Multi-point synchronous glue feeding mechanism for injection mold

Abstract

This utility model relates to the field of injection mold technology, and in particular to a multi-point synchronous injection mechanism for injection molds. Installed within the upper mold cavity, the cavity has an injection hole at its bottom. It includes a shell with an opening and a sealing cover plate. The shell contains a centrally located collecting chamber and a group of injection chambers distributed circumferentially thereafter. The cover plate's inlet connects to the collecting chamber, which in turn connects to each injection chamber via side-wall outlets. Each injection chamber's bottom wall has an injection nozzle extending to its corresponding injection hole. The cover plate, near the upper mold, is equipped with an opening and closing assembly containing a floating valve stem to control the opening and closing of the injection nozzles. A heating assembly heats the shell. Molten plastic is received through the collecting chamber, evenly distributed to each injection chamber via the outlets, and then synchronously injected through the injection nozzles, ensuring consistent flow rate and pressure across all nozzles. The opening and closing assembly prevents drooling or backflow, and the heating assembly maintains the molten plastic to prevent flow channel blockage, effectively improving product quality and production stability.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, and in particular to a multi-point synchronous glue injection mechanism for injection molds. Background Technology

[0002] In injection molding, the injection mold's injection mechanism is a key component for accurately injecting molten material into the mold cavity. Its performance directly affects the molding quality, production efficiency, and product consistency of the plastic parts. For plastic parts with complex structures or large dimensions, multi-point injection is usually required to avoid problems such as excessive material flow distance, uneven filling, and internal stress concentration caused by single-point injection. However, how to ensure uniform material flow at each injection point, synchronized injection timing, and avoid material solidification and blockage during the injection process are technical challenges that urgently need to be solved in the design of injection mold injection mechanisms. Utility Model Content

[0003] To overcome the shortcomings of the prior art, this utility model provides a multi-point synchronous glue injection mechanism for injection molds, which solves the technical problems of uneven material flow and asynchronous glue injection timing at each injection point when using multi-point glue injection in injection molds.

[0004] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0005] A multi-point synchronous injection mechanism for injection molds is used to install on the upper mold of the injection mold. The upper mold has a cavity, and the injection mechanism is disposed within the cavity. A set of injection holes is provided at the bottom of the cavity. The mechanism includes:

[0006] The housing has an opening at the top and a cover plate. The cover plate is installed to seal the opening at the top of the housing. The housing contains a material collection chamber and a set of injection chambers. The material collection chamber is centrally located inside the housing. The set of injection chambers are arranged sequentially along the circumference of the material collection chamber. The cover plate has a material inlet that is connected to the material collection chamber. The side wall of the material collection chamber has a set of material outlets that are connected to the set of injection chambers respectively. Each injection chamber has a glue injection nozzle on its bottom wall. The glue injection nozzle is connected to the corresponding injection chamber and extends axially into the corresponding injection hole.

[0007] A set of opening and closing components, wherein the set of opening and closing components is installed on the side of the cover plate near the upper mold, the opening and closing components include: a floating valve stem, the valve stem being used for opening and closing the injection nozzle;

[0008] A heating assembly for heating the housing.

[0009] Based on the above structure, the principle of the multi-point synchronous injection mechanism for injection molds is as follows: First, the injection mechanism is installed on the upper mold. The inlet is connected to the injection molding machine (not shown) through a pipe. Molten plastic enters the collecting chamber from the inlet on the cover plate. The molten plastic gathers in the collecting chamber and flows synchronously into each injection chamber through a set of flow outlets on its side wall. At this time, the opening and closing component is activated, the valve stem opens, and the molten plastic is ejected from each injection chamber through the injection nozzle at its bottom. The injection nozzle extends into the injection hole, and the molten plastic enters multiple preset positions in the mold cavity (not shown) through the injection hole, realizing multi-point synchronous filling. After injection, the opening and closing component may be deactivated, and the valve stem resets. The corresponding injection nozzle is closed to prevent drooling or backflow. The heating component is used to maintain the temperature of the shell and keep the plastic in the shell in a molten state, so as to avoid the plastic from cooling and solidifying during the flow process, blocking the flow channel or affecting the flowability. The molten plastic input from the inlet is received through the centrally located collection chamber, and then the molten plastic is evenly distributed to a group of injection chambers through the flow outlet. Finally, it is injected into the mold cavity synchronously through the injection nozzles on the bottom wall of each injection chamber. This realizes the synchronous distribution of molten plastic from the inlet to multiple injection nozzles, ensuring that the flow rate and pressure of each injection nozzle are consistent. Multi-point synchronous injection makes the molten plastic flow more evenly in the mold cavity, avoiding defects such as weld lines, shrinkage marks, and warping caused by single injection.

