Auxiliary ejection demolding mechanism for mold insert and fan blade injection mold

Abstract

The mechanism comprises a front mold assembly, a rear mold assembly, an ejection mechanism and a limiting structure, the front mold assembly comprises a front mold core, the rear mold assembly and the front mold assembly are assembled to form a mold cavity, the rear mold assembly comprises a rear mold core and at least one movable rear mold insert, and the ejection mechanism is arranged on the rear mold insert. The ejection mechanism is used for driving the rear mold insert to move relative to the rear mold core; the limiting structure is arranged on the rear mold assembly; when the mold is opened, the ejection mechanism drives the rear mold insert and a product part formed on the rear mold insert to synchronously perform a first section of ejection stroke, and the limiting structure is used for preventing the rear mold insert from continuously moving at the end point of the first section of ejection stroke; and then the ejection mechanism continues to drive the product to carry out a second section of ejection stroke, so that the product is completely separated from the rear mold assembly. According to the invention, the structure is greatly simplified, the processing difficulty and the manufacturing cost of the die are obviously reduced, and the working reliability of the die is improved.

Description

Technical Field

[0001] This invention relates to the field of fan manufacturing technology, and in particular to a mold insert-assisted ejection and demolding mechanism and a fan blade injection mold. Background Technology

[0002] In existing mold manufacturing, demolding is a technical challenge for plastic parts with extremely thin plastic sections (e.g., only 0.2mm), such as axial fan blades. The commonly used solution is to design a two-stage demolding structure, with the cavity portion of the molded fan blade designed as multiple independent inserts manufactured by wire cutting. This existing technical solution has the following main drawbacks: Complex structure and high cost: The secondary demolding mechanism itself contains more moving parts (such as push plate, delay mechanism, etc.), which makes the mold structure more complex, the design and assembly more difficult, and significantly increases the manufacturing cost of the mold.

[0003] Long manufacturing cycle: The fan blade cavity adopts the form of wire cutting insert, which requires high processing precision and complicated process, thus extending the manufacturing cycle of the entire mold.

[0004] Insufficient strength and short lifespan of inserts: In order to form thin-walled fan blades, these inserts are usually designed to be very thin. Under the cyclic stress of continuous high temperature and high pressure during injection molding, they are prone to deformation or even breakage, which not only affects the stability of product quality, but also increases the maintenance cost of molds and downtime.

[0005] Therefore, there is an urgent need for a demolding mechanism that has a simplified structure, can effectively protect thin-walled inserts, and can improve demolding reliability. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a mold insert auxiliary ejection and demolding mechanism and a fan blade injection mold.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: On one hand, the present invention provides a mold insert-assisted ejection and demolding mechanism, comprising: Front mold assembly, including the front mold core; The rear mold assembly is molded together with the front mold assembly to form a mold cavity. The rear mold assembly includes a rear mold core and at least one movable rear mold insert. An ejection mechanism is used to drive the rear mold insert to move relative to the rear mold core; A limiting structure is provided on the rear mold assembly; During mold opening, the ejection mechanism drives the rear mold insert and the product portion formed thereon to perform a first ejection stroke simultaneously. The limiting structure is used to prevent the rear mold insert from continuing to move at the end of the first ejection stroke. Subsequently, the ejection mechanism continues to drive the product to perform a second ejection stroke so that the product is completely separated from the rear mold assembly.

[0008] Furthermore, there are multiple rear mold inserts, and at least some of the rear mold inserts are nested together.

[0009] Furthermore, the plurality of rear mold inserts include a first rear mold insert, a second rear mold insert, and a third rear mold insert, wherein the second rear mold insert is nested within the first rear mold insert, and the third rear mold insert is nested within the second rear mold insert.

[0010] Furthermore, the limiting structure includes a notch provided on the first rear mold insert and a convex ring provided at the bottom of the second rear mold insert, wherein the convex ring abuts against the side wall of the notch at the end of the first ejection stroke.

[0011] Furthermore, the ejection mechanism includes a first ejector pin, which passes through the first rear mold insert and the top end of the first ejector pin corresponds to the first part of the product.

