A runner blocking structure for a plastic mold

Abstract

The utility model discloses a runner intercepting structure for plastic mould, which is installed on a runner plate and a movable plate to adjust injection flow of a branch runner, comprising an intercepting ejector pin, a crowbar and a screw, the intercepting ejector pin is elastically movably installed on the runner plate and the top of the intercepting ejector pin abuts against the branch runner, the bottom of the intercepting ejector pin abuts against one end of the crowbar, the crowbar is hingedly installed in a mounting cavity of the movable plate and the other end of the crowbar abuts against the screw, and the screw is threadedly fastened on the runner plate. The device has simple structure design, convenient and fast operation, and can adjust and change the cross-sectional size of the branch runner by using the lever principle to control the runner glue amount.

Description

Technical Field

[0001] This utility model relates to the field of flow channel improvement design technology for injection molds, and in particular to a flow channel interception structure for plastic molds. Background Technology

[0002] In injection molding production, due to capacity considerations, it's common to encounter situations where products molded from the same mold can vary in size or structure. This is often a 1+1 shared runner production process, where smaller, round products are filled first, while larger, square products are not. Figure 4 As shown. For the same product, produced in a multi-cavity mold, due to temperature differences and flow imbalances, a small number of cavities may not be fully filled. This is a common problem in injection molding. To address this, it's necessary to intervene and control the size of the branch runners (i.e., to adjust the corresponding injection flow rate). For the branch runners of round products that fill faster, a flow-stopping valve is added to control the flow rate, aiming to achieve balanced filling at the same time, thereby improving the quality and processing efficiency of the injection molded products. Currently, devices used for runner flow control have drawbacks in injection molding, including cumbersome operation, difficulty in processing, low adjustment precision, and excessively large volumes for controlling cold runners, leading to material waste from runner solidification.

[0003] In the prior art, patent CN221518643U discloses an adjustable flow-stopping structure for injection molds, which includes a mold core and a flow-stopping component. One side of the mold core has interconnected injection channels and molding grooves. The flow-stopping component includes a fixed base, a stud, and a flow-stopping insert. One end of the fixed base has a connecting channel. The fixed base is disposed within the mold core to connect the connecting channel with the injection channel. The stud is rotatably disposed within the fixed base, and the flow-stopping insert is slidably disposed within the fixed base, with the flow-stopping insert and stud screwed together. One end of the flow-stopping insert faces the connecting channel. When the stud rotates, it causes the end of the flow-stopping insert to extend into or retract from the connecting channel. This allows for precise adjustment of the diameter of the connecting channel, eliminating the need to replace the entire flow-stopping structure, making it convenient to use. Furthermore, it does not require occupying the lateral area of ​​the mold core, thus reducing the mold's size and effectively lowering costs.

[0004] Patent CN213166720U discloses a device for controlling the flow rate and pressure of a colloid in an injection mold runner. The device includes a baffle plate for blocking the runner and a driving mechanism. The driving mechanism drives the baffle plate through a channel on the side wall of the runner to enter and exit the runner, with the shape of the channel matching the profile of the baffle plate's cross-section. The driving mechanism includes a driving member and a driven member. The driving member drives the driven member in a linear reciprocating motion. The baffle plate and the driven member are connected, and the driving member and the transmission member are connected by a gear transmission. The driven member is positioned near the runner cavity of the injection mold and drives the driven member through the driving member to move the baffle plate in and out of the runner. The area of ​​the baffle plate entering the runner is used to adjust the runner diameter.

[0005] In order to solve one of the above problems, this application provides a flow channel interception structure for plastic molds. Utility Model Content

[0006] The purpose of this invention is to solve the problems existing in the prior art by proposing a flow channel interception structure for plastic molds. The structure is simple in design and easy and quick to operate. It uses the lever principle to adjust and change the cross-sectional size of the branch flow channel, thereby controlling the amount of glue flowing through the channel.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a flow channel interception structure for plastic molds, which is installed on the flow channel plate and the moving platen to adjust the injection flow of the branch flow channel, including a flow interception ejector pin, a pry bar, and a screw. The flow interception ejector pin is elastically and movably installed on the flow channel plate and the top of the flow interception ejector pin abuts against the branch flow channel. The bottom of the flow interception ejector pin abuts against one end of the pry bar. The pry bar is hinged and installed in the mounting cavity of the moving platen and the other end of the pry bar abuts against the screw. The screw is threadedly fastened to the flow channel plate.