[0010] Furthermore, in a multi-point synchronous injection mechanism for injection molds disclosed in this application, a first sealing element is provided at the contact point between the housing and the cover plate, and the first sealing element is arranged along the circumference of the housing. As a preferred embodiment of this application, in a multi-point synchronous injection mechanism for injection molds disclosed in this application, the first sealing element is used to fill the gap between the housing and the cover plate, preventing molten plastic in the collecting chamber and the injection chamber from leaking through the gap between them, thereby reducing material waste.

[0011] Furthermore, in this application, a multi-point synchronous injection mechanism for an injection mold includes a flow channel within the injection chamber, arranged in a U-shape. As a preferred embodiment of this application, the U-shaped flow channel in this multi-point synchronous injection mechanism for an injection mold ensures that the molten plastic, after entering the injection chamber through the sprue, flows along a U-shaped trajectory—from the outside in—rather than flowing directly to the injection nozzle in a straight line. Through multiple turns and flow buffering, the pressure distribution of the molten plastic within the injection chamber becomes more uniform. Simultaneously, the heating effect of the heating components ensures a stable temperature for the molten plastic.

[0012] Furthermore, in a multi-point synchronous injection mechanism for injection molds disclosed in this application, the heating component includes a heating wire embedded in the bottom and side walls of the housing. As a preferred embodiment of this application, the heating wire generates heat after energization to ensure that the molten plastic inside the housing remains at a set melting temperature, preventing the molten plastic from increasing in viscosity or solidifying due to cooling.

[0013] Furthermore, in this application, a multi-point synchronous injection mechanism for injection molds includes an injection nozzle comprising: a nozzle body detachably mounted on the bottom wall of a housing; a central through-hole communicating with a corresponding injection chamber; and an extension extending radially along one end of the nozzle body near the cover plate. As a preferred embodiment of this application, the through-hole communicating with the injection chamber provides a channel for molten plastic to flow from the injection chamber to the injection hole of the mold, acting as a directional guide to ensure that the molten plastic is injected into the mold cavity along a preset path, preventing diversion or leakage. The nozzle body is detachably mounted on the bottom wall of the housing for easy disassembly, cleaning, or replacement. The extension is used to limit the nozzle body when it is mounted on the housing.

[0014] Furthermore, in this application, a multi-point synchronous injection mechanism for an injection mold includes an opening and closing assembly comprising: a middle shell, an electromagnet, and an elastic element. The middle shell is detachably mounted on the side of the cover plate near the upper mold. The middle shell includes: an inner cavity, a valve stem floatingly mounted within the inner cavity, the valve stem extending axially into a through hole, a protrusion at the end of the valve stem away from the nozzle, the protrusion extending radially along the valve stem, the electromagnet mounted within the inner cavity, the electromagnet located on the side of the protrusion away from the nozzle, the elastic element sleeved on the valve stem, and both ends of the valve stem connected to the middle shell and the side of the protrusion near the nozzle, respectively. As a preferred embodiment of this application, a multi-point synchronous injection mechanism for an injection mold is provided. When the through hole needs to be opened, the electromagnet is energized to generate magnetic force, which attracts the protrusion and drives the valve rod to float away from the nozzle. At this time, the elastic element is stretched, and the end of the valve rod disengages from the through hole, thus opening the flow channel. When closing, the electromagnet is de-energized and the magnetic force disappears. The elastic element releases its elastic potential energy, which drives the valve rod to float closer to the nozzle. The end of the valve rod blocks the through hole, thus closing the flow channel.

