A biodegradable box injection mold and injection method based on negative pressure assisted injection

Abstract

The invention relates to the technical field of injection molds, and specifically to a biodegradable box injection mold and an injection molding method based on negative pressure assisted injection, comprising: a fixed mold and a movable mold, wherein the fixed mold is provided with symmetrically arranged guide holes, the movable mold is fixed with guide columns slidably connected to the guide holes, and the fixed mold and the movable mold are combined with each other to form an injection molding chamber; a feeding pipe is fixedly installed in the movable mold, the side wall of the feeding pipe is connected with a conveying pipe that runs through the movable mold, and a reflux kettle is also fixed on the top of the movable mold; a conducting feeding mechanism is arranged in the feeding pipe, and a conveying hole connected to the injection molding chamber is formed on the conducting feeding mechanism; a conducting reflux mechanism is arranged in the feeding pipe and connected to the conducting feeding mechanism, and a negative pressure suction mechanism connected to the conducting reflux mechanism is arranged in the reflux kettle. The present invention can automatically adjust the conducting state of the conveying hole according to the injection molding state, and clean the raw materials remaining in the feeding pipe to ensure that the feeding pipe is not blocked.

Description

Technical Field

[0001] The invention relates to the technical field of injection molds, in particular to a biodegradable box injection mold and an injection method based on negative pressure auxiliary injection. Background Art

[0002] Biodegradable plastics refer to a type of plastic that is degraded by microorganisms such as bacteria, molds (fungi) and algae that exist in nature. An ideal biodegradable plastic is a polymer material that has excellent performance, can be completely decomposed by environmental microorganisms after being discarded, and eventually becomes inorganic and becomes a part of the carbon cycle in nature.

[0003] Injection molding is the process of injecting heated plastic materials into an injection molding machine and curing them after high-pressure injection. Injection molding of biodegradable plastics is efficient, precise, and repeatable, and can produce a variety of precision plastic products.

[0004] When the existing injection molding materials enter the mold cavity through the injection port, some of the materials may remain in the injection port of the injection molding machine, which will result in insufficient gate solidification or excessive stress, causing the gate to be unable to be completely disconnected from the product. In addition, due to the mold clamping error, the consistency of the injection volume cannot be accurately guaranteed, resulting in the injection volume being too large or too small, affecting the cost and quality. Summary of the invention

[0005] The object of the present invention is to provide a biodegradable box injection mold and an injection molding method based on negative pressure assisted injection to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a biodegradable box injection mold based on negative pressure assisted injection, comprising: a fixed mold and a movable mold, the fixed mold is provided with symmetrically arranged guide holes, the movable mold is fixed with guide columns slidably connected to the guide holes, the fixed mold and the movable mold are combined with each other to form an injection chamber; further comprising: a feed pipe fixedly installed in the movable mold, the side wall of the feed pipe is connected with a conveying pipe running through the movable mold, and a reflux kettle is also fixed on the top of the movable mold; a conducting feed mechanism is arranged in the movable mold. A conveying hole connected to the injection molding chamber is formed on the conductive feeding mechanism in the feeding pipe, and the conductive feeding mechanism can be activated when the pressure in the feeding pipe changes to adjust the conductive state of the conveying hole; a conductive reflux mechanism is arranged in the feeding pipe and connected to the conductive feeding mechanism, and a negative pressure suction mechanism connected to the conductive reflux mechanism is arranged in the reflux kettle, and the negative pressure suction mechanism can be activated when the conductive reflux mechanism moves to suck the raw material remaining in the feeding pipe into the reflux kettle through the conductive reflux mechanism.

[0007] As a further solution of the present invention: the conductive feeding mechanism includes a fixed disk fixedly installed on the end of the feeding pipe away from the reflux kettle, the conveying hole is formed on the fixed disk, a sealing disk abutting the fixed disk is slidably installed in the feeding pipe, a conductive hole conductively matched with the conveying hole is opened on the sealing disk, and a follower component is arranged in the feeding pipe.

[0008] As a further solution of the present invention: the follower assembly includes a rotating rod rotatably installed in the reflux kettle and fixedly connected to the sealing disk, a guide groove is provided on the circumferential outer wall of the rotating rod, a sliding disk slidably connected to the rotating rod is slidingly sealed in the feed pipe, a first limit block slidably engaged with the guide groove is fixed to the inner wall of the sliding disk, and a limit structure connected to the sliding disk is provided in the feed pipe.

[0009] As a further solution of the present invention: the limiting structure includes a limiting groove provided on the inner wall of the feeding tube, and a limiting rod slidably connected to the limiting groove is fixed to the circumferential outer wall of the sliding disk.