[0012] Furthermore, the ejection mechanism includes a second ejector pin, which passes through the second rear mold insert and the top end of the second ejector pin corresponds to the second part of the product.

[0013] Furthermore, the ejection mechanism also includes an ejector plate and an ejector base plate. The ejector plate is movably disposed, and the first ejector and the second ejector are fixed on the ejector plate. The first ejector and the second ejector move synchronously with the ejector plate and the ejector base plate.

[0014] Furthermore, the front mold assembly also includes an A plate, and the front mold core is fixed to the A plate.

[0015] Furthermore, the rear mold assembly also includes a B plate, and the rear mold core is fixed to the B plate.

[0016] On the other hand, the present invention also provides a fan blade injection mold, including the above-mentioned mold insert-assisted ejection and demolding mechanism.

[0017] The beneficial effects of this invention compared with the prior art are as follows: A mold insert-assisted ejection and demolding mechanism includes a front mold assembly, a rear mold assembly, an ejection mechanism, and a limiting structure. The front mold assembly includes a front mold core, and the rear mold assembly is closed with the front mold assembly to form a mold cavity. The rear mold assembly includes a rear mold core and at least one movable rear mold insert. The ejection mechanism is used to drive the rear mold insert to move relative to the rear mold core. The limiting structure is disposed on the rear mold assembly. When the mold is opened, the ejection mechanism drives the rear mold insert and the product portion formed on it to synchronously perform the first ejection stroke. The limiting structure is used to prevent the rear mold insert from continuing to move at the end of the first ejection stroke. Subsequently, the ejection mechanism continues to drive the product to perform the second ejection stroke so that the product is completely detached from the rear mold assembly. By adopting a movable rear mold insert in conjunction with a segmented ejection and limiting structure, the shortcomings of existing thin-walled part molds, such as complex secondary demolding mechanisms and easily damaged inserts, are effectively overcome. This achieves a significant simplification of the structure, significantly reduces the processing difficulty and manufacturing cost of the mold, and shortens the manufacturing cycle. At the same time, this mechanism effectively protects the thin-walled insert during the demolding process, preventing it from deforming or breaking under stress, thereby greatly improving the working reliability, service life, and quality stability of the molded thin-walled products.

[0018] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other objectives, features and advantages of the present invention more obvious and understandable, preferred embodiments are described in detail below. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the structure of a fan blade injection mold provided in a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the first mold opening provided in a specific embodiment of the present invention; Figure 3 A partial structural schematic diagram of a mold insert auxiliary ejection and demolding mechanism provided in a specific embodiment of the present invention; Figure 4 This is a structural diagram of the first ejection of the rear mold provided in a specific embodiment of the present invention; Figure 5 This is a structural diagram of the second ejection of the rear mold provided in a specific embodiment of the present invention; Figure 6 A cross-sectional view of a fan blade injection mold provided for a specific embodiment of the present invention.

[0021] Figure Labels 1. Front mold assembly; 11. Front mold core; 12. A plate; 2. Rear mold assembly; 21. Rear mold core; 22. B plate; 23. First rear mold insert; 231. Notch; 24. Second rear mold insert; 25. Third rear mold insert; 26. Fourth rear mold insert; 3. First ejector pin; 4. Second ejector pin; 5. Ejector pin faceplate; 6. Ejector pin base plate; 100. Fan blade. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 invention 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 invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0027] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0028] like Figures 1 to 6 As shown, this embodiment of the invention provides a fan blade injection mold, including a mold insert-assisted ejection and demolding mechanism. This mechanism includes a front mold assembly 1, a rear mold assembly 2, an ejection mechanism, and a limiting structure. The front mold assembly 1 includes an A plate 12 and a front mold core 11 fixedly mounted thereon. The front mold core 112 constitutes part of the cavity surface of the fan blade 100. The rear mold assembly 2 and the front mold assembly 1 are closed to form a mold cavity. The rear mold assembly 2 includes a B plate 22, a rear mold core 21 fixed on the B plate 22, and at least one movable rear mold insert. Multiple movable rear mold inserts are provided, and at least some of the rear mold inserts are nested within each other. The ejection mechanism is used to drive the rear mold insert to move relative to the rear mold core 21; the limiting structure is set on the rear mold assembly 2 to control the stroke of the movable rear mold insert; when the mold is opened, the ejection mechanism drives the rear mold insert and the fan blade 100 formed on it to perform the first ejection stroke simultaneously, and the limiting structure is used to prevent the rear mold insert from continuing to move at the end of the first ejection stroke; then the ejection mechanism continues to drive the fan blade 100 to perform the second ejection stroke so that the fan blade 100 is completely separated from the rear mold assembly 2.

