In-mold cut-and-injection device

Abstract

The application discloses a kind of in-mold cutting injection molding devices, including mould base, fixed mould, movable mould and top cutting mechanism;Fixed mould is set in mould base, movable mould is detachably connected to fixed mould, the die core between fixed mould and movable mould constitutes the cavity of the shape required by product, movable mould also has water gap for injecting liquid plastic;Top cutting mechanism includes cutter, bottom plate, limit plate, jacking piece and elastic piece, limit plate is set in mould base, bottom plate is slidably connected with limit plate, one end of cutter is set in bottom plate, the cutting edge of the other end of cutter is set corresponding to the interface of cavity and water gap, elastic piece is set between bottom plate and limit plate to make cutter away from water gap to let out glue channel, when fixed mould and movable mould are closed, jacking piece can be driven by external power source to lift bottom plate and cutter to cut off material head.The application can realize automatic cutting and separation of material head and finished product when mold is not opened, reduce subsequent trimming process, simple structure and convenient operation, reduce production cost, realize automatic production.

Description

Technical Field

[0001] This application relates to the technical field of plastic molding, and more specifically, to an in-mold injection molding apparatus. Background Technology

[0002] Injection molding is a method of injecting hot, molten plastic material at high speed into a closed molding space with the desired shape in a mold. After the plastic material cools and solidifies, the mold is opened and the solidified plastic material is ejected to obtain the molded product. Usually, when molding plastic products with large sprue molds, the sprue is often attached to the product. The removed plastic product needs to be cut off manually or by secondary processing with other equipment to remove the plastic product and the plastic material remaining at the sprue.

[0003] In existing technologies, in-mold cutting devices are manufactured or purchased. These devices typically include small hydraulic cylinders, transmission rods, ball bearings, etc., working in conjunction with a cutter to achieve the effect of the cutter moving up and down within the mold to cut the material head. Although the in-mold cutting device cuts off the material head, its structure is very complex, and the mold cost is greatly increased. Utility Model Content

[0004] This application provides an in-mold cutting injection molding device that can automatically cut and separate the sprue and the finished product when the mold is not open, reducing the subsequent sprue trimming process. It has a simple structure and is easy to operate, reducing production costs and realizing automated production.

[0005] The in-mold injection molding device provided in this application adopts the following technical solution:

[0006] An in-mold injection molding device includes: a mold base, a fixed mold, a moving mold, and an ejector mechanism;

[0007] The fixed mold is disposed on the mold base, and the moving mold is detachably connected to the fixed mold. The mold cores of the fixed mold and the moving mold form a cavity with the required shape of the product. The moving mold also has a sprue for injecting liquid plastic.

[0008] The top-cutting mechanism includes a cutter, a base plate, a limiting plate, a lifting member, and an elastic member. The limiting plate is disposed on the mold base, and the base plate is slidably connected to the limiting plate. One end of the cutter is disposed on the base plate, and the cutting edge of the other end of the cutter is disposed at the interface between the cavity and the sprue. The elastic member is disposed between the base plate and the limiting plate to move the cutter away from the sprue to make room for the glue inlet channel. When the fixed mold and the moving mold are closed, the lifting member can be driven by an external power source to lift the base plate and the cutter to cut off the material head.

[0009] In some technical solutions, the elastic element includes a first elastic sheet and a second elastic sheet arranged coaxially, with the first elastic sheet and the second elastic sheet partially in contact with each other and the remaining parts having a gap between them;

[0010] When the first elastic sheet and the second elastic sheet are in their normal state, there is a travel gap between the base plate and the limiting plate; when the first elastic sheet and the second elastic sheet are compressed, the travel gap becomes smaller and the portion of the first elastic sheet and the second elastic sheet in contact with each other increases.

[0011] In some technical solutions, the base plate is provided with a mounting sleeve and a receiving groove, the elastic element is coaxially arranged with the mounting sleeve and located in the receiving groove, and the end of the mounting sleeve away from the elastic element is located outside the receiving groove; when the elastic element is compressed, the mounting sleeve is located in the receiving groove and abuts against the limiting plate.

