A servo supported core back injection mold

Abstract

The application relates to the technical field of injection molds, and discloses a follow-up supporting core-pulling injection mold, which comprises a lower mold, a movable block, a core-pulling rod, a core-stabilizing locking plate, a rotating ring, a moving rod, a fixed pipe, a piston plate and a driving structure, a connecting circular plate is arranged on the core-pulling rod, an axial avoiding groove and a circumferential locking groove are arranged on the connecting circular plate, clamping blocks are arranged on the inner wall of the rotating ring, when the driving structure drives the rotating ring to rotate, the clamping blocks are turned into the circumferential locking groove to limit the connecting circular plate, the core-pulling rod is inserted into an injection area, and the core-stabilizing locking plate on the side close to the injection area is obtained; the moving rods on the two sides of the movable block extend into the fixed pipe and are connected with the piston plate, a baffle is arranged in an air inlet channel, the driving structure synchronously drives the baffle to shield or open the air inlet channel, the fixed pipe forms gas damping in an injection stage to limit the movement of the movable block, and the piston plate is moved to extract the gas released from the injection area in a mold opening and core-pulling stage. The application can improve the injection stability of the slender core-pulling rod and realize near-source collection of harmful gas in the mold opening.

Description

Technical Field

[0001] This application relates to the field of injection mold technology, specifically to a follower-support core-removing injection mold. Background Technology

[0002] When molding plastic parts with side holes, deep holes, or elongated holes, injection molds usually need to set core-pulling mechanisms on both sides of the lower mold. The core-pulling mechanism generally uses the inclined guide post on the upper mold to cooperate with the inclined hole on the movable block, so that the movable block drives the core-pulling rod to insert or withdraw from the injection area during the mold opening and closing process, thereby completing the molding of the product cavity and the removal of the core.

[0003] In existing core-pulling structures, the core-pulling rod is usually fixed at one end to the movable block, and the other end extends into the injection molding area. When the core-pulling rod is long and the diameter is small, it is easily affected by the pressure of the molten plastic, mold vibration and slight movement of the movable block during the injection molding and holding pressure stage, which can cause it to wobble. This can lead to problems such as deviation of the product cavity position, reduced hole wall molding quality and increased wear of the core-pulling rod.

[0004] To improve the stability of the core-pulling rod, existing methods usually improve the guiding accuracy of the movable block or increase the rigidity of the core-pulling rod root. However, this method mainly relies on the positioning of the movable block itself, making it difficult to further limit the core-pulling rod on the side of the core-pulling rod close to the injection area. When the movable block is subjected to injection reaction force or equipment vibration, the core-pulling rod may still experience slight axial movement with the movable block, affecting the positional stability of the core-pulling rod during the injection stage.

[0005] In addition, when the mold is opened and the core is removed after injection molding, hot air, odor and volatile harmful gases will be released in the injection area and near the product cavity. Existing molds mostly rely on external exhaust hoods or centralized ventilation in the workshop for collection. The extraction position is far away from the gas release source, which can easily lead to collection delay and gas overflow. If an independent extraction component is added to the mold, it will increase the complexity of the mold structure and the cost of drive control. Summary of the Invention

[0006] The purpose of this application is to provide a follow-up support core-removing injection mold to solve the problems in the prior art where slender core-pulling rods are prone to wobbling during the injection stage due to slight movement of the moving block, and the harmful gases released from the injection area during mold opening and core removal are difficult to collect in a timely manner near the source.

[0007] To achieve the above objectives, this application provides the following technical solution: a follow-up support core-removing injection mold, comprising a lower mold and a movable block movably disposed on the lower mold. A core-pulling rod is disposed on the side of the movable block near the injection area of ​​the lower mold. A core-stabilizing locking plate is fixedly disposed on the lower mold between the movable block and the injection area. The core-stabilizing locking plate has a through hole for the core-pulling rod to pass through. A connecting circular plate that can enter the through hole is fixedly disposed on the core-pulling rod. An axial clearance groove and a circumferential locking groove are disposed on the connecting circular plate. A rotating ring is rotatably disposed inside the core-stabilizing locking plate. A locking block for entering the axial clearance groove and rotating into the circumferential locking groove is disposed on the inner wall of the rotating ring. Moving rods are disposed on both sides of the movable block. A core-stabilizing locking plate is provided with... A fixed tube is provided for the insertion of the moving rod. The end of the moving rod is connected to a piston plate located inside the fixed tube. The fixed tube is connected to an air inlet channel and an air outlet. A baffle is movably installed in the air inlet channel. A drive structure is provided on the core-locking plate to synchronously drive the rotating ring and the baffle to move. After the core-pulling rod is inserted into the injection area, it is limited by the locking block and the air inlet channel is blocked by the baffle. When the core-pulling rod is withdrawn from the injection area, the limiting of the connecting plate is released and the air inlet channel is opened for air extraction. This structure can limit the side of the core-pulling rod close to the injection area during the injection stage and use the gas in the fixed tube to form a damping constraint on the moving block. At the same time, during the mold opening and core withdrawal stage, the gas extraction of the injection area is completed by the retraction action of the moving block.

