in a single injection cycle, have been widely used in mass production of plastic products. In stacked injection molds, molding cavities are formed between the central fixed module and the two sliding modules on either side. After injection molding, the products on both sides need to be demolded separately, placing high demands on the spatial adaptability, synchronization, and reliability of the ejection mechanism. Existing stacked injection mold ejection devices typically employ a distributed ejector pin structure, which has the following shortcomings:

[0003] Firstly, the ejector pin is fixedly fitted to the mold base, and installation and maintenance require disassembling the entire sliding module, which is cumbersome and has high maintenance costs.

[0004] Secondly, under the pneumatic drive method, it is difficult for each ejector rod to be strictly synchronized. Differences in frictional resistance or air pressure difference may lead to uneven local stress on the product, resulting in quality defects such as whitening, marks, and warping deformation.

[0005] Third, the cooling and shrinkage between the product and the mold cavity can easily create a vacuum suction force, requiring a large initial ejection force for direct ejection, which can easily damage the product. Existing solutions with independent air blowing systems require additional air path control components, making the system complex.

[0006] Therefore, it is necessary to provide a dual-station synchronous injection molding machine for stacked injection molds to solve the problems mentioned in the background art. Summary of the Invention

[0007] To achieve the above objectives, the present invention provides the following technical solution: a dual-station synchronous injection molding machine for stacked injection molds, comprising an intermediate fixed module and a first sliding module and a second sliding module symmetrically arranged on both sides of the intermediate fixed module. A first molding cavity is provided between the first sliding module and the intermediate module, and a second molding cavity is provided between the second sliding module and the intermediate module. Multiple mounting slots are provided on the first sliding module and / or the second sliding module, and a push module is detachably provided within each mounting slot. The push module comprises: a sleeve rod, embedded in the mounting slot; a push rod, slidably disposed at the front end of the sleeve rod, with a driving cavity at its rear end; and a drive rod, one end of which is slidably disposed in the sleeve rod, and the other end of which is slidably disposed in the driving cavity.

[0008] Preferably, the sleeve rod has a first sliding groove and a second sliding groove, the first sliding groove and the second sliding groove are coaxially arranged and communicate with each other; the drive rod is sealed and slidably arranged along the first sliding groove, and a first air pressure chamber is formed between the drive rod and the first sliding groove;

[0009] A sealing ring is fixedly provided on the outer wall of the push rod. The sealing ring is slidably disposed along the second slide groove. A second air pressure chamber is formed between the push rod, the sealing ring and the second slide groove. The first air pressure chamber and the second air pressure chamber are connected by multiple air passages.

[0010] Preferably, the inner wall of the driving cavity is provided with a spiral groove and a straight groove, the spiral groove and the straight groove are connected end to end, and the depth of the straight groove gradually changes from one end to the other end; a guide block is fixedly provided at one end of the driving rod near the driving cavity, the guide block extends into the spiral groove or the straight groove and slides along it.

[0011] Preferably, the guide block includes a fixed rod fixedly mounted on the drive rod, a telescopic rod slidably mounted within the fixed rod, and an elastic element disposed between the fixed rod and the telescopic rod, wherein the extended end of the telescopic rod is spherical.

[0012] Preferably, a first permanent magnet block is embedded at the deepest point of each of the two connecting ends of the spiral groove and the straight groove, and a second permanent magnet block is embedded in the spherical protruding end of the telescopic rod, and there is a magnetic attraction between the first permanent magnet block and the second permanent magnet block.

[0013] Preferably, the front end of the sleeve rod is provided with a plurality of air holes along the circumference. One end of each air hole is connected to the second air pressure chamber, and the other end is connected to the first molding cavity or the second molding cavity. When air pressure enters the first air pressure chamber, the drive rod is driven to slide, and the guide block slides along the spiral groove to drive the push rod to rotate. When the guide block slides to the end of the spiral groove and switches to the straight groove, the air passage is opened, air pressure enters the second air pressure chamber to push the push rod to slide, the guide block slides along the straight groove, and air pressure is blown out through the air holes.