[0010] As a further solution of the present invention: the conductive reflux mechanism includes a follower disk slidably installed in the feeding tube and slidably connected to the rotating rod, the follower disk abuts against the sliding disk, the follower disk is provided with a second reflux hole, the sliding disk is provided with a first reflux hole conductively matched with the second reflux hole, and a driven component connected to the follower disk is arranged in the feeding tube.

[0011] As a further solution of the present invention: the driven component includes a rotating disk rotatably mounted on the end of the feeding pipe and rotatably connected to the reflux kettle, a supporting sleeve connected to the second reflux hole is fixed on the following disk, a hollow tube penetrating the rotating disk is slidably mounted in the supporting sleeve, a first spring is sleeved on the rotating rod, and two ends of the first spring are respectively abutted against the following disk and the rotating disk; it also includes a hollow disk fixedly mounted in the reflux kettle and connected to the hollow tube, and a conduit penetrating the reflux kettle is connected to the hollow disk.

[0012] As a further solution of the present invention: the negative pressure suction mechanism includes a fourth spiral groove, a fourth vertical groove, and annular groove opened on the circumferential outer wall of the rotating rod, the fourth spiral groove, the fourth vertical groove, and the annular groove are connected to each other in sequence, the side wall of the reflux kettle is connected with a discharge pipe and an absorption pipe, and a one-way valve connected to the discharge pipe and the absorption pipe is installed on the reflux kettle, and a guide assembly connected to the rotating rod is arranged in the reflux kettle.

[0013] As a further solution of the present invention: the guide assembly includes support columns fixedly installed in the reflux kettle and symmetrically arranged, a piston disk slidably installed on the support column and slidably connected to the rotating rod, a second limit block is fixed to the inner wall of the piston disk, the second limit block can slide along the fourth spiral groove, the fourth vertical groove, and the annular groove, and an elastic structure is arranged in the reflux kettle.

[0014] As a further solution of the present invention: the elastic structure includes a second spring sleeved on the rotating rod, and two ends of the second spring are respectively in contact with the piston disk and the hollow disk.

[0015] An injection molding method of a biodegradable box injection mold based on negative pressure assisted injection comprises the following steps:

[0016] Step 1: The injection molding raw material is transported into the feeding pipe through the conveying pipe, so that the pressure in the feeding pipe gradually increases;

[0017] Step 2: Under the action of pressure, the conducting feeding mechanism is driven to move, so that the conveying hole is connected, and the raw material will enter the injection molding chamber through the conveying hole;

[0018] Step 3: When the injection molding chamber is fully filled, the pressure in the feeding pipe continues to increase, and the feeding hole is blocked again by controlling the conducting feeding mechanism. At the same time, the negative pressure suction mechanism and the conducting reflux mechanism can also be driven to move;

[0019] Step 4: Under the action of the reflux mechanism, the feed pipe is connected to the reflux kettle. At the same time, under the action of the negative pressure suction mechanism, the raw materials remaining in the feed pipe are sucked into the reflux kettle.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: the present application can automatically adjust the conduction state of the delivery hole according to the raw material delivery amount to perform material injection processing on the injection molding chamber. Specifically, in the initial state, under the action of the conduction feeding mechanism, the delivery hole is in a blocked state. When the raw material is added into the feeding pipe, the pressure in the feeding pipe increases, causing the conduction feeding mechanism to move. When the pressure reaches a certain value, under the action of the conduction feeding mechanism, the delivery hole is conducted to deliver the raw material into the injection molding chamber. When the injection molding chamber is filled, the conduction feeding mechanism is turned on. Under the action of the mechanism, the delivery hole can be controlled to be blocked again to ensure that the amount of raw materials entering the injection chamber each time remains consistent, so as to ensure the consistency of product production. A gate will be formed in the delivery hole. After the injection chamber is filled, the delivery hole will be in a blocked state. Therefore, the size and shape of the gate formed each time are consistent to ensure that the residual stress near the gate is small, the gate can be easily separated from the product, and it can also prevent the gate from becoming brittle or soft due to insufficient solidification of the gate, causing the front end of the gate to remain on the product side.