[0012] In some technical solutions, a machine tool push rod is also included. The machine tool push rod passes through the mold base and slides with the mold base. One end of the machine tool push rod is used to connect to an external power source, and the other end of the machine tool push rod abuts against the lifting member. The end of the lifting member away from the machine tool push rod abuts against the base plate.

[0013] In some technical solutions, the mold base is provided with an ejector plate and a return pin on the end face facing the fixed mold. There is a gap between the ejector plate and the fixed mold, and the ejector plate slides with the fixed mold. One end of the return pin is provided on the ejector plate, and the other end of the return pin passes through the fixed mold. When the fixed mold and the moving mold are closed, the upper end face of the return pin abuts against the moving mold.

[0014] In some technical solutions, the end face of the machine tool push rod and the ejector plate have a cutting stroke, the stroke gap between the base plate and the limiting plate is equal to the cutting stroke, and when the end face of the machine tool push rod abuts against the ejector plate, the base plate compresses the elastic element and abuts against the limiting plate through the elastic element.

[0015] In some technical solutions, a product ejector pin is also included, with one end of the product ejector pin disposed on the ejector plate and the other end of the product ejector pin disposed corresponding to the cavity; the cavity is provided with a relief groove, and the end face of the product ejector pin away from the ejector plate is located in the relief groove and is flush with the bottom surface of the cavity.

[0016] In some technical solutions, a material head ejector pin is also included, one end of which is disposed on the limiting plate, and the other end of which passes through the fixed mold and is disposed corresponding to the sprue.

[0017] In some technical solutions, the ejector plate is provided with a limiting component, and the limiting component is provided with a flange. After the fixed mold and the moving mold are opened, the machine tool ejector rod drives the ejector plate to move. The flange abuts against the fixed mold, and the product ejector and the material head ejector simultaneously eject the finished product and the material head.

[0018] In some technical solutions, a buffer is provided between the ejector plate and the fixed mold. The buffer is sleeved on the peripheral wall of the return pin and is used to buffer the force between the ejector plate and the fixed mold.

[0019] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0020] After the fixed mold and moving mold are closed, when there is no ejection force, the base plate, under the force of the elastic element, carries the cutter away from the sprue to make way for the glue inlet channel, facilitating the smooth entry of the glue into the cavity to form the finished product. When it is necessary to cut the sprue, an external power source drives the lifting element to lift the base plate. At this time, the base plate gradually compresses the elastic element and moves towards the limiting plate. The base plate carries the cutter upward so that the cutter gradually approaches the interface between the cavity and the sprue until it cuts the sprue, thus completing the action of cutting the sprue and separating the sprue from the product. This application can realize the automatic cutting and separation of the sprue and the finished product when the mold is not opened, reducing the subsequent sprue trimming process. The structure is simple and easy to operate, eliminating the need for external hydraulic devices and the purchase of in-mold cutting devices, reducing production costs and realizing automated production. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0022] Figure 1 This is a schematic diagram of the overall structure of an in-mold injection molding device disclosed in an embodiment of this application;

[0023] Figure 2 This is a cross-sectional view of the overall structure of an in-mold injection molding device disclosed in an embodiment of this application;

[0024] Figure 3 This is a schematic diagram of the structure of an in-mold injection molding device that highlights the cavity, as disclosed in an embodiment of this application.

[0025] Figure 4 This is a schematic diagram of the structure of the ejector mechanism 4 of an in-mold injection molding device disclosed in an embodiment of this application;

[0026] Figure 5This is an exploded view of the structure of the in-mold injection molding device disclosed in this application, showing the ejector mechanism 4, the product ejector pin, and the material head ejector pin;

[0027] Figure 6 This is a schematic diagram of the structure of an in-mold injection molding device that highlights the elastic element, the base plate, and the limiting plate, as disclosed in an embodiment of this application.

