Injection molding machine melt pressure self-adapting back injection interface device

Abstract

This invention discloses an adaptive return injection interface device for injection molding machine melt pressure, relating to the field of plastic processing technology. It aims to solve the technical problem of poor adaptability in existing pressure relief structures. The device includes a return injection cylinder and a connecting pipe. The return injection cylinder has a return injection channel, a redundant channel, and an inclined discharge channel. A feed screw is rotatably installed in the return injection channel. The outlet of the return injection channel is connected to a return pipe through the inclined discharge channel. One end of the connecting pipe is connected to the injection molding machine's barrel, and the other end is connected to the inlet of the redundant channel. A stop block and a baffle are slidably and sealingly installed in the redundant channel. The stop block is connected to the inner wall of the redundant channel via a first spring. A flow channel extends vertically through the stop block, and a blockage block is connected to the flow channel via a second spring. This invention has the advantage of dynamically and adaptively adjusting the pressure relief flow rate as the plastic melt pressure increases.

Description

Technical Field

[0001] This invention relates to the field of plastic processing technology, and more specifically, to an adaptive return interface device for melt pressure in injection molding machines. Background Technology

[0002] In the intelligent manufacturing equipment industry, injection molding is the mainstream process in plastic processing. Injection molding machines melt solid plastic particles into molten plastic by heating the barrel and shearing and pushing with a screw. This molten plastic is then injected into the mold cavity under high pressure, and after cooling, the molded product is obtained. In actual industrial production, factors such as fluctuations in raw material grade, screw speed switching, changes in injection rate, uneven mold flow resistance, and alternating operations at multiple stations can all lead to problems such as gradual increases, frequent fluctuations, and even instantaneous pressure bursts in the molten material pressure inside the barrel.

[0003] To address the issue of melt overpressure, the industry currently widely employs external reflux pipelines for pressure relief and material return. However, existing reflux structures have significant shortcomings. Most simple reflux pipelines are normally open designs, resulting in continuous melt circulation and recirculation. This not only increases equipment energy consumption but also fails to adapt to dynamic changes in melt pressure, exhibiting poor self-adaptability. Furthermore, the flow area of ​​conventional reflux channels is fixed, preventing the pressure relief flow rate from automatically matching the pressure level. Pressure relief is delayed when the pressure rises slowly, and insufficient flow capacity hinders rapid pressure release during sudden overpressure events, resulting in poor pressure relief performance. Therefore, we propose an adaptive melt pressure recirculation interface device for injection molding machines. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive return injection interface device for injection molding machine melt pressure, so as to solve the technical problem of poor adaptability of existing pressure relief structures.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an injection molding machine melt pressure adaptive return interface device, including a return cylinder and a connecting pipe. The outer wall of the return cylinder is provided with a heating module. The return cylinder has a return channel, a redundant channel and an inclined discharge channel inside. A feeding screw is rotatably arranged in the return channel. The outlet of the return channel is connected to a return pipe through the inclined discharge channel. The return pipe is used to connect to the feeding hopper of the injection molding machine. One end of the connecting pipe is used to connect to the barrel of the injection molding machine, and the other end of the connecting pipe is connected to the inlet of the redundant channel. A stop block and a stop block are slidably and sealingly arranged in the redundant channel. The stop block is connected to the inner wall of the redundant channel through a first spring. In the initial state, the stop block presses against the stop block to block the outlet of the connecting pipe. A flow channel is formed through the stop block from top to bottom. A block is connected to the flow channel through a second spring. The block can seal or open the bottom inlet of the flow channel according to the change of melt pressure.

[0006] Preferably, the flow channel is a frustum structure with a larger top and a smaller bottom, and the bottom shape of the block is adapted to the bottom inlet of the flow channel. When the upward movement of the block increases with the increase of the melt pressure, the flow cross-section of the flow channel increases synchronously.

[0007] Preferably, a cross is fixed to the upper sidewall of the flow channel, a cylindrical insert plate is fixed to the bottom of the cross, a slot is provided on the top of the block, and the cylindrical insert plate is slidably inserted into the slot; an exhaust port communicating with the slot is provided on the inner sidewall of the block, an exhaust channel is provided on the inner top of the cylindrical insert plate, and the outlet of the exhaust channel extends to the side of the stop block.

[0008] Preferably, a sliding tube is fixed to the side of the stop block near the inclined drain channel, and an emergency channel connecting the redundant channel and the inclined drain channel is also provided in the reinjection cylinder. The sliding tube is slidably and sealed in the emergency channel, and the first spring is sleeved on the outer circumferential wall of the sliding tube.

[0009] Preferably, the end of the stop block near the stop block has an inclined surface structure, and a groove is provided on the inclined surface structure. The inclined surface of the stop block and the stop block together form a dynamic redundant cavity, and the dynamic redundant cavity is connected to the reinjection channel through the groove.

[0010] Preferably, when the melt flow rate exceeds the conveying capacity of the feed screw, the excess melt enters the dynamic redundancy cavity through the groove, pushing the stop block to compress the first spring and slide towards the emergency channel. The volume of the dynamic redundancy cavity expands as the sliding stroke increases.