[0021] Through the cooperation of the second limit block and the fourth spiral groove, the second spring can be continuously compressed and stored with energy to ensure that when the first reflux hole is connected to the second reflux hole, the second spring is elastically released, so that a negative pressure is formed in the reflux kettle to quickly absorb the residual raw material, thereby preventing the residual raw material from cooling and solidifying and causing blockage in the feeding pipe, which results in the inability to transport the subsequent molten raw material to the injection molding chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of an embodiment of a biodegradable box injection mold based on negative pressure assisted injection;

[0023] Figure 2 It is a structural schematic diagram of another angle of an embodiment of a biodegradable box injection mold based on negative pressure assisted injection;

[0024] Figure 3 It is a schematic diagram of the exploded structure of a movable mold and a fixed mold in one embodiment of a biodegradable box injection mold based on negative pressure assisted injection;

[0025] Figure 4 It is a structural schematic diagram of a movable mold, a feeding pipe, a conveying hole, and a reflux kettle in one embodiment of a biodegradable box injection mold based on negative pressure assisted injection;

[0026] Figure 5 A schematic diagram of a partially half-section structure of an embodiment of a biodegradable box injection mold based on negative pressure assisted injection;

[0027] Figure 6 A schematic diagram of the connection relationship between the conductive feeding mechanism, the conductive reflux mechanism, and the negative pressure suction mechanism in one embodiment of a biodegradable box injection mold based on negative pressure assisted injection;

[0028] Figure 7 It is a schematic diagram of the explosion structure of the conducting feeding mechanism in one embodiment of the biodegradable box injection mold based on negative pressure assisted injection;

[0029] Figure 8 for Figure 7 A schematic diagram of the structure enlargement at the center A;

[0030] Fig. 9 It is a structural schematic diagram of a rotating rod and a rotating disk in one embodiment of a biodegradable box injection mold based on negative pressure assisted injection;

[0031] Fig.10 for Fig. 9 A schematic diagram of the structure enlarged at B in the middle;

[0032] Fig.11The exploded structure schematic diagram of a partially conductive reflux mechanism in an embodiment of a biodegradable box injection mold based on negative pressure assisted injection.

[0033] In the figure: 1, fixed mold; 101, guide hole; 102, injection molding chamber; 2, movable mold; 201, guide column; 3, feeding pipe; 4, reflux kettle; 5, conveying pipe; 6, fixed plate; 7, conveying hole; 8, sealing plate; 9, conducting hole; 10, rotating rod; 1001, first vertical groove; 1002, first spiral groove; 1003, second vertical groove; 1004, second spiral groove; 1005, third vertical groove; 1006, third spiral groove; 1007, fourth spiral groove Rotary groove; 1008, fourth vertical groove; 1009, annular groove; 11, sliding disk; 12, first reflux hole; 13, first limit block; 14, follow-up disk; 15, second reflux hole; 16, support sleeve; 17, rotating disk; 18, hollow tube; 19, first spring; 20, support column; 21, piston disk; 22, second limit block; 23, second spring; 24, discharge pipe; 25, infrared sensor; 26, hollow disk; 27, conduit; 28, absorption tube. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In addition, when an element in the present invention is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0036] See also Figure 1 to Figure 11In an embodiment of the present invention, a biodegradable box injection mold based on negative pressure assisted injection includes: a fixed mold 1 and a movable mold 2, wherein the fixed mold 1 is provided with guide holes 101 which are symmetrically arranged, and the movable mold 2 is fixed with guide posts 201 which are slidably connected with the guide holes 101, and the fixed mold 1 and the movable mold 2 are combined with each other to form an injection chamber 102; further comprising: a feeding pipe 3 which is fixedly installed in the movable mold 2, and the side wall of the feeding pipe 3 is connected with a conveying pipe 5 which passes through the movable mold 2, and a reflux kettle 4 is also fixed on the top of the movable mold 2; a conducting feeding mechanism is arranged at A conveying hole 7 connected to the injection molding chamber 102 is formed on the conductive feeding mechanism in the feeding tube 3, and the conductive feeding mechanism can be actuated when the pressure in the feeding tube 3 changes to adjust the conduction state of the conveying hole 7; a conductive reflux mechanism is arranged in the feeding tube 3 and connected to the conductive feeding mechanism, and a negative pressure suction mechanism connected to the conductive reflux mechanism is arranged in the reflux kettle 4, and the negative pressure suction mechanism can be actuated when the conductive reflux mechanism moves to suck the raw materials remaining in the feeding tube 3 into the reflux kettle 4 through the conductive reflux mechanism.

[0037] Specifically, when the movable mold 2 and the fixed mold 1 cooperate with each other, an injection molding chamber 102 will be formed. At this time, the raw material is transported to the feeding pipe 3 through the conveying pipe 5, and the pressure in the feeding pipe 3 will increase. Under the action of the pressure, the conductive feeding mechanism is driven to move, so that the conveying hole 7 is conductive, and the material in the feeding pipe 3 will enter the injection molding chamber 102 through the conveying hole 7. When the injection molding is completed, the pressure in the feeding pipe 3 continues to increase, so as to block the conveying hole 7 again through the conductive feeding mechanism, and under the action of the pressure, it will also drive the conductive feeding mechanism to move. The flow mechanism and the negative pressure suction mechanism move, and under the action of the reflux mechanism, the feeding pipe 3 is connected with the reflux kettle 4. Under the action of the negative pressure suction mechanism, the raw material remaining in the feeding pipe 3 is sucked into the reflux kettle 4, so that the injection molding chamber 102 is automatically injected according to the pressure change in the feeding pipe 3, and the delivery hole 7 is automatically blocked after the injection is completed. The raw material remaining in the feeding pipe 3 can also be cleaned to prevent the feeding pipe 3 from being blocked due to the cooling and hardening of the raw material remaining in the feeding pipe 3 during subsequent injection molding.

