Cup body injection mold with improved demolding effect

Abstract

The utility model relates to injection mold technical field, especially improve the cup body injection mold of demoulding effect, including mutually cooperate's upper die main part and lower die main body, be provided with at least one die core assembly between upper die main part and lower die main body, and die core assembly includes upper die core, lower die core, ejector rod and ejector insert, and the movable joint of ejector rod and lower die core, and the connection on ejector rod of ejector insert, and the butt joint on lower die core of ejector insert, the cavity for shaping the chamber of inverted cup body is formed by cooperation of upper die core, lower die core and ejector insert, and the lower half portion in the cup body is used for shaping ejector insert, and ejector insert includes inner insert and outer insert, realize the balanced support and synchronous ejection of the lower half portion in the cup body, effectively avoid the problem of the traditional single ejector insert because of close fit leads to the strain, and the probability of vacuum adsorption between cup body and mould cavity is greatly reduced by double insert synchronous ejection, further reduce the risk of cup body deformation, strain.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, and in particular to a cup injection mold that improves the demolding effect. Background Technology

[0002] Disposable milk tea cups are a common packaging material for everyday beverages, and their production primarily utilizes injection molding, which allows for mass production of the cups using injection molds. In the demolding process after injection molding, efficiently and without damage removing the cups from the mold is crucial for ensuring both production efficiency and product quality.

[0003] Currently, the traditional demolding methods commonly used in the industry mainly involve two core steps: air-blowing separation and ejection insert ejection. First, air is introduced between the mold cavity and the cup body using an air-blowing device. The gas pressure initially separates the cup body from the inner wall of the mold cavity, eliminating the adhesion between them. Then, an ejection insert placed inside the mold abuts against the lower half of the cup body, applying a pushing force to eject the cup body from the mold cavity. However, this traditional process has significant technical defects, hindering the improvement of production automation and product qualification rates.

[0004] On the one hand, the lower part of the cup body after ejection remains tightly fitted with the ejector insert, resulting in significant friction between them. If the cup body is directly removed by a robotic arm, the relative friction between the mating surfaces can easily cause scratches, pulls, and other defects on the inner wall of the cup, affecting the product's appearance and structural integrity. Therefore, the existing process must add a robotic arm-assisted separation step; that is, the robotic arm applies a pulling force to the cup body along the mold opening direction, separating the cup body from the ejector insert to a certain extent before the removal operation can be completed. This additional step not only increases equipment investment and production process complexity but also reduces production efficiency, failing to achieve automatic cup detachment, which contradicts the high-efficiency operation requirements of automated production lines.

[0005] On the other hand, to address the issue of a tight fit between the cup body and the ejector insert, some solutions attempt to reduce the contact area of ​​the ejector insert to only contact the middle of the cup bottom. However, this improvement introduces new technical problems: due to the large contact area between the inner side of the cup body and the mold cavity, a sealed space easily forms between the cup body and the cavity during ejection, creating a vacuum adsorption effect. This vacuum effect causes the cup body to experience a reverse adsorption force, which not only increases ejection resistance but also easily leads to defects such as tearing and deformation on the sidewalls or bottom of the cup body due to uneven stress, seriously affecting the stability of product quality.

[0006] In summary, the existing injection molding demolding process for disposable milk tea cups has significant shortcomings in achieving automatic cup detachment, avoiding tearing defects, and improving production efficiency. An improved demolding technology solution is urgently needed to solve the above technical problems. Utility Model Content

[0007] To overcome the shortcomings mentioned above, this utility model aims to provide a technical solution that can solve the above problems.

[0008] A cup injection mold for improving demolding effect includes an upper mold body and a lower mold body that cooperate with each other. At least one mold core assembly is disposed between the upper mold body and the lower mold body. The mold core assembly includes an upper mold core, a lower mold core, an ejector pin, and an ejector insert. The ejector pin is movably connected to the lower mold core, and the ejector insert is connected to the ejector pin and abuts against the lower mold core. The upper mold core, lower mold core, and ejector insert cooperate to form a cavity for molding an inverted cup body. The ejector insert is used to mold the cup body. The lower part of the inner part includes an inner insert and an outer insert. The outer insert is a ring-shaped structure that surrounds the inner insert. The ejector rod is fixedly connected to the inner insert, and a constraint structure is formed between the abutting walls of the outer insert and the inner insert so that the inner insert can drive the outer insert to dock together with the lower mold core when the mold is closed. The lower mold core is also provided with a limiting rod and a spring that act on the outer insert. The outer insert is separated from the lower mold core by the elastic force of the spring and the constraint of the limiting rod.