[0015] Furthermore, in a multi-point synchronous injection mechanism for injection molds disclosed in this application, a limiting protrusion is provided on the outer wall of the middle shell, the limiting protrusion extending radially along the middle shell, and a third annular seal is provided on the limiting protrusion. When the middle shell is installed on the side of the cover plate near the upper mold, the limiting protrusion and the cover plate abut against each other axially in the middle shell. As a preferred embodiment of this application, in a multi-point synchronous injection mechanism for injection molds disclosed in this application, the limiting protrusion is used to limit excessive axial displacement of the middle shell during installation, avoiding improper installation and ensuring alignment of the valve stem and the through hole; the third annular seal is used to fill the assembly gap between the middle shell and the cover plate, preventing molten plastic from entering the inner cavity.

[0016] Furthermore, in a multi-point synchronous injection mechanism for injection molds disclosed in this application, a set of mounting portions is provided on the outer side of the cover plate, and the set of mounting portions is spaced apart along the circumference of the cover plate. A set of receiving grooves is provided on the upper mold, and the set of receiving grooves corresponds one-to-one with the set of mounting portions. As a preferred embodiment of this application, in the multi-point synchronous injection mechanism for injection molds disclosed in this application, during installation, the mounting portions are embedded into the receiving grooves to ensure that the relative positions of the cover plate and the upper mold are fixed, preventing displacement of the injection mechanism during mold opening and closing, and ensuring axial alignment of the injection nozzle with the injection hole on the upper mold.

[0017] As can be seen from the above technical solution, this utility model has the following beneficial effects:

[0018] The purpose of this invention is to provide a multi-point synchronous injection mechanism for injection molds. It receives molten plastic through a centrally located collecting chamber and distributes it evenly to a group of injection chambers via a flow outlet. The molten plastic is then synchronously injected into the mold cavity through injection nozzles on the bottom walls of each injection chamber. This achieves synchronous distribution of molten plastic from the inlet to multiple injection nozzles, ensuring consistent flow rate and pressure across all nozzles. It solves defects such as weld lines, shrinkage marks, and warping caused by single injection. Simultaneously, it uses an opening and closing component to prevent drooling or backflow, and a heating component to maintain the molten plastic in a molten state to avoid flow channel blockage, thereby improving the quality and production stability of injection molded products. Attached Figure Description

[0019] Figure 1 This is a top view of a multi-point synchronous injection mechanism for an injection mold according to an embodiment of this application;

[0020] Figure 2 This is a bottom view of a multi-point synchronous injection mechanism for an injection mold according to an embodiment of this application;

[0021] Figure 3 This is a bottom view of the cover plate in a multi-point synchronous injection mechanism for an injection mold according to an embodiment of this application;

[0022] Figure 4 This is an exploded view of a multi-point synchronous glue injection mechanism for an injection mold according to an embodiment of this application;

[0023] Figure 5 This is a cross-sectional view of a multi-point synchronous injection mechanism for an injection mold according to an embodiment of this application.

[0024] In the diagram: 1-Upper mold; 10-Cavity; 100-Injection hole; 11-Groove; 2-Shell; 20-Collection chamber; 200-Flow port; 21-Injection chamber; 210-Flow channel; 22-First seal; 3-Cover plate; 30-Inlet; 31-Mounting part; 4-Injection nozzle; 41-Nozzle body; 410-Through hole; 411-Extension; 412-Second seal; 5-Opening and closing assembly; 51-Valve stem; 511-Protrusion; 52-Middle shell; 520-Inner cavity; 521-Limiting protrusion; 522-Third annular seal; 53-Electromagnet; 54-Elastic element; 6-Heating assembly; 61-Heating wire. Detailed Implementation

[0025] like Figure 1 , 2 As shown in Figures 3 and 4, a multi-point synchronous injection mechanism for injection molds is used to install on the upper mold 1 of an injection mold. The upper mold 1 has a cavity 10, and the injection mechanism is disposed within the cavity 10. A set of injection holes 100 are provided at the bottom of the cavity 10; including:

[0026] The housing 2 has an opening at the top, and a cover plate 3 is installed to seal the opening at the top of the housing 2. The housing 2 contains a material collection chamber 20 and a set of injection chambers 21. The material collection chamber 20 is centrally located inside the housing 2. The set of injection chambers 21 are arranged sequentially around the circumference of the material collection chamber 20. The cover plate 3 has a material inlet 30, which is connected to the material collection chamber 20. The side wall of the material collection chamber 20 has a set of material outlets 200, which are respectively connected to the set of injection chambers 21. Each injection chamber 21 has a glue injection nozzle 4 on its bottom wall, which is connected to the corresponding injection chamber 21. The glue injection nozzle 4 extends axially into the corresponding injection hole 100.