[0011] Preferably, the end of the reinjection cylinder is detachably connected to a cover block. The inner wall of the connecting pipe has a sliding cavity extending into the cover block. A trigger head is slidably and sealed within the sliding cavity. A push rod is fixed to the side wall of the trigger head. The push rod movably penetrates the side wall of the cover block and is fixed with a limit frame. A third spring is sleeved on the outer wall of the push rod. The cover block also has an interconnected upper sliding cavity and a vertical sliding cavity. A movable rod is fixed to the side wall of the stop block, and the movable rod slidably resides within the upper sliding cavity. The movable rod has a slot on its side wall; a locking plate is slidably disposed in the vertical sliding cavity, and the top of the locking plate can be engaged with the slot to lock the position of the stop block; the side wall of the locking plate is provided with a toothed opening, the top of the limiting frame is provided with a toothed opening, and the lower side wall of the vertical sliding cavity is rotatably provided with a toothed wheel, which meshes with the toothed opening and the toothed opening respectively; when there is instantaneous overpressure, the trigger head retracts, which can drive the locking plate to move down and release the locking of the movable rod.

[0012] Preferably, the stop block has an emergency chamber that communicates with the slide pipe inside, and the inlet of the emergency chamber is located at the bottom of the stop block; after the stop block is unlocked, the first spring pushes the stop block and the stop block to slide synchronously, so that the inlet of the emergency chamber connects with the outlet of the pipe, and the high-pressure melt flows into the return pipe through the emergency chamber, the emergency channel, and the inclined drain.

[0013] Preferably, the elastic coefficient of the third spring is greater than that of the first spring and the second spring.

[0014] Preferably, a sensor is installed on the side wall of the cover block, and a positioning block is fixed on the side wall of the movable rod. The positioning block is arranged on the outside of the cover block, and the sensor is used to monitor the displacement of the positioning block to trigger an overpressure alarm.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention designs a backfill interface device. When the barrel is working and the pressure of the molten plastic in the inner cavity is normal, the plug is held in place by the elastic force of the second spring, forming a sealed connection at the bottom inlet of the flow channel. The molten plastic in the barrel is only normally conveyed along the main channel towards the injection mold. At this time, the stop block in the redundant channel is pressed tightly against the stop block by the first spring, and the passage of the pipe is completely blocked. The backfill channel and the emergency channel are both disconnected, and the entire backfill structure does not participate in the operation. The equipment operates according to the conventional injection molding process. When the pressure of the molten plastic inside the barrel continues to rise and exceeds the preset safety threshold, the high-pressure molten plastic flows from the pipe into the flow channel of the stop block, and the molten plastic pressure... The force overcomes the second spring, causing it to contract, and the block disengages from the bottom inlet of the flow channel, opening the flow channel. The high-pressure plastic melt sequentially passes through the connecting pipe and the flow channel into the return channel. Pushed by the conveying screw, it flows through the inclined discharge channel and return pipe into the feeding hopper, eventually returning to the inside of the barrel. This diversion and pressure relief keeps the melt pressure in the barrel within a safe range. When the melt pressure in the barrel drops back to the normal range, the second spring causes the block to seal the flow channel again, automatically terminating the return process and returning the device to standby mode. This achieves adaptive adjustment of the melt pressure, solving the problem that traditional injection molding machines are prone to sudden increases in melt pressure during injection, and that conventional pressure relief structures cannot achieve adaptive on / off switching based on melt pressure.

[0016] 2. This invention also designs the flow channel as a frustum structure with a larger upper part and a smaller lower part. When the pressure of the plastic melt inside the barrel continues to rise, the high-pressure plastic melt pushes the block to move upward against the second spring, thus opening the flow channel. As the pressure of the plastic melt increases, the upward stroke of the block increases, the distance between the side wall of the block and the inner side wall of the flow channel gradually increases, and the flow cross section gradually expands. The pressure relief flow rate is dynamically and adaptively adjusted with the melt pressure, achieving a gradual increase in the pressure relief rate. This effectively prevents the problem of continuous accumulation and excessive surge of melt pressure in the barrel if the flow rate of the flow channel does not change when the melt pressure gradually increases.

[0017] 3. The present invention also designs the end of the stop block as an inclined surface structure with a groove. When the melt pressure in the barrel continues to increase and the melt flow rate exceeds the conveying flow rate of the feed screw in the reinjection channel, the excess melt will accumulate at the entrance of the reinjection channel and enter the dynamic redundant cavity through the groove. The pressure in the dynamic redundant cavity will increase accordingly, thereby pushing the stop block to squeeze the first spring and slide towards the emergency channel in the redundant channel, increasing the space of the dynamic redundant cavity, providing temporary buffer space for the interference melt, and reducing the melt pressure.

[0018] 4. This invention, through the design of an emergency chamber and emergency channel structure, addresses the issue that when the melt pressure inside the barrel experiences an abnormal, instantaneous surge, the large flow rate of melt cannot be quickly diverted and buffered through the flow channel and dynamic redundant cavity. An abnormal instantaneous pressure forms inside the pipe cavity, which pushes the trigger head to overcome the elasticity of the third spring and retract into the sliding cavity. This causes the push rod and limit frame to move synchronously, and the toothed transmission structure drives the clamping plate downwards, releasing the limiting lock on the moving rod and the stop block. At this time, the stop block, due to the elasticity of the first spring, pushes the stop block to move synchronously, causing the entire stop block to slide away from the emergency channel. The originally misaligned emergency chamber inlet connects with the pipe outlet, allowing the large flow rate of high-pressure melt to no longer be restricted by the flow channel and directly and quickly pass through the emergency chamber into the emergency channel. It then flows back to the feeding hopper via the inclined discharge channel and return pipe to complete rapid pressure relief. This emergency passage can be instantly opened when pressure suddenly surges, significantly improving the discharge capacity and quickly mitigating the risk of abnormal instantaneous overpressure.