[0008] Furthermore, the axial clearance groove extends through the connecting circular plate along its axial direction to the side of the connecting circular plate near the core-stabilizing locking plate, and the circumferential locking groove is opened along the circumferential direction of the connecting circular plate at its edge. The axial clearance groove and the circumferential locking groove are connected, and the locking block can enter the entrance position of the circumferential locking groove along the axial clearance groove. This structure allows the connecting circular plate to first enter the through hole along its axial direction, and then complete the axial limiting of the connecting circular plate by rotation locking.

[0009] Furthermore, the rotating ring is coaxially arranged on the outside of the through hole, and the outer wall of the rotating ring is provided with toothed blocks. The locking block is fixedly arranged on the inner wall of the rotating ring. When the rotating ring rotates, the locking block can move from the corresponding position of the axial clearance groove to the circumferential locking groove. This structure can drive the locking block to complete locking and unlocking through the circumferential movement of the rotating ring, thereby improving the synchronization of the limiting action at the root of the core-pulling rod.

[0010] Furthermore, the drive structure includes a motor fixedly mounted on the core locking plate. The output end of the motor is fixedly equipped with a first gear and a second gear. The first gear meshes with the tooth block on the outer wall of the rotating ring, and the second gear is connected to the baffle. This structure can use the same drive source to simultaneously control the rotating ring and the baffle, so that the core pulling rod limiting action and the intake channel throttling blocking action occur synchronously.

[0011] Furthermore, the top of the core locking plate has two air intake channels, each with a baffle movably installed. Each baffle has a rack, which is located on the upper and lower sides of the second gear and meshes with it. When the second gear rotates, it drives the two baffles to move in opposite directions to the throttling and blocking positions of the corresponding air intake channels. When the second gear rotates in the opposite direction, it drives the two baffles to move away from the throttling and blocking positions of the corresponding air intake channels. This structure can synchronously drive the two baffles to switch positions through a single gear, keeping the throttling and blocking states of the air intake channels on both sides consistent.

[0012] Furthermore, there are two fixed tubes, and two moving rods are located on both sides of the movable block. The two moving rods extend into the two fixed tubes, and a piston plate is fixedly connected to the end of each moving rod. This structure can form a symmetrical gas damping and air extraction structure on both sides of the movable block, reducing the deviation of the movable block caused by unilateral force.

[0013] Furthermore, each fixed tube has an air inlet at its top, and each air inlet is connected to an air intake channel. An air intake check valve is installed at the air inlet. The air intake check valve only allows gas to enter the fixed tube through the air intake channel. This structure enables gas near the injection area to enter the fixed tube in one direction through the air intake channel when the movable block retracts, preventing gas in the fixed tube from being discharged in the opposite direction from the air intake channel.

[0014] Furthermore, each fixed tube has an air outlet at its bottom, and a one-way valve is installed at the air outlet. The one-way valve only allows gas to be discharged out of the fixed tube. This structure can discharge the gas in the fixed tube through the air outlet in one direction when the movable block moves to the injection area, which is convenient for exporting the gas extracted in the previous mold opening cycle.

[0015] Furthermore, the movable block is provided with an oblique hole. The follow-up support core-pulling injection mold also includes an upper mold, on which an oblique guide post is fixedly provided. When the oblique guide post is inserted into the oblique hole, it can drive the movable block to move towards the injection area. When the oblique guide post is withdrawn from the oblique hole, it can drive the movable block to move away from the injection area. This structure can use conventional mold opening and closing actions to drive the movable block to reciprocate, so that the core-pulling rod can be inserted into and withdrawn from the injection area.

[0016] Furthermore, a reset rod is fixedly installed on the side of the movable block away from the core-pulling rod, and a reset fixing plate is fixedly installed on the lower mold. The reset rod is movably inserted through the reset fixing plate, and a reset spring is installed between the reset rod and the reset fixing plate. The reset spring is used to drive the movable block away from the injection area to reset. This structure can assist the movable block in resetting during the mold opening process and improve the reliability of the core-pulling rod exiting the injection area.

[0017] The technical solution provided in this application has the following advantages compared with the prior art: This application sets a core-stabilizing locking plate between the movable block and the injection area, and makes the connecting circular plate, rotating ring, locking block, axial clearance groove and circumferential locking groove cooperate to limit the side of the core-pulling rod close to the injection area after the core-pulling rod is inserted into the injection area. At the same time, the baffle blocks the main cross section of the air intake channel and restricts the rapid replenishment of external gas into the fixed pipe, so that the gas in the fixed pipe forms gas damping on the piston plate. This reduces the instantaneous movement of the movable block under the action of injection pressure and mold vibration, and reduces the risk of slender core-pulling rod wobble, cavity position deviation and reduced hole wall forming quality.