[0014] Preferably, the sealing ring has a plurality of protrusions at one end near the drive rod. When the sealing ring slides to the end of the second slide groove near the first slide groove, each of the protrusions abuts against the end face of the second slide groove, so that a communication gap is formed between the sealing ring and the end face of the second slide groove, and the air hole is kept in communication with the second air pressure chamber through the communication gap.

[0015] Preferably, the volume of the first air pressure chamber is greater than the volume of the second air pressure chamber; the depth of the straight groove at the end near the drive rod is greater than the depth of the spiral groove, and the depth of the straight groove at the end away from the drive rod is less than the depth of the spiral groove.

[0016] Preferably, a valve core structure is formed between the drive rod and the first slide groove. When the drive rod is in a first position where it has not slid out of the first slide groove, the drive rod closes the air passage. When the drive rod is in a second position where it slides along the first slide groove to its maximum limit, the air passage opens.

[0017] Preferably, a connecting rod is fixedly provided at the rear end of the drive rod. The connecting rod slides through the rear end wall of the sleeve rod and extends to the outside of the sleeve rod. All the protruding ends of the connecting rods located in the same sliding module are fixedly connected to the same limiting plate.

[0018] Compared with the prior art, the present invention provides a dual-station synchronous injection molding machine for stacked injection molds, which has the following beneficial effects:

[0019] In this invention, the jacking module adopts a sleeve-type independent structure and is detachably embedded in the mounting groove. Replacement and maintenance do not require disassembling the sliding module, which greatly reduces maintenance costs and time and improves equipment maintainability.

[0020] In this invention, the spiral groove and the guide block work together to drive the push rod to rotate before axial ejection, thereby breaking the adhesion between the push rod and the product, effectively reducing the initial ejection resistance and lowering the risk of damage to the product. At the same time, the magnetic attraction between the first permanent magnet block and the second permanent magnet block, combined with the elastic element, enables reliable automatic switching of the guide block between the spiral groove and the straight groove, avoiding the risk of mechanical jamming and improving the reliability of the operation.

[0021] In this invention, the air vent and the second air pressure chamber are directly connected in parallel. By utilizing the inherent load difference between the air vent passage and the starting resistance of the push rod, the blowing action is completed before the pushing action, without the need for external sensors, controllers, or additional delay mechanisms. This timing control is entirely determined by the basic principles of fluid mechanics and is not affected by electromagnetic interference, signal delay, or control accuracy, thus improving the reliability of the air-assisted timing. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the second sliding module in this invention;

[0024] Figure 3 This is a schematic diagram of the pusher module in this invention;

[0025] Figure 4 This is a schematic diagram of the internal structure of the sleeve rod in this invention;

[0026] Figure 5 This is a schematic diagram of the push rod structure in this invention;

[0027] Figure 6 This is a schematic cross-sectional view of the push rod in this invention;

[0028] Figure 7 This is a schematic diagram of the drive rod structure in this invention;

[0029] Figure 8a This is a schematic diagram of the initial sliding state of the drive rod and the push rod in this invention;

[0030] Figure 8b This is a schematic diagram of the structure of the drive rod and the push rod in the fully slid-out state in this invention;

[0031] In the diagram: 100, fixed module; 200, first sliding module; 300, second sliding module; 1, push rod; 11, sleeve rod; 12, drive cavity; 121, spiral groove; 122, straight groove; 13, sealing ring; 131, protrusion; 14, air passage; 2, drive rod; 21, guide block; 211, fixed rod; 212, telescopic rod; 22, connecting rod; 3, first sliding groove; 4, second sliding groove; 5, air hole; 6, limiting plate. Detailed Implementation

[0032] Please see Figure 1 Figure 8 illustrates a dual-station synchronous injection molding machine for stacked injection molds in this embodiment of the invention. It includes an intermediate fixed module 100 and a first sliding module 200 and a second sliding module 300 symmetrically arranged on both sides of the intermediate fixed module 100. A first molding cavity is provided between the first sliding module 200 and the intermediate fixed module 100, and a second molding cavity is provided between the second sliding module 300 and the intermediate fixed module 100. The first and second molding cavities are formed by the cavity surfaces on the first and second sliding modules 200 and 300 respectively fitting together with the cavity surfaces on both sides of the intermediate fixed module 100 during mold closing. During injection molding, molten plastic is injected into the first and second molding cavities respectively through a hot runner system in the intermediate fixed module 100, achieving dual-station synchronous injection molding.