[0028] Figure 7 This is a cross-sectional view of the structure of the in-mold injection molding device disclosed in this application, showing the ejector mechanism 4, the product ejector pin, and the material head ejector pin;

[0029] Figure 8 This is a cross-sectional view of the structure of the in-mold injection device disclosed in this application, showing the cutter, product ejector pin, and material head ejector pin.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Mold base; 11. Ejector plate; 12. Return pin; 13. Limiting component; 131. Flange; 14. Buffer component; 2. Fixed mold; 3. Moving mold; 31. Sprue; 4. Ejection cutting mechanism; 41. Cutting blade; 42. Base plate; 421. Mounting sleeve; 422. Receiving groove; 43. Limiting plate; 44. Ejector component; 45. Elastic component; 451. First elastic plate; 452. Second elastic plate; 46. Stroke clearance; 5. Cavity; 51. Clearance groove; 6. Machine ejector rod; 61. Ejection cutting stroke; 7. Product ejector pin; 8. Material head ejector pin; 9. Connecting block. Detailed Implementation

[0032] The present application will be further described in detail below with reference to the accompanying drawings.

[0033] This application provides an in-mold cutting injection molding device that can automatically cut and separate the sprue and the finished product when the mold is not open, reducing the subsequent sprue trimming process. It has a simple structure and is easy to operate, reducing production costs and realizing automated production.

[0034] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all of them. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0035] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] Please see Figure 1 and Figure 2 This is one embodiment of the in-mold injection molding device in this application. The in-mold injection molding device includes a mold base 1, a fixed mold 2, a moving mold 3, and an ejector mechanism 4. The fixed mold 2 is disposed on the mold base 1, and the moving mold 3 is detachably connected to the fixed mold 2. The mold cores of the fixed mold 2 and the moving mold 3 form a cavity 5 with the required shape of the product. The moving mold 3 also has a sprue 31 for injecting liquid plastic. The sprue 31 communicates with the cavity 5 to form a glue inlet channel. After the fixed mold 2 and the moving mold 3 are closed, the liquid plastic is injected through the sprue 31, flows through the glue inlet channel, and enters the cavity 5. After the product in the cavity 5 is formed, the ejector mechanism 4 is used to cut off the product sprue after forming, so that the sprue is separated from the finished product. Then the fixed mold 2 and the moving mold 3 separate to remove the product.

[0037] Please see Figures 2 to 4 Specifically, the top-cutting mechanism 4 includes a cutter 41, a base plate 42, a limiting plate 43, a lifting member 44, and an elastic member 45. The limiting plate 43 is disposed on the mold base 1, and the base plate 42 is located between the limiting plate 43 and the mold base 1 and is slidably connected to the limiting plate 43. One end of the cutter 41 is disposed on the base plate 42, and the cutting edge of the other end of the cutter 41 is disposed at the interface between the cavity 5 and the sprue 31. The elastic member 45 is disposed between the base plate 42 and the limiting plate 43 to move the cutter 41 away from the sprue 31 to make room for the glue inlet channel. When the fixed mold 2 and the moving mold 3 are closed, the lifting member 44 can be driven by an external power source to lift the base plate 42 and the cutter 41 to cut off the material head. In this embodiment, the base plate 42 and the cutter 41 can be lifted synchronously by the lifting member 44; the base plate 42 and the cutter 41 can also be lifted sequentially by the lifting member 44. Specifically, the lifting member 44 is driven by an external power source to lift the base plate 42 first, and the base plate 42 moves upward to lift the cutter 41.

[0038] After the fixed mold 2 and the moving mold 3 are closed, when there is no ejection force, the base plate 42, under the action of the elastic element 45, drives the cutter 41 away from the gate 31 to make room for the glue inlet, so that the glue can smoothly enter the cavity 5 through the gate 31 to form the finished product. When it is necessary to cut the sprue, the external power source drives the lifting element 44 to lift the base plate 42. At this time, the base plate 42 gradually compresses the elastic element 45 and moves towards the limiting plate 43. The base plate 42 carries the cutter 41 upward so that the cutter 41 gradually approaches the interface between the cavity 5 and the gate 31 until it cuts the sprue, thus completing the action of cutting the sprue and separating the sprue from the product. This application can realize the automatic cutting and separation of the sprue and the finished product when the mold is not opened, reducing the subsequent sprue trimming process. The structure is simple and easy to operate. There is no need to connect an external hydraulic device or purchase an in-mold cutting device, which reduces production costs and realizes automated production.