[0008] Furthermore, as described above, the flow channel plate is machined with a first mounting hole and a second mounting hole. A flow-stopping pin is elastically and movably installed in the first mounting hole, and the first mounting hole communicates with the branch flow channel. A threaded screw is connected in the second mounting hole.

[0009] Furthermore, as described above, the first mounting hole and the second mounting hole respectively penetrate the flow channel plate and communicate with the mounting cavity.

[0010] Furthermore, as described above, the first mounting hole includes a fine through hole and a coarse through hole, the fine through hole communicating with the branch flow channel and the coarse through hole communicating with the mounting cavity.

[0011] Furthermore, as described above, the flow-stopping pin includes a rod and an end, the rod being movably inserted into a narrow through hole and the end being located in a wide through hole.

[0012] Furthermore, as described above, a spring is fitted around the rod, with the two ends of the spring abutting against the inner wall and the end of the coarse through hole, respectively.

[0013] Furthermore, as described above, the end abuts against one end of the pry bar.

[0014] Furthermore, as mentioned above, the second mounting hole is machined with internal threads, and the screw is machined with external threads. The threaded connection can play a locking role.

[0015] Furthermore, as mentioned above, the screw is a headless screw, which reduces the machining difficulty of the second mounting hole.

[0016] Furthermore, as described above, the pry bar is rotatably connected to the rotating shaft, with both ends of the rotating shaft installed on both sides of the mounting cavity, making installation simple.

[0017] Compared with the prior art, the beneficial effects of this utility model are: the structure of this device is simple and the operation is convenient and quick. It uses the lever principle to adjust and change the cross-sectional size of the branch flow channel, thereby controlling the amount of glue flowing through the channel. It is especially suitable for balancing the filling speed when producing multiple cavities in one mold or when different products are produced in the same mold.

[0018] For multi-cavity plastic products, the number of runner interception structures can be determined based on the number of cavities in the mold and the number of unbalanced products. This structure can be used for both two-plate large gates and three-plate small gates. Attached Figure Description

[0019] Figure 1 This is a top view of the device of this utility model in the lower mold;

[0020] Figure 2 for Figure 1 Partial sectional view along the AA direction;

[0021] Figure 3 for Figure 2 Schematic diagram of the middle branch channel after closure;

[0022] Figure 4 This is a schematic diagram showing how two different injection molded parts can be obtained by injection molding simultaneously in one mold.

[0023] In the diagram: 10. Branch channel solidified material; 11. Spring; 12. Cut-off ejector pin; 13. Channel parting surface; 14. Headless screw; 15. Channel plate; 151. First mounting hole; 152. Second mounting hole; 16. Pry bar; 160. Mounting cavity; 17. Moving template; 18. Rotating shaft; 2. First plastic part; 3. Second plastic part. Detailed Implementation

[0024] In the description of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "fixed," "installed," "connected," "set," etc., should be interpreted broadly. For example, when an element is said to be "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is said to be "installed" on another element, it can be directly installed on the other element or there may be an intervening element. When an element is said to be "connected" to another element, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within the two elements.

[0026] Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] Example 1

[0029] Reference Figure 1-3As shown, this utility model discloses a runner interception structure for plastic molds. In the prior art, this runner interception structure is installed on the runner plate 15 and the moving platen 17 to adjust the injection flow of the branch runners. The runner plate 15 and the moving platen 17 are fixed together. The parting surface of the branch runners is located on the upper surface of the runner plate 15. The cavity mold is installed on the runner plate 15 (generally using a standard gate to inject plastic products with a smaller thickness) or between the runner plate 15 and the moving platen 17 (generally using a submarine gate to inject plastic products with a larger height). The runner interception structure includes an ejector pin 12, a pry bar 16, and a screw. The ejector pin 12 is elastically and movably installed on the runner plate 15 and the ejector pin 16... The top of pin 2 abuts against the branch channel, allowing the flow-stopping pin 12 to move elastically within the channel plate 15 to change the cross-sectional area of ​​the branch channel. The bottom of the flow-stopping pin 12 abuts against one end of the pry bar 16. The pry bar is hinged to the mounting cavity 160 of the moving template 17, and the other end of the pry bar 16 abuts against the screw. The pry bar 16 is equivalent to a lever, and the height of both ends of the pry bar 16 can be controlled by lever principle. The screw is threaded and fastened to the channel plate 15. The rotation of the screw can change its position within the channel plate 15, that is, it can change the position of the contact point between the screw and the pry bar 16 within the channel plate 15. By finely adjusting the screw's screw insertion depth, the height of the flow-stopping pin 12 can be precisely raised and lowered.