[0009] Preferably, the sidewalls of the inner insert and the inner wall of the outer insert both have inclined surfaces, and the inner insert and the outer insert form a constraint structure through the inclined surfaces.

[0010] Preferably, the lower mold core has multiple evenly spaced receiving holes corresponding to the outer insert, and the spring is disposed in the receiving holes and can extend out of the receiving holes to form an elastic force on the outer insert.

[0011] Preferably, the lower mold core has multiple through holes that are evenly corresponding to the outer insert, and the bottom of the outer insert has a pair of threaded holes corresponding to the through holes. A countersunk elongated hole is provided at the end of the through hole away from the outer insert. The limiting rod has multiple rods that match the through holes. The limiting rod passes through the through hole along one end of the countersunk elongated hole and is threadedly connected to the threaded hole. The end of the limiting rod is constrained in the countersunk elongated hole.

[0012] Preferably, the number of through holes is the same as the number of receiving holes, and the multiple through holes are connected to the multiple receiving holes respectively, so that the spring is sleeved on the limiting rod for constraint.

[0013] Preferably, the upper mold core is provided with a hot nozzle connection groove that connects to the cavity, and the upper mold body is provided with a glue injection system, which connects to the cavity through the hot nozzle connection groove.

[0014] Compared with the prior art, the beneficial effects of this utility model are: By innovatively designing the ejector insert as a combination of inner and outer inserts, and coordinating with the constraint structure, limiting rods, and springs, the inner insert can precisely align the outer insert with the lower mold core during mold closing, ensuring the cavity molding accuracy. During demolding, the ejector push rod moves the inner insert upwards, while the springs push the outer insert to separate from the lower mold core, achieving balanced support and synchronous ejection of the lower half of the cup body. This effectively avoids the tearing problem caused by the tight fit of traditional single ejector inserts. Furthermore, the synchronous ejection of the two inserts significantly reduces the probability of vacuum adhesion between the cup body and the mold cavity, further reducing the risk of cup body deformation and tearing, and ensuring product molding quality. When the outer insert is constrained by the limiting rod, the inner insert continues to move upwards and separates from the outer insert, gradually releasing the constraint from the inside of the cup body, ultimately achieving automatic and smooth cup body detachment. This eliminates the need for additional robotic arms to assist in the separation process, simplifying the production process, reducing equipment investment and operating steps, significantly improving production efficiency, and meeting the high-efficiency operation requirements of automated production lines.

[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model in the mold-closed state; Figure 2 This is a schematic diagram of the structure of this utility model in the mold-open state; Figure 3 This is a schematic diagram of the mold core assembly in the mold-closed state in this utility model; Figure 4 This is a schematic diagram of the mold core assembly in the mold-opening state through the upper mold body and the lower mold body of this utility model; Figure 5 This is a schematic diagram of the structure of the mold core assembly in this utility model, in which the ejector push rod and spring pusher push the ejector insert in the state of being in motion. Figure 6 This is a schematic diagram of the structure of the mold core assembly in this utility model, which separates the inner insert and the outer insert by means of an ejector push rod.

[0018] The reference numerals and names in the figure are as follows: Cup body 1, upper mold body 10, lower mold body 20, upper mold core 30, hot nozzle connecting groove 31, lower mold core 40, receiving hole 41, through hole 42, countersunk elongated hole 43, ejector push rod 50, ejector insert 60, inner insert 61, outer insert 62, threaded hole 621, limiting rod 63, spring 64. Detailed Implementation