[0019] 5. This invention also incorporates a toothed wheel transmission structure. When the trigger head retracts under pressure and the limiting frame moves synchronously, the second toothed opening drives the toothed wheel to rotate in a specific direction. Then, the toothed wheel, in conjunction with the first toothed opening, actively and forcibly drives the locking plate to move vertically downward, releasing the locking plate from the limiting lock of the movable rod and the stop block. This transmission method effectively avoids the problem of the stop block continuously bearing the resistance force of the stop block, which causes the movable rod's slot to generate a lateral thrust on the locking plate, resulting in the locking plate becoming stuck and difficult to remove. This ensures a smooth and reliable unlocking action and guarantees that the subsequent pressure relief structure can operate normally. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 This is a schematic diagram of the material cylinder and refill interface device of the present invention.

[0022] Figure 3 This is a schematic diagram of the cross-sectional structure of the material cylinder of the present invention.

[0023] Figure 4 This is a cross-sectional structural diagram of the reinjection interface device of the present invention.

[0024] Figure 5 This is a schematic diagram of the stop block structure of the present invention.

[0025] Figure 6 This is a schematic diagram of the cross-sectional structure of the stop block of the present invention.

[0026] Figure 7 This is a schematic diagram of the cross-sectional structure of the blocking block of the present invention.

[0027] Figure 8 for Figure 4 Enlarged schematic diagram of the structure at point A in the middle.

[0028] Figure 9 This is a schematic diagram of the disassembled cover block structure of the present invention.

[0029] Figure 10 This is a schematic diagram of the card slot and card plate structure of the present invention.

[0030] Explanation of the labels in the diagram: 1. Material cylinder; 2. Feed hopper; 3. Refill interface device; 31. Refill cylinder; 32. Connecting pipe; 33. Return pipe; 34. Heating module; 35. Drive assembly; 36. Cover block; 3101. Refill channel; 3102. Redundant channel; 3103. Emergency channel; 3104. Inclined discharge channel; 3105. Conveying screw; 3106. Stop block; 3107. Stop block; 3108. Slide tube; 3109. First spring; 3110. Flow channel; 3111. Cross-shaped plate; 3112. Cylindrical insert plate; 3113. Second spring; 3114. Block; 3115. Slot; 3116. Groove; 3117. Vent; 3118. Vent channel; 3119. Emergency chamber 3601, Sliding cavity; 3602, Trigger head; 3603, Push rod; 3604, Limit frame; 3605, Third spring; 3606, Upper sliding cavity; 3607, Vertical sliding cavity; 3608, Movable rod; 3609, Slot; 3610, Card plate; 3611, Toothed opening one; 3612, Toothed opening two; 3613, Toothed wheel; 3614, Toothed opening three; 3615, Sensor; 3616, Positioning block. Detailed Implementation

[0031] like Figures 1 to 10 As shown, the present invention relates to an injection molding machine melt pressure adaptive return interface device, including an injection molding machine body, the injection molding machine body including a barrel 1, a feeding hopper 2 and a return interface device 3 installed on the barrel 1. The material enters the barrel 1 through the feeding hopper 2, is conveyed by the screw in the barrel 1, heated and plasticized into a molten state, and then conveyed to the injection mold cavity through the output end of the barrel 1. The return interface device 3 is connected to the melt flow channel of the barrel 1, and can guide part of the high-pressure melt back to the feeding hopper 2 in real time, and reflow back into the barrel 1.

[0032] In an embodiment of the present invention, the reinjection interface device 3 includes a reinjection cylinder 31, a connecting pipe 32, a return pipe 33, a heating module 34, and a drive component 35.

[0033] Specifically, the bottom of the connecting pipe 32 forms a detachable threaded seal connection with the side wall of the material cylinder 1 near its output end, and the top of the connecting pipe 32 is connected to the side wall of the return cylinder 31; one end of the return pipe 33 is connected to one end of the return cylinder 31, and the other end of the return pipe 33 is detachably connected to the side wall of the feeding hopper 2; the inner cavity of the return cylinder 31 is connected to the inner cavity of the material cylinder 1 through the connecting pipe 32, and the inner cavity of the return cylinder 31 is also connected to the inner cavity of the feeding hopper 2 through the return pipe 33; and the connecting pipe 32 and the return pipe 33 can form an installation support effect for the return cylinder 31.

[0034] Furthermore, the heating module 34 is installed on the outer wall of the return cylinder 31. The heating module 34 is a conventional heating device in this example. Its function is to heat the material inside the return cylinder 31 at a constant temperature to prevent the material from cooling down and solidifying, reducing its fluidity, and ensuring smooth material transport during the return circulation process.

