An injection molding die for thick-walled thinning of automobile rear door pillar plastic parts

Abstract

The present application relates to an injection molding mold for thinning the thick-walled plastic parts of automobile tailgate pillars, comprising a movable mold, a fixed mold, a gas-assisted molding mechanism, and a deflation mechanism. The gas-assisted molding mechanism includes a portion provided in a chute, and the deflation mechanism includes a push rod, a second driving member, a cutting assembly, and a gas guide assembly. The bottom surface of the chute is provided with a first chute, on which the push rod slides, and the second driving member drives the push rod to move. The top end of the push rod is used to lift a portion of the chute that has not been fully cooled before mold opening. The cutting assembly is provided on the push rod and cuts the stretched portion of the chute caused by the push rod. The gas guide assembly guides the gas within the chute out of the mold through the incision. The push rod causes the chute to deform under local force, and the cutter cuts the stretched portion of the chute, making it easier to cut the chute. After the stretched portion is cut, the push rod continues to support the deformed portion, thereby forcing the incision to open, allowing the gas within the chute to be discharged through the incision.

Description

Technical Field

[0001] The invention relates to the field of molds, in particular to an injection molding mold for a thick-wall thinning treatment of a plastic part of a rear door pillar of an automobile. Background Art

[0002] The plastic parts on the left and right pillars on the car trunk door are as follows Figure 1 As shown, the pillar plastic part 8 has a deep undercut 81 formed on its edge. The undercut 81 has a relatively thick wall. To reduce the weight of the pillar plastic part 8, gas-assisted thinning is used to create a hollow section within the thick-walled part by maintaining gas pressure.

[0003] During the gas-assisted molding process, an overflow trough is usually set on the movable mold. Under the push of gas, the excess molten plastic and gas will enter the overflow trough, forming a high-pressure inflated overflow block in the overflow trough. When the mold is opened, there is a risk of the overflow block exploding, which may injure the operator. Therefore, the current method is to use a needle to puncture the overflow block before the mold is opened, and then drain the gas inside the overflow block. However, this method has certain problems. Since the temperature inside the mold is still certain before the mold is opened, although the plastic can maintain the molding state, it is not completely solidified. If the diameter of the needle is small, the vent hole will close automatically after the needle is withdrawn. If the diameter of the needle is large, the needle needs a larger driving force and a larger displacement to puncture the overflow block. This places requirements on the depth of the overflow trough, which increases the limitations of the mold design. At the same time, waste formed by extreme stretching may adhere to the top surface of the needle, requiring the operator to clean it up. Summary of the Invention

[0004] In order to better deflate the overflow block, the present application provides an injection molding die for thick-walled thinning of automobile rear door pillar plastic parts.

[0005] The present application provides an injection molding die for thick-walled thinning of automobile rear door pillar plastic parts, which adopts the following technical solutions:

[0006] An injection molding mold for thinning the thick-walled plastic parts of automobile rear door pillars, comprising a movable mold, a fixed mold, a gas-assisted molding mechanism, and a deflation mechanism. A cavity is formed between the movable mold and the fixed mold. The gas-assisted molding mechanism comprises an air inlet nozzle, a first driving member, a shutoff rod, and an overflow channel, a shutoff groove, and an overflow groove provided on the movable mold. The air inlet nozzle is in communication with one end of the cavity, the overflow channel is in communication with the other end of the cavity, the end of the overflow channel away from the cavity is in communication with the overflow groove, the top of the shutoff groove is in communication with the middle of the overflow channel, the first driving member drives the shutoff rod to slide within the shutoff groove, and the shutoff rod is used to control the on-off of the overflow channel during the injection molding process and to eject waste segments in the overflow channel after the mold is opened.

[0007] The degassing mechanism includes a push rod, a second driving member, a cutting assembly and an air guide assembly. A first slide groove is provided on the bottom surface of the overflow trough. The push rod slides on the first slide groove. The second driving member drives the push rod to move. The top end of the push rod is used to lift the part of the overflow block that has not been completely cooled before the mold is opened. The cutting assembly is arranged on the push rod and is used to cut the stretched part of the overflow block produced by the action of the push rod. The air guide assembly is used to guide the gas in the overflow block to the outside of the mold from the incision.