[0038] See also Figure 1-Figure 9, the conductive feeding mechanism includes a fixed disk 6 fixedly mounted on the end of the feeding pipe 3 away from the reflux kettle 4, the fixed disk 6 is formed with the conveying hole 7, a sealing disk 8 abutting against the fixed disk 6 is slidably mounted in the feeding pipe 3, and a conducting hole 9 is formed on the sealing disk 8 and is conductively matched with the conveying hole 7, a follower component is arranged in the feeding pipe 3, wherein the follower component includes a rotating rod 10 rotatably mounted in the reflux kettle 4 and fixedly connected to the sealing disk 8, a guide groove is formed on the circumferential outer wall of the rotating rod 10, a sliding disk 11 slidably connected to the rotating rod 10 is slidably sealed in the feeding pipe 3, a first limit block 13 slidably engaged with the guide groove is fixed on the inner wall of the sliding disk 11, a limiting structure connected to the sliding disk 11 is arranged in the feeding pipe 3, the above-mentioned limiting structure includes a limit groove formed on the inner wall of the feeding pipe 3, and a limit rod slidably connected to the limit groove is fixed on the circumferential outer wall of the sliding disk 11.

[0039] In detail, the guide groove can be divided into multiple sections, namely a first vertical groove 1001, a first spiral groove 1002, a second vertical groove 1003, a second spiral groove 1004, a third vertical groove 1005, and a third spiral groove 1006. The first vertical groove 1001, the first spiral groove 1002, the second vertical groove 1003, the second spiral groove 1004, the third vertical groove 1005, and the third spiral groove 1006 are connected to each other from head to tail in sequence. The number of spiral turns of the first spiral groove 1002 is a quarter turn, and the number of spiral turns of the second spiral groove 1004 is a quarter turn. The number of spiral turns of the first vertical groove 1004 is one-half turn, and the number of spiral turns of the third spiral groove 1006 is one-quarter turn. Therefore, the first vertical groove 1001 is just connected with the third spiral groove 1006. In the initial state, the first limit block 13 is located at the connection position of the first vertical groove 1001 and the third spiral groove 1006, so that the distance between the sliding plate 11 and the sealing plate 8 is minimized, the sealing plate 8 and the fixed plate 6 abut against each other, and the conveying hole 7 and the conducting hole 9 are in a misaligned state. Therefore, the conveying hole 7 and the conducting hole 9 are both in the sealing state. In the blocked state, a one-way valve is installed on the feeding pipe 3, and the one-way valve is connected to the conveying pipe 5. When the molten plastic raw material is conveyed to the feeding pipe 3 through the conveying pipe 5, since the conveying hole 7 is in the blocked state, the material will be located between the sealing disk 8 and the sliding disk 11. As the amount of raw material increases, the pressure in the feeding pipe 3 increases. Under the action of the pressure, the sliding disk 11 is pushed toward the direction away from the sealing disk 8, so as to drive the limit rod to move along the length direction of the limit groove. The sliding disk 11 will also drive the first The limit block 13 moves along the length direction of the first vertical groove 1001. Under the action of the first limit block 13 and the first vertical groove 1001, the rotating rod 10 is in a locked state. When the first limit block 13 disengages from the first vertical groove 1001 and enters the first spiral groove 1002, the rotating rod 10 will rotate, thereby driving the sealing disk 8 to rotate. The sealing disk 8 will drive the conducting hole 9 to move to a connection position with the conveying hole 7, so that the raw material enters the injection molding chamber 102 through the conducting hole 9 and the conveying hole 7.

[0040] Preferably, when the injection molding chamber 102 is filled, as the delivery pipe 5 continues to deliver, the pressure in the feed pipe 3 will continue to increase, thereby pushing the sliding disk 11 to continue to move, so that the first limit block 13 continues to move, and when the first limit block 13 moves to the end of the stroke of the first spiral groove 1002, the conducting hole 9 will be separated from the delivery hole 7 again, so that the delivery hole 7 is blocked again. By adjusting the conduction state of the delivery hole 7, it is possible to ensure that the amount of raw materials entering the injection molding chamber 102 each time remains consistent, so as to ensure the consistency of product production. A gate will be formed in the delivery hole 7. After the injection molding chamber 102 is filled, the delivery hole 7 will be in a blocked state. Therefore, the size and shape of the gate formed each time remain consistent, so as to ensure that the residual stress near the gate is small, the gate can be easily separated from the product, and it can also prevent the gate from becoming brittle or soft due to insufficient solidification of the gate other than the part that should be disconnected when opening the mold, resulting in the front end of the gate remaining on the product side.