[0035] In an embodiment of the present invention, the inner cavity of the reinjection cylinder 31 is provided with a reinjection channel 3101, a redundant channel 3102, an emergency channel 3103, and an inclined drain channel 3104; the inner cavity of the connecting pipe 32 is connected to the inlet of the reinjection channel 3101 through the redundant channel 3102, and the output end of the reinjection channel 3101 is connected to the return pipe 33 through the inclined drain channel 3104; the redundant channel 3102 is connected to the inclined drain channel 3104 through the emergency channel 3103.

[0036] The return channel 3101 is rotatably arranged with a conveying screw 3105, which is used to convey the plastic melt in the return channel 3101 forward and return it to the feed end of the feed cylinder 1 through the inclined channel 3104, the return pipe 33 and the feeding hopper 2.

[0037] In an embodiment of the present invention, the drive assembly 35 includes a gearbox mounted on the top of the return cylinder 31. A motor is arranged inside the gearbox. The output end of the motor is connected to a drive gear, and the end of the feeding screw 3105 is connected to a transmission gear. The drive gear and the transmission gear are meshed and connected. The motor controls the rotation of the drive gear, which in turn drives the transmission gear to rotate, thereby realizing the rotational feeding function of the feeding screw 3105.

[0038] In an embodiment of the present invention, a stop block 3106 and a stop block 3107 are slidably arranged in the redundant channel 3102. The stop block 3106 can be held in a fixed position in the redundant channel 3102. A slide tube 3108 is connected to the side wall of the stop block 3107. A first spring 3109 is sleeved on the outer circumference of the slide tube 3108. One end of the first spring 3109 is connected to the side wall of the stop block 3107 and the other end is connected to the inner wall of the redundant channel 3102. The slide tube 3108 is slidably arranged in the emergency channel 3103.

[0039] Among them, the stop block 3107 is subjected to the elastic force of the first spring 3109, which can keep it in contact with the side wall of the stop block 3106, so that the stop block 3107 is located at the top of the pipe 32, which can block and seal the flow in the inner cavity of the pipe 32.

[0040] Furthermore, the stop block 3107 has a flow channel 3110 from top to bottom. A cross 3111 is connected to the upper side wall of the flow channel 3110. A cylindrical insert plate 3112 is connected to the bottom of the cross 3111. A second spring 3113 is arranged in the inner cavity of the cylindrical insert plate 3112. A blocking block 3114 is connected to the bottom of the second spring 3113. A slot 3115 with an annular structure is opened at the top of the blocking block 3114. The cylindrical insert plate 3112 is movably inserted into the slot 3115. The blocking block 3114 can form a sealed insertion state or a separated state with the bottom inlet of the flow channel 3110.

[0041] This invention designs a return injection interface device 3. When the barrel 1 is working and the pressure of the plastic melt in the inner cavity is normal, the plug 3114 is held in place by the elastic force of the second spring 3113, forming a sealed insertion state at the bottom inlet of the flow channel 3110. The plastic melt in the barrel 1 is only normally conveyed along the main channel towards the injection mold. At this time, the stop block 3107 in the redundant channel 3102 is pressed tightly against the stop block 3106 by the push of the first spring 3109, and the passage of the pipe 32 is completely blocked. The return injection channel 3101 and the emergency channel 3103 are both in the disconnected state. The entire return injection structure does not participate in the work, and the equipment operates according to the conventional injection molding process. When When the pressure of the plastic melt inside the barrel 1 continues to rise and exceeds the preset safety threshold, the high-pressure plastic melt flows from the pipe 32 into the flow channel 3110 of the stop block 3107. The pressure of the plastic melt overcomes the second spring 3113, causing it to contract. The block 3114 disengages from the bottom inlet of the flow channel 3110, and the flow channel 3110 is opened. The high-pressure plastic melt passes through the pipe 32 and the flow channel 3110 in sequence and enters the return channel 3101. Under the push of the conveying screw 3105, it flows into the feeding hopper 2 through the inclined discharge channel 3104 and the return pipe 33, and finally returns to the inside of the barrel 1. This diversion and pressure relief keeps the melt pressure in the barrel 1 within a safe range. The heating module 34 maintains a constant temperature for the return cylinder 31 throughout the process, preventing the backflow melt from cooling and solidifying, and ensuring smooth melt flow. When the melt pressure in the barrel 1 drops back to the normal range, the second spring 3113 drives the block 3114 to seal the flow channel 3110 again, the return process automatically terminates, and the device returns to standby mode, realizing adaptive adjustment of melt pressure. This solves the problem that the melt pressure of traditional injection molding machines is prone to sudden rise during injection, and that conventional pressure relief structures are difficult to achieve adaptive on / off switching according to melt pressure.

[0042] In another embodiment of the present invention, the flow channel 3110 is a frustum-shaped structure with a larger top and a smaller bottom, the bottom of the block 3114 is a structure that fits the bottom inlet of the flow channel 3110, and the sidewall of the block 3114 is a cylindrical structure. As the block 3114 gradually rises, the distance between the sidewall of the block 3114 and the inner sidewall of the frustum-shaped flow channel 3110 with a larger top and a smaller bottom gradually increases, that is, the flow cross section changes smoothly from small to large.