[0008] By adopting the above technical solution, the function of the push rod is not to puncture the overflow block, but to cause the overflow block to deform under local force. The cutter cuts the stretched part of the overflow block after deformation, which can make the overflow block easier to cut. After the stretched part is cut, the push rod will continue to support the deformed part, thereby forcing the incision to open, so that the gas inside the overflow block can be discharged through the incision. Compared with the traditional needle deflation method, it avoids the closure of the vent hole due to the needle diameter problem or the increase in mold design restrictions. At the same time, there will be no problem of waste material adhering to the top surface of the needle, which reduces the cleaning workload of the operator, improves the reliability and safety of deflation, and makes the overflow block deflation process more efficient and stable.

[0009] Preferably, the cutting assembly includes a cutting knife, a rotating rod and a driving member. A rotating groove is provided on the top rod along the sliding direction of the top rod. The rotating rod rotates in the rotating groove. A fan-shaped groove is provided on the top rod. The central axis of the fan-shaped groove is parallel to and away from the central axis of the top rod. One end of the cutting knife is detachably connected to the rotating rod. The driving member drives the rotating rod to rotate. The cutting knife moves in the fan-shaped groove. The blade head of the cutting knife faces the opening of the fan-shaped groove and is used to cut the stretched part of the overflow block.

[0010] By adopting the above technical solution, the driving member three drives the rotating rod to rotate, and the rotating rod drives the cutting knife to move in the fan-shaped groove, and the cutting knife is used to cut the stretched part generated after the ejector rod lifts the overflow block. Compared with other cutting methods, this structural design makes the movement trajectory of the cutting knife more controllable, and can accurately cut the stretched part of the overflow block to ensure the cutting effect. At the same time, the cutting knife moves in the fan-shaped groove, which can effectively avoid the cutting knife from interfering with other parts of the mold when it is not working, thereby ensuring the smooth deflation operation of the overflow block.

[0011] Preferably, the top end of the rotating groove is located above the fan-shaped groove.

[0012] By adopting the above technical solution, this arrangement allows the rotating rod to extend above the fan-shaped groove to support the top rod, further supporting the top rod, while also improving the rotation stability of the rotating rod to ensure the normal rotation of the cutter and the smooth execution of the cutting action.

[0013] Preferably, a through hole is formed on the cutting knife to cooperate with the rotating rod, and the cutting knife and the rotating rod are connected by an internal spline and an external spline.

[0014] Preferably, the second driving member is a secondary oil cylinder, the third driving member is a fixed block, the secondary oil cylinder has a primary output shaft and a secondary output shaft that are ejected successively, the primary output shaft is detachably connected to the push rod, the fixed block is fixedly set on the secondary output shaft, and a movable groove for sliding of the secondary output shaft and the fixed block is opened in the push rod, the fixed block is threadedly connected to the rotating rod, and the bottom end of the rotating rod abuts against the top surface of the primary output shaft.

[0015] By adopting the above technical solution, the first-level output shaft of the secondary cylinder drives the push rod to partially lift the overflow block, and then the secondary output shaft drives the fixed block to push the rotating rod to rotate, so that the cutting knife cuts the stretched part of the overflow block. By utilizing the output of the secondary cylinder at different stages, the orderly connection of the two actions of the push rod lifting the overflow block and the cutting knife cutting is achieved. There is no need to set up multiple additional drive devices, which simplifies the structure of the mold and reduces the mold cost. At the same time, this integrated drive method makes the action coordination more precise and efficient, and improves the work efficiency and reliability of the overflow block deflation treatment.

[0016] Preferably, the air guide assembly includes an air duct provided in the push rod and a control member for controlling the on / off of the air duct, and both ends of the air duct are respectively connected to the fan-shaped groove and the outside.

[0017] By adopting the above technical solution, the air duct connects the fan-shaped groove with the outside world. When the cutting knife cuts the overflow block, the gas can be discharged from the incision outside the mold through the air duct. The setting of this air guide component provides a special exhaust channel for the gas in the overflow block, ensuring that the gas can be discharged quickly and smoothly, thereby improving the deflation efficiency. At the same time, compared with the open exhaust method, exhaust through the air duct can better control the direction and speed of gas discharge, avoid affecting other parts of the mold during gas discharge, and ensure the stability and safety of mold operation.

