A secondary ejection structure

Abstract

This utility model relates to a secondary ejection structure, comprising a base plate and a locking mechanism. A push plate and an ejector pin assembly are sequentially arranged on the upper surface of the base plate. A B plate is fixedly connected to the top of the base plate via guide pillars, and a rear mold core is embedded in the B plate to form a plastic part molding cavity. The locking mechanism includes a locking mechanism base fixedly connected to the side of the base plate, a slider fixedly connected to the side of the push plate, and a linkage block fixedly connected to the ejector pin assembly. The locking mechanism base is slidably connected to the slider, and the slider is engaged with the linkage block. The locking mechanism is used to control the linkage between the push plate and the ejector pin assembly, realizing simultaneous primary ejection of the push plate and the ejector pin assembly and individual secondary ejection of the ejector pin assembly. This utility model has the effects of improving demolding efficiency, increasing demolding reliability, and reducing maintenance costs by optimizing the ejection path.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, and in particular to a secondary ejection structure. Background Technology

[0002] In the field of injection molding, the ejection mechanism is a key component for demolding plastic parts, and its performance directly affects the molding quality and production efficiency. As injection molded products become more complex and precise, efficient and reliable demolding technology is particularly important for plastic parts with complex structures such as deep cavities, undercuts, and multi-layer inserts.

[0003] Currently, existing technologies commonly employ a single ejection structure, which typically ejects the plastic part from the mold through a single ejection action. However, this single ejection structure has the following drawbacks when dealing with complex plastic parts: First, the concentrated ejection force leads to excessive local stress. When demolding deep-cavity or undercut plastic parts, the ejection force is concentrated in a local area, causing quality problems such as tearing, deformation, or even breakage. Second, a single ejection path cannot adapt to multi-stage demolding requirements: a single ejection action is insufficient to meet the multi-stage demolding requirements of complex plastic parts, easily leading to incomplete demolding or sticking, affecting product appearance quality and yield. Third, the demolding efficiency is low and maintenance costs are high, making it unable to match the cycle time requirements of high-precision automated production lines, resulting in low production efficiency and difficulty in meeting the needs of modern mass production. Utility Model Content

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a secondary ejection structure that improves demolding efficiency, enhances the reliability of demolding complex plastic parts, and reduces maintenance costs by optimizing the ejection path.

[0005] The above-mentioned utility model objective is achieved through the following technical solution:

[0006] A secondary ejection structure includes a base plate and a fastener. A push plate and an ejector pin assembly are sequentially arranged on the upper surface of the base plate. A B plate is fixedly connected above the base plate by a guide post. A rear mold core is embedded in the B plate to form a plastic part molding cavity.

[0007] The fastening mechanism includes a fastening base fixedly connected to the side of the base plate, a slider fixedly connected to the side of the push plate, and a linkage block connecting the ejector pin assembly; the slider is slidably connected to the fastening base, and the slider is engaged with the linkage block; the fastening mechanism is used to control the linkage between the push plate and the ejector pin assembly, so as to realize the push plate and the ejector pin assembly being ejected synchronously once and the ejector pin assembly being ejected separately twice.

[0008] Through the above technical solutions, the linkage between the push plate and the ejector pin assembly is locked or released, realizing synchronous single ejection and separate secondary ejection of the ejector pin assembly. This solves the problem that traditional single ejection is prone to stress concentration and deformation in deep cavity and undercut plastic parts, making the demolding stress distribution of plastic parts uniform. At the same time, the staged ejection is suitable for complex plastic parts, improving demolding reliability and avoiding demolding failure due to a single demolding path. In addition, by shortening the demolding time, reducing interference damage between the ejector pin and the mold, and reducing the wear frequency of parts, the mold maintenance cycle is extended, significantly reducing maintenance costs.

[0009] As a further technical solution of this utility model: a groove is provided on the inner side of the buckle base, and the side of the groove away from the base plate is an unlocking slope;

[0010] The slider has a first groove that matches the buckle base and a second groove that matches the linkage block.

[0011] The linkage block has a wedge-shaped mating surface on one side facing the buckle base that fits with the unlocking slope, and the other side of the linkage block away from the buckle base is connected to the ejector pin assembly via a compression spring.