[0030] Combination Figure 2 and Figure 3 As shown in the schematic diagram, when it is found that the larger square second plastic part 3 is difficult to fill during injection molding, an Allen wrench should be used to rotate the screw downwards on the parting surface of the branch flow channel. The screw transmits force to one end of the pry bar 16, and the rotation of the pry bar 16 itself will transmit force to the flow-stopping ejector pin 12. The flow-stopping ejector pin 12 will rise as the screw moves downwards. At this time, the flow-stopping ejector pin 12 will move towards the branch flow channel, reducing the cross-sectional size of the branch flow channel and reducing the injection flow rate of the branch flow channel to achieve the flow-stopping effect. Figure 3 The black part in the middle is the branch flow channel solidified material 10 generated after injection molding, which is about half of the branch flow channel intercepted by the cut-off ejector pin 12. By controlling and adjusting the flow rate of the branch flow channel, the plastic product in each cavity can be filled at the same time. Conversely, when manually adjusted, the cut-off flow rate may be adjusted too much, causing the injection molding machine to find that the larger square second plastic part 3 is filled first, while the smaller round first plastic part 2 is not filled. At this time, the screw should be moved upward with an Allen wrench. Then, the pry bar 16 rotates in the opposite direction under the elastic force of the spring 11. The cut-off ejector pin 12 will move downward under the elastic force to increase the cross-sectional area of ​​the branch flow channel and increase the injection flow rate, so as to achieve the purpose of balancing the two plastic parts as much as possible during injection.

[0031] Example 2

[0032] Reference Figure 1-3 As shown, based on the technical solution of Embodiment 1, a flow channel interception structure for plastic molds, combined with... Figure 2 and Figure 3 It is understood that the flow channel plate 15 is machined with a first mounting hole 151 and a second mounting hole 152. A flow-stopping pin 12 is elastically and movably installed in the first mounting hole 151, and the first mounting hole 151 communicates with the branch flow channel. The dimension of the portion of the first mounting hole 151 that communicates with the branch flow channel must be no smaller than the larger end dimension of the U-shaped cross-section of the branch flow channel, generally 0.5-1mm larger. A screw is threaded into the second mounting hole 152. Furthermore, the first mounting hole 151 and the second mounting hole 152 respectively penetrate the flow channel plate 15 and communicate with the mounting cavity 160. The two mounting holes are machined through the flow channel plate 15 to facilitate through-hole machining.

[0033] Furthermore, the first mounting hole 151 includes a narrow through hole and a wide through hole. The narrow through hole communicates with the branch flow channel, and the wide through hole communicates with the mounting cavity 160. The flow-stopping pin 12 includes a rod and an end. The rod is movably inserted into the narrow through hole, and the end is located in the wide through hole. In addition, a spring 11 is fitted around the rod. The two ends of the spring 11 abut against the inner wall of the wide through hole and the end, respectively. The force of the spring 11 can play a restoring role. In addition, the end abuts against one end of the pry bar 16. In order to increase the contact area with the pry bar 16 and ensure the fitting limit of the spring 11, the size of the end must be larger than the outer diameter of the rod. Since the rod needs to change the cross-sectional size of the branch flow channel, the diameter of the rod must be larger than the width of the large end of the U-shaped cross-section of the branch flow channel, generally 0.5-1 mm larger.

[0034] Example 3

[0035] Reference Figure 1-4 As shown, based on the technical solution of the above embodiments, a flow channel interception structure for plastic molds, combined with... Figure 2 and Figure 3 It is known that the second mounting hole 152 is machined with internal threads, and the screw is machined with external threads. The threaded connection can play a locking role. The screw is a headless screw 14, meaning that the second mounting hole 152 can be directly drilled without the need for countersunk hole design. In addition, it should be noted that the screw must be a screw with anti-loosening function to prevent it from loosening during the injection molding opening and closing movement, which would cause the adjusted cut-off ejector pin 12 to loosen, resulting in the failure of the branch flow channel cut-off adjustment operation.

[0036] Furthermore, the pry bar 16 is rotatably connected to the rotating shaft 18, with both ends of the rotating shaft 18 installed on both sides of the mounting cavity 160. Installation is simple. The rotating shaft 18, as part of the hinge structure, serves the dual purpose of supporting and rotating the pry bar 16. In addition, the pry bar 16 must not interfere with any of the plates during movement. It must have sufficient space for movement according to the cutoff length (the lifting height of the cutoff pin 12 and the screw screw insertion depth), and care must be taken to avoid any gaps.