[0018] Preferably, the top of the air duct is close to the center of the fan-shaped groove, and the control component includes a first spring, a block and a protrusion. An oblique groove is provided on the bottom surface of the fan-shaped groove along the moving direction of the cutting knife. The bottom end of the air duct is connected to the oblique groove, and the block slides in the oblique groove. The two ends of the first spring are respectively arranged on the block and the end wall of the oblique groove, which are used to drive the block to block the air duct. The protrusion is arranged on the top surface of the block, and the protrusion is located on the moving path of the cutting knife. The block moves away from the air duct at the end of the cutting path of the cutting knife.

[0019] By adopting the above technical solution, when the cutting knife does not cut the overflow block, the first spring drives the block to block the air duct, preventing the plastic in the stretched part under the action of air pressure from entering the fan-shaped groove and causing blockage in the air duct; when the cutting knife cuts the overflow block and moves to the end of the cutting path, the incision is already in an open state, and the cutting knife pushes the protrusion to move the block away from the air duct, ensuring that the air guide operation is performed at the right time, improving the accuracy and reliability of the deflation operation, and avoiding the adverse effects of the gas on the air guide component due to premature discharge of gas; the top of the air duct is close to the center of the fan-shaped groove. This setting can make the gas be discharged more evenly and efficiently from the position where the overflow cut opening is largest. At the same time, because it is close to the center of the fan-shaped groove, the gas encounters relatively small resistance during the discharge process, and can be discharged out of the mold through the air duct more quickly, further improving the deflation efficiency.

[0020] Preferably, it also includes an ejection mechanism, the top end of the ejector rod has a rounded corner, and a notch groove is provided on the rounded surface of the ejector rod, the notch groove is located directly above the fan-shaped groove, and the angle of the notch groove is inclined toward the side of the rotating rod; the ejection mechanism includes a first driving member, a ejector plate, and a plurality of ejector blocks, the first driving member drives the ejector plate to move along the direction of mold opening and closing, the ejector block and the ejector plate are connected by a connecting rod, the secondary oil cylinder is arranged on the ejector plate, and the plurality of ejector blocks lift the plastic parts and the overflow block for demolding after the mold is opened.

[0021] By adopting the above technical solution, the rounded corner design of the top of the ejector rod can effectively avoid the tearing phenomenon of the overflow block caused by stress concentration when the ejector rod lifts the overflow block, ensuring the integrity of the overflow block during the lifting process and providing good conditions for the subsequent cutting operation of the cutting knife; in the gas-assisted molding stage, the molten plastic will enter the notch groove to form a convex corner, and the air pressure will act on the two sides of the notch groove. The part of the ejector block located between the fan-shaped groove and the notch groove is the end head, and the component force of the air pressure will drive the end head to press against the inner wall of the first slide groove, thereby maintaining The shape of the fan-shaped groove; in the exhaust stage, the cooperation of the convex corner and the notch groove can ensure that the ejector pin always has a certain connection with the stretching part of the overflow block, preventing the stretching part from completely separating from the ejector pin under the action of the stretching force, and preventing the ejector pin from completely penetrating the overflow block, so that the incision can always remain in the open state until the demolding stage; in the demolding stage after mold opening, the ejector plate moves up, driving the ejector block and the ejector pin to move up. The ejector block mainly plays the role of ejecting the overflow block, and the ejector pin assists the ejector block to jointly demold the overflow block, which can improve the balance of the overflow block demolding and improve the demolding effect.

[0022] The technical effects of the present invention are mainly reflected in the following aspects:

[0023] 1. The function of the ejector pin of the present invention is not to puncture the flash block, but to cause the flash block to deform under local force. The cutter cuts the stretched part of the flash block after deformation, which can make the flash block easier to cut. After the stretched part is cut, the ejector pin will continue to support the deformed part, thereby forcing the incision to open, so that the gas inside the flash block can be discharged through the incision.