[0029] By adopting a movable rear mold insert in conjunction with a segmented ejection and limiting structure, the shortcomings of existing thin-walled part molds, such as complex secondary demolding mechanisms and easily damaged inserts, are effectively overcome. This achieves a significant simplification of the structure, significantly reduces the processing difficulty and manufacturing cost of the mold, and shortens the manufacturing cycle. At the same time, this mechanism effectively protects the thin-walled insert during the demolding process, preventing it from deforming or breaking under stress, thereby greatly improving the working reliability, service life, and quality stability of the molded thin-walled fan blade 100.

[0030] In the embodiment shown in the accompanying drawings, the plurality of rear mold inserts include a first rear mold insert 23, a second rear mold insert 24, a third rear mold insert 25, and a fourth rear mold insert 26. The second rear mold insert 24 is nested within the first rear mold insert 23, the third rear mold insert 25 is nested within the second rear mold insert 24, and the fourth rear mold insert 26 is nested within the third rear mold insert 25.

[0031] Specifically, the first rear mold insert 23 is fixedly installed in the rear mold core 21 by screws, forming the basis and reference of the nested structure. The second rear mold insert 24 is configured to be slidably nested in the inner cavity of the first rear mold insert 23 along its axial direction. Specifically, a sliding fit surface is provided between the outer wall of the second rear mold insert 24 and the inner wall of the first rear mold insert 23, possibly supplemented by guide keys or grooves to prevent relative rotation. Similarly, the third rear mold insert 25 is further slidably nested in the inner cavity of the second rear mold insert 24, and the fourth rear mold insert 26 is finally slidably nested in the inner cavity of the third rear mold insert 25. The fourth rear mold insert 26 typically directly forms the profile of the finest, deepest, or most tightly bound local features on the fan blade 100 (such as the thinnest area or deep ribs at the tip of the fan blade 100). Precise sliding fit is maintained between each layer of inserts to ensure no overflow occurs during high-temperature and high-pressure injection molding, while allowing smooth relative movement during the ejection stage.

[0032] In some embodiments, the limiting structure includes a notch 231 disposed on the first rear mold insert 23 and a protruding ring disposed on the bottom of the second rear mold insert 24, wherein the protruding ring abuts against the side wall of the notch 231 at the end of the first ejection stroke.

[0033] Specifically, notch 231 is machined on the bottom end face of the first rear mold insert 23. The shape of notch 231 is not limited to rectangle; it can also be arc-shaped or other adaptable shapes. Correspondingly, a raised ring portion is integrally formed or additionally installed on the bottom of the second rear mold insert 24 (i.e., the movable insert that can be directly driven by the ejection mechanism). This raised ring portion can be a continuous annular protrusion surrounding the outer periphery of the bottom of the second rear mold insert 24, or it can be multiple bosses spaced apart, whose outer diameter or maximum radial dimension is larger than the opening width or radial dimension of notch 231 on the first rear mold insert 23. In the assembled state, the second rear mold insert 24 is nested inside the first rear mold insert 23, and the raised ring portion at its bottom corresponds axially to the position of notch 231 on the first rear mold insert 23.

[0034] In the initial mold-closed state, the protruding ring of the second rear mold insert 24 is located below or to one side of the notch 231 of the first rear mold insert 23, leaving sufficient space for the protruding ring to move upward. When the ejection mechanism operates after mold opening, driving the second rear mold insert 24 upward (i.e., in the demolding direction) for the first ejection stroke, the protruding ring at its bottom moves upward synchronously. As the ejection stroke progresses, the protruding ring gradually approaches the side wall of the notch 231. When the first ejection stroke reaches the preset end point, the upper surface of the protruding ring rigidly abuts against the lower inner side wall of the notch 231. Since the first rear mold insert 23 itself is fixed or restricted, this abutment effectively prevents the second rear mold insert 24 from continuing to move in the original direction, thus forcing it to stop. At this time, the force applied by the ejection mechanism will no longer be used to push the second rear mold insert 24, but will be converted into all or most of the force to disengage the fan blade 100 from the stopped insert, thereby triggering the second ejection stroke.