[0018] This application uses a drive structure to synchronously control the limiting state of the core-pulling rod and the opening and closing state of the air intake channel. When the core-pulling rod unlocks and the core is removed, the air intake channel opens synchronously. The retraction of the movable block drives the moving rod and piston plate to move, increasing the volume of the fixed tube and extracting the gas released from the mold opening near the injection area. The gas is then discharged through the air outlet during the next mold closing and core insertion. This achieves near-source collection of harmful gases without adding a separate air extraction drive source, reducing gas escape and lowering the complexity of the mold structure. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of the mold in the embodiments of this application; Figure 2 This is a schematic diagram of the lower mold structure in an embodiment of this application; Figure 3 This is a schematic diagram of the upper mold structure in an embodiment of this application; Figure 4 This is a schematic diagram of the core-pulling rod in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of the active block in an embodiment of this application; Figure 6 for Figure 5 Enlarged view of the structure of section A; Figure 7 This is a schematic diagram of the rotating ring and rack in the embodiments of this application; Figure 8 This is a schematic diagram of the rotating ring structure in an embodiment of this application; Figure 9 This is a cross-sectional view of the fixing tube in an embodiment of this application.

[0021] Explanation of icon numbers: 1. Lower mold; 11. Injection area; 12. Reset fixing plate; 13. Reset spring; 2. Movable block; 21. Angled hole; 22. Reset rod; 3. Core pulling rod; 31. Connecting round plate; 311. Axial clearance groove; 312. Circumferential locking groove; 4. Core stabilizing locking plate; 41. Through hole; 42. Fixing tube; 421. Air inlet; 422. Air outlet; 43. Air inlet channel; 44. Baffle; 441. Rack; 5. Rotating ring; 51. Locking block; 52. Tooth block; 6. Moving rod; 61. Piston plate; 7. Drive structure; 71. Motor; 72. First gear; 73. Second gear; 10. Upper mold; 101. Angled guide post. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] The present application will be further described below with reference to embodiments.

[0024] Example 1: Reference Figure 1 - Figure 7 This first embodiment of the present application provides a follow-up support core-removing injection mold, including a lower mold 1, a movable block 2, a core-pulling rod 3, a core-stabilizing locking plate 4, a rotating ring 5, a moving rod 6, and a driving structure 7. An injection area 11 is formed in the middle of the lower mold 1. The injection area 11 is used to cooperate with the upper mold 10 to form a plastic part molding cavity. The specific cavity structure of the injection area 11 can be conventionally designed according to the shape of the plastic part to be molded. The focus of this embodiment is on the core-stabilizing limit and air extraction structure of the core-pulling rods 3 on both sides of the injection area 11. Therefore, the internal gate, cooling water channel and ejection structure of the injection area 11 will not be described in detail.

[0025] The movable block 2 is movably mounted on the lower mold 1. The movable block 2 can reciprocate along the direction close to the injection area 11 and away from the injection area 11. A core-pulling rod 3 is fixedly mounted on the side of the movable block 2 close to the injection area 11. The core-pulling rod 3 is used to extend into the injection area 11 when the movable block 2 is close to the injection area 11 and form the side hole, deep hole, and elongated hole structure of the plastic part. The core-pulling rod 3 is a cylindrical slender rod with a diameter of 3mm-12mm, preferably 6mm. The effective length of the core-pulling rod 3 extending into the injection area 11 is 60mm-200mm, preferably 120mm, making this structure suitable for core-pulling molding conditions with a large length-to-diameter ratio.

[0026] A core-stabilizing locking plate 4 is fixedly installed on the lower mold 1 between the movable block 2 and the injection area 11. The core-stabilizing locking plate 4 is fixed to the lower mold 1 by screws and positioning pins. The plate surface of the core-stabilizing locking plate 4 is perpendicular to the moving direction of the core-pulling rod 3. A through hole 41 is opened on the core-stabilizing locking plate 4. The through hole 41 is coaxially arranged with the core-pulling rod 3. The through hole 41 is used for the core-pulling rod 3 to pass through and for the connecting round plate 31 to enter. The diameter of the through hole 41 is larger than the outer diameter of the connecting round plate 31. A 0.2mm-0.8mm radial clearance is left between the inner wall of the through hole 41 and the outer wall of the connecting round plate 31. Preferably, the 0.4mm radial clearance is left. Correspondingly, when the preferred outer diameter of the connecting round plate 31 is 22mm, the preferred diameter of the through hole 41 is 22.8mm, so that the connecting round plate 31 can smoothly enter the through hole 41 and avoid the outer wall of the connecting round plate 31 from scratching the inner wall of the through hole 41.

[0027] A connecting circular plate 31 is fixedly installed at one end of the core-pulling rod 3 near the movable block 2. The connecting circular plate 31 is coaxially arranged with the core-pulling rod 3. The connecting circular plate 31 can be connected to the core-pulling rod 3 by one of the following fixing methods: threaded connection, interference fit, and welding. In this embodiment, the connecting circular plate 31 and the core-pulling rod 3 are connected by thread and prevented from loosening by a lock screw. The outer diameter of the connecting circular plate 31 matches the diameter of the through hole 41. The outer diameter of the connecting circular plate 31 is 12mm-35mm, preferably 22mm. The thickness of the connecting circular plate 31 is 4mm-12mm, preferably 8mm. After the connecting circular plate 31 enters the through hole 41, it can form a positioning support for the core-pulling rod 3 at a position near the molding cavity.