[0019] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0020] Please see Figure 1-6 In this embodiment of the present invention, a cup injection mold for improving demolding effect includes an upper mold body 10 and a lower mold body 20 that cooperate with each other. At least one mold core assembly is provided between the upper mold body 10 and the lower mold body 20. The mold core assembly includes an upper mold core 30, a lower mold core 40, an ejector rod 50, and an ejector insert 60. The ejector rod 50 is movably connected to the lower mold core 40. The ejector insert 60 is connected to the ejector rod 50 and abuts against the lower mold core 40. The upper mold core 30, the lower mold core 40, and the ejector insert 60 cooperate to form a cavity for molding an inverted cup body. The ejector insert 60 is used to mold the lower half of the cup body 1. The ejector insert 60 includes an inner insert 61 and an outer insert 62. 2. The outer insert 62 has a ring-shaped structure, surrounding the inner insert 61. The ejector rod 50 is fixedly connected to the inner insert 61, and a constraint structure is formed between the abutting walls of the outer insert 62 and the inner insert 61, so that when the mold is closed, the inner insert 61 can drive the outer insert 62 to dock together on the lower mold core 40. The lower mold core 40 is also provided with a limiting rod 63 and a spring 64 acting on the outer insert 62. The outer insert 62 is separated from the lower mold core 40 by the elastic force of the spring 64 and the constraint of the limiting rod 63. The upper mold core 30 is provided with a hot nozzle connection groove 31 that docks with the cavity. The upper mold body 10 is provided with a glue injection system, which docks with the cavity through the hot nozzle connection groove 31.

[0021] During injection molding, the mold closing operation is performed first. During this process, the inner insert 61, which is fixedly connected to the ejector pin 50, will use the constraint structure between itself and the outer insert 62 abutting the wall to drive the outer insert 62 to overcome the elastic force of the spring 64 on the lower mold core 40, and together they will abut against the lower mold core 40, so that the upper mold core 30, lower mold core 40, inner insert 61 and outer insert 62 together enclose and form a cavity for molding the inverted cup body; then, the injection molding material passes through the upper mold main body The injection system of body 10 injects the glue into the cavity through the hot nozzle connection groove 31 on the upper mold core 30, which is connected to the cavity, to complete the injection molding of cup body 1. Then, it enters the demolding stage. The upper mold core 30 is installed on the upper mold body 10, and the lower mold core 40 is installed on the lower mold body 20. The upper mold core 30 and the lower mold core 40 are separated by the separation of the upper mold body 10 and the lower mold body 20. If an air blowing system is provided, the mold cavity is blown before separation to make cup body 1 separate from the mold cavity. Separate and open the upper mold core 30 and lower mold core 40. At this time, the ejector rod 50 is driven by the hydraulic power system, which drives the inner insert 61 to move upward. The constraint between the inner insert 61 and the outer insert 62 is released. The spring 64 on the lower mold core 40 pushes the outer insert 62 to separate from the lower mold core 40 under the action of elastic force. That is, the inner insert 61 is driven by the ejector rod 50, and the outer insert 62 is driven by the spring 64, which will simultaneously separate from the lower mold core 40. At this time, the formed inverted cup 1 moves upward synchronously with the inner insert 61 and the outer insert 62, and gets away from the cavity constraint of the lower mold core 40. When it gets away from the constraint of the limit rod 63 on the outer insert 62, the ejector rod 50 continues to move, driving the inner insert 61 to separate from the outer insert 62. At this time, the formed inverted cup 1 will move upward synchronously with the inner insert 61, and finally the inner side of the cup 1 is completely freed from the constraint, thus successfully demolding.

[0022] Therefore, by innovatively designing the ejector insert 60 as a combination of an inner insert 61 and an outer insert 62, and in conjunction with the synergistic effect of the constraint structure, the limiting rod 63, and the spring 64, the inner insert 61 can drive the outer insert 62 to precisely align with the lower mold core 40 during mold closing, ensuring the cavity forming accuracy. During the demolding stage, the ejector push rod 50 drives the inner insert 61 to move upward, while the spring 64 pushes the outer insert 62 to simultaneously separate from the lower mold core 40, achieving balanced support and synchronous ejection of the lower half of the cup body 1, effectively avoiding the problems caused by the tight fit of the traditional single ejector insert 60. The problem of tearing is eliminated, and the simultaneous ejection of the two inserts greatly reduces the probability of vacuum adsorption between the cup body 1 and the mold cavity, further reducing the risk of deformation and tearing of the cup body 1 and ensuring the product molding quality. When the cup body 1 is ejected to the limit rod 63 to constrain the outer insert 62, the inner insert 61 continues to move upward and separates from the outer insert 62, so that the inner side of the cup body 1 is gradually released from the constraint, and finally the cup body 1 is automatically and smoothly detached. No additional robotic arm is required to assist in the separation process, which simplifies the production process, reduces equipment investment and operation steps, significantly improves production efficiency, and meets the high-efficiency operation requirements of automated production lines.