[0033] The first sliding module 200 and the second sliding module 300 are respectively provided with multiple mounting slots, each mounting slot is provided through the thickness direction of the sliding module (i.e., perpendicular to the mold closing direction); each mounting slot is detachably embedded with a push module; the push module is used to push the molded product out from the cavity surface of the sliding module after injection molding.

[0034] like Figure 3 As shown, the push module is cylindrical in shape and includes a sleeve rod 11, a push rod 1, and a drive rod 2. The outer diameter of the sleeve rod 11 is precisely matched with the inner diameter of the mounting groove, and the sleeve rod 11 is slidably embedded in the mounting groove. The rear end face of the sleeve rod 11 (i.e., the end away from the cavity) is flush with or slightly protruding from the back of the sliding module to facilitate the operator's grip and removal. The front end of the sleeve rod 11 has a front opening for the push rod 1 to extend, and the push rod 1 is slidably disposed in the front opening. The diameter of the push rod 1 is precisely matched with the inner diameter of the front opening, and a sealing structure is provided between the two to prevent molten plastic from seeping in along the gap between the push rod 1 and the sleeve rod 11 during injection molding.

[0035] In addition, the outer wall of the sleeve rod 11 is provided with a positioning key, and the groove wall of the mounting groove is provided with a keyway that matches the positioning key. The matching of the positioning key and the keyway ensures that the circumferential angle positioning of the sleeve rod 11 after it is inserted into the mounting groove is accurate, so that the starting angle of the internal spiral groove of each push module is consistent after installation. The outer wall of the sleeve rod 11 is also embedded with an O-ring seal, which seals between the sleeve rod 11 and the groove wall of the mounting groove to prevent molten plastic from seeping in along the gap between the sleeve rod 11 and the mounting groove during injection molding.

[0036] In this embodiment, the sleeve rod 11 is provided with a first sliding groove 3 and a second sliding groove 4 that are coaxial and interconnected along the axial direction. The first sliding groove 3 is located at the rear section of the sleeve rod 11, and the second sliding groove 4 is located at the front section of the sleeve rod 11. The diameter of the first sliding groove 3 is larger than the diameter of the second sliding groove 4, and a stepped surface is formed between the two. The drive rod 2 is slidably disposed in the first sliding groove 3. The outer wall of the rear section of the drive rod 2 and the groove wall of the first sliding groove 3 are slidably sealed by an O-ring, thereby forming a first air pressure chamber between the rear end face of the drive rod 2 and the bottom wall of the first sliding groove 3. The first air pressure chamber is connected to an external air pressure source (such as a compressed air pipeline or a vacuum generator) through an air inlet at the rear end of the sleeve rod 11.

[0037] The push rod 1 is slidably disposed in the second slide groove 4; a sealing ring 13 is fixedly sleeved on the outer wall of the push rod 1 near the rear end, and the outer wall of the sealing ring 13 and the groove wall of the second slide groove 4 are slidably sealed by an O-ring; the push rod 1, the sealing ring 13 and the groove wall of the second slide groove 4 together form a second air pressure chamber; the first air pressure chamber and the second air pressure chamber are connected by multiple air passages 14; the multiple air passages 14 are evenly distributed circumferentially, and are opened in the wall of the sleeve rod 11, connecting the first slide groove 3 and the second slide groove 4.

[0038] In addition, the front end of the sleeve rod 11 is provided with a plurality of air holes 5 along the circumferential direction; each air hole 5 extends along the axial direction of the sleeve rod 11, one end of which is connected to the second air pressure chamber, and the other end penetrates the front end face of the sleeve rod 11 and is connected to the molding cavity.

[0039] Specifically, the volume of the first air pressure chamber is larger than that of the second air pressure chamber. This volume difference design ensures that during the negative pressure suction in the reset phase, the reset force on the drive rod 2 is greater than that on the push rod 1, thereby ensuring that the drive rod 2 resets first. At the same time, driven by the drive rod 2, the push rod 1 is also reset.