[0041] See also Figure 5-Figure 7 , Fig. 9 , Fig.11 The conducting reflux mechanism includes a follower disk 14 slidably mounted in the feed pipe 3 and slidably connected to the rotating rod 10, the follower disk 14 abuts against the sliding disk 11, a second reflux hole 15 is opened on the follower disk 14, and a first reflux hole 12 conducting and cooperating with the second reflux hole 15 is opened on the sliding disk 11, and a driven component connected to the follower disk 14 is arranged in the feed pipe 3, wherein the driven component includes a driven component rotatably mounted at the end of the feed pipe 3 and rotatably connected to the reflux kettle 4 The rotating disk 17 is fixed with a supporting sleeve 16 connected with the second reflux hole 15 on the following disk 14, and a hollow tube 18 penetrating the rotating disk 17 is slidably installed in the supporting sleeve 16. The rotating rod 10 is sleeved with a first spring 19, and the two ends of the first spring 19 are respectively abutted against the following disk 14 and the rotating disk 17. It also includes a hollow disk 26 fixedly installed in the reflux kettle 4 and connected with the hollow tube 18, and the hollow disk 26 is connected with a conduit 27 penetrating the reflux kettle 4.

[0042] It should be noted that an infrared sensor 25 is installed on the rotating disk 17 for measuring the distance between the rotating disk 17 and the follower disk 14. In the initial state, the first spring 19 is in a compressed state, so that the follower disk 14 and the sliding disk 11 are located at the end of the stroke in the direction of the fixed disk 6, so that the first limit block 13 is located at the connection position between the first vertical groove 1001 and the first spiral groove 1002. At this time, the first reflow hole 12 and the second reflow hole 15 are in a separated state. When the raw material is transported into the feeding pipe 3, the sliding hole 15 is pushed under the action of pressure. The disk 11 moves in a direction away from the fixed disk 6, thereby driving the first limit block 13 to slide along the first vertical groove 1001. The sliding disk 11 also drives the follower disk 14 to move synchronously to compress the first spring 19. When the first limit block 13 is separated from the first vertical groove 1001 and enters the first spiral groove 1002, the rotating rod 10 rotates, and the conveying hole 7 is connected with the conducting hole 9. At this time, the injection chamber 102 can be injected. The rotating rod 10 also drives the rotating disk 17 to rotate synchronously, thereby passing through the support sleeve 16 and the hollow tube 18. The follower plate 14 is driven to rotate, so as to drive the second return hole 15 to move. When the injection is completed, the pressure in the feeding pipe 3 continues to increase, so that the sliding plate 11 continues to move, so as to drive the first limit block 13 to continue to move. When the first limit block 13 is separated from the first spiral groove 1002 and enters the second vertical groove 1003, the rotating rod 10 rotates a quarter of a circle, and the conveying hole 7 is separated from the conducting hole 9 again, so that the conveying hole 7 is in a blocked state. At this time, the first return hole 12 and the second return hole 15 are still in a separated state. When the first limit block 13 is separated from the first spiral groove 1002, the conveying hole 7 and the conducting hole 9 are separated from each other. When leaving the second vertical groove 1003 and entering the second spiral groove 1004, the rotating rod 10 continues to rotate, so that the follower disk 14 continues to rotate. When the first limit block 13 moves to the connection position between the second spiral groove 1004 and the third vertical groove 1005, at this time, the distance between the follower disk 14 and the rotating disk 17 is the smallest. Under the action of the infrared sensor 25, a signal is sent to the control unit, so that the conveying pipe 5 no longer conveys materials. The control unit is used to control the feeding and stopping of the conveying pipe 5. This is an application of the prior art and will not be elaborated in this application.