[0039] Please see Figure 2 and Figure 5 In this embodiment, the limiting plate 43 has a receiving cavity for accommodating the base plate 42. The limiting plate 43 is locked to the mold base 1 by bolts, and the limiting plate 43 moves synchronously with the mold base 1. The base plate 42 and the elastic element 45 are both located within the receiving cavity. The cutter 41 passes through the limiting plate 43, and one end of the cutter 41 connected to the base plate 42 is locked to the base plate 42 by bolts. When the elastic element 45 is in its normal state, there is a stroke gap 46 between the base plate 42 and the limiting plate 43 under the action of the elastic element 45 and gravity. This stroke gap 46 is configured as the range of motion of the cutter 41. That is, when the elastic element 45 is in its normal state, the cutter 41 passes through the limiting plate 43 and is away from the sprue 31 to make way for the glue inlet channel; the external power source drives the lifting member 44, which lifts the bottom plate 42 to compress the elastic element 45, and the distance between the bottom plate 42 and the limiting plate 43 gradually decreases. The cutter 41 moves synchronously with the bottom plate 42, and the cutter 41 slides and engages with the limiting plate 43. The cutter 41 gradually approaches the interface between the cavity 5 and the sprue 31 until the material head is cut off when the cutter 41 is at the maximum value of its movement range. The switching between the normal state and the compressed state of the elastic element 45 synchronously changes the size of the stroke clearance 46.

[0040] In an optional embodiment of the above embodiments, the elastic element 45 may be a spring.

[0041] Please see Figure 5 and Figure 6In an optional embodiment of the above embodiments, the elastic member 45 includes a first elastic sheet 451 and a second elastic sheet 452 coaxially arranged, with the first elastic sheet 451 and the second elastic sheet 452 partially in contact with each other and the remaining portions having a gap between them; when the first elastic sheet 451 and the second elastic sheet 452 are in their normal state, there is a stroke gap 46 between the base plate 42 and the limiting plate 43; when the first elastic sheet 451 and the second elastic sheet 452 are compressed, the stroke gap 46 becomes smaller and the portion of the first elastic sheet 451 and the second elastic sheet 452 in contact with each other increases.

[0042] Specifically, the first elastic sheet 451 and the second elastic sheet 452 are coaxially arranged and circular. The first elastic sheet 451 and the second elastic sheet 452 have the same structure. In this embodiment, the elastic element 45 is a butterfly-shaped spring. When the first elastic sheet 451 and the second elastic sheet 452 are in their normal state, the central region of the first elastic sheet 451 and the central region of the second elastic sheet 452 are in contact with each other. The edge regions of the first elastic sheet 451 and the edge regions of the second elastic sheet 452 are folded outward in a direction away from the center of the elastic element 45, so that the edge regions of the first elastic sheet 451 and the edge regions of the second elastic sheet 452 are spaced apart. When the first elastic sheet 451 and the second elastic sheet 452 are compressed, the edge regions of the first elastic sheet 451 and the edge regions of the second elastic sheet 452 can move towards each other, causing the elastic element 45 as a whole to deform. The contact area between the first elastic sheet 451 and the second elastic sheet 452 gradually increases, thereby changing the stroke gap 46 between the base plate 42 and the limiting plate 43.

[0043] Similarly, when the first elastic sheet 451 and the second elastic sheet 452 are in their normal state, the edge regions of the first elastic sheet 451 and the second elastic sheet 452 fold inward toward the center of the elastic member 45, and the edge regions of the first elastic sheet 451 and the second elastic sheet 452 are in contact with each other, while the central regions of the first elastic sheet 451 and the second elastic sheet 452 are far apart, so that there is a gap between the central regions of the first elastic sheet 451 and the second elastic sheet 452. When the first elastic sheet 451 and the second elastic sheet 452 are compressed, the central regions of the first elastic sheet 451 and the second elastic sheet 452 can move toward each other, causing the elastic member 45 as a whole to deform. The contact area between the first elastic sheet 451 and the second elastic sheet 452 gradually increases, thereby changing the travel gap 46 between the base plate 42 and the limiting plate 43.