[0028] An axial clearance groove 311 and a circumferential locking groove 312 are formed on the connecting circular plate 31. The axial clearance groove 311 extends through the connecting circular plate 31 along its axial direction and passes near the stabilizing locking plate 4 on one side of the connecting circular plate 31. The circumferential locking groove 312 is formed along the circumference of the connecting circular plate 31 at its edge. The axial clearance groove 311 and the circumferential locking groove 312 are connected. The width of the axial clearance groove 311 is 0.1 mm to 0.4 mm larger than the width of the locking block 51. mm, preferably larger than 0.2 mm, the groove depth of the circumferential locking groove 312 is 1 mm to 4 mm, preferably 2.5 mm, the central angle of the circumferential locking groove 312 extending circumferentially along the connecting circular plate 31 is 20° to 70°, preferably 45°, so that the locking block 51 can first enter the entrance position of the circumferential locking groove 312 along the axial clearance groove 311, and then enter the circumferential locking groove 312 to form axial limitation as the rotating ring 5 rotates.

[0029] A rotating ring 5 is rotatably installed inside the core-stabilizing locking plate 4. The rotating ring 5 is coaxially installed outside the through hole 41. An annular mounting cavity is opened inside the core-stabilizing locking plate 4. The rotating ring 5 is installed in the annular mounting cavity and can rotate around the axis of the through hole 41. A rotational fit clearance of 0.03mm-0.15mm is set between the rotating ring 5 and the annular mounting cavity, preferably 0.08mm. A locking block 51 is fixedly installed on the inner wall of the rotating ring 5, and a toothed block 52 is installed on the outer wall of the rotating ring 5. There are two locking blocks 51, which are symmetrically arranged around the circumference of the rotating ring 5. Two axial clearance grooves 311 and two circumferential locking grooves 312 are correspondingly opened on the connecting circular plate 31 to balance the force on the connecting circular plate 31 and reduce the unilateral sway of the core-pulling rod 3.

[0030] The drive structure 7 includes a motor 71 fixedly mounted on the core locking plate 4. A first gear 72 and a second gear 73 are fixedly mounted on the output end of the motor 71. The first gear 72 and the second gear 73 are arranged axially along the output shaft of the motor 71. The first gear 72 meshes with the tooth block 52 on the outer wall of the rotating ring 5. The motor 71 is a stepper motor with a rated output torque of 0.2 N·m-1.5 N·m, preferably 0.6 N·m. The first gear 72 and the tooth block 52 form a reduction transmission. In this embodiment, the ratio of the rotation angle of the output shaft of the motor 71 to the rotation angle of the rotating ring 5 is preferably 2:1, so that the motor 71 can drive the rotating ring 5 to rotate stably and control the locking block 51 to switch between the corresponding position of the axial clearance groove 311 and the locking position of the circumferential locking groove 312.

[0031] Movable rods 6 are provided on both sides of the movable block 2. Fixed tubes 42 are provided on the core locking plate 4 for the movable rods 6 to extend into. There are two fixed tubes 42. The two movable rods 6 are located on both sides of the movable block 2 and extend into the two fixed tubes 42 respectively. A piston plate 61 is fixedly connected to the end of each movable rod 6. The axis of the fixed tube 42 is parallel to the moving direction of the movable block 2. The inner diameter of the fixed tube 42 is 8mm-25mm, preferably 16mm. The effective cavity length of the fixed tube 42 is 30mm-120mm, preferably 70mm. The piston plate 61 slides and seals with the inner wall of the fixed tube 42, so that when the movable block 2 moves, the piston plate 61 can be driven to reciprocate within the fixed tube 42 by the movable rods 6.

[0032] An air inlet 421 is provided at the top of the fixed pipe 42. Each air inlet 421 is connected to an air intake channel 43. An air intake one-way valve is provided at the air inlet 421, which only allows gas to enter the fixed pipe 42 through the air intake channel 43. An air outlet 422 is provided at the bottom of the fixed pipe 42. An air outlet one-way valve is provided at the air outlet 422, which only allows gas to be discharged out of the fixed pipe 42. The orifice diameter of the air inlet 421 is 2mm-8mm, preferably. The diameter of the air outlet 422 is 4mm, and the diameter of the air outlet 422 is 2mm-8mm, preferably 4mm. The opening pressure difference between the air inlet check valve and the air outlet check valve is 0.5kPa-3kPa, preferably 1.2kPa. This allows the fixed pipe 42 to draw in gas near the injection molding area 11 through the air inlet channel 43 when the movable block 2 is far away from the injection molding area 11, and to discharge the gas in the fixed pipe 42 through the air outlet 422 when the movable block 2 is close to the injection molding area 11.