[0012] Through the above technical solutions, the buckling machine solves the problems of uncontrollable unlocking timing and easy jamming in existing buckling machines by cooperating with the buckling machine base, slider, and linkage block, as well as the fitting design of the unlocking slope and wedge mating surface. It achieves precise switching of linkage relationship during ejection, ensures reliable linkage or separation action of the push plate and ejector pin assembly, and improves the continuity of automated mold production.

[0013] As a further technical solution of this utility model: when the buckle is in the locked state, the linkage block is embedded in the second groove, and the push plate and the ejector pin assembly are in a state of synchronous movement;

[0014] When the latch is released, the wedge-shaped mating surface of the linkage block and the unlocking slope of the latch base are in a pressing state, causing the linkage block to compress the spring. At the same time, the linkage block and the slider disengage to a non-fitted state. At this time, the push plate is in a stationary state, and the ejector pin assembly is in an independent movement state and completes partial demolding.

[0015] Through the above technical solution, when the machine is locked, the push plate and the ejector pin assembly move synchronously. When the lock is released, the push plate stops and the ejector pin assembly continues to move. This solves the problems of continuous ejection by the push plate causing deformation of weak parts of the plastic part and the inability to handle multiple demolding stages in a single ejection. Staged ejection can first eject the loose plastic part in a large area of ​​strong mold sticking through the push plate, and then the ejector pin assembly can accurately eject to complete local demolding, reducing plastic part deformation and improving demolding efficiency.

[0016] As a further technical solution of this utility model: the ejector assembly includes an ejector panel and an ejector base plate that are stacked and fixed. A plurality of ejector pins are vertically fixedly connected to the ejector base plate. The ejector pins pass through the ejector panel and the B plate in sequence and extend to the molding area of ​​the rear mold core.

[0017] Through the above technical solution, the ejector assembly adopts a stacked and fixed ejector panel and ejector base plate. The ejector pin is vertically fixed to the ejector base plate and extends through the B plate to the molding area, which solves the problem of insufficient rigidity of traditional ejector assembly, which causes ejector pin bending and plastic part ejection deviation. The stacked structure enhances the overall rigidity of the ejector assembly, ensures the precise ejection direction of the ejector pin, and is suitable for stable demolding of complex plastic parts.

[0018] As a further technical solution of this utility model: a groove matching the size of the linkage block is provided at the connection between the ejector plate and the ejector base plate, and the linkage block is connected to the inner wall of the groove by two springs.

[0019] Through the above technical solution, a groove matching the size of the linkage block is opened at the connection between the ejector plate and the base plate. The linkage block is connected to the inner wall of the groove by two springs, which solves the problems of insufficient movement space of the linkage block causing jamming and uneven force of a single spring causing unlocking deviation. The groove provides sufficient movement space for the linkage block, and the symmetrical layout of the two springs ensures that the linkage block is evenly stressed, improving the stability and reliability of the latching and unlocking action.

[0020] As a further technical solution of this utility model: it also includes a reset rod, the bottom end of which is fixedly connected to the base plate, the top end of which extends to the bottom surface of the B plate, the ejector pin assembly and the push plate are both provided with guide sleeves, and the rod of the reset rod is inserted into the guide sleeve and is clearance-fitted with the guide sleeve.

[0021] Through the above technical solution, the bottom end of the reset rod is fixed to the base plate, and the top end extends to the bottom surface of the B plate. The rod body is installed in the guide sleeve with clearance fit, which solves the problem of the ejector pin interfering with the front mold due to incomplete reset and the ejector plate jamming caused by reset misalignment. Through the sliding fit between the reset rod and the guide sleeve, the B plate pushes the reset rod to force the ejector plate to reset accurately when the mold is closed, ensuring that the ejection mechanism returns to the initial position and prepares for the next ejection.

[0022] In summary, this utility model has at least one of the following beneficial technical effects:

[0023] 1. This utility model discloses a secondary ejection structure, which sets a push plate and an ejector pin assembly on the base plate, and sets a fastener between the push plate and the ejector pin assembly to lock or release the linkage relationship, so as to realize the simultaneous one-time ejection of the push plate and the ejector pin assembly and the separate two-time ejection of the ejector pin assembly, thereby reducing stress concentration and deformation of the plastic part and improving the demolding reliability of complex plastic parts.

[0024] 2. This utility model discloses a secondary ejection structure, which achieves precise control of the ejection timing and rigid support of the ejection assembly through the cooperation of the fastening base, the slider, the linkage block, the stacked and fixed structure of the ejector pin assembly, and the connection design of the linkage block and the double spring, ensuring reliable staged ejection action and avoiding unlocking jamming and ejector pin bending.