[0023] Please see Figure 3 and Figure 6 Based on the above technical solution, it is further proposed that the side wall of the inner insert 61 and the inner wall of the outer insert 62 both have inclined surfaces. The inner insert 61 and the outer insert 62 form a constraint structure through the inclined surfaces. The inclined surface structure can form a stable guiding and force transmission effect through the inclined surface contact. When the mold is closed, the inner insert 61 moves downward and can accurately drive the outer insert 62 to synchronously connect with the lower mold core 40 through the inclined surface, avoiding the mold closing deviation caused by the misalignment of the constraint surface. At the same time, during the synchronous separation process of the inner insert 61 and the outer insert 62 in the early stage of demolding, the inclined surface can disperse the contact stress, reduce the wear between the inserts, and extend the service life of the mold.

[0024] Alternatively, the sidewalls of the inner insert 61 and the inner wall of the outer insert 62 may have stepped structures. The inner insert 61 and the outer insert 62 form a constraint structure through the stepped structure. The stepped structure can achieve more reliable constraint positioning through the rigid contact of the stepped surface. When the mold is closed, the locking action of the stepped surface can ensure the accurate relative position of the inner insert 61 and the outer insert 62, prevent the insert from radially shifting during the ejection process, further ensure the molding accuracy of the lower half of the cup body 1, and avoid the defect of uneven wall thickness of the cup body 1 caused by the misalignment of the insert.

[0025] Therefore, both the inclined surface and the stepped structure can accommodate the assembly gap requirements of the inner insert 61 and the outer insert 62, ensuring the stability of the constraint during mold closing and reserving reasonable space for the separation of the inner insert 61 and the outer insert 62 in the later stage of demolding. When the outer insert 62 is constrained by the limit rod 63 after ejection, the inner insert 61 can quickly detach along the inclined surface or the stepped surface, avoiding the phenomenon of constraint jamming, ensuring a smoother process of gradually releasing the constraint on the inner side of the cup body 1, and further reducing the risk of damage to the cup body 1.

[0026] Please see Figure 3-6 Based on the above technical solution, it is further proposed that multiple receiving holes 41 evenly corresponding to the outer insert 62 be opened on the lower mold core 40. The spring 64 is set in the receiving hole 41 and can extend out of the receiving hole 41 to form an elastic force on the outer insert 62. The receiving hole 41 provides a precise installation and positioning space for the spring 64, so that the spring 64 can be stably set below the outer insert 62. The multiple springs 64 are evenly distributed, which can apply a balanced elastic force to the outer insert 62, avoiding the outer insert 62 from tilting or jamming due to uneven spring force. This ensures that the outer insert 62 can be released from the lower mold core 40 synchronously and smoothly with the inner insert 61 during demolding, further ensuring the balanced force on the cup body 1 and reducing the risk of deformation and tearing.

[0027] The lower mold core 40 has multiple through holes 42 that are evenly corresponding to the outer insert 62, and the bottom of the outer insert 62 has a pair of threaded holes 621 corresponding to the through holes 42. A countersunk elongated hole 43 is provided at the end of the through hole 42 away from the outer insert 62. The limiting rod 63 has multiple rods that match the through holes 42. The limiting rod 63 passes through the through hole 42 along one end of the countersunk elongated hole 43 and is threadedly connected to the threaded hole 621. The end of the limiting rod 63 is constrained in the countersunk elongated hole 43. The limiting rod 63 passes through the countersunk elongated hole 43 into the through hole 42 and connects with the threaded hole 621 at the bottom of the outer insert 62. This not only achieves a firm fixation between the limiting rod 63 and the outer insert 62, but also uses the countersunk elongated hole 43 to constrain the end of the limiting rod 63, precisely limiting the up and down movement of the outer insert 62. This prevents the outer insert 62 from excessively displacing or detaching from the lower mold core 40 due to the spring force. At the same time, the threaded connection structure facilitates the disassembly and maintenance of the limiting rod 63 and the outer insert 62, reducing mold maintenance costs.