[0040] like Figure 5 and Figure 6 As shown, a drive cavity 12 is provided at the rear end of the push rod 1, and the opening of the drive cavity 12 faces the rear end of the sleeve rod 11 (i.e., towards the drive rod 2); the drive cavity 12 is blind hole shaped, and its axis coincides with the axis of the push rod 1; a spiral groove 121 and a straight groove 122 are provided on the inner side wall of the drive cavity 12 (i.e., the cylindrical inner wall of the drive cavity 12); the spiral groove 121 extends spirally along the inner wall of the drive cavity 12, with its starting end located near the opening end of the drive cavity 12 and its end located deep within the drive cavity 12; the straight groove 122 extends axially along the drive cavity 12, and its two ends are respectively connected to the two ends of the spiral groove 121, that is, the spiral groove 121 and the straight groove 122 are connected end to end to form a closed composite channel.

[0041] The depth of the straight groove 122 gradually changes from one end to the other. Specifically, the depth of the end of the straight groove 122 that connects to the starting end of the spiral groove 121 is greater than the depth of the spiral groove 121, and the depth of the end of the straight groove 122 that connects to the end of the spiral groove 121 is less than the depth of the spiral groove 121. The depth of the spiral groove 121 remains constant along its extension direction. This arrangement allows the guide block 21 to be gradually compressed or released as it slides along the straight groove 122, thereby achieving automatic switching of the guide block 21 between the spiral groove 121 and the straight groove 122.

[0042] Furthermore, a guide block 21 is fixedly provided at one end of the drive rod 2 near the drive cavity 12 (i.e., the front end of the drive rod 2); the guide block 21 extends outward along the radial direction of the drive cavity 12, and its extended end extends into the spiral groove 121 or the straight groove 122 and can slide along the groove.

[0043] like Figure 7 As shown, the guide block 21 includes a fixed rod 211, a telescopic rod 212, and an elastic element; one end of the fixed rod 211 is fixedly disposed at the front end of the drive rod 2, and the other end extends radially along the drive cavity 12; the telescopic rod 212 is slidably sleeved in the other end of the fixed rod 211, and its protruding end is spherical, which is used to extend into the spiral groove 121 or the straight groove 122; the elastic element (preferably a compression spring) is disposed between the fixed rod 211 and the telescopic rod 212, and always applies a radially outward tendency force to the telescopic rod 212, so that the spherical protruding end can always press against the bottom of the channel.

[0044] Meanwhile, a first permanent magnet block is embedded in the deepest part of the two connecting ends (i.e. the starting end connection and the ending end connection) of the spiral groove 121 and the straight groove 122; a second permanent magnet block is embedded in the spherical protruding end of the telescopic rod 212; there is a magnetic attraction between the first permanent magnet block and the second permanent magnet block, and the magnetic attraction and the elastic force of the elastic element work together to ensure that the spherical protruding end can reliably switch to the target channel when it reaches the connection between the spiral groove 121 and the straight groove 122.

[0045] It should be noted that the drive rod 2 has dual functions as both a drive and a valve core. Specifically, the outer wall of the rear section of the drive rod 2 forms a sliding seal with the groove wall of the first slide groove 3. The outer wall of the drive rod 2 directly serves as the working surface of the valve core, used to control the opening and closing of the air passage 14. The inlet of the air passage 14 is located on the groove wall of the first slide groove 3. The position of this inlet is configured such that when the drive rod 2 is in the initial position (i.e., the first position), the outer wall of the drive rod 2 just covers and closes the inlet of the air passage 14, thus blocking the gas passage between the first and second pressure chambers. At this time, since the outer wall of the drive rod 2 and the groove wall of the first slide groove 3 are sealed, the gas in the first pressure chamber cannot enter the air passage 14. When the drive rod 2 slides forward along the first slide groove 3 to a predetermined position (i.e., the second position) under the action of air pressure, the inlet of the air passage 14 leaves the coverage area of ​​the outer wall of the drive rod 2 and is exposed in the first pressure chamber, thus achieving gas communication between the first pressure chamber and the air passage 14.