[0044] Understandably, when the elastic element 45 is compressed, because the disc-shaped spring has a first elastic piece 451 and a second elastic piece 452, the first elastic piece 451 and the second elastic piece 452 have a small floating distance and uniform force when compressed, and occupy less height space compared to ordinary springs. The advantage of ejecting the cutter 41 is more obvious in areas where the stroke clearance 46 is short.

[0045] Please see Figure 6 Furthermore, to enhance the installation stability of the elastic element 45, the base plate 42 is provided with a mounting sleeve 421 and a receiving groove 422. The elastic element 45 is coaxially arranged with the mounting sleeve 421 and located within the receiving groove 422. The end of the mounting sleeve 421 away from the elastic element 45 is located outside the receiving groove 422. When the elastic element 45 is compressed, the mounting sleeve 421 is located within the receiving groove 422 and abuts against the limiting plate 43. Specifically, the mounting sleeve 421 has a circular cross-section, and the mounting groove is a circular groove. The mounting groove can accommodate the first elastic piece 451, the second elastic piece 452, and the mounting sleeve 421. The receiving groove 422 restricts the horizontal displacement of the first elastic piece 451, the second elastic piece 452, and the mounting sleeve 421, and the first elastic piece 451, the second elastic piece 452, and the mounting sleeve 421 only move in the vertical direction.

[0046] Understandably, when the base plate 42 is lifted by the lifting member 44, the limiting plate 43 abuts against the upper end face of the mounting sleeve 421 and gradually compresses the first elastic sheet 451 and the second elastic sheet 452, causing the first elastic sheet 451 and the second elastic sheet 452 to deform and change the stroke gap 46, thereby allowing the cutter 41 to move toward the material head to cut it off. When the lifting member 44 retracts its lifting action on the base plate 42, the base plate 42 gradually moves away from the limiting plate 43 under the action of gravity and the elastic reset action of the elastic member 45. At this time, the first elastic sheet 451 and the second elastic sheet 452 gradually return to their original state, the stroke gap 46 gradually increases, and the base plate 42 drives the cutter 41 away from the gate 31 to make room for the glue inlet channel, so that the glue can smoothly enter the cavity 5 through the gate 31 during the next glue injection.

[0047] Please see Figure 2 and Figure 7 The external power source and the lifting member 44 are connected by a machine tool push rod 6. The machine tool push rod 6 passes through the mold base 1 and slides with it. One end of the machine tool push rod 6 is connected to the external power source, and the other end of the machine tool push rod 6 abuts against the lifting member 44. The end of the lifting member 44 away from the machine tool push rod 6 abuts against the base plate 42. When the external power source lifts the machine tool push rod 6, the machine tool push rod 6 lifts the lifting member 44, and the lifting member 44 drives the base plate 42 to move synchronously.

[0048] In this embodiment, the mold base 1 is provided with an ejector plate 11 and a return pin 12 on the end face facing the fixed mold 2. There is a gap between the ejector plate 11 and the fixed mold 2, and the ejector plate 11 and the fixed mold 2 slide in a vertical direction. One end of the return pin 12 is provided on the ejector plate 11, and the other end of the return pin 12 passes through the fixed mold 2. When the fixed mold 2 and the moving mold 3 are closed, the upper end face of the return pin 12 abuts against the moving mold 3.

[0049] Please see Figure 7 and Figure 8 To achieve precise displacement of the cutter 41, the end face of the machine tool push rod 6 and the ejector plate 11 have a cutting stroke 61. The stroke gap 46 between the base plate 42 and the limiting plate 43 is equal to the cutting stroke 61. When the end face of the machine tool push rod 6 abuts against the ejector plate 11, the base plate 42 compresses the elastic element 45 and abuts against the limiting plate 43. Specifically, the machine tool push rod 6 is located in the area below the ejector plate 11, and the lifting element 44 slides vertically onto the ejector plate 11. The upper end face of the machine tool push rod 6 is larger than the bottom surface area of ​​the lifting element 44. When the machine tool push rod 6 is lifted, the upper end face of the machine tool push rod 6 abuts against the bottom surface of the ejector plate 11, and the bottom surface of the lifting element 44 extends out of the plane containing the bottom surface of the ejector plate 11. The end face of the machine tool push rod 6 and the ejector plate 11 have a top cutting stroke 61, which is the distance between the bottom surface of the lifting part 44 and the bottom surface of the ejector plate 11.