[0027] A set of opening and closing components 5, wherein the set of opening and closing components 5 is installed on the side of the cover plate 3 near the upper mold 1, the opening and closing components 5 include: a floating valve stem 51, the valve stem 51 being used for opening and closing the injection nozzle 4;

[0028] Heating component 6, which is used for heating the housing 2.

[0029] Based on the above structure, the principle of the multi-point synchronous injection mechanism for injection molds is as follows: First, the injection mechanism is installed on the upper mold 1. The inlet 30 is connected to the injection molding machine (not shown) through a pipe. Molten plastic enters the collecting chamber 20 from the inlet 30 on the cover plate 3. The molten plastic gathers in the collecting chamber 20 and flows synchronously into each injection chamber 21 through a set of flow ports 200 on its side wall. At this time, the opening and closing component 5 is activated, the valve stem 51 is opened, and the molten plastic is ejected from each injection chamber 21 through the injection nozzle 4 at its bottom. The injection nozzle 4 extends into the injection hole 100, and the molten plastic enters multiple preset positions in the mold cavity (not shown) through the injection hole 100, realizing multi-point synchronous filling. After injection, the opening and closing component 5 may be activated, the valve stem 51 is reset, and the corresponding injection nozzle 4 is closed to prevent drooling or... The backflow heating component 6 is used to maintain the temperature of the shell 2 and keep the plastic in the shell 2 in a molten state, so as to prevent the plastic from cooling and solidifying during the flow process, blocking the flow channel or affecting the flowability. The molten plastic input from the feed port 30 is received through the centrally located collection chamber 20, and then the molten plastic is evenly distributed to a set of injection chambers 21 through the flow port 200. Finally, it is injected into the mold cavity synchronously through the injection nozzles 4 on the bottom wall of each injection chamber, realizing the synchronous distribution of molten plastic from the feed port 30 to multiple injection nozzles 4, ensuring that the flow rate and pressure of each injection nozzle 4 are consistent. The synchronous injection at multiple points makes the molten plastic flow more evenly in the mold cavity, avoiding defects such as weld lines, shrinkage marks, and warping caused by single injection. There are 4 injection chambers 21 in a set, and correspondingly, there are 4 flow ports 200, injection nozzles 4, and opening and closing components 5 in a set.

[0030] In this embodiment, a first sealing element 22 is provided at the contact point between the housing 2 and the cover plate 3, and the first sealing element 22 is arranged along the circumference of the housing 2. The first sealing element 22 is used to fill the gap between the housing 2 and the cover plate 3, preventing the molten plastic in the collecting chamber 20 and the injection chamber 21 from leaking out of the gap between them, thereby reducing material waste. The first sealing element 22 is a high-temperature resistant silicone rubber sealing ring.

[0031] In this embodiment, the injection chamber 21 is provided with a flow channel 210, which is arranged in a U-shape. The U-shape structure of the flow channel 210 ensures that after the molten plastic enters the injection chamber 21 through the chute 200, it must flow along a U-shaped trajectory, that is, from the outside to the inside, rather than flowing directly to the injection nozzle 4 in a straight line. Through multiple turns and flow buffering, the pressure distribution of the molten plastic in the injection chamber 21 is more uniform. At the same time, in conjunction with the heating effect of the heating component 6, the temperature of the molten plastic is ensured to be stable.

[0032] In this embodiment, as Figure 5As shown, the heating assembly 6 includes a heating wire 61, which is embedded in the bottom wall and side wall of the housing 2. When energized, the heating wire 61 generates heat to ensure that the molten plastic inside the housing 2 remains at a set melting temperature, preventing the molten plastic from increasing in viscosity or solidifying due to cooling. On the bottom wall of the housing 2, the heating wire 61 is arranged in a ring shape, forming multiple concentric circles along the center of the bottom wall; on the side wall of the housing 2, the heating wire 61 is arranged along the circumference and axial direction of the housing 2, respectively.