[0028] The number of through holes 42 is the same as the number of receiving holes 41, and the multiple through holes 42 are connected to the multiple receiving holes 41 respectively, so that the spring 64 is fitted on the limiting rod 63 for constraint; the limiting rod 63 can guide and limit the spring 64, prevent the spring 64 from shifting or twisting during compression or rebound, ensure that the spring 64 always exerts force stably along the axial direction, and extend the service life of the spring 64. At the same time, this structural design realizes the integrated assembly of the spring 64 and the limiting rod 63, reduces the redundant structure inside the mold, and improves the overall compactness and space utilization of the mold.

[0029] Therefore, the evenly distributed receiving holes 41 and through holes 42 correspond to the outer insert 62, making the stress and movement state of each part of the outer insert 62 highly consistent, further adapting to the molding and demolding requirements of the inverted cup body 1, ensuring the molding accuracy of the lower half of the cup body 1, providing a stable structural foundation for the subsequent separation operation of the inner insert 61 and the outer insert 62, and ultimately achieving a comprehensive improvement in the mold demolding performance, structural reliability and maintenance convenience.

[0030] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

Claims

1. A cup injection mold for improving demolding effect, comprising an upper mold body (10) and a lower mold body (20) that cooperate with each other, wherein at least one mold core assembly is provided between the upper mold body (10) and the lower mold body (20), the mold core assembly comprising an upper mold core (30), a lower mold core (40), an ejector rod (50) and an ejector insert (60), the ejector rod (50) being movably connected to the lower mold core (40), the ejector insert (60) being connected to the ejector rod (50) and abutting against the lower mold core (40), the upper mold core (30), the lower mold core (40) and the ejector insert (60) cooperating to form a cavity for molding an inverted cup body, characterized in that, The ejector insert (60) is used to form the lower half of the cup body (1). The ejector insert (60) includes an inner insert (61) and an outer insert (62). The outer insert (62) is a ring-shaped structure. The outer insert (62) surrounds the inner insert (61). The ejector push rod (50) is fixedly connected to the inner insert (61). A constraint structure is formed between the abutting walls of the outer insert (62) and the inner insert (61) so that the inner insert (61) can drive the outer insert (62) to dock together on the lower mold core (40) when the mold is closed. A limiting rod (63) and a spring (64) acting on the outer insert (62) are also provided on the lower mold core (40). The outer insert (62) is separated from the lower mold core (40) by the elastic force of the spring (64) and the constraint of the limiting rod (63).

2. The cup injection mold for improving demolding effect according to claim 1, characterized in that, The sidewalls of the inner insert (61) and the inner wall of the outer insert (62) both have inclined surfaces, and the inner insert (61) and the outer insert (62) form a constraint structure through the inclined surfaces.

3. The cup injection mold for improving demolding effect according to claim 1, characterized in that, Multiple receiving holes (41) are evenly provided on the lower mold core (40) corresponding to the outer insert (62). The spring (64) is provided in the receiving hole (41) and can extend out of the receiving hole (41) to form an elastic force on the outer insert (62).

4. A cup injection mold for improving demolding effect according to claim 3, characterized in that, The lower mold core (40) has multiple through holes (42) that are evenly corresponding to the outer insert (62), and the bottom of the outer insert (62) has a pair of threaded holes (621) corresponding to the through holes (42). A countersunk long hole (43) is provided at one end of the through hole (42) away from the outer insert (62). The limiting rod (63) has multiple rods that match the through hole (42). The limiting rod (63) passes through the through hole (42) along one end of the countersunk long hole (43) and is threaded to the threaded hole (621). The end of the limiting rod (63) is constrained in the countersunk long hole (43).

5. A cup injection mold for improving demolding effect according to claim 4, characterized in that, The number of through holes (42) is the same as the number of receiving holes (41), and multiple through holes (42) are connected to multiple receiving holes (41) respectively, so that the spring (64) is sleeved on the limiting rod (63) for constraint.

6. A cup injection mold for improving demolding effect according to claim 1, characterized in that, The upper mold core (30) is provided with a hot nozzle connection groove (31) that connects to the cavity, and the upper mold body (10) is provided with a glue injection system, which connects to the cavity through the hot nozzle connection groove (31).

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