[0050] It is important to emphasize that after injection molding, before the moving mold 3 and the fixed mold 2 separate, an external power source is used to perform an ejection. When the ejector rod 6 moves upward for the distance of the ejection stroke 61, the end face of the ejector rod 6 abuts against the bottom surface of the ejector plate 11. At the same time, the lifting member 44 lifts the base plate 42 under the action of the ejector rod 6. The base plate 42 compresses the elastic member 45 and abuts against the limiting plate 43 through the elastic member 45, so that the cutter 41 gradually approaches the interface between the cavity 5 and the gate 31 until the sprue is cut off. Since the upper end face of the return pin 12 abuts against the moving mold 3, the ejector plate 11 will not be ejected upward. After the lifting member 44 completes the ejection stroke 61, it is restricted from ejection, thus completing the ejection of the sprue.

[0051] Please see Figure 2 , Figure 3 and Figure 8 To facilitate the removal of the product and the sprue, the in-mold injection molding device also includes a product ejector pin 7 and a sprue ejector pin 8. The product ejector pin 7 is used to eject the product, and the sprue ejector pin 8 is used to eject the sprue. One end of the product ejector pin 7 is set on the ejector plate 11, and the other end of the product ejector pin 7 is set corresponding to the cavity 5. The cavity 5 is provided with a relief groove 51, and the end of the product ejector pin 7 away from the ejector plate 11 is located in the relief groove 51 and is flush with the bottom surface of the cavity 5.

[0052] One end of the ejector pin 8 is set on the limiting plate 43, and the other end of the ejector pin 8 passes through the mold 2 and is set corresponding to the sprue 31. Specifically, a connecting block 9 is provided at the end of the ejector pin 8 near the limiting plate 43. The connecting block 9 is fixedly set on the limiting plate 43, and the ejector pin 8 achieves synchronous movement with the limiting plate 43 by being fixed to the connecting block 9.

[0053] To control the ejection height of the product ejector pin 7 and the sprue ejector pin 8, the ejector plate 11 is provided with a limiting member 13. The limiting member 13 is provided with a flange 131. After the fixed mold 2 and the moving mold 3 are opened, the machine tool ejector rod 6 drives the ejector plate 11 to move, and the flange 131 abuts against the fixed mold 2. The product ejector pin 7 and the sprue ejector pin 8 eject the finished product and the sprue simultaneously. Multiple limiting members 13 are provided, and each limiting member 13 is locked to the ejector plate 11 by bolts. In this embodiment, one end of the limiting member 13 is slidably disposed in the fixed mold 2, and the flange 131 is configured to be near the end of the limiting member 13 close to the ejector plate 11, and there is a gap between the flange 131 and the fixed mold 2.

[0054] Furthermore, a buffer 14 is provided between the ejector plate 11 and the fixed mold 2. The buffer 14 is sleeved on the periphery of the return pin 12 and is used to buffer the force between the ejector plate 11 and the fixed mold 2. After the moving mold 3 and the fixed mold 2 separate, the machine tool ejector rod 6 continues to lift the ejector plate 11 upward. At this time, the buffer 14 can alleviate the impact force of the flange 131 on the fixed mold 2. When the ejector plate 11 moves to the point where the flange 131 abuts against the fixed mold 2, the product ejector pin 7 and the sprue ejector pin 8 can smoothly eject the finished product and the sprue.

[0055] It should be emphasized that after the material head is cut off, the moving mold 3 and the fixed mold 2 separate, and the secondary ejection is continued using an external power source. When the end face of the machine tool ejector 6 abuts against the bottom surface of the ejector plate 11, the machine tool ejector 6 continues to move upward to lift the ejector plate 11 and move upward synchronously. Since the upper end of the return pin 12 is no longer restricted by the moving mold 3, the ejector plate 11 carries the product ejector pin 7 and the ejection cutting mechanism 4 upward. The product ejector pin 7 ejects the product, and the limiting plate 43 in the ejection cutting mechanism 4 drives the material head ejector pin 8 to move upward to eject the material head. Until the flange 131 approaches the fixed mold 2 and contacts the fixed mold 2 to stop the ejection of the machine tool ejector 6, the ejection of the product and the material head is completed.