[0033] Two air intake channels 43 are provided on the top of the core-locking plate 4. The two air intake channels 43 are respectively connected to the air inlets 421 on the top of the two fixed tubes 42. The end of the air intake channel 43 near the injection molding area 11 forms an air intake. The air intake faces both sides of the injection molding area 11 and is close to the position where the core-pulling rod 3 enters the injection molding area 11. The distance between the air intake and the outer periphery of the core-pulling rod 3 is 3mm-20mm, preferably 8mm. The cross-sectional area of ​​the air intake channel 43 is 20mm². 2 -150mm 2 The preferred cross-sectional area is 80mm². 2 This allows the hot air, odors, and volatile gases released from the injection area 11 and near the product cavity during mold opening and core removal to be drawn into the air intake channel 43.

[0034] A baffle 44 is movably installed within the intake passage 43. One baffle 44 is installed in each of the two intake passages 43. The baffle 44 slides perpendicular to the extending direction of the intake passage 43. The thickness of the baffle 44 is 1mm-5mm, preferably 3mm. The clearance between the baffle 44 and the inner wall of the intake passage 43 is 0.02mm-0.15mm, preferably 0.06mm. When the baffle 44 moves to the throttling / blocking position, it covers the main cross-section of the corresponding intake passage 43. The periphery of the baffle 44 is flush with the intake passage. The fit gap between the inner walls of 43 forms a narrow throttling passage to restrict the rapid inflow of external gas into the fixed pipe 42. A rack 441 is provided on the baffle 44. The two racks 441 are located on the upper and lower sides of the second gear 73 respectively and are meshed with the second gear 73. When the second gear 73 rotates in the forward direction, it drives the two baffles 44 to move in opposite directions to the throttling and blocking position of the corresponding air intake channel 43. When the second gear 73 rotates in the reverse direction, it drives the two baffles 44 to move away from the throttling and blocking position of the corresponding air intake channel 43.

[0035] The injection locking process in this embodiment is as follows: When the upper mold 10 closes downwards, the inclined guide post 101 inserts into the inclined hole 21 on the movable block 2 and drives the movable block 2 to move towards the injection area 11. The movable block 2 drives the core-pulling rod 3 to insert into the injection area 11. At the same time, the movable block 2 drives the moving rod 6 and the piston plate 61 to move into the fixed tube 42. The gas temporarily stored in the fixed tube 42 in the previous cycle is compressed by the piston plate 61 and discharged through the air outlet 422 and the air outlet check valve. After the core-pulling rod 3 is inserted into place, the connecting round plate 31 enters the through hole 41 of the core-stabilizing locking plate 4, and the locking block 51 enters the entrance position of the circumferential locking groove 312 along the axial clearance groove 311.

[0036] After the core-pulling rod 3 is inserted into place, the motor 71 rotates in the forward direction. The first gear 72 drives the rotating ring 5 to rotate through the tooth block 52. The rotating ring 5 drives the locking block 51 to rotate from the corresponding position of the axial clearance groove 311 into the circumferential locking groove 312. After the locking block 51 cooperates with the circumferential locking groove 312, it restricts the connecting round plate 31 from exiting in the direction away from the injection molding area 11, so that the side of the core-pulling rod 3 close to the injection molding area 11 is restricted again. At the same time, the second gear 73 drives the two baffles 44 to move in the opposite direction and block the two air intake channels 43, so that the air intake path at the top of the fixed tube 42 is closed.

[0037] During the injection molding and pressure holding process, the pressure of the molten plastic acts on one end of the core-pulling rod 3 that extends into the injection area 11. The core-pulling rod 3 is subjected to a reverse pushing tendency in the direction away from the injection area 11. The connecting circular plate 31 is axially limited by the locking block 51 and the circumferential locking groove 312 and is not easy to move backward with the core-pulling rod 3. At the same time, if the movable block 2 causes a slight lateral movement in the direction away from the injection area 11 due to vibration, the moving rod 6 will drive the piston plate 61 to increase the volume of the fixed tube 42. Since the baffle 44 covers the main cross section of the air intake channel 43, the fitting gap around the baffle 44 forms a narrow throttling passage. The speed at which the external gas enters the fixed tube 42 through the air intake channel 43 is less than the speed at which the volume of the fixed tube 42 increases due to the movement of the piston plate 61. Moreover, the one-way valve for the exhaust gas only allows the gas to be discharged outward from the fixed tube 42. Therefore, a momentary negative pressure damping can be formed in the fixed tube 42 and the momentary lateral movement of the movable block 2 can be suppressed.

[0038] Through the above structure, the core-pulling rod 3 is simultaneously subject to mechanical limiting formed by the connecting circular plate 31 and the clamping block 51, as well as gas damping constraint formed by the moving rod 6, piston plate 61 and fixed tube 42 during the injection molding stage. The mechanical limiting mainly restricts the axial withdrawal of the core-pulling rod 3 on the side close to the injection molding area 11, while the gas damping mainly suppresses the instantaneous micro-movement of the moving block 2 under the action of mold vibration and injection back thrust. Together, they reduce the risk of slender core-pulling rod 3 swaying, hole position displacement and hole wall forming quality degradation during the injection molding stage.