[0024] 2. The first-level output shaft of the secondary oil cylinder of the present invention drives the push rod to partially lift the overflow block, and then the secondary output shaft drives the fixed block to push the rotating rod to rotate, so that the cutting knife cuts the stretched part of the overflow block. By utilizing the output of the secondary oil cylinder at different stages, the orderly connection of the two actions of the push rod lifting the overflow block and the cutting knife cutting is achieved. There is no need to set up multiple driving devices additionally, which simplifies the structure of the mold and reduces the mold cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a structural diagram of a plastic part of a rear door pillar of an automobile.

[0026] Figure 2 It is a schematic diagram of the overall structure of the mold in the embodiment of the present application.

[0027] Figure 3 It is a structural schematic diagram of the gas-assisted molding mechanism on the movable mold in an embodiment of the present application.

[0028] Figure 4 yes Figure 3 Enlarged view of point A in the middle.

[0029] Figure 5 It is along Figure 4 Cross-sectional view along line BB.

[0030] Figure 6 yes Figure 5 Enlarged view of point C in the middle.

[0031] Figure 7 yes Figure 5 Enlarged view of point D in the middle.

[0032] Figure 8 It is a structural schematic diagram of the top end of the push rod in the embodiment of the present application.

[0033] Figure 9 It is a partial structural diagram of the air guide component of an embodiment of the present application.

[0034] Explanation of the accompanying symbols: 1. movable mold; 11. first slide groove; 2. fixed mold; 3. gas-assisted molding mechanism; 31. shut-off rod; 32. overflow channel; 33. shut-off groove; 34. overflow trough; 35. overflow block; 4. air release mechanism; 41. ejector rod; 411. fan-shaped groove; 412. inclined groove; 413. rotating groove; 414. missing corner groove; 415. movable groove; 42. secondary oil cylinder; 421. primary output shaft; 422. secondary output shaft; 5. cutting assembly; 51. cutting knife; 52. rotating rod; 53. fixed block; 6. air guide assembly; 61. air duct; 62. first spring; 63. blocking block; 64. protrusion; 7. ejection mechanism; 71. ejector plate; 72. ejector block; 8. column plastic part; 81. undercut. DETAILED DESCRIPTION

[0035] The following is combined with Figures 1-9 The present application is further described in detail to make the technical solution of the present application easier to understand and grasp.

[0036] The embodiment of the present application discloses an injection molding die for a thick-walled thinning treatment of a plastic part of a rear door pillar of an automobile.

[0037] Reference Figure 1-Figure 5 In this embodiment, an injection molding mold for thick-walled thinning of a plastic part of a rear door pillar of an automobile includes a movable mold 1, a fixed mold 2, a gas-assisted molding mechanism 3, and a deflation mechanism 4. A cavity is formed between the movable mold 1 and the fixed mold 2. The gas-assisted molding mechanism 3 includes an air inlet nozzle, a driving member 1, a shutoff rod 31, and an overflow channel 32, a shutoff groove 33, and an overflow groove 34 provided on the movable mold 1. The air inlet nozzle is connected to one end of the cavity, and inert gas enters the cavity from the air inlet nozzle. The overflow channel 32 is connected to the other end of the cavity. The end of the overflow channel 32 away from the cavity is connected to the overflow groove 34. The top of the shutoff groove 33 is connected to the middle of the overflow channel 32. The driving member 1 drives the shutoff rod 31 to slide in the shutoff groove 33. The shutoff rod 31 is used to control the opening and closing of the overflow channel 32 during the injection molding process and to eject the waste segment in the overflow channel 32 after the mold is opened.

[0038] Reference Figure 4-Figure 6 The deflation mechanism 4 includes a push rod 41, a second driving member, a cutting assembly 5 and an air guide assembly 6. A first slide groove 11 is provided on the bottom surface of the overflow trough 34. The push rod 41 slides on the first slide groove 11. The second driving member drives the push rod 41 to move. The top end of the push rod 41 is used to lift the part of the overflow block 35 that has not been completely cooled before the mold is opened. The cutting assembly 5 is set on the push rod 41 and is used to cut the stretched part of the overflow block 35 caused by the action of the push rod 41. The air guide assembly 6 is used to guide the gas in the overflow block 35 to the outside of the mold from the incision.