[0056] The above-described 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 do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An in-mold injection molding device, characterized in that, include: Mold base, fixed mold, moving mold, and ejector mechanism; The fixed mold is disposed on the mold base, and the moving mold is detachably connected to the fixed mold. The mold cores of the fixed mold and the moving mold form a cavity with the required shape of the product. The moving mold also has a sprue for injecting liquid plastic. The top-cutting mechanism includes a cutter, a base plate, a limiting plate, a lifting member, and an elastic member. The limiting plate is disposed on the mold base, and the base plate is slidably connected to the limiting plate. One end of the cutter is disposed on the base plate, and the cutting edge of the other end of the cutter is disposed at the interface between the cavity and the sprue. The elastic member is disposed between the base plate and the limiting plate to move the cutter away from the sprue to make room for the glue inlet channel. When the fixed mold and the moving mold are closed, the lifting member can be driven by an external power source to lift the base plate and the cutter to cut off the material head.

2. The in-mold injection molding device according to claim 1, characterized in that, The elastic element includes a first elastic sheet and a second elastic sheet arranged coaxially, with the first elastic sheet and the second elastic sheet partially in contact with each other and the remaining portions having a gap between them. When the first elastic sheet and the second elastic sheet are in their normal state, there is a travel gap between the base plate and the limiting plate; when the first elastic sheet and the second elastic sheet are compressed, the travel gap becomes smaller and the portion of the first elastic sheet and the second elastic sheet in contact with each other increases.

3. The in-mold injection molding device according to claim 1 or 2, characterized in that, The base plate is provided with a mounting sleeve and a receiving groove. The elastic element is coaxially arranged with the mounting sleeve and located in the receiving groove. The end of the mounting sleeve away from the elastic element is located outside the receiving groove. When the elastic element is compressed, the mounting sleeve is located in the receiving groove and abuts against the limiting plate.

4. The in-mold injection molding device according to claim 2, characterized in that, It also includes a machine tool push rod, which passes through the mold base and slides with the mold base. One end of the machine tool push rod is used to connect to an external power source, and the other end of the machine tool push rod abuts against the lifting member. The end of the lifting member away from the machine tool push rod abuts against the base plate.

5. The in-mold injection molding device according to claim 4, characterized in that, The mold base is provided with an ejector plate and a return pin on the end face facing the fixed mold. There is a gap between the ejector plate and the fixed mold, and the ejector plate slides with the fixed mold. One end of the return pin is provided on the ejector plate, and the other end of the return pin passes through the fixed mold. When the fixed mold and the moving mold are closed, the upper end face of the return pin abuts against the moving mold.

6. The in-mold injection molding device according to claim 5, characterized in that, The end face of the machine tool push rod and the ejector plate have a cutting stroke. The stroke gap between the base plate and the limiting plate is equal to the cutting stroke. When the end face of the machine tool push rod abuts against the ejector plate, the base plate compresses the elastic element and abuts against the limiting plate through the elastic element.

7. The in-mold injection molding device according to claim 5, characterized in that, It also includes a product ejector pin, one end of which is disposed on the ejector plate and the other end of which is disposed corresponding to the cavity; the cavity is provided with a relief groove, and the end face of the product ejector pin away from the ejector plate is located in the relief groove and is flush with the bottom surface of the cavity.

8. The in-mold injection molding device according to claim 7, characterized in that, It also includes a material head ejector pin, one end of which is disposed on the limiting plate, and the other end of which passes through the fixed mold and is disposed corresponding to the sprue.

9. The in-mold injection molding device according to claim 8, characterized in that, The ejector plate is provided with a limiting component, and the limiting component is provided with a flange. After the fixed mold and the moving mold are opened, the machine tool ejector rod drives the ejector plate to move. The flange abuts against the fixed mold, and the product ejector and the material head ejector simultaneously eject the finished product and the material head.

10. The in-mold injection molding device according to claim 5, characterized in that, A buffer is provided between the ejector plate and the fixed mold. The buffer is sleeved on the peripheral wall of the return pin and is used to buffer the force between the ejector plate and the fixed mold.

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