[0039] Example 2: Reference Figure 7 - Figure 9This is the second embodiment of the present application, which provides a mold opening and venting process for a follow-up support core-removing injection mold. Based on the structure of embodiment 1, this embodiment further illustrates the cooperative working mode of the drive structure 7, rotating ring 5, baffle 44, moving rod 6, fixed tube 42 and piston plate 61 in the mold opening and core-removing stage.

[0040] Before the injection molding is completed and the mold is opened, the motor 71 rotates in reverse. The first gear 72 drives the rotating ring 5 to rotate in reverse through the tooth block 52. The rotating ring 5 drives the locking block 51 to exit from the circumferential locking groove 312 and return to the position corresponding to the axial clearance groove 311, so that the connecting circular plate 31 can exit axially along the through hole 41. At the same time, the second gear 73 drives the two racks 441 to move in reverse. The two racks 441 drive the two baffles 44 to move respectively, so that the two air intake channels 43 switch from the throttling and blocking state to the open state.

[0041] When the upper mold 10 opens upwards, the inclined guide post 101 exits the inclined hole 21 on the movable block 2 and drives the movable block 2 away from the injection area 11. The movable block 2 drives the core-pulling rod 3 to exit the injection area 11 and complete the core removal. The connecting round plate 31 exits along the through hole 41 with the core-pulling rod 3. The locking block 51 will not block the exit of the connecting round plate 31 because it is in the corresponding position of the axial clearance groove 311. At the same time, the movable block 2 drives the two moving rods 6 to move away from the core-stabilizing locking plate 4. The moving rods 6 drive the piston plate 61 to move in the opposite direction in the fixed tube 42, so that the internal volume of the fixed tube 42 increases and a negative pressure is formed.

[0042] When a negative pressure is formed in the fixed tube 42, the inlet check valve opens and the outlet check valve closes. The hot air, odor and volatile gases released from both sides of the injection area 11 and near the withdrawal position of the core-pulling rod 3 enter the inlet 421 through the inlet channel 43, and then enter the fixed tube 42 for temporary storage through the inlet 421. The suction inlet of the inlet channel 43 is located near the withdrawal position of the core-pulling rod 3 near the injection area 11, so the gas can be sucked in from near the source when it is just released, reducing its diffusion to the outside of the mold and the workshop space.

[0043] In this embodiment, the theoretical single-cycle pumping volume of a single fixed tube 42 is calculated according to V=πD. 2 The calculation is L / 4, where D is the inner diameter of the fixed tube 42 and L is the effective stroke of the piston plate 61. When the inner diameter of the fixed tube 42 is preferably 16 mm and the effective stroke of the piston plate 61 is preferably 45 mm, the theoretical single-time pumping volume of a single fixed tube 42 is about 9 mL, and the total theoretical single-time pumping volume of the two fixed tubes 42 is about 18 mL, which is used to perform near-source pumping of the gas concentratedly released near the injection area 11 in the initial stage of mold opening.

[0044] During the next mold closing, the upper mold 10 drives the inclined guide post 101 to re-enter the inclined hole 21. The movable block 2 moves towards the injection area 11 under the action of the inclined guide post 101. The core-pulling rod 3 re-inserts into the injection area 11. The moving rod 6 drives the piston plate 61 to compress into the fixed tube 42. The gas sucked in during the previous mold opening stage is compressed and causes the exhaust one-way valve to open, and it is discharged through the exhaust port 422. The exhaust port 422 is connected to the exhaust gas treatment device outside the mold through a pipeline. The exhaust gas treatment device adopts an activated carbon adsorption box and a centralized exhaust pipe connection structure in the workshop to centrally treat the discharged harmful gases.

[0045] The directional settings of the inlet and outlet check valves ensure that when the movable block 2 is far from the injection area 11, the fixed pipe 42 only takes in air through the inlet channel 43, and when the movable block 2 is close to the injection area 11, it only exhausts air through the outlet 422. The baffle 44 blocks the main cross section of the inlet channel 43 and restricts rapid air replenishment during the injection locking stage, preventing the fixed pipe 42 from rapidly replenishing air through the inlet channel 43 during the injection holding pressure stage, thus weakening the gas damping effect. At the same time, during the core removal and air extraction stage, the inlet channel 43 is opened, allowing the fixed pipe 42 to extract gas near the injection area 11 in a timely manner.

[0046] In this embodiment, the action sequence of the drive structure 7 is coordinated with the mold opening and closing action. After the mold core is inserted into place, the motor 71 rotates in the forward direction to lock the locking block 51 and the baffle 44 throttles and blocks. Before the mold core is removed, the motor 71 rotates in the reverse direction to unlock the locking block 51 and open the baffle 44. The rotation angle of the motor 71 is determined according to the angular transmission ratio between the output shaft of the motor 71 and the rotating ring 5 and the circumferential extension angle of the circumferential locking groove 312. In this embodiment, the ratio of the rotation angle of the output shaft of the motor 71 to the rotation angle of the rotating ring 5 is preferably 2:1, and the circumferential extension angle of the circumferential locking groove 312 is preferably 45°. Therefore, the motor 71 preferably rotates 90° each time, which corresponds to driving the rotating ring 5 to rotate 45°, so that the locking block 51 can reliably enter or exit the circumferential locking groove 312. At the same time, the second gear 73 drives the baffle 44 to switch between the throttle blocking position and the open position.