[0046] like Figure 5 As shown, the sealing ring 13 has a plurality of protrusions 131 evenly arranged circumferentially at one end (i.e., the rear end face) near the drive rod 2. When the sealing ring 13 slides to the end (i.e., the maximum retraction position) of the second slide groove 4 near the first slide groove 3, the end face of each protrusion 131 abuts against the step surface (i.e., the end face of the second slide groove 4) between the first slide groove 3 and the second slide groove 4, so that a ring-shaped connecting gap is formed between the rear end face of the sealing ring 13 and the step surface. The existence of this connecting gap allows the gas in the second air pressure chamber to flow to the inlet end of the air hole 5 through this connecting gap.

[0047] The air hole 5 is arranged along the axial direction of the sleeve rod 11. Its rear end (i.e., the end near the sealing ring 13) opens into the rear end groove wall of the second sliding groove 4, and its front end opens into the front end face of the sleeve rod 11. When the sealing ring 13 is in the maximum retracted position, the rear end opening of the air hole 5 is connected to the second air pressure chamber through the aforementioned connecting gap. This arrangement ensures that no matter how the sealing ring 13 slides, that is, how the push rod 1 slides, the connection between the air hole 5 and the second air pressure chamber will not be affected. When the air pressure in the first air pressure chamber enters the second air pressure chamber, the air pressure will be preferentially discharged from the air hole 5. That is, the air pressure first flows from the air hole 5 into the cavity. After breaking the vacuum between the cavity and the finished product, the push rod 1 is pushed as the air pressure continues to increase, thereby better protecting the finished product and preventing the push rod 1 from damaging the finished product.

[0048] In this embodiment, a connecting rod 22 is fixedly provided at the rear end of the drive rod 2. The connecting rod 22 extends axially backward, sealingly sliding through the rear end wall of the sleeve rod 11 and extending to the outside of the sleeve rod 11. A sealing ring is used to achieve a sliding seal between the connecting rod 22 and the through hole of the rear end wall of the sleeve rod 11 to prevent gas in the first air pressure chamber from leaking out from there. The extended ends of all the connecting rods 22 located in the same sliding module are fixedly connected to the same limiting plate 6. The setting of the limiting plate 6 enables all the drive rods 2 in the same sliding module to achieve mechanically forced synchronous action - when one drive rod 2 is pushed by air pressure, through the rigid connection of the limiting plate 6, it will drive all other drive rods 2 to move synchronously, eliminating the problem of asynchronous action caused by air pressure difference or friction difference between the push modules.

[0049] In addition, the push module in the first sliding module 200 and the push module in the second sliding module 300 share the same air pressure source, and the air paths of the two push modules are configured independently to ensure that each of the two workstations can independently adjust the air pressure parameters.

[0050] Work process

[0051] (I) Injection Molding Stage

[0052] In the mold-closed state, the push module is in the initial position; at this time, the drive rod 2 is located at the rear end of the first slide 3 (i.e., the first position), and the outer wall of the rear section of the drive rod 2 covers and closes the entrance of the air passage 14; the first air pressure chamber and the second air pressure chamber are not connected.

[0053] At the start of injection molding, molten plastic is injected into the first molding cavity and the second molding cavity. During the injection molding process, the air in the cavity can be discharged through structures such as the venting groove. Since the outer wall of the drive rod 2 seals the air passage 14, the first air pressure cavity and the second air pressure cavity are both in a normal pressure state, and the air hole 5 is in a closed state, so the injection molding material will not enter the air hole 5 and cause blockage.

[0054] At the same time, an external air pressure source introduces compressed air at a predetermined pressure into the first air pressure chamber through the air inlet; however, since the drive rod 2 closes the air passage 14, the compressed air is trapped in the first air pressure chamber, and the drive rod 2 is subjected to air pressure but has not yet started to slide.

[0055] (II) Rotational Debonding Stage

[0056] After injection molding is completed and the product has cooled and solidified, demolding is required; at this time, the external air pressure source is controlled to continue to supply compressed air to the first air pressure chamber.

[0057] As the air pressure in the first air pressure chamber gradually increases, the air pressure on the drive rod 2 is greater than its static friction force, and the drive rod 2 begins to slide forward along the first slide groove 3; during the forward sliding of the drive rod 2, the connecting rod 22 drives the limiting plate 6 to move forward together, and all the drive rods 2 in the same sliding module achieve completely synchronized action through the forced connection of the limiting plate 6.