[0039] Reference Figure 4-Figure 6The function of the ejector pin 41 is not to puncture the overflow block 35, but to cause the overflow block 35 to deform under local force. The cutter 51 cuts the stretched part of the overflow block 35 after deformation, which can make the overflow block 35 easier to cut. After the stretched part is cut, the ejector pin 41 will continue to support the deformed part, thereby forcing the incision to open, so that the gas inside the overflow block 35 can be discharged through the incision. Compared with the traditional needle deflation method, this method avoids the closure of the vent hole due to the needle diameter problem or the increase in mold design restrictions. At the same time, there will be no problem of waste material adhering to the top surface of the needle, which reduces the cleaning workload of the operator, improves the reliability and safety of deflation, and makes the deflation process of the overflow block 35 more efficient and stable.

[0040] Reference Figure 5-Figure 9 The cutting assembly 5 includes a cutter 51, a rotating rod 52, and a third driver. A rotating groove 413 is defined on the push rod 41 along its sliding direction. The rotating rod 52 rotates within the rotating groove 413. The rotating axis of the rotating rod 52 is parallel to the moving direction of the push rod 41, which in turn is parallel to the mold opening and closing direction. A fan-shaped groove 411 is defined on the push rod 41. The central axis of the fan-shaped groove 411 is parallel to and spaced from the central axis of the push rod 41. One end of the cutter 51 is detachably connected to the rotating rod 52. The third driver drives the rotating rod 52 to rotate, allowing the cutter 51 to move within the fan-shaped groove 411. The cutting tip of the cutter 51 faces the opening of the fan-shaped groove 411, thereby cutting the stretched portion of the flash block 35.

[0041] Reference Figure 5-Figure 9 The driving member three drives the rotating rod 52 to rotate, and the rotating rod 52 drives the cutting knife 51 to move in the fan-shaped groove 411, and uses the cutting knife 51 to cut the stretched part generated after the ejector rod 41 lifts the overflow block 35. Compared with other cutting methods, this structural design makes the movement trajectory of the cutting knife 51 more controllable, and can accurately cut the stretched part of the overflow block 35 to ensure the cutting effect. At the same time, the cutting knife 51 is completely located in the fan-shaped groove 411 when not working, which can effectively avoid interference between the cutting knife 51 and other parts of the mold, thereby ensuring the smooth deflation operation of the overflow block 35.

[0042] Reference Figure 5-Figure 9 The overall operating angle of the cutter 51 is at least an obtuse angle, and the angle at which the cutter 51 actually cuts the stretched portion of the overflow block 35 is an acute angle. The stretched portion will continue to break after the cutter 51 cuts, but since the diameter of the ejector rod 41 itself is relatively large and the ejection distance is short, the stretched portion will not be completely separated from the overflow block 35 body.

[0043] Reference Figure 5-Figure 9The top of the rotating groove 413 is located above the fan-shaped groove 411. This arrangement allows the rotating rod 52 to extend above the fan-shaped groove 411 to support the top rod 41, further supporting the top rod 41, and also improves the rotation stability of the rotating rod 52 to ensure the normal rotation of the cutting knife 51 and the smooth execution of the cutting action.

[0044] Reference Figure 5-Figure 9 The cutter 51 has a through hole that mates with the rotating rod 52. The cutter 51 and the rotating rod 52 are connected by internal and external splines. This connection method is more complicated during adjustment, but it has the advantage of being more stable. The cutter 51 and the rotating rod 52 can also be connected by screws, which facilitates adjustment of the position of the cutter 51.