[0043] This invention also designs the flow channel 3110 as a frustum structure with a larger upper part and a smaller lower part. When the pressure of the plastic melt inside the barrel 1 continues to rise, the high-pressure plastic melt pushes the block 3114 to overcome the second spring 3113 and move upward, so that the flow channel 3110 is open. As the pressure of the plastic melt increases, the upward stroke of the block 3114 increases, the distance between the side wall of the block 3114 and the inner side wall of the flow channel 3110 gradually increases, and the flow cross section gradually expands synchronously. The pressure relief flow rate is dynamically and adaptively adjusted with the melt pressure, so as to achieve a gradual increase in the pressure relief rate. This effectively prevents the problem of continuous accumulation and excessive surge of melt pressure in the barrel 1 if the flow rate of the flow channel 3110 does not change when the melt pressure gradually increases.

[0044] In another embodiment of the present invention, the end of the stop block 3107 is an inclined surface structure, and a groove 3116 is provided on the inclined surface structure. A dynamic redundant cavity is formed between the inclined surface structure at the end of the stop block 3107 and the stop block 3106. When the side wall of the stop block 3107 and the stop block 3106 are in contact, the dynamic redundant cavity can be connected to the reinjection channel 3101 through the groove 3116.

[0045] The present invention also designs the end of the stop block 3107 as an inclined surface structure and provides a groove 3116. When the melt pressure in the barrel 1 continues to increase and the melt flow rate exceeds the conveying flow rate of the feed screw 3105 in the return channel 3101, the excess melt will accumulate at the entrance of the return channel 3101 and enter the dynamic redundancy cavity through the groove 3116. The pressure in the dynamic redundancy cavity will increase accordingly, thereby pushing the stop block 3107 to squeeze the first spring 3109 and slide in the redundancy channel 3102 towards the emergency channel 3103, increasing the space of the dynamic redundancy cavity, providing temporary buffer space for the interference melt, and reducing the melt pressure.

[0046] In another embodiment of the present invention, the cylindrical insert plate 3112 and the slot 3115 are in a sealed sliding fit to prevent molten material from entering the inner cavity of the plug block 3114 and the slot 3115. The inner wall of the plug block 3114 has multiple vents 3117, which communicate with the slot 3115. The top of the cylindrical insert plate 3112 has a venting channel 3118, whose outlet is located on the side of the stop block 3107 near the slide tube 3108, thus avoiding interference from the molten material. When the plug block 3114 moves upward, the cylindrical insert plate 3112 is inserted downward into the slot 3115. Gas in the slot 3115 can enter the inner cavity of the plug block 3114 through the vents 3117 and exit through the venting channel 3118, preventing high internal pressure in the slot 3115 that would hinder the upward movement of the plug block 3114.

[0047] In another embodiment of the present invention, the end of the reinjection cylinder 31 is detachably connected to a cover block 36 by bolts. After the cover block 36 is removed, it is convenient to inspect and clean the inner cavity of the reinjection cylinder 31. The redundant channel 3102 of the inner cavity of the reinjection cylinder 31 extends into the inner cavity of the cover block 36.

[0048] In another embodiment of the present invention, a sliding cavity 3601 extending into the cover block 36 is provided on the inner side wall of the pipe 32. A trigger head 3602 is slidably arranged in the sliding cavity 3601. A push rod 3603 is connected to the side wall of the trigger head 3602. The push rod 3603 moves through the side wall of the cover block 36 and is connected to a limit frame 3604. A third spring 3605 is sleeved on the outer circumference of the push rod 3603. The third spring 3605 is arranged in the sliding cavity 3601. The elastic coefficient of the third spring 3605 is greater than that of the first spring 3109 and the second spring 3113.

[0049] The trigger head 3602 has a concave arc-shaped sidewall. Initially, the trigger head 3602 is held at the sliding cavity 3601 port near the inner cavity of the connector 32 by the elastic force of the third spring 3605. It is also limited by the limiting frame 3604, which adheres to the sidewall of the cover block 36, making the concave arc-shaped structure of the trigger head 3602 part of the inner cavity sidewall of the connector 32. When the melt pressure in the barrel 1 normally increases, the melt can enter the flow channel 3110 through the inner cavity of the connector 32, pushing the block 3114 upward to open the return channel. This pressure is insufficient to push the trigger head 3602 to retract. Because the elastic coefficient of the third spring 3605 is much greater than that of the first spring 3109 and the second spring 31009, the trigger head 3602 is not retracted. 13. The trigger head 3602 always remains in its original position, and the device only relies on the return channel 3101 to complete the normal adaptive pressure relief. However, when the melt pressure in the barrel 1 increases abnormally and instantaneously, the large flow of melt is difficult to quickly divert and buffer through the flow channel 3110 and the dynamic redundant cavity. Because the flow channel 3110 has a limited flow cross-section, the flow efficiency of the large flow of melt is limited, making it difficult for the melt to quickly enter the dynamic redundant cavity through the groove 3116 and push the stop block 3107 to move. It is difficult to quickly increase the space of the dynamic redundant cavity to provide temporary buffer space for the interference melt. An abnormal instantaneous pressure is formed in the inner cavity of the pipe 32. This pressure will push the trigger head 3602 to overcome the elastic force of the third spring 3605 and retract into the sliding cavity 3601.