[0037] The application scenarios for this utility model device are: plastic molds with multiple cavities and branched flow channels where uneven filling occurs; and plastic molds where different product sizes, volumes, and structures result in different filling speeds for different products, leading to uneven filling due to uneven glue injection in the branched flow channels. Figure 4 As shown.

[0038] Working principle: When it is found that a plastic product is difficult to fill during injection molding, an Allen wrench should be used to adjust the anti-loosening extended headless screw 14 downwards on the parting surface 13 of the runner. The headless screw 14 will transmit force to the pry bar 16 through the lever principle. The pry bar 16 will rotate through the rotating shaft to the shut-off valve pin. At this time, the shut-off valve pin will rise as the headless screw 14 moves downwards, and the shut-off valve pin will block the injection flow of the "U"-shaped branch runner, thus achieving the shut-off effect. Conversely, when manually adjusted, excessive shut-off may occur during adjustment, causing... When adjusting the injection molding machine, if a larger square product fills the mold first, while a smaller round product does not, an Allen wrench should be used to move the extended headless screw 14 upwards. Subsequently, the pry bar 16 will reset under the elastic force of the spring 11, and the cut-off valve ejector pin will move downwards to increase the injection flow of the branch runner. Ultimately, this achieves a more balanced injection of the two products. For multi-cavity products, the number of this runner cut-off structure can be determined according to the number of cavities in the mold and the number of unbalanced products. This structure can be used for both two-plate large gates and three-plate small gates.

[0039] In this utility model device, the assembly and cooperation relationships of various components, such as the ejector pin, spring 11, screws, and various plates of the mold, are all existing technologies or materials. The relevant technical personnel can directly purchase or order them from the market according to the required product model and specifications.

[0040] All electrical components mentioned in the text are connected to an external main controller and 220V AC mains power or industrial power. The main controller can be a conventional known device such as a computer that plays a control role.

[0041] The above description is merely a preferred embodiment of this utility model, and common knowledge regarding specific structures and characteristics is not described in detail here. It is obvious to those skilled in the art that this utility model is not limited to the details of the above embodiments, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the protection scope of this utility model.

Claims

1. A flow channel interception structure for a plastic mold, the flow channel interception structure being installed on a flow channel plate (15) and a moving platen (17) to adjust the injection flow rate of branch flow channels, characterized in that, Includes a flow-blocking pin (12), a pry bar (16), and a screw. The flow-blocking pin (12) is elastically mounted on the flow channel plate (15), and the top of the flow-blocking pin (12) abuts against the branch flow channel. The bottom of the flow-blocking pin (12) abuts against one end of the pry bar (16). The pry bar (16) is hinged in the mounting cavity (160) of the moving template (17), and the other end of the pry bar (16) abuts against the screw. The screw is threadedly fastened to the flow channel plate (15).

2. The flow channel interception structure for plastic molds according to claim 1, characterized in that, The flow channel plate (15) is machined with a first mounting hole (151) and a second mounting hole (152). A flow-blocking pin (12) is elastically and movably installed in the first mounting hole (151) and the first mounting hole (151) is connected to the branch flow channel. A screw is threaded into the second mounting hole (152).

3. The flow channel interception structure for plastic molds according to claim 2, characterized in that, The first mounting hole (151) and the second mounting hole (152) respectively penetrate the flow channel plate (15) and are connected to the mounting cavity (160).

4. The flow channel interception structure for plastic molds according to claim 3, characterized in that, The first mounting hole (151) includes a fine through hole and a coarse through hole. The fine through hole is connected to the branch flow channel, and the coarse through hole is connected to the mounting cavity (160).

5. The flow channel interception structure for plastic molds according to claim 4, characterized in that, The cut-off pin (12) includes a rod and an end, the rod being movably inserted into the narrow through hole and the end being located in the coarse through hole.

6. The flow channel interception structure for plastic molds according to claim 5, characterized in that, The rod is fitted with a spring (11), and the two ends of the spring (11) abut against the inner wall and the end of the coarse through hole, respectively.

7. The flow channel interception structure for plastic molds according to claim 6, characterized in that, The end of the rod abuts against one end of the lever (16).

8. The flow channel interception structure for plastic molds according to claim 3, characterized in that, The second mounting hole (152) is machined with internal threads, and the screw is machined with external threads.

9. A flow channel interception structure for a plastic mold according to claim 8, characterized in that, The screw in question is a headless screw (14).

10. A flow channel interception structure for a plastic mold according to any one of claims 1-9, characterized in that, The pry bar (16) is rotatably connected to the rotating shaft (18), and the two ends of the rotating shaft (18) are respectively installed on both sides of the mounting cavity (160).

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