[0025] 3. This utility model discloses a secondary ejection structure, which achieves forced and precise reset of the ejector plate during mold closing by fixing the bottom end of the reset rod to the base plate, abutting the top end to the B plate and having a clearance fit with the push plate guide sleeve, thereby preventing interference between the ejector pin and the front mold and ensuring the continuity of automated mold production. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of a secondary ejection structure according to Embodiment 1 of this utility model.

[0027] Figure 2 This is a front view of a secondary ejection structure according to an embodiment of the present invention.

[0028] Figure 3 This is a partial structural diagram of a secondary ejection structure according to Embodiment 1 of this utility model.

[0029] Figure 4 This is a schematic diagram of the buckle mechanism in a secondary ejection structure according to Embodiment 1 of this utility model.

[0030] Reference numerals: 1. B plate; 2. Rear mold core; 3. Ejector plate; 4. Ejector base plate; 5. Push plate; 6. Snap-fit ​​mechanism; 61. Snap-fit ​​mechanism base; 611. Unlocking ramp; 62. Slider; 621. First groove; 622. Second groove; 63. Linkage block; 631. Wedge-shaped mating surface; 64. Spring; 7. Base plate; 8. Ejector pin; 9. Reset rod; 10. Guide post; 11. Guide sleeve. Detailed Implementation

[0031] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0032] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" 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 two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0034] Example 1:

[0035] Reference Figure 1 , Figure 2 and Figure 3 This utility model discloses a secondary ejection structure, including a base plate 7, which serves as a base. A B plate 1 is fixedly connected to the top of the base plate 7 via guide posts 10. The B plate 1 has a rear mold core 2 embedded in it to form a plastic part molding cavity, constituting the basic frame of the mold. A push plate 5 and an ejector pin assembly are provided on the upper surface of the base plate 7, with the push plate 5 supporting the ejector pin assembly.

[0036] Reference Figure 3 The ejector assembly includes an ejector panel 3 and an ejector base plate 4 that are fixed together by bolts. Multiple ejector pins 8 are vertically fixed on the ejector base plate 4. The ejector pins 8 pass through the ejector panel 3 and the B plate 1 in sequence and extend to the plastic part forming area of ​​the rear mold core 2.

[0037] Reference Figure 4To achieve phased ejection, a latch 6 is provided, which includes a latch base 61, a slider 62, and a linkage block 63. The bottom of the latch base 61 is fixedly connected to the side of the base plate 7 by bolts. A groove is provided on the inner side of the latch base 61, and the upper side of the groove is an unlocking ramp 611. In addition, the inclination angle of the unlocking ramp 611 can be set to 45°. At the same time, the surface of the unlocking ramp 611 can be nitrided and coated with a molybdenum disulfide coating to reduce the coefficient of friction (for example, the coefficient of friction is stabilized in the range of 0.06-0.08). The bottom of the slider 62 is fixedly connected to the side of the push plate 5 by bolts. A first groove 621 and a second groove 622 are provided on the inner side of the slider 62. The first groove 621 runs through the vertical direction, and the groove width is 0.05mm larger than that of the latch base 61. After the latch base 61 is inserted, it restricts the vertical displacement of the slider 62. The second groove 622 is formed on the first groove 621 and runs through the first groove 621. In the horizontal direction, the cavity of the second groove 622 is adapted to the linkage block 63 to transmit the ejection power; one side of the linkage block 63 is a wedge-shaped mating surface 631, the inclination angle of the wedge-shaped mating surface 631 is completely consistent with the unlocking slope 611 (e.g., 45°), and the contact area with the unlocking slope 611 is ≥95%. The other side of the linkage block 63 is elastically connected to the ejector pin assembly through a spring 64; when the push plate 5 drives the slider 62 to rise until the wedge-shaped mating surface 631 contacts the unlocking slope 611, the inclination angle of the unlocking slope 611 causes the linkage block 63 to be subjected to a horizontal component force. This component force pushes the linkage block 63 to compress the spring 64 and disengage from the second groove 622, realizing the movement separation of the push plate 5 and the ejector pin assembly. The push plate 5 stops moving, and the ejector pin assembly is driven by the ejection system to complete the secondary ejection. The unlocking ramp 611 and the wedge-shaped mating surface 631 are designed with a 45° inclination angle. This inclination angle, through the principle of force decomposition (F horizontal = F vertical × tan45°), makes the vertical ejection force form an equivalent component force in the horizontal direction, ensuring that the spring 64 compression is ≥5mm under the condition of ejection force ≤1000N, thus achieving reliable unlocking. At the same time, both the unlocking ramp 611 and the wedge-shaped mating surface 631 can be treated with a composite coating of nitriding and molybdenum disulfide to form an ultra-low friction coefficient of 0.06-0.08, reducing energy loss during unlocking and reducing wear after multiple cycles, effectively extending the service life of the buckle 6.