[0050] In another embodiment of the present invention, the inner cavity of the cover block 36 is further provided with an upper sliding cavity 3606 and a vertical sliding cavity 3607 communicating with the upper sliding cavity 3606, and a limiting frame 3604 is arranged below the vertical sliding cavity 3607; a movable rod 3608 is connected to the side wall of the stop block 3106, the movable rod 3608 is slidably arranged in the upper sliding cavity 3606, and a slot 3609 is provided on the side wall of the movable rod 3608; a locking plate 3610 is movably arranged in the vertical sliding cavity 3607, the top of the locking plate 3610 is a wedge-shaped locking head structure, and the wedge-shaped locking head structure at the top of the locking plate 3610 can form a locking state with the slot 3609, so that the stop block 3106 is kept in a fixed position in the redundant channel 3102.

[0051] Furthermore, the side wall of the card plate 3610 is provided with a toothed opening 3611, the top of the limiting frame 3604 is provided with a toothed opening 3612, and the lower side wall of the vertical sliding cavity 3607 is rotatably provided with a toothed wheel 3613. The outer circumference of the toothed wheel 3613 is provided with two sets of toothed openings 3614. One set of toothed openings 3614 of the toothed wheel 3613 is engaged with toothed opening 3611, and the other set of toothed openings 3614 is engaged with toothed opening 3612. When an abnormal instantaneous pressure is formed in the inner cavity of the connecting pipe 32, the pressure will push the trigger head 36. 02 When the spring force of the third spring 3605 is overcome and the device retracts into the sliding cavity 3601, the limiting frame 3604 moves synchronously, and the second toothed mouth 3612 drives the toothed wheel 3613 to rotate in the forward direction around the axis of rotation. The toothed wheel 3613 drives the first toothed mouth 3611 to move down through another set of third toothed mouths 3614, driving the locking plate 3610 to slide down along the vertical sliding cavity 3607. The wedge-shaped locking head at the top of the locking plate 3610 disengages from the slot 3609 on the movable rod 3608, releasing the limiting lock on the movable rod 3608.

[0052] As another embodiment of the present invention, the inner cavity of the stop block 3107 is also provided with an emergency cavity 3119 that communicates with the inner cavity of the slide pipe 3108. The inlet of the emergency cavity 3119 is located at the bottom of the stop block 3107. The inlet diameter of the emergency cavity 3119 is the same as the outlet diameter of the pipe 32. The outlet of the emergency cavity 3119 communicates with the emergency channel 3103.

[0053] This invention, through the design of the emergency chamber 3119 and emergency channel 3103, addresses the issue that when an abnormal, instantaneous increase in melt pressure occurs within the barrel 1, the large flow rate of melt cannot be quickly diverted and buffered through the flow channel 3110 and the dynamic redundant chamber. An abnormal instantaneous pressure forms within the inner cavity of the pipe 32. This pressure pushes the trigger head 3602 to overcome the elastic force of the third spring 3605 and retract into the sliding cavity 3601. This causes the push rod 3603 and the limiting frame 3604 to move synchronously, driving the clamping plate 3610 downwards via a toothed transmission structure, releasing the limiting lock on the movable rod 3608 and the stop block 3106. At this time, the stop block... Due to the elastic force of the first spring 3109, the stop block 3106 moves synchronously, causing the stop block 3107 to slide away from the emergency channel 3103. The originally misaligned inlet of the emergency chamber 3119 connects with the outlet of the pipe 32. The high-flow-rate high-pressure melt is no longer restricted by the flow channel 3110 and directly and quickly enters the emergency channel 3103 through the emergency chamber 3119. Then, it flows back to the feeding hopper 2 through the inclined discharge channel 3104 and the return pipe 33 to complete the rapid pressure relief. This emergency passage can be opened instantly when the pressure suddenly rises, greatly improving the discharge capacity and quickly resolving the risk of abnormal instantaneous overpressure.

[0054] The present invention also designs a transmission structure for the toothed wheel 3613. When the trigger head 3602 is pressed and retracts, and the limiting frame 3604 moves synchronously, the second tooth 3612 drives the toothed wheel 3613 to rotate in a specific direction. Then, the toothed wheel 3613, in conjunction with the first tooth 3611, actively and forcibly drives the locking plate 3610 to move vertically downward, thereby releasing the locking plate 3610 from limiting and locking the movable rod 3608 and the stop block 3106. This transmission method can effectively avoid the problem that the stop block 3106 continuously bears the resistance force of the stop block 3107, which causes the groove 3609 of the movable rod 3608 to generate a lateral thrust on the locking plate 3610, making the locking plate 3610 stuck and difficult to remove. This ensures that the unlocking action is smooth and reliable, and ensures that the subsequent pressure relief structure can operate normally.