[0047] A reset rod 22 is fixedly installed on the side of the movable block 2 away from the core-pulling rod 3. A reset fixing plate 12 is fixedly installed on the lower mold 1. The reset rod 22 is movably inserted through the reset fixing plate 12. A reset spring 13 is installed between the reset rod 22 and the reset fixing plate 12. The spring force of the reset spring 13 is used to assist the movable block 2 in resetting away from the injection area 11. The spring force of the reset spring 13 is 20N-120N, preferably 60N, so that the movable block 2 can stably complete the core-pulling reset when the inclined guide post 101 exits the inclined hole 21, and ensure that the moving rod 6 and the piston plate 61 complete the air extraction stroke.

[0048] As can be seen from Embodiments 1 and 2, the follow-up support core-removing injection mold provided in this application forms a limiting structure for the core-pulling rod 3 near the injection area 11 by means of a core-stabilizing locking plate 4, a connecting circular plate 31, a rotating ring 5, a locking block 51, an axial clearance groove 311, and a circumferential locking groove 312. A gas cavity structure with gas damping and mold opening evacuation functions is formed by means of a moving rod 6, a fixed tube 42, a piston plate 61, an air inlet channel 43, an air outlet 422, and a baffle 44. The rotating ring 5 and the baffle 44 are synchronously controlled by the driving structure 7, so that the mechanical limiting of the core-pulling rod 3 and the establishment of gas damping of the fixed tube 42 can be completed simultaneously during the injection locking stage. During the mold opening and core removal stage, the limiting of the core-pulling rod 3 can be released simultaneously and the air inlet channel 43 can be opened for near-source evacuation.

[0049] The significant advantages of this application are: The same structure set between the movable block 2 and the injection area 11 can simultaneously solve the problems of insufficient stability of the slender core-pulling rod 3 during the injection stage and the leakage of harmful gases during the mold opening and core removal stage. The cooperation between the locking block 51 and the circumferential locking groove 312 can restrict the retraction of the core-pulling rod 3 near the injection area 11. After the baffle 44 blocks the main cross section of the air intake channel 43, the fixed tube 42 forms negative pressure damping on the piston plate 61 to limit the slight movement of the movable block 2. After the baffle 44 is opened, the fixed tube 42 can also be used as a temporary air extraction chamber when the movable block 2 retracts, thereby reducing the need for independent locking mechanisms and independent air extraction drive mechanisms.

[0050] The working principle of this application is as follows: When the mold is closed and the core is inserted, the movable block 2 drives the core-pulling rod 3 to insert into the injection area 11 and the connecting circular plate 31 enters the through hole 41. The motor 71 drives the first gear 72 and the second gear 73 to rotate synchronously. The first gear 72 drives the rotating ring 5 through the tooth block 52 to make the locking block 51 rotate into the circumferential locking groove 312. The second gear 73 drives the baffle 44 through the rack 441 to block the main cross section of the air intake channel 43. During the injection process, the core-pulling rod 3 is mechanically limited by the locking block 51 and the circumferential locking groove 312. The movable block 2 is damped by the gas in the fixed tube 42 on the piston plate 61. Before the mold is opened, the motor 71 rotates in the opposite direction to unlock the locking block 51 and open the air intake channel 43 with the baffle 44. When the mold is opened and the core is removed, the movable block 2 retracts and drives the piston plate 61 to increase the volume of the fixed tube 42, thereby drawing gas near the injection area 11 through the air intake channel 43. When the mold is closed again, the piston plate 61 compresses the gas in the fixed tube 42 and discharges it through the air outlet 422.

[0051] In summary, this application integrates the near-end locking of the core-pulling rod 3, the gas damping of the movable block 2, and the near-source gas extraction during mold opening into the core-stabilizing locking plate 4 and its supporting structure. This enables the core-pulling rod 3 to have better positional stability during the injection molding stage and allows the gas released during the mold opening and core removal stage to be extracted and discharged in a timely manner, thereby improving the molding stability of slender hole injection molded parts and the safety of the mold working environment.

[0052] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of this application.