[0038] Furthermore, a groove is provided at the connection between the ejector plate 3 and the ejector base plate 4. This groove matches the size of the linkage block 63. One end of the linkage block 63 is connected to the inner wall of the groove via two compression springs 64. The two springs 64 are symmetrically arranged on the inner wall of the groove, providing symmetrical elastic support for the linkage block 63. When the springs 64 are fully compressed, the linkage block 63 can be fully embedded in the groove. At this time, the vertical side of the linkage block 63 with the wedge-shaped mating surface 631 is flush with the ejector plate 3 and the vertical side, avoiding interference with the assembly and movement of the ejector assembly and other components, and ensuring that the linkage block 63 is subjected to balanced force and operates reliably during the secondary ejection process.

[0039] Reference Figure 3 and Figure 4 During the first ejection stage, the ejector plate 5 and the ejector pin assembly move synchronously to loosen the plastic part from the area where it strongly sticks to the mold. After injection molding is completed, the ejector mechanism of the injection molding machine pushes the ejector plate 5 upward. At this time, the latch 6 is in the initial locked state. In the initial locked state, the engaging boss of the linkage block 63 is embedded in the second groove 622 of the slider 62, so that the ejector plate 5 and the ejector pin assembly form a rigid linkage. At this time, the ejector mechanism of the injection molding machine pushes the ejector plate 5 upward, and the ejector pin assembly moves synchronously. The ejector pin connected to the ejector plate 5 contacts the back of the plastic part, evenly releasing the adhesion force between the plastic part and the rear mold core 2, and simultaneously driving the ejector pin 8 to be ejected from the molding cavity, completing the first ejection and realizing the initial loosening of the plastic part from the area where it strongly sticks to the mold.

[0040] Reference Figure 3 and Figure 4 When the ejection action advances to the preset distance, the slider 62 drives the linkage block 63 to move to the unlocking slope 611 area of ​​the locking base 61. The unlocking slope 611 presses against the wedge-shaped mating surface 631 of the linkage block 63, forcing the linkage block 63 to compress the spring 64 and disengage from the slider 62, thus releasing the locking mechanism 6. At this time, the push plate 5 stops moving, while the ejector pin assembly continues to move upward under the push of the ejection mechanism. The ejector pin 8 precisely acts on the complex structural parts of the plastic part, such as undercuts and deep cavities, to complete the secondary ejection and achieve complete demolding of the plastic part.

[0041] Reference Figure 3 In addition, to ensure accurate resetting of the ejection mechanism, the structure also includes a reset rod 9. The bottom end of the reset rod 9 is fixed to the base plate 7, and the top end extends to the bottom surface of plate B 1. The rod body of the reset rod 9 passes through guide sleeves 11 corresponding to the push plate 5 and the ejector assembly (ejector panel 3 and ejector base plate 4), forming a clearance fit of 0.05-0.1mm with the guide sleeves 11. During mold closing, plate B 1 moves towards the base plate 7 along with the injection molding machine template, and its bottom surface presses against the top end of the reset rod 9. Since the bottom end of the reset rod 9 is fixed to the base plate 7, the pressure of plate B 1 is rigidly transmitted to push the push plate 5 and the ejector assembly to slide downwards along the rod body of the reset rod 9, achieving synchronous resetting. The push plate 5 and the ejector assembly are guided by the clearance fit between the reset rod 9 and the guide sleeve 11, and the resetting accuracy is controlled within ±0.1mm, ensuring that each component accurately returns to its initial position, preparing for the next injection molding.