[0055] In another embodiment of the present invention, a sensor 3615 is arranged on the side wall of the cover block 36. The sensor 3615 is an industrial high-temperature resistant displacement sensor, which can adapt to the high-temperature environment generated by melt operation for a long time, and has the characteristics of resisting melt fumes and vibration. It can stably collect displacement signals. A positioning block 3616 is connected to the side wall of the movable rod 3608. The positioning block 3616 is arranged on the outer side wall of the cover block 36, and the sensor 3615 is arranged above the positioning block 3616 for monitoring the movement of the positioning block 3616. When the melt pressure is abnormal and triggers the emergency pressure relief mechanism, and the movable rod 3608 moves synchronously with the stop block 3106, the positioning block 3616 will move accordingly. The moving rod 3608 moves synchronously, and the sensor 3615 can capture the position change and movement stroke of the positioning block 3616 in real time, and convert the displacement data into an electrical signal and transmit it to the injection molding machine's main control system. The main control system determines that the equipment has a momentary overpressure fault in the melt based on the received signal, and simultaneously triggers an audible and visual alarm to prompt the staff to check the equipment, raw materials and process parameters. At the same time, the system can record data such as the time of the fault occurrence and the frequency of pressure triggering, which is convenient for subsequent equipment operation and maintenance and production process optimization. When the melt pressure returns to normal and the moving rod 3608 and the positioning block 3616 are reset, the sensor 3615 outputs a normal signal, the alarm state is automatically cleared, and the device returns to the normal monitoring mode.

[0056] Working principle: This embodiment provides an injection molding machine melt pressure adaptive return interface device. When in use, the plastic raw material enters the barrel 1 through the feeding hopper 2, is heated by the barrel and pushed by the screw to melt into a melt, and is transported to the injection mold along the main channel to complete the normal injection molding operation. Furthermore, when the melt pressure inside the barrel 1 is within the normal and safe range, the second spring 3113 pushes the blocking block 3114 to seal the bottom inlet of the flow channel 3110, while the first spring 3109 presses the stop block 3107 against the stop block 3106, blocking the passage of the pipe 32. The return channel 3101 and the emergency channel 3103 are both disconnected, and the entire return interface device 3 is on standby, maintaining normal injection molding operation. The heating module 34 is in standby mode throughout the process, maintaining the temperature around the return barrel 31. Furthermore, as the melt pressure gradually increases and exceeds the preset threshold, the high-pressure melt flows into the flow channel 3110 through the pipe 32. The melt pressure overcomes the elastic force of the second spring 3113, pushing the block 3114 upward, and the flow channel 3110 is opened. Because the flow channel 3110 is a frustum structure with a larger upper part and a smaller lower part, the upward stroke of the block 3114 gradually increases with the increase of pressure, the flow cross section increases steadily, and the pressure relief flow rate increases adaptively, achieving smooth pressure relief. The melt enters the return channel 3101 along the flow channel 3110, is conveyed by the conveying screw 3105, and flows back to the feeding hopper 2 through the inclined discharge channel 3104 and the return pipe 33, and re-enters the material cylinder 1, completing the diversion and pressure relief. If the melt flow rate exceeds the conveying capacity of the conveying screw 3105, the excess melt enters the dynamic redundant cavity through the groove 3116 on the stop block 3107, squeezing the stop block 3107 to compress the first spring 3109, expanding the redundant cavity space to temporarily buffer the melt, and further buffering the pressure. Furthermore, in extreme cases where the melt pressure suddenly increases, the pressure relief passage cannot release the pressure quickly. The instantaneous high pressure in the connector 32 pushes the trigger head 3602 to compress the third spring 3605 and retract it into the sliding cavity 3601, causing the push rod 3603 and the limit frame 3604 to move synchronously. Through the meshing transmission of the toothed gear 3612, the toothed wheel 3613, and the toothed gear 3611, the clamping plate 3610 is driven to move down, releasing the limit on the movable rod 3608 and the stop block 3106. At this time, the first spring 3109 pushes the stop block 3107 and the stop block 3106 to slide as a whole, and the inlet of the emergency chamber 3119 connects with the outlet of the connector 32. The high-pressure melt flows back quickly through the emergency chamber 3119 and the emergency channel 3103, opening the emergency pressure relief mode and mitigating the risk of instantaneous overpressure. Finally, throughout the entire operation of the device, the heating module 34 continuously maintains a constant temperature for the return injection cylinder 31 to prevent the backflow melt from cooling and solidifying, ensuring smooth melt flow. Simultaneously, the sensor 3615 monitors the displacement of the movable rod 3608 and the positioning block 3616 in real time. If an emergency pressure relief is triggered, a signal is immediately transmitted to the injection molding machine's main control system, activating an audible and visual alarm and recording fault data, facilitating maintenance and process optimization by staff.

[0057] The embodiments disclosed in this invention are preferred embodiments, but are not limited thereto. Those skilled in the art can easily understand the spirit of this invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of this invention, they are all within the protection scope of this invention.

Claims

1. A melt pressure adaptive return injection interface device for injection molding machines, characterized in that, include: A return cylinder (31) is provided with a heating module (34) on its outer wall. The return cylinder (31) is provided with a return channel (3101), a redundant channel (3102) and an inclined channel (3104) inside. A feeding screw (3105) is rotatably provided in the return channel (3101). The outlet of the return channel (3101) is connected to a return pipe (33) through the inclined channel (3104). The return pipe (33) is used to connect to the feeding hopper (2) of the injection molding machine. Connector (32), one end of which is used to connect to the barrel (1) of the injection molding machine, and the other end of which is connected to the inlet of the redundant channel (3102); The redundant channel (3102) is sealed and slidably equipped with a stop block (3107) and a stop block (3106). The stop block (3107) is connected to the inner wall of the redundant channel (3102) through a first spring (3109). In the initial state, the stop block (3107) abuts against the stop block (3106) to block the outlet of the pipe (32). The stop block (3107) has a flow channel (3110) extending through the top and bottom. A block (3114) is connected to the flow channel (3110) by a second spring (3113). The block (3114) can seal or open the bottom inlet of the flow channel (3110) as the melt pressure changes.