[0058] As the drive rod 2 slides forward, the spherical protruding end of the guide block 21 slides in the spiral groove 121. Since the spiral groove 121 is spirally extended, the guide block 21 will generate a circumferential force when it slides along the spiral groove 121. This circumferential force acts on the inner wall of the drive cavity 12 of the push rod 1, driving the push rod 1 to rotate around its axis. The rotation of the push rod 1 changes the contact state between its front end face and the product, destroying the adhesion force that may exist between the product and the front end face of the push rod 1, thus preparing for the subsequent axial ejection.

[0059] It should be noted that during the sliding process of the drive rod 2, since the air passage 14 is still closed by the drive rod 2 and there is a vacuum adsorption force between the cavity and the finished product, the second air pressure chamber 41 is in a closed negative pressure state. Under this negative pressure state, the push rod 1 is subject to an adsorption force towards the inside of the sleeve rod 11 and cannot slide forward. Therefore, during the entire sliding process of the drive rod 2, the push rod 1 only rotates and its axial position remains unchanged. Only when the drive rod 2 slides to the maximum position of the first slide groove 3 and the air passage 14 is opened, the negative pressure state of the second air pressure chamber 41 is broken, and the push rod 1 can slide axially.

[0060] (III) Gas Path Switching Stage

[0061] When the guide block 21 slides along the spiral groove 121 to its end (i.e., the drive rod 2 moves forward to the predetermined position), the spherical protrusion end of the guide block 21 reaches the connection end between the spiral groove 121 and the straight groove 122. At this time, due to the combined action of the magnetic attraction between the first permanent magnet block and the second permanent magnet block and the elastic force of the elastic element, the spherical protrusion end is "sucked" from the end of the spiral groove 121 to the beginning of the straight groove 122, realizing the automatic switching of the groove.

[0062] At the same time, the drive rod 2 moves forward to the second position, and the inlet of the air passage 14 is exposed to the first air pressure chamber after leaving the coverage area of ​​the outer wall of the drive rod 2. The air passage 14 is opened; the compressed air in the first air pressure chamber enters the second air pressure chamber through the air passage 14.

[0063] It should be noted that at the instant the outer wall of the drive rod 2 begins to open the inlet of the air passage 14, the drive rod 2 is still moving forward and the guide block 21 has not yet completed the end stroke of the spiral groove 121. That is, the opening of the air passage 14 and the completion of the spiral groove 121 by the guide block 21 occur simultaneously, and the two are driven by the continuous sliding of the same drive rod 2.

[0064] Since the second air pressure chamber is connected to the cavity through air hole 5, and the cavity is still in a state close to atmospheric pressure (or slightly lower than atmospheric pressure, because there may be a vacuum adsorption force between the product and the cavity) at the beginning of demolding, the air hole 5 passage is a low-pressure passage; therefore, the compressed air entering the second air pressure chamber preferentially flows out from the air hole 5 and blows towards the mating surface of the product and the cavity, breaking the vacuum adsorption force between them and forming an air film lubrication.

[0065] (iv) Gas-assisted ejection stage

[0066] As air continues to be blown through the vent 5, the vacuum adsorption force between the product and the cavity is gradually eliminated, and the pressure inside the cavity gradually increases. At the same time, the air pressure in the second air pressure chamber gradually accumulates and increases. When the thrust generated by the air pressure in the second air pressure chamber on the sealing ring 13 is greater than the starting resistance of the push rod 1 (including static friction, residual adhesion of the product, etc.), the sealing ring 13 drives the push rod 1 to begin sliding forward.

[0067] When the push rod 1 slides forward, the spherical protruding end of the guide block 21 switches from the spiral groove 121 to the straight groove 122 and slides along the straight groove 122. Since the straight groove 122 extends axially, the guide block 21 does not generate circumferential force when sliding along the straight groove 122. The push rod 1 does not rotate during the axial sliding process (i.e., it maintains the angle state after rotation) and stably pushes the product out of the cavity.

[0068] During the axial sliding of the push rod 1, the air hole 5 continuously blows air, forming a continuous air film lubrication between the front end face of the push rod 1 and the product, which effectively reduces the frictional resistance during the pushing process and avoids defects such as whitening, marks, or local warping deformation of the product.