[0035] The limiting is achieved directly by utilizing the structure of the first rear mold insert 23 and the second rear mold insert 24, avoiding the cumulative error of the fitting clearance caused by additional parts. This makes the termination position of the first ejection stroke precise and controllable, with a compact structure that does not occupy additional mold space.

[0036] In some embodiments, the ejection mechanism includes an integrated ejector system comprising an ejector panel 5, an ejector base plate 6, a base plate, and a plurality of ejector pins mounted thereon, located at the bottom of the mold. The ejection mechanism includes a first ejector pin 3, which passes through a first rear mold insert 23 and whose tip corresponds to a first portion of the fan blade 100. The ejection mechanism also includes a second ejector pin 4, which passes through a second rear mold insert 24 and whose tip corresponds to a second portion of the fan blade 100.

[0037] The first ejector pin 3 is a key component that drives the movable rear mold insert and participates in the subsequent ejection of the fan blade 100. One end of the first ejector pin 3 is fixed to the ejector plate 5, and the other end passes upward through the first rear mold insert 23. When the ejector plate is pushed upward by the injection molding machine ejector rod, the first ejector pin 3 directly drives the second rear mold insert 24 to move upward synchronously, completing the first ejection stroke. At the same time, the tip of the first ejector pin 3 or its extension is usually positioned corresponding to or adjacent to the first part of the fan blade 100 during the second ejection stroke, so that after the second rear mold insert 24 is stopped, it can directly or indirectly act on the fan blade 100 to continue providing ejection force.

[0038] The second ejector pin 4 primarily assists in ejecting or directly ejects other areas of the fan blade 100. This second ejector pin 4 is also fixed to the ejector plate 5, passes through the second rear mold insert 24, and its top end directly aligns with and contacts the second part of the fan blade 100. The function of the second ejector pin 4 is as follows: during the first ejection stroke, it may move synchronously with the first ejector pin 3, but mainly serves as auxiliary support; during the second ejection stroke, when the first ejector pin 3 is unable to continue pushing the insert due to the limitation of the second rear mold insert 24, the second ejector pin 4 becomes one of the main force-applying elements that continuously pushes the fan blade 100, forcibly disengaging it from the stopped insert. Because the first ejector pin 3 and the second ejector pin 4 are mounted on the same ejector plate 5, they maintain synchronous movement throughout the ejection process.

[0039] The synchronous movement of the first ejector pin 3 and the second ejector pin 4 ensures that the fan blade 100 is supported by a uniform and stable ejection force throughout the demolding process, effectively preventing the thin-walled fan blade 100 from whitening, deforming or breaking due to uneven local force.

[0040] The entire work process is as follows: The mold is in the closed state, with the front mold assembly 1 and the rear mold assembly 2 tightly closed, together forming a complete cavity for the molded fan blade 100. Molten plastic is injected into the cavity through the gating system, and solidifies after pressure holding and cooling. Then, the injection molding machine pulls the moving mold part of the mold apart from the front mold assembly 1, completing the mold opening action, with the fan blade 100 remaining in the rear mold. Subsequently, the injection molding machine ejector rod acts on the mold ejector pin base plate 6, driving the entire ejection system to move upward synchronously. The first ejector pin 3 directly pushes the second rear mold insert 24 upward. Since the second rear mold insert 24 nests the third and fourth rear mold inserts 26, and the blade part of the fan blade 100 covers these moving inserts, the moving insert assembly drives the fan blade 100 part in close contact with it to move upward together; this is the first ejection stroke. During this stroke, the product gradually separates from the fixed front mold core 11 and the relatively fixed first rear mold insert 23 in the rear mold, and the whole thing begins to loosen. At the same time, the top of the second ejector pin 4 always presses against the hub of the fan blade 100 and other second parts to provide auxiliary support and ensure that the product moves smoothly.