[0045] Reference Figure 5-Figure 9 The second driving component is a secondary oil cylinder 42, and the third driving component is a fixed block 53. The secondary oil cylinder 42 has a primary output shaft 421 and a secondary output shaft 422 that are ejected in sequence. The primary output shaft 421 is detachably connected to the push rod 41, and the fixed block 53 is fixedly mounted on the secondary output shaft 422. The push rod 41 defines a movable slot 415 for sliding movement of the secondary output shaft 422 and the fixed block 53. The fixed block 53 is threadedly connected to the rotating rod 52, and the bottom end of the rotating rod 52 abuts the top surface of the primary output shaft 421. The threads of the fixed block 53 and the rotating rod 52 have a large pitch, allowing the rotating rod 52 to rotate smoothly. Simultaneously, the secondary output shaft 422 can be extended and retracted, allowing the cutting knife 51 to rotate back and forth between two extreme positions near the end wall of the fan-shaped groove 411.

[0046] Reference Figure 5-Figure 9 The first-level output shaft 421 of the secondary oil cylinder 42 drives the push rod 41 to partially lift the overflow block 35, and then the secondary output shaft 422 drives the fixed block 53 to push the rotating rod 52 to rotate, so that the cutting knife 51 cuts the stretched part of the overflow block 35. By utilizing the output of the secondary oil cylinder 42 at different stages, the orderly connection of the two actions of the push rod 41 lifting the overflow block 35 and the cutting knife 51 is achieved. There is no need to set up multiple driving devices additionally, which simplifies the structure of the mold and reduces the mold cost. At the same time, this integrated driving method makes the action coordination more precise and efficient, and improves the work efficiency and reliability of the deflation treatment of the overflow block 35.

[0047] Reference Figure 5-Figure 9 The air guide assembly 6 includes an air passage 61 opened in the top rod 41 and a control member for controlling the opening and closing of the air passage 61. The two ends of the air passage 61 are respectively connected to the fan-shaped groove 411 and the outside world.

[0048] Reference Figure 5-Figure 9The air duct 61 connects the fan-shaped groove 411 with the outside world. When the cutter 51 cuts the overflow block 35, the gas can be discharged from the incision outside the mold through the air duct 61. The setting of this air guide component 6 provides a special exhaust channel for the gas in the overflow block 35, ensuring that the gas can be discharged quickly and smoothly, thereby improving the degassing efficiency. At the same time, compared with the open exhaust method, exhaust through the air duct 61 can better control the direction and speed of gas discharge, avoid affecting other parts of the mold during the gas discharge process, and ensure the stability and safety of the mold operation.

[0049] Reference Figure 5-Figure 9 The control part includes a first spring 62, a block 63 and a protrusion 64. An oblique groove 412 is opened on the bottom surface of the fan-shaped groove 411 along the moving direction of the cutting knife 51. The bottom end of the air duct 61 is connected to the oblique groove 412. The block 63 slides in the oblique groove 412. The two ends of the first spring 62 are respectively arranged on the block 63 and the end wall of the oblique groove 412, which are used to drive the block 63 to block the air duct 61. The protrusion 64 is arranged on the top surface of the block 63. The protrusion 64 is located on the moving path of the cutting knife 51. The block 63 moves away from the air duct 61 at the end of the cutting path of the cutting knife 51.

[0050] Reference Figure 5-Figure 9 When the cutting knife 51 has not cut the overflow block 35, the first spring 62 drives the blocking block 63 to block the air channel 61, preventing the plastic in the stretched part under the action of air pressure from entering the fan-shaped groove 411 and the air channel 61 to cause blockage; when the cutting knife 51 cuts the overflow block 35 and moves to the end of the cutting path, the incision is already in an open state, and the cutting knife 51 pushes the protrusion 64 to make the blocking block 63 move away from the air channel 61, ensuring that the air guide operation is performed at the right time, improving the accuracy and reliability of the deflation operation, and avoiding the adverse effects of the gas on the air guide component 6 caused by premature discharge of gas.

[0051] Reference Figure 5-Figure 9 The top of the vent 61 is located close to the center of the fan-shaped groove 411. This arrangement allows the gas to be discharged more evenly and efficiently from the position where the overflow opening is largest. At the same time, because it is close to the center of the fan-shaped groove 411, the resistance encountered by the gas during the discharge process is relatively small, and the gas can be discharged from the mold more quickly through the vent 61, further improving the degassing efficiency.