[0043] Preferably, at this time, the second reflux hole 15 just moves to the position connected with the first reflux hole 12, so that the support sleeve 16 and the hollow tube 18 are connected with the feeding pipe 3, and under the action of the hollow disk 26 and the conduit 27, the feeding pipe 3 is connected with the outside air. At the same time, under the action of the negative pressure suction mechanism, the raw material remaining in the feeding pipe 3 is sucked into the reflux kettle 4. As the raw material in the feeding pipe 3 continues to decrease, the raw material in the support sleeve 16 and the hollow tube 18 will flow back into the feeding pipe 3, and the first spring 19 is elastically released, so that the follower disk 14 and the sliding disk 11 move toward the initial position to drive the first limit block 13 to slide along the third vertical groove 1005. When the first limit block 13 disengages from the third vertical groove 1005 and enters the third spiral groove 1006, the rotating rod 10 rotates again to drive the follower disk 14 to move. Since the size of the first reflux hole 12 is larger than that of the second reflux hole 15, The raw material in the feed pipe 3 is still in an absorbed state until the first limit block 13 returns to the connection position of the third spiral groove 1006 and the first vertical groove 1001, and the rotating rod 10 just rotates one circle. At this time, the raw material remaining in the feed pipe 3 is completely absorbed, and the first reflow hole 12 and the second reflow hole 15 are in a blocked state again. By adjusting the conduction state of the first reflow hole 12 and the second reflow hole 15, it is possible to absorb the raw material remaining in the feed pipe 3 to prevent the feed pipe 3 from being blocked after the residual raw material is cooled and solidified, resulting in the subsequent molten raw material being unable to be transported to the injection molding chamber 102. The remaining raw material can also be collected and reused. In the entire recycling process, after the raw material fills the injection molding chamber 102, the conduction state of the first reflow hole 12 and the second reflow hole 15 will be quickly adjusted. Therefore, the raw materials are in a molten and flowable state to ensure that the raw materials can be completely absorbed.

[0044] See also Figure 5-Figure 7 , Fig. 9 , Fig.10The negative pressure suction mechanism includes a fourth spiral groove 1007, a fourth vertical groove 1008, and an annular groove 1009 provided on the circumferential outer wall of the rotating rod 10, and the fourth spiral groove 1007, the fourth vertical groove 1008, and the annular groove 1009 are connected to each other in sequence. A guide assembly connected to the rotating rod 10 is provided in the reflux kettle 4, wherein the guide assembly includes a support column 20 fixedly installed in the reflux kettle 4 and symmetrically arranged, and a piston disk 21 slidably connected to the rotating rod 10 is slidably installed on the support column 20, and a second limit block 22 is fixed on the inner wall of the piston disk 21, and the second limit block 22 can slide along the fourth spiral groove 1007, the fourth vertical groove 1008, and the annular groove 1009, and an elastic structure is provided in the reflux kettle 4, and the elastic structure mentioned above includes a second spring 23 sleeved on the rotating rod 10, and the two ends of the second spring 23 are respectively abutted against the piston disk 21 and the hollow disk 26.

[0045] Furthermore, the side wall of the reflux kettle 4 is connected with a discharge pipe 24 and an absorption pipe 28, and a one-way valve connected to the discharge pipe 24 and the absorption pipe 28 is installed on the reflux kettle 4, so that the raw material can only enter the reflux kettle 4 through the absorption pipe 28 and be discharged through the discharge pipe 24. The discharge pipe 24 is located at the lower end of the reflux kettle 4 close to the movable mold 2, and its height is lower than the absorption pipe 28, ensuring that the raw material in the reflux kettle 4 can be completely discharged. The end of the absorption pipe 28 is inserted into the conduction hole 9, and the gap between the absorption pipe 28 and the fixed disk 6 is small, ensuring that the absorption pipe 28 can completely absorb the residual raw material in the feeding pipe 3. The tube body of the absorption pipe 28 inserted into the conduction hole 9 is made of soft material and can be bent to a certain extent, ensuring that the absorption pipe 28 can give way when the sealing disk 8 moves. The number of spiral turns of the four spiral grooves 1007 is three quarters of a turn, and the number of turns of the annular groove 1009 is one quarter of a turn. In the initial state, the first limit block 13 is located at the connection position between the first vertical groove 1001 and the third spiral groove 1006, and the second limit block 22 is located at the connection position between the annular groove 1009 and the fourth spiral groove 1007, so that the distance between the piston disk 21 and the rotating disk 17 is the largest, and the second spring 23 is in a compressed state. When injection molding is required, as the amount of raw material added into the feeding pipe 3 increases, the sliding disk 11 is pushed to move under the action of pressure, thereby controlling the movement of the first limit block 13. When the first limit block 13 slides in the first spiral groove 1002, the rotating rod 10 rotates to make the conveying hole 7 conductive. At the same time, the rotating rod 10 will also The fourth spiral groove 1007 is driven to move. Under the action of the second limit block 22, the piston disk 21 moves along the length direction of the support column 20 and moves toward the direction of the rotating disk 17 to compress the second spring 23. When the first limit block 13 disengages from the first spiral groove 1002 and enters the second spiral groove 1004 through the second vertical groove 1003, the rotating rod 10 continues to rotate. At this time, the second limit block 22 continues to slide along the fourth spiral groove 1007, so that the distance between the piston disk 21 and the rotating disk 17 continues to decrease. When the first limit block 13 moves to the connection position of the second spiral groove 1004 and the third vertical groove 1005, the second limit block 22 just moves to the connection position of the fourth spiral groove 1007 and the fourth vertical groove 1008. The compression amount of the second spring 23 reaches the maximum. At this time, the first reflux hole 12 and the second reflux hole 15 are in the conducting state, and the end of the absorption tube 28 just enters the conducting hole 9. The second spring 23 is elastically released and drives the piston disk 21 to move toward the initial position, so that negative pressure is formed in the reflux kettle 4. Under the action of the negative pressure, the raw materials remaining in the feeding pipe 3 are sucked into the reflux kettle 4 through the absorption tube 28. As the raw materials in the feeding pipe 3 decrease, the raw materials in the support sleeve 16 and the hollow tube 18 will also flow back into the feeding pipe 3 and be sucked into the reflux kettle 4. When the second limit block 22 moves to the connecting position of the fourth vertical groove 1008 and the annular groove 1009, since the amount of raw materials that can be absorbed by the reflux kettle 4 is greater than the residual amount of raw materials remaining in the feeding pipe 3,It can ensure that no raw material remains in the feeding tube 3. When the first stop block 13 enters the third spiral groove 1006, the rotating rod 10 continues to rotate, so that the second stop block 22 slides along the annular groove 1009 until the first stop block 13 and the second stop block 22 return to the initial position, thus completing the absorption of the raw material remaining in the feeding tube 3.