[0033] In this embodiment, the injection nozzle 4 includes: a nozzle body 41, which is detachably mounted on the bottom wall of the housing 2. The nozzle body 41 has a central through hole 410 communicating with the corresponding injection chamber 21. An extension 411 is provided at one end of the nozzle body 41 near the cover plate 3, extending radially along the nozzle body 41. The through hole 410 communicates with the injection chamber 21, providing a channel for the molten plastic to flow from the injection chamber 21 to the mold injection hole 100, thus acting as a guide to ensure that the molten plastic is injected into the mold cavity along a preset path, preventing diversion or leakage. The nozzle body 41 is detachably mounted on the bottom wall of the housing 2 for easy disassembly, cleaning, or replacement. The extension 411 is used to limit the nozzle body 41 when it is mounted on the housing 2. The nozzle body 41 is threadedly connected to the housing 2, and a second sealing element 412 is provided at the contact point between the nozzle body 41 and the housing 2, the second sealing element 412 being arranged circumferentially along the nozzle body 41.

[0034] In this embodiment, the opening and closing assembly 5 includes: a middle shell 52, an electromagnet 53, and an elastic element 54. The middle shell 52 is detachably installed on the side of the cover plate 3 near the upper mold 1. The middle shell 52 includes: an inner cavity 520. The valve stem 51 is floatingly installed in the inner cavity 520. The valve stem 51 extends axially into the through hole 410. The valve stem 51 has a protrusion 511 at the end away from the mouthpiece 41. The protrusion 511 extends radially along the valve stem 51. The electromagnet 53 is installed in the inner cavity 520. The electromagnet 53 is located on the side of the protrusion 511 away from the mouthpiece 41. The elastic element 54 is sleeved on the valve stem 51. The two ends of the valve stem 51 are respectively connected to the middle shell 52 and the side of the protrusion 511 near the mouthpiece 41. When the through hole 410 needs to be opened, the electromagnet 53 is energized to generate magnetic force, attracting the protrusion 511 and causing the valve stem 51 to float away from the nozzle body 41. At this time, the elastic element 54 is stretched, and the end of the valve stem 51 disengages from the through hole 410, opening the flow channel. When closing, the electromagnet 53 is de-energized and the magnetic force disappears. The elastic element 54 releases its elastic potential energy, causing the valve stem 51 to float closer to the nozzle body 41. The end of the valve stem 51 blocks the through hole 410, closing the flow channel. The middle shell 52 is threadedly connected to the cover plate 3. The elastic element 54 is a spring. A sealing ring is provided at the axial floating point of the valve stem 51 and the middle shell 52. The sealing ring is sleeved on the valve stem 51 and installed on the middle shell 52.

[0035] In this embodiment, a limiting protrusion 521 is provided on the outer wall of the middle shell 52. The limiting protrusion 521 extends radially along the middle shell 52, and a third annular seal 522 is provided on the limiting protrusion 521. When the middle shell 52 is installed on the side of the cover plate 3 near the upper mold 1, the limiting protrusion 521 and the cover plate 3 abut against each other axially in the middle shell 52. The limiting protrusion 521 is used to limit the excessive axial displacement of the middle shell 52 during installation, to avoid improper installation, and to ensure the alignment of the valve stem 51 with the through hole 410. The third annular seal 522 is used to fill the assembly gap between the middle shell 52 and the cover plate 3, to prevent molten plastic from entering the inner cavity 520. The third annular seal 522 is an O-ring rubber seal.

[0036] In this embodiment, a set of mounting portions 31 is provided on the outer side of the cover plate 3. The set of mounting portions 31 is spaced apart along the circumference of the cover plate 3. A set of receiving grooves 11 is provided on the upper mold 1. The set of receiving grooves 11 is correspondingly provided with the set of mounting portions 31. During installation, the mounting portions 31 are embedded in the receiving grooves 11 to ensure that the relative position of the cover plate 3 and the upper mold 1 is fixed, preventing the glue injection mechanism from shifting during the opening and closing of the mold, and ensuring that the glue injection nozzle 4 is axially aligned with the injection hole 100 on the upper mold. The mounting portions 31 and the receiving grooves 11 are detachably connected by bolts (not shown).