[0052] Reference Figure 5-Figure 9 The column plastic part 8 also has reinforcing ribs and plug-in blocks. The shape of the plug-in blocks is relatively special, and the demoulding angle of the special-shaped surface on the plug-in blocks is staggered with the demoulding angles of other surfaces.

[0053] Reference Figure 5-Figure 9An injection molding mold for thick-walled thinning of automobile rear door pillar plastic parts also includes an ejection mechanism 7, which includes a first driving member, a top plate 71 and a plurality of ejector blocks 72. The ejector blocks 72 are connected to the top plate 71 by a connecting rod. The first driving member drives the top plate 71 to move along the mold opening and closing direction. After the mold is opened, the plurality of ejector blocks 72 lift the plastic parts and the overflow block 35 for demolding.

[0054] Reference Figure 5-Figure 9 Both the first and second drive members can be hydraulic cylinders. The secondary hydraulic cylinder 42 is fixed to the top plate 71 via a connecting frame. The top of the push rod 41 has a rounded corner. A notched groove 414 is defined on the rounded surface of the push rod 41. The notched groove 414 is located directly above the fan-shaped groove 411 and is tilted toward the rotating rod 52.

[0055] Reference Figure 5-Figure 9 The rounded corner design of the top of the push rod 41 can effectively avoid the tearing phenomenon of local damage to the overflow block 35 due to stress concentration when the push rod 41 lifts the overflow block 35, ensuring the integrity of the overflow block 35 during the lifting process and providing good conditions for the subsequent cutting operation of the cutting knife 51.

[0056] Reference Figure 5-Figure 9 In the gas-assisted molding stage, the molten plastic will enter the notched groove 414 to form a convex angle. At the same time, the air pressure will act on the two sides of the notched groove 414. The part of the top block 72 located between the fan-shaped groove 411 and the notched groove 414 is the end head. The component force of the air pressure will drive the end head to press against the inner wall of the first slide groove 11, thereby maintaining the shape of the fan-shaped groove 411. In the exhaust stage, the cooperation between the convex angle and the notched groove 414 can ensure that there is always a certain distance between the ejector pin 41 and the stretching part of the overflow block 35. The connection prevents the stretched part from being completely separated from the ejector pin 41 under the action of the stretching force, and prevents the ejector pin 41 from completely penetrating the overflow block 35, so that the incision can always remain in the open state until the demolding stage; in the demolding stage after the mold is opened, the top plate 71 moves up, driving the ejector block 72 and the ejector pin 41 to move up, and the ejector block 72 mainly plays the role of ejecting the overflow block 35, and the ejector pin 41 assists the ejector block 72 to jointly demold the overflow block 35, which can improve the balance of the demolding of the overflow block 35 and improve the demolding effect.

[0057] The top and bottom, up and down mentioned in this article are based on the placement direction of the drawings, not the actual placement direction of the mold. Of course, the above are only typical examples of this application. In addition, this application can also have many other specific implementations. Any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection claimed in this application.