2. The injection molding machine melt pressure adaptive return interface device according to claim 1, characterized in that, The flow channel (3110) is a frustum structure with a larger top and a smaller bottom. The bottom shape of the block (3114) is adapted to the bottom inlet of the flow channel (3110). When the upward stroke of the block (3114) increases with the increase of the melt pressure, the flow cross section of the flow channel (3110) increases synchronously.

3. The injection molding machine melt pressure adaptive return interface device according to claim 2, characterized in that, A cross (3111) is fixed to the upper side wall of the flow channel (3110), and a cylindrical insert plate (3112) is fixed to the bottom of the cross (3111). A slot (3115) is provided on the top of the block (3114), and the cylindrical insert plate (3112) is sealed and slidably inserted into the slot (3115). An exhaust port (3117) communicating with the slot (3115) is provided on the inner side wall of the block (3114), and an exhaust channel (3118) is provided on the inner top of the cylindrical insert plate (3112). The outlet of the exhaust channel (3118) extends to the side of the stop block (3107).

4. The injection molding machine melt pressure adaptive return interface device according to claim 3, characterized in that, The stop block (3107) is fixed with a slide tube (3108) on the side near the inclined drain channel (3104). The return cylinder (31) is also provided with an emergency channel (3103) that connects the redundant channel (3102) and the inclined drain channel (3104). The slide tube (3108) is sealed and slidably disposed in the emergency channel (3103). The first spring (3109) is sleeved on the outer circumferential wall of the slide tube (3108).

5. The injection molding machine melt pressure adaptive return interface device according to claim 4, characterized in that, The end of the stop block (3107) near the stop block (3106) is an inclined surface structure, and a groove (3116) is provided on the inclined surface structure. The inclined surface of the stop block (3107) and the stop block (3106) together form a dynamic redundant cavity, and the dynamic redundant cavity is connected to the reinjection channel (3101) through the groove (3116).

6. The injection molding machine melt pressure adaptive return interface device according to claim 5, characterized in that, When the melt flow rate exceeds the conveying capacity of the feed screw (3105), the excess melt enters the dynamic redundant cavity through the groove (3116), pushing the stop block (3107) to compress the first spring (3109) and slide towards the emergency channel (3103). The volume of the dynamic redundant cavity expands as the sliding stroke increases.

7. The injection molding machine melt pressure adaptive return interface device according to claim 4, characterized in that, The end of the reinjection cylinder (31) is detachably connected to a cover block (36). The inner side wall of the connecting pipe (32) is provided with a sliding cavity (3601) extending into the inside of the cover block (36). A trigger head (3602) is slidably and sealed inside the sliding cavity (3601). A push rod (3603) is fixed to the side wall of the trigger head (3602). The push rod (3603) moves through the side wall of the cover block (36) and is fixed with a limit frame (3604). A third spring (3605) is sleeved on the outer wall of the push rod (3603). The cover block (36) is further provided with an interconnected upper sliding cavity (3606) and a vertical sliding cavity (3607). A movable rod (3608) is fixed to the side wall of the stop block (3106). The movable rod (3608) is slidably disposed in the upper sliding cavity (3606). A slot (3609) is provided on the side wall of the movable rod (3608). A locking plate (3610) is slidably disposed in the vertical sliding cavity (3607). The top of the locking plate (3610) can be engaged with the slot (3609) to lock the stop block (3106). The position of the plate (3610) is such that the side wall of the plate (3610) is provided with a toothed opening (3611), the top of the limiting frame (3604) is provided with a toothed opening (3612), and the lower side wall of the vertical sliding cavity (3607) is rotatably provided with a toothed wheel (3613). The toothed wheel (3613) is engaged with the toothed opening (3611) and the toothed opening (3612) respectively. When there is instantaneous overpressure, the trigger head (3602) retracts, which can drive the plate (3610) to move down and release the lock on the movable rod (3608).

8. The injection molding machine melt pressure adaptive return interface device according to claim 7, characterized in that, The stop block (3107) has an emergency chamber (3119) inside that communicates with the slide tube (3108). The inlet of the emergency chamber (3119) is located at the bottom of the stop block (3107). After the stop block (3106) is unlocked, the first spring (3109) pushes the stop block (3107) and the stop block (3106) to slide synchronously, so that the inlet of the emergency chamber (3119) connects to the outlet of the pipe (32). The high-pressure melt flows into the return pipe (33) through the emergency chamber (3119), the emergency channel (3103), and the inclined drain (3104).

9. The injection molding machine melt pressure adaptive return interface device according to claim 8, characterized in that, The elastic coefficient of the third spring (3605) is greater than that of the first spring (3109) and the second spring (3113).

10. The injection molding machine melt pressure adaptive return interface device according to claim 7, characterized in that, A sensor (3615) is installed on the side wall of the cover block (36), and a positioning block (3616) is fixed on the side wall of the movable rod (3608). The positioning block (3616) is arranged on the outside of the cover block (36), and the sensor (3615) is used to monitor the displacement of the positioning block (3616) to trigger an overpressure alarm.

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