[0046] Preferably, during the injection molding process, and when the first reflux hole 12 and the second reflux hole 15 are in a blocked state, the cooperation of the second limit block 22 and the fourth spiral groove 1007 can realize continuous compression and energy storage of the second spring 23 to ensure that when the first reflux hole 12 and the second reflux hole 15 are connected, the elastic potential energy of the second spring 23 forms a negative pressure in the reflux kettle 4 to quickly absorb the residual raw material, and because the amount that the reflux kettle 4 can absorb is greater than the residual raw material amount in the feeding pipe 3, it can ensure that the raw material can be completely sucked into the reflux kettle 4 to achieve the effect of not clogging the feeding pipe 3, wherein a resistance heater can also be installed in the reflux kettle 4, and when absorbing the residual raw material, the raw material is heated to ensure that the raw material always maintains the required fluidity, and when the piston disk 21 moves toward the rotating disk 17, the raw material in the reflux kettle 4 can be transported to the raw material bin through the discharge pipe 24 for reuse, thereby realizing the recycling of the raw material and ensuring that the raw material is not wasted.

[0047] An injection molding method of a biodegradable box injection mold based on negative pressure assisted injection comprises the following steps:

[0048] Step 1: conveying the injection molding raw material into the feeding pipe 3 through the conveying pipe 5, so that the pressure in the feeding pipe 3 gradually increases;

[0049] Step 2: Under the action of pressure, the conducting feeding mechanism is driven to move, so that the conveying hole 7 is conducted, and the raw material will enter the injection molding chamber 102 through the conveying hole 7;

[0050] Step 3: When the injection molding chamber 102 is filled, the pressure in the feeding pipe 3 continues to increase, and the feeding hole 7 is blocked again by controlling the conducting feeding mechanism. At the same time, the negative pressure suction mechanism and the conducting reflux mechanism can also be driven to move;

[0051] Step 4: Under the action of the reflux conduction mechanism, the feed pipe 3 is connected to the reflux kettle 4. At the same time, under the action of the negative pressure suction mechanism, the raw materials remaining in the feed pipe 3 are sucked into the reflux kettle 4.