Claims

1. A follow-up support core-pulling injection mold, comprising a lower mold (1) and a movable block (2) movably disposed on the lower mold (1), wherein a core-pulling rod (3) is provided on the side of the movable block (2) near the injection area (11) of the lower mold (1), characterized in that: A core-stabilizing locking plate (4) is fixedly installed on the lower mold (1) between the movable block (2) and the injection area (11). The core-stabilizing locking plate (4) has a through hole (41) for the core-pulling rod (3) to pass through. A connecting circular plate (31) that can enter the through hole (41) is fixedly installed on the core-pulling rod (3). An axial clearance groove (311) and a circumferential locking groove (312) are provided on the connecting circular plate (31). A rotating ring (5) is rotatably installed inside the core-stabilizing locking plate (4). The inner wall of the rotating ring (5) is provided with a groove for entering the axial clearance groove (311) and rotating into the circumferential groove. The locking groove (312) has a locking block (51), and the movable block (2) has moving rods (6) on both sides. The core-stabilizing locking plate (4) has a fixed tube (42) for the moving rods (6) to extend into. The end of the moving rod (6) is connected to a piston plate (61) located inside the fixed tube (42). The fixed tube (42) is connected to an air inlet channel (43) and an air outlet (422). A baffle (44) is movably installed inside the air inlet channel (43). The core-stabilizing locking plate (4) has a drive structure (7) for synchronously driving the rotating ring (5) and the baffle (44) to move. After the core-pulling rod (3) is inserted into the injection area (11), it is limited by the locking block (51) to connect the circular plate (31), and the main cross section of the air intake channel (43) is blocked by the baffle (44) to restrict the air supply. When the core-pulling rod (3) exits the injection area (11), the limiting of the connecting circular plate (31) is released, and the baffle (44) is moved away from the blocking position of the air intake channel (43) to perform air extraction. The axial clearance groove (311) passes through the connecting circular plate (31) along the axial direction and is close to the core-stabilizing locking plate (4) on the side of the connecting circular plate (31). The circumferential locking groove (312) is along the connecting circular plate (31) 1) is circumferentially opened on the edge of the connecting circular plate (31). The axial clearance groove (311) is connected to the circumferential locking groove (312). The locking block (51) can enter the entrance position of the circumferential locking groove (312) along the axial clearance groove (311). The rotating ring (5) is coaxially arranged on the outside of the through hole (41). The outer wall of the rotating ring (5) is provided with a toothed block (52). The locking block (51) is fixedly arranged on the inner wall of the rotating ring (5). When the locking block (51) rotates with the rotating ring (5), it can move from the corresponding position of the axial clearance groove (311) to the circumferential locking groove (312).

2. The follow-up support core-removing injection mold according to claim 1, characterized in that: The drive structure (7) includes a motor (71) fixedly mounted on the core locking plate (4). The output end of the motor (71) is fixedly provided with a first gear (72) and a second gear (73). The first gear (72) meshes with the tooth block (52) on the outer wall of the rotating ring (5), and the second gear (73) is connected to the baffle (44).

3. The follow-up support core-removing injection mold according to claim 2, characterized in that: The top of the core locking plate (4) has two air intake channels (43), and each of the two air intake channels (43) is movably provided with a baffle (44). Each of the two baffles (44) is provided with a rack (441). The two racks (441) are located on the upper and lower sides of the second gear (73) and mesh with the second gear (73) so that when the second gear (73) rotates, it drives the two baffles (44) to move in opposite directions to the throttling and blocking position of the corresponding air intake channel (43), and when the second gear (73) rotates in the opposite direction, it drives the two baffles (44) to move away from the throttling and blocking position of the corresponding air intake channel (43).

4. The follow-up support core-removing injection mold according to claim 1, characterized in that: There are two fixed tubes (42), and the two moving rods (6) are located on both sides of the movable block (2). The two moving rods (6) extend into the two fixed tubes (42), and a piston plate (61) is fixedly connected to the end of each moving rod (6).

5. A follower-support core-removing injection mold according to claim 4, characterized in that: Each of the fixed tubes (42) has an air inlet (421) at the top. Each air inlet (421) is connected to an air intake channel (43). An air intake one-way valve is provided at the air inlet (421). The air intake one-way valve only allows gas to enter the fixed tube (42) through the air intake channel (43).

6. The follow-up support core-removing injection mold according to claim 5, characterized in that: Each of the fixed tubes (42) has an air outlet (422) at its bottom. A one-way valve is provided at the air outlet (422), which only allows gas to be discharged from the fixed tube (42).

7. The follow-up support core-removing injection mold according to claim 1, characterized in that: The movable block (2) is provided with an oblique hole (21). The follow-up support core-removing injection mold also includes an upper mold (10). An oblique guide post (101) is fixedly provided on the upper mold (10). When the oblique guide post (101) is inserted into the oblique hole (21), it can drive the movable block (2) to move towards the injection area (11). When the oblique guide post (101) is withdrawn from the oblique hole (21), it can drive the movable block (2) to move away from the injection area (11).

8. A follower-support core-removing injection mold according to claim 7, characterized in that: A reset rod (22) is fixedly installed on the side of the movable block (2) away from the core-pulling rod (3). A reset fixing plate (12) is fixedly installed on the lower mold (1). The reset rod (22) is movably inserted through the reset fixing plate (12). A reset spring (13) is provided between the reset rod (22) and the reset fixing plate (12). The reset spring (13) is used to drive the movable block (2) away from the injection area (11) to reset.

Images