[0041] When the first ejection stroke reaches the preset distance, the protruding ring at the bottom of the second rear mold insert 24 moves to rigidly abut against the notch 231 on the first rear mold insert 23. Since the first rear mold insert 23 is fixed, this abutment forms a reliable mechanical limit, forcing the second rear mold insert 24 to stop moving. At this time, the thin-walled blade portion of the fan blade 100 has separated from the rear mold core 21 and the first rear mold insert 23 by a gap, and the product is in a state of being loose but not completely demolded.

[0042] The ejector force continues to operate, and the ejector plate 5 continues to drive the first ejector pin 3 and the second ejector pin 4 to move upward synchronously. Since the second rear mold insert 24 is already stopped, the first ejector pin 3 can no longer push the insert. The thrust at its tip and the continuous ejection force of the second ejector pin 4 then act entirely on the fan blade 100. The ejection force overcomes the remaining clamping force and static friction between the product and the stopped second rear mold insert 24, third rear mold insert 25, and fourth rear mold insert 26, forcing the fan blade 100 to move upward relative to these stationary inserts until the product is completely separated from all the rear mold inserts and the rear mold core 21. This is the second ejection stroke. After completion, the fan blade 100 can be safely removed. After the product is removed, the injection molding machine ejector pin retracts, and the mold begins to close.

[0043] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A mold insert-assisted ejection and demolding mechanism, characterized in that, include: Front mold assembly, including the front mold core; The rear mold assembly is molded together with the front mold assembly to form a mold cavity. The rear mold assembly includes a rear mold core and at least one movable rear mold insert. An ejection mechanism is used to drive the rear mold insert to move relative to the rear mold core; A limiting structure is provided on the rear mold assembly; During mold opening, the ejection mechanism drives the rear mold insert and the product portion formed thereon to perform a first ejection stroke simultaneously. The limiting structure is used to prevent the rear mold insert from continuing to move at the end of the first ejection stroke. Subsequently, the ejection mechanism continues to drive the product to perform a second ejection stroke so that the product is completely separated from the rear mold assembly.

2. The mold insert auxiliary ejection and demolding mechanism according to claim 1, characterized in that, There are multiple rear mold inserts, and at least some of the rear mold inserts are nested together.

3. The mold insert-assisted ejection and demolding mechanism according to claim 2, characterized in that, The plurality of rear mold inserts include a first rear mold insert, a second rear mold insert, and a third rear mold insert, wherein the second rear mold insert is nested within the first rear mold insert, and the third rear mold insert is nested within the second rear mold insert.

4. The mold insert auxiliary ejection and demolding mechanism according to claim 3, characterized in that, The limiting structure includes a notch provided on the first rear mold insert and a convex ring provided at the bottom of the second rear mold insert. The convex ring abuts against the side wall of the notch at the end of the first ejection stroke.

5. The mold insert auxiliary ejection and demolding mechanism according to claim 3, characterized in that, The ejection mechanism includes a first ejector pin, which passes through the first rear mold insert and the top of the first ejector pin corresponds to the first part of the product.

6. The mold insert-assisted ejection and demolding mechanism according to claim 5, characterized in that, The ejection mechanism includes a second ejector pin, which passes through the second rear mold insert and the top of the second ejector pin corresponds to the second part of the product.

7. The mold insert-assisted ejection and demolding mechanism according to claim 6, characterized in that, The ejection mechanism further includes an ejector base plate and an ejector panel. The ejector panel is movably configured, and the first ejector and the second ejector are fixed on the ejector panel. The first ejector and the second ejector move synchronously with the ejector panel and the ejector base plate.

8. The mold insert auxiliary ejection and demolding mechanism according to claim 1, characterized in that, The front mold assembly also includes an A plate, and the front mold core is fixed to the A plate.

9. The mold insert auxiliary ejection and demolding mechanism according to claim 1, characterized in that, The rear mold assembly also includes a B plate, and the rear mold core is fixed to the B plate.

10. A fan blade injection mold, characterized in that, Includes the mold insert auxiliary ejection and demolding mechanism as described in any one of claims 1-9.

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