[0069] (V) Reset Phase

[0070] After the product is completely demolded, a reset operation is required; at this time, the external air pressure source is switched to negative pressure mode to suck up the first air pressure chamber.

[0071] Since the volume of the first air pressure chamber is greater than that of the second air pressure chamber, that is, the effective force-bearing area of ​​the first air pressure chamber is greater than that of the second air pressure chamber, under the same negative pressure, the restoring force on the drive rod 2 is much greater than that on the push rod 1; therefore, the drive rod 2 begins to slide backward first.

[0072] During the retraction of the drive rod 2, the outer wall of the rear section of the drive rod 2 covers and seals the entrance of the air passage 14, cutting off the gas connection between the first and second air pressure chambers. Subsequently, the drive rod 2 pulls the push rod 1 backward together through the cooperation of the guide block 21 and the straight groove 122. During this process, the gas in the second air pressure chamber is slowly discharged through the air hole 5, and the push rod 1 gradually retracts into the sleeve rod 11.

[0073] Furthermore, when the push rod 1 extends to its maximum position, that is, when the guide block 21 slides from one end of the straight groove 122 to the other end, the spherical protruding end of the guide block 21 is once again "sucked" into the starting end of the spiral groove 121 by magnetic attraction from the end of the straight groove 122, completing the automatic switching of the groove. When the drive rod 2 retracts, the entire push module returns to its initial state, waiting for the next injection cycle.

[0074] Specifically, the synchronous operation of the multiple pushing modules on the first sliding module 200 and the second sliding module 300 is ensured by the following mechanism:

[0075] Firstly, within the same sliding module, all drive rods 2 are fixedly connected to the same limiting plate 6 via connecting rods 22, thereby achieving mechanical forced synchronization of each pushing module within the same sliding module.

[0076] Secondly, the push module in the first sliding module 200 and the push module in the second sliding module 300 share the same air pressure source, and each air path is independently configured. The synchronous action of the two workstations is achieved through unified air pressure control commands.

[0077] Third, as mentioned earlier, the "priority air blowing" function in each push module is automatically implemented by the physical structure (the load difference between the air hole and the push rod starting resistance), without relying on the electronic control timing. Therefore, even if there are slight differences in the air paths on both sides, it will not affect the basic timing logic of "air blowing first and then pushing out".

[0078] Furthermore, since the push module adopts a sleeve-type independent modular design, when the push rod 1 of a certain push module is worn, broken, or the seal is aged, it is not necessary to disassemble the entire sliding module. Simply pull the sleeve rod 11 of the push module out of the mounting groove as a whole, perform maintenance or replace parts outside the machine, and then reinsert it. The positioning key on the outer wall of the sleeve rod 11 cooperates with the keyway on the wall of the mounting groove to ensure that the initial angle of the guide block 21 and the spiral groove 121 / straight groove 122 are correctly aligned after insertion. The O-ring on the outer wall of the sleeve rod 11 ensures the seal between the sleeve rod 11 and the mounting groove, preventing molten plastic from seeping in along the wall of the mounting groove during injection molding.

[0079] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A dual-station synchronous injection molding machine for stacked injection molds, comprising an intermediate fixed module and a first sliding module and a second sliding module symmetrically disposed on both sides of the intermediate fixed module, wherein a first molding cavity is provided between the first sliding module and the intermediate module, and a second molding cavity is provided between the second sliding module and the intermediate module, characterized in that, The first sliding module and / or the second sliding module are provided with multiple mounting slots, and a push module is detachably provided in each mounting slot; The pushing module includes: The sleeve (11) is embedded in the mounting groove; The push rod (1) is slidably disposed at the front end of the sleeve rod (11), and a drive cavity (12) is opened at its rear end; The drive rod (2) has one end slidably disposed in the sleeve rod (11) and the other end slidably disposed in the drive cavity (12).