Claims

1. An injection molding die for thick-walled thinning of automobile rear door pillar plastic parts, characterized by: The invention comprises a movable mold (1), a fixed mold (2), a gas-assisted molding mechanism (3) and a deflation mechanism (4), wherein a mold cavity is formed between the movable mold (1) and the fixed mold (2), and the gas-assisted molding mechanism (3) comprises an air inlet nozzle, a driving member, a shutoff rod (31) and an overflow channel (32), a shutoff groove (33) and an overflow groove (34) provided on the movable mold (1), wherein the air inlet nozzle is connected to one end of the mold cavity, the overflow channel (32) is connected to the other end of the mold cavity, the end of the overflow channel (32) away from the mold cavity is connected to the overflow groove (34), the top end of the shutoff groove (33) is connected to the middle part of the overflow channel (32), the driving member drives the shutoff rod (31) to slide in the shutoff groove (33), and the shutoff rod (31) is used to control the on-off of the overflow channel (32) during the injection molding process and to eject the waste section in the overflow channel (32) after the mold is opened; The degassing mechanism (4) comprises a push rod (41), a second driving member, a cutting assembly (5) and an air guide assembly (6); a first chute (11) is provided on the bottom surface of the overflow trough (34); the push rod (41) slides on the first chute (11); the second driving member drives the push rod (41) to move; the top end of the push rod (41) is used to lift a part of the overflow block (35) that has not been completely cooled before the mold is opened; the cutting assembly (5) is arranged on the push rod (41) and is used to cut the stretched part of the overflow block (35) generated by the action of the push rod (41); the air guide assembly (6) is used to guide the gas in the overflow block (35) from the incision to the outside of the mold; The cutting assembly (5) includes a cutting knife (51), a rotating rod (52) and a third driving member. A rotating groove (413) is provided on the top rod (41) along the sliding direction of the top rod (41). The rotating rod (52) rotates in the rotating groove (413). A fan-shaped groove (411) is provided on the top rod (41). The central axis of the fan-shaped groove (411) is parallel to and away from the central axis of the top rod (41). One end of the cutting knife (51) is detachably connected to the rotating rod (52). The third driving member drives the rotating rod (52) to rotate. The cutting knife (51) moves in the fan-shaped groove (411). The cutting head of the cutting knife (51) faces the opening of the fan-shaped groove (411) and is used to cut the stretched part of the overflow block (35). The air guide assembly (6) includes an air duct (61) provided in the top rod (41) and a control member for controlling the opening and closing of the air duct (61), and both ends of the air duct (61) are respectively connected to the fan-shaped groove (411) and the outside world; The top of the air duct (61) is close to the center of the fan-shaped groove (411), and the control component includes a first spring (62), a block (63) and a protrusion (64). An inclined groove (412) is provided on the bottom surface of the fan-shaped groove (411) along the moving direction of the cutting knife (51). The bottom end of the air duct (61) is connected to the inclined groove (412), and the block (63) slides in the inclined groove (412). The two ends of the first spring (62) are respectively arranged on the block (63) and the end wall of the inclined groove (412) for driving the block (63) to block the air duct (61). The protrusion (64) is arranged on the top surface of the block (63). The protrusion (64) is located on the moving path of the cutting knife (51), and the block (63) moves away from the air duct (61) at the end of the cutting path of the cutting knife (51).

2. The thick-walled thinning injection molding die for automobile rear door pillar plastic parts according to claim 1, characterized in that: The top end of the rotating groove (413) is located above the fan-shaped groove (411).

3. The thick-walled thinning injection molding die for automobile rear door pillar plastic parts according to claim 1, characterized in that: A through hole is formed on the cutting knife (51) to cooperate with the rotating rod (52), and the cutting knife (51) and the rotating rod (52) are connected by an internal spline and an external spline.

4. The thick-walled thinning injection molding die for automobile rear door pillar plastic parts according to claim 1, characterized in that: The second driving member is a secondary oil cylinder (42), and the third driving member is a fixed block (53). The secondary oil cylinder (42) has a primary output shaft (421) and a secondary output shaft (422) which are ejected successively. The primary output shaft (421) is detachably connected to the push rod (41). The fixed block (53) is fixedly arranged on the secondary output shaft (422). A movable groove (415) for sliding the secondary output shaft (422) and the fixed block (53) is provided in the push rod (41). The fixed block (53) is threadedly connected to the rotating rod (52). The bottom end of the rotating rod (52) abuts against the top surface of the primary output shaft (421).

5. The thick-walled thinning injection molding die for automobile rear door pillar plastic parts according to claim 4, characterized in that: The invention also includes an ejection mechanism (7), wherein the top end of the ejector rod (41) is rounded, and a corner-cut groove (414) is provided on the rounded surface of the ejector rod (41), wherein the corner-cut groove (414) is located directly above the fan-shaped groove (411), and the angle of the corner-cut groove (414) is inclined toward the side of the rotating rod (52); the ejection mechanism (7) includes a first driving member, a top plate (71), and a plurality of ejecting blocks (72), wherein the first driving member drives the top plate (71) to move along the mold opening and closing direction, and the ejecting blocks (72) are connected to the top plate (71) by a connecting rod, and the secondary oil cylinder (42) is arranged on the top plate (71), and the plurality of ejecting blocks (72) lift the plastic parts and the overflow blocks (35) to perform demolding after the mold is opened.

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