[0052] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0053] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A biodegradable box injection mold based on negative pressure assisted injection, comprising: A fixed mold (1) and a movable mold (2), wherein the fixed mold (1) and the movable mold (2) are combined to form an injection molding chamber (102); It is characterized by further comprising: A feed pipe (3) is fixedly installed in the movable mold (2); a side wall of the feed pipe (3) is connected to a delivery pipe (5) that passes through the movable mold (2); and a reflux kettle (4) is also fixed on the top of the movable mold (2); A conducting feeding mechanism is arranged in the feeding pipe (3), a delivery hole (7) connected to the injection molding chamber (102) is formed on the conducting feeding mechanism, and the conducting feeding mechanism can be activated when the pressure in the feeding pipe (3) changes to adjust the conducting state of the delivery hole (7); The conductive feeding mechanism comprises a fixed disk (6) fixedly mounted on the end of the feeding pipe (3) away from the reflux kettle (4), the fixed disk (6) being provided with the conveying hole (7), a sealing disk (8) slidably mounted in the feeding pipe (3) and abutting against the fixed disk (6), a conductive hole (9) being formed in the sealing disk (8) and being conductively matched with the conveying hole (7), and a follower assembly being arranged in the feeding pipe (3); The follower assembly comprises a rotating rod (10) rotatably mounted in the reflux kettle (4) and fixedly connected to the sealing disk (8); a guide groove is provided on the circumferential outer wall of the rotating rod (10); a sliding disk (11) slidably connected to the rotating rod (10) is slidably sealed in the feeding pipe (3); a first limiting block (13) slidably engaged with the guide groove is fixed on the inner wall of the sliding disk (11); and a limiting structure connected to the sliding disk (11) is provided in the feeding pipe (3); It also includes a conducting reflux mechanism, which is arranged in the feed pipe (3) and connected to the conducting feed mechanism. The reflux kettle (4) is provided with a negative pressure suction mechanism connected to the conducting reflux mechanism. The negative pressure suction mechanism can be activated when the conducting reflux mechanism moves, so as to suck the raw materials remaining in the feed pipe (3) into the reflux kettle (4) through the conducting reflux mechanism. The negative pressure suction mechanism comprises a fourth spiral groove (1007), a fourth vertical groove (1008), and an annular groove (1009) which are provided on the circumferential outer wall of the rotating rod (10); the fourth spiral groove (1007), the fourth vertical groove (1008), and the annular groove (1009) are connected to each other in sequence from head to tail; a discharge pipe (24) and an absorption pipe (28) are connected to the side wall of the reflux kettle (4); a one-way valve connected to the discharge pipe (24) and the absorption pipe (28) is installed on the reflux kettle (4); and a guide assembly connected to the rotating rod (10) is provided in the reflux kettle (4).

2. The biodegradable box injection mold based on negative pressure assisted injection according to claim 1, characterized in that: The conducting reflux mechanism comprises a follower disk (14) slidably mounted in the feeding tube (3) and slidably connected to the rotating rod (10); the follower disk (14) abuts against the sliding disk (11); a second reflux hole (15) is provided on the follower disk (14); a first reflux hole (12) conducting and cooperating with the second reflux hole (15) is provided on the sliding disk (11); and a driven component connected to the follower disk (14) is provided in the feeding tube (3).

3. The biodegradable box injection mold based on negative pressure assisted injection according to claim 2, characterized in that: The driven assembly comprises a rotating disk (17) rotatably mounted on the end of the feeding pipe (3) and rotatably connected to the reflux kettle (4); a supporting sleeve (16) connected to the second reflux hole (15) is fixed on the following disk (14); a hollow tube (18) penetrating the rotating disk (17) is slidably mounted in the supporting sleeve (16); a first spring (19) is sleeved on the rotating rod (10); two ends of the first spring (19) are respectively in contact with the following disk (14) and the rotating disk (17); It also includes a hollow disk (26) fixedly installed in the reflux kettle (4) and connected to the hollow tube (18), and the hollow disk (26) is connected to a conduit (27) that runs through the reflux kettle (4).

4. The biodegradable box injection mold based on negative pressure assisted injection according to claim 3, characterized in that: The guide assembly comprises a support column (20) fixedly mounted in the reflux kettle (4) and symmetrically arranged, a piston disc (21) slidably mounted on the support column (20) and slidably connected to the rotating rod (10), a second limit block (22) being fixed to the inner wall of the piston disc (21), the second limit block (22) being able to slide along the fourth spiral groove (1007), the fourth vertical groove (1008), and the annular groove (1009), and an elastic structure is arranged in the reflux kettle (4).

5. The biodegradable box injection mold based on negative pressure assisted injection according to claim 4, characterized in that: The elastic structure comprises a second spring (23) sleeved on the rotating rod (10), and two ends of the second spring (23) are respectively in contact with the piston disc (21) and the hollow disc (26).

6. An injection molding method of a biodegradable box injection mold based on negative pressure assisted injection, using the biodegradable box injection mold based on negative pressure assisted injection as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: conveying the injection molding raw material into the feeding pipe (3) through the conveying pipe (5), so that the pressure in the feeding pipe (3) gradually increases; Step 2: Under the action of pressure, the conducting feeding mechanism is driven to move, so that the conveying hole (7) is connected, and the raw material will enter the injection molding chamber (102) through the conveying hole (7); Step 3: When the injection molding chamber (102) is fully filled, the pressure in the feeding pipe (3) continues to increase, and the feeding hole (7) is blocked again by controlling the feeding mechanism, and at the same time, the negative pressure suction mechanism and the reflux mechanism are driven to move; Step 4: Under the action of the reflux conduction mechanism, the feed pipe (3) is connected to the reflux kettle (4). At the same time, under the action of the negative pressure suction mechanism, the raw materials remaining in the feed pipe (3) are sucked into the reflux kettle (4).

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