2. A dual-station synchronous injection molding machine for stacked injection molds according to claim 1, characterized in that, The sleeve (11) is provided with a first sliding groove (3) and a second sliding groove (4), the first sliding groove (3) and the second sliding groove (4) are coaxially arranged and interconnected; The drive rod (2) is slidably disposed along the first slide groove (3), and a first air pressure chamber is formed between the drive rod (2) and the first slide groove (3); A sealing ring (13) is fixedly provided on the outer wall of the push rod (1). The sealing ring (13) is slidably disposed along the second slide groove (4). A second air pressure chamber is formed between the push rod (1), the sealing ring (13) and the second slide groove (4). The first air pressure chamber and the second air pressure chamber are connected by multiple air passages (14).

3. A dual-station synchronous injection molding machine for stacked injection molds according to claim 2, characterized in that, The inner wall of the drive cavity (12) is provided with a spiral groove (121) and a straight groove (122). The spiral groove (121) and the straight groove (122) are connected end to end, and the depth of the straight groove (122) gradually changes from one end to the other end. A guide block (21) is fixedly provided at one end of the drive rod (2) near the drive cavity (12). The guide block (21) extends into the spiral groove (121) or the straight groove (122) and slides along it.

4. A dual-station synchronous injection molding machine for stacked injection molds according to claim 3, characterized in that, The guide block (21) includes a fixed rod (211) fixedly mounted on the drive rod (2), a telescopic rod (212) slidably mounted in the fixed rod (211), and an elastic element disposed between the fixed rod (211) and the telescopic rod (212), wherein the extended end of the telescopic rod (212) is spherical.

5. A dual-station synchronous injection molding machine for stacked injection molds according to claim 4, characterized in that, The deepest part of the two connecting ends of the spiral groove (121) and the straight groove (122) is respectively embedded with a first permanent magnet block, and the spherical protruding end of the telescopic rod (212) is embedded with a second permanent magnet block. The first permanent magnet block and the second permanent magnet block have a magnetic attraction.

6. A dual-station synchronous injection molding machine for stacked injection molds according to claim 3, characterized in that, The sleeve (11) has a plurality of air holes (5) circumferentially opened at the front end. One end of the air hole (5) is connected to the second air pressure chamber, and the other end is connected to the first molding cavity or the second molding cavity. When air pressure enters the first air pressure chamber, the drive rod (2) is driven to slide, and the guide block (21) slides along the spiral groove (121) to drive the push rod (1) to rotate; when the guide block (21) slides to the end of the spiral groove (121) and switches to the straight groove (122), the air passage (14) opens, air pressure enters the second air pressure chamber to push the push rod (1) to slide, the guide block (21) slides along the straight groove (122), and air pressure is blown out through the air hole (5).

7. A dual-station synchronous injection molding machine for stacked injection molds according to claim 6, characterized in that, The sealing ring (13) has a plurality of protrusions (131) at one end near the drive rod (2). When the sealing ring (13) slides to the end of the second slide groove (4) near the first slide groove (3), each of the protrusions (131) abuts against the end face of the second slide groove (4), so that a communication gap is formed between the sealing ring (13) and the end face of the second slide groove (4), and the air hole (5) is connected to the second air pressure chamber through the communication gap.

8. A dual-station synchronous injection molding machine for stacked injection molds according to claim 3, characterized in that, The volume of the first pressure chamber is greater than the volume of the second pressure chamber; The straight groove (122) has a greater groove depth at the end closest to the drive rod (2) than the spiral groove (121), and the straight groove (122) has a less groove depth at the end furthest from the drive rod (2) than the spiral groove (121).

9. A dual-station synchronous injection molding machine for stacked injection molds according to claim 2, characterized in that, A valve core structure is formed between the drive rod (2) and the first slide groove (3). When the drive rod (2) is in the first position where it has not slid out of the first slide groove (3), the drive rod (2) closes the air passage (14). When the drive rod (2) is in the second position where it slides along the first slide groove (3) to the maximum limit, the air passage (14) opens.

10. A dual-station synchronous injection molding machine for stacked injection molds according to claim 1, characterized in that, A connecting rod (22) is fixedly provided at the rear end of the drive rod (2). The connecting rod (22) slides through the rear end wall of the sleeve rod (11) and extends to the outside of the sleeve rod (11). The extended ends of all the connecting rods (22) located in the same sliding module are fixedly connected to the same limiting plate (6).

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