[0042] The principle of this invention is as follows: by using the time-sequential control and rigid design of the mechanical structure, the traditional one-time ejection is decomposed into staged actions to solve the problem of demolding complex plastic parts. Specifically, utilizing the locking and unlocking functions of the clamping mechanism 6, the ejector plate 5 and the ejector pin assembly (including the ejector pin panel 3 and ejector pin base plate 4 fixed by bolts) and the ejector pin 8 move synchronously to achieve one ejection. The ejector pin connected to the clamping mechanism 5 evenly loosens the plastic part from the area where it is strongly stuck to the mold. Then, the unlocking ramp 611 of the clamping mechanism 6 presses the linkage block 63 to trigger the unlocking, allowing the ejector pin assembly to complete a second ejection independently, accurately acting on complex structures such as the plastic part's undercut. During the reset phase, the reset rod 9, with the rigid support of the bottom fixed to the base plate 7, transmits the thrust to the clamping mechanism 5 through the pressure of the B plate 1 during mold closing to achieve forced reset. The bolted fixing structure of the ejector pin assembly and the symmetrical layout of the double springs 64 of the linkage block 63 improve the stability of the mechanism from the perspectives of rigidity enhancement and force balance, respectively. Finally, the sequential and distributed control of the demolding force of the plastic part is achieved, effectively solving problems such as stress concentration and unreliable demolding.

[0043] The embodiments described herein are preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape, and principle of this utility model should be included within the scope of protection of this utility model.

Claims

1. A secondary ejection structure comprising a base plate (7), a clamping device (6), characterized in that, The upper surface of the base plate (7) is provided with a push plate (5) and an ejector pin assembly in sequence. A B plate (1) is fixedly connected above the base plate (7) by a guide post (10). A rear mold core (2) is embedded in the B plate (1) to form a plastic part molding cavity. The fastening mechanism (6) includes a fastening base (61) fixedly connected to the side of the base plate (7), a slider (62) fixedly connected to the side of the push plate (5), and a linkage block (63) connecting the ejector pin assembly. The slider (62) is slidably connected to the fastening base (61), and the slider (62) is engaged with the linkage block (63). The fastening mechanism (6) is used to control the linkage between the push plate (5) and the ejector pin assembly, so as to realize the synchronous one-time ejection of the push plate (5) and the ejector pin assembly and the separate two-time ejection of the ejector pin assembly.

2. The secondary ejection structure according to claim 1, characterized in that, The inner side of the buckle base (61) is provided with a groove, and the side of the groove away from the base plate (7) is an unlocking slope (611); The slider (62) has a first groove (621) that matches the buckle base (61) and a second groove (622) that matches the linkage block (63); The linkage block (63) has a wedge-shaped mating surface (631) on the side facing the buckle base (61) that fits against the unlocking inclined surface (611). The other side of the linkage block (63) away from the buckle base (61) is connected to the ejector pin assembly through a compression spring (64).

3. The secondary ejection structure according to claim 2, characterized in that, When the buckle (6) is in the locked state, the linkage block (63) is embedded in the second groove (622), and the push plate (5) and the ejector pin assembly are in a state of synchronous movement; When the latch (6) is unlocked, the wedge-shaped mating surface (631) of the linkage block (63) and the unlocking inclined surface (611) of the latch base (61) are in a pressing state, causing the linkage block (63) to compress the spring (64). At the same time, the linkage block (63) and the slider (62) disengage to a non-fitted state. At this time, the push plate (5) is in a stationary state, and the ejector pin assembly is in an independent motion state and completes partial demolding.

4. The secondary ejection structure of claim 1, wherein The ejector assembly includes an ejector panel (3) and an ejector base plate (4) that are stacked and fixed together. Multiple ejector pins (8) are vertically fixedly connected to the ejector base plate (4). The ejector pins (8) pass through the ejector panel (3) and the B plate (1) in sequence and extend to the plastic part forming area of ​​the rear mold core (2).

5. A secondary ejection structure according to claim 4, characterized in that, The connection between the ejector plate (3) and the ejector base plate (4) is provided with a groove that matches the size of the linkage block (63). The linkage block (63) is connected to the inner wall of the groove by two springs (64).

6. The secondary ejection structure according to claim 1, characterized in that, It also includes a reset rod (9), the bottom end of which is fixedly connected to the base plate (7), the top end of which extends to the bottom surface of the B plate (1), the ejector pin assembly and the push plate (5) are both provided with guide sleeves (11), the rod of the reset rod (9) is inserted into the guide sleeve (11) and is clearance-fitted with the guide sleeve (11).

Images