[0037] The technical principles of this utility model have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on the explanation herein, those skilled in the art can conceive of other specific embodiments of this utility model without creative effort, and these embodiments will all fall within the scope of protection of this utility model.

Claims

1. A multi-point synchronous injection mechanism for injection molds, used for mounting on the upper mold (1) of an injection mold, wherein the upper mold (1) is provided with a cavity (10), the injection mechanism is disposed within the cavity (10), and a set of injection holes (100) are provided at the bottom of the cavity (10); characterized in that: include: The shell (2) with an opening at the top and the cover plate (3) are sealed and installed at the opening at the top of the shell (2). The shell (2) is provided with a material collection chamber (20) and a set of injection chambers (21). The material collection chamber (20) is centrally located in the shell (2). The set of injection chambers (21) are arranged sequentially along the circumference of the material collection chamber (20). The cover plate (3) is provided with a feed inlet (30). The feed inlet (30) is connected to the material collection chamber (20). The side wall of the material collection chamber (20) is provided with a set of flow outlets (200). The set of flow outlets (200) is connected to the set of injection chambers (21) respectively. Each injection chamber (21) is provided with a glue injection nozzle (4) on its bottom wall. The glue injection nozzle (4) is connected to the corresponding injection chamber (21). The glue injection nozzle (4) extends axially into the corresponding injection hole (100). A set of opening and closing components (5) is installed on the side of the cover plate (3) near the upper mold (1). The opening and closing components (5) include: a floating valve stem (51) for opening and closing the injection nozzle (4). Heating component (6) is used for heating the housing (2).

2. The multi-point synchronous injection mechanism for injection molds according to claim 1, characterized in that: The housing (2) and the cover plate (3) are provided with a first sealing element (22), which is arranged along the circumference of the housing (2).

3. The multi-point synchronous injection mechanism for injection molds according to claim 1, characterized in that: The injection chamber (21) is provided with a flow channel (210), which is arranged in a U-shape.

4. The multi-point synchronous injection mechanism for injection molds according to claim 1, characterized in that: The heating assembly (6) includes a heating wire (61) embedded in the bottom and side walls of the housing (2).

5. The multi-point synchronous injection mechanism for injection molds according to claim 1, characterized in that: The injection nozzle (4) includes: a nozzle body (41), which is detachably mounted on the bottom wall of the housing (2). The nozzle body (41) is provided with a central through hole (410), which communicates with the corresponding injection chamber (21). The nozzle body (41) is provided with an extension (411) at one end near the cover plate (3), which extends radially along the nozzle body (41).

6. The multi-point synchronous injection mechanism for injection molds according to claim 5, characterized in that: The opening and closing assembly (5) includes: a middle shell (52), an electromagnet (53), and an elastic element (54). The middle shell (52) is detachably installed on the side of the cover plate (3) near the upper mold (1). The middle shell (52) includes: an inner cavity (520). The valve stem (51) is floatingly installed in the inner cavity (520). The valve stem (51) extends axially into the through hole (410). The valve stem (51) has a protrusion (511) at one end away from the mouthpiece (41). The protrusion (511) extends radially along the valve stem (51). The electromagnet (53) is installed in the inner cavity (520). The electromagnet (53) is located on the side of the protrusion (511) away from the mouthpiece (41). The elastic element (54) is sleeved on the valve stem (51). The two ends of the valve stem (51) are respectively connected to the middle shell (52) and the side of the protrusion (511) near the mouthpiece (41).

7. A multi-point synchronous injection mechanism for injection molds according to claim 6, characterized in that: The outer wall of the middle shell (52) is provided with a limiting protrusion (521), which extends radially along the middle shell (52). The limiting protrusion (521) is provided with a third annular seal (522). When the middle shell (52) is installed on the side of the cover plate (3) near the upper mold (1), the limiting protrusion (521) and the cover plate (3) abut against each other in the axial direction of the middle shell (52).

8. The multi-point synchronous injection mechanism for injection molds according to claim 1, characterized in that: The cover plate (3) is provided with a set of mounting parts (31) on the outside. The set of mounting parts (31) is arranged at intervals along the circumference of the cover plate (3). The upper mold (1) is provided with a set of receiving grooves (11). The set of receiving grooves (11) is arranged in a one-to-one correspondence with the set of mounting parts (31).

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