Injection mold with rear mold blank secondary bounce-off structure
By introducing multi-stage ejection mechanisms such as limiting grooves and snap-fit points into the injection mold, the problems of product tearing during demolding in existing molds have been solved, achieving a stable and smooth demolding process and improving product quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-13
- Publication Date
- 2026-04-03
AI Technical Summary
Existing injection molds are prone to problems such as product tearing, misalignment, penetration, and whitening during demolding, especially for products with slanted pillars, slanted holes, or slanted ribs on the rear mold side, making it difficult to achieve smooth demolding.
The mold adopts a secondary ejection structure for the rear mold blank, including a limiting groove, snap-fit points, limiting screws, spring plate, ejector pins, ejector plate, connecting plate, stroke block and auxiliary ejection mechanism. The multi-stage ejection mechanism and guiding structure ensure stable demolding of the mold.
It improves the smoothness of product demolding, reduces defects such as whitening, penetration, and misalignment, and enhances production quality and product qualification rate.
Smart Images
Figure CN224074852U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of injection molds, and in particular to an injection mold with a secondary spring-opening structure for the rear mold blank. Background Technology
[0002] Injection molds are a common type of mold used in industrial production for molding complex plastic parts. However, some molds have many rear mold ribs with thin walls or numerous undercut structures, making single ejection difficult for demolding. Currently, a simple double-ejector plate secondary ejection structure is used, which simply involves placing a spring on the ejector plate and locking it with a limit screw. While simple and feasible in the short term, spring failure occurs at a certain stage of mass production, leading to product damage. This frequently results in ejection misalignment, ejection penetration, ejection whitening, and the production of defective products, severely impacting production quality. This is especially problematic for molds with slanted pillars, slanted holes, or slanted ribs on the rear mold side, where products have clips, making it difficult to implement slanted ejector and slider demolding structures. Utility Model Content
[0003] To address the aforementioned technical problems, this application provides an injection mold with a secondary spring-out structure for the rear mold blank, comprising:
[0004] The rear mold template is equipped with limit slots and snap-fit points;
[0005] The first ejection mechanism includes a limiting screw and a spring plate. One end of the limiting screw is disposed in the limiting groove, and the other end of the limiting screw is disposed in the spring plate.
[0006] The second ejection mechanism includes an ejector pin, a top plate, a connecting plate, and a stroke block. One end of the ejector pin abuts against the mold blank, and the other end of the ejector pin is fixed to the top plate. One end of the connecting plate is provided with a slot, which is located at the snap-fit point. The stroke block is fixedly mounted on the top plate, and the other end of the connecting plate abuts against the stroke block.
[0007] Preferably, it further includes an auxiliary ejection mechanism, which includes a return needle and a return needle insert. The return needle passes through the rear mold plate, the spring plate, and the ejector plate in sequence, and the return needle insert is disposed at the top of the return needle.
[0008] Preferably, it also includes a limiting post, which passes through the rear mold template and the elastic plate.
[0009] Preferably, a guide sleeve is fitted onto the part of the ejector pin that passes through the mold blank.
[0010] Preferably, the return thread is locked to the top plate. Attached Figure Description
[0011] 1. Rear mold template; 11. Limiting groove; 12. Snap-on point; 2. First ejection mechanism; 21. Limiting screw; 22. Spring plate; 3. Second ejection mechanism; 31. Ejector pin; 32. Ejector plate; 33. Connecting plate; 34. Stroke block; 4. Auxiliary ejection mechanism; 41. Return pin; 42. Return pin spacer; 5. Limiting post; 6. Guide sleeve; 7. Mold base.
[0012] Figure 1 This is a cross-sectional view of an injection mold with a secondary spring-opening structure for the rear mold blank, according to an embodiment of this utility model.
[0013] Figure 2 This is a schematic diagram of the opening structure of the injection mold with the secondary spring-opening structure of the rear mold blank according to an embodiment of the present invention. Detailed Implementation
[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, please refer to the accompanying drawings and embodiments below. Figure 1 as well as Figure 2 This invention provides a more detailed description of an injection mold with a secondary spring-opening structure for the rear mold blank. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.
[0015] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more; the terms "center," "longitudinal," "lateral," "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0016] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0017] This application discloses an injection mold with a secondary spring-opening structure for the rear mold blank, comprising: a rear mold template 1, which is provided with a limiting groove 11 and a snap-fit point 12; a first ejection mechanism 2, which includes a limiting screw 21 and a spring plate 22, one end of the limiting screw 21 being disposed in the limiting groove 11 and the other end of the limiting screw 21 being disposed in the spring plate 22; and a second ejection mechanism 3, which includes an ejector pin 31, an ejector plate 32, a connecting plate 33 and a stroke block 34, one end of the ejector pin 31 abutting inside the mold blank 7 and the other end of the ejector pin 31 being fixedly connected to the ejector plate 32, one end of the connecting plate 33 being provided with a snap-fit groove, the snap-fit groove being disposed in the snap-fit point 12, the stroke block 34 being fixedly disposed in the ejector plate 32, and the other end of the connecting plate 33 abutting against the stroke block 34.
[0018] In the above embodiment, during mold opening, the front and rear mold plates separate, and the rear mold plate 1 begins to move under the drive of the injection molding machine. During the movement, the spring inside the spring plate 22 releases the previously accumulated pressure, pushing the spring plate 22 upward. The spring plate 22 is also in a pre-compression state in the initial stage, so it can drive the rear mold blank 7 to move upward together. During the upward movement, the spring plate 22 will push the mold blank 7 upward a certain initial distance, which helps the subsequent demolding process.
[0019] One end of the limiting screw 21 is located within the limiting groove 11, and the other end is connected to the spring plate 22. As the rear mold plate 1 continues to move upward, the reserved space in the limiting groove 11 gradually decreases until it contacts the limiting screw 21. This contact point marks the upper limit of the movement of the spring plate 22, at which point the spring plate 22 stops moving further.
[0020] At the same time, the locking point 12 on the rear mold template 1 also moves as the template rises. When the locking point 12 moves to a certain position, it abuts against the edge of the slot on the connecting plate 33. This contact causes the locking point 12 to drive the connecting plate 33 to move upward synchronously. The other end of the connecting plate 33 abuts against the travel block 34, so the movement of the connecting plate 33 will trigger the travel block 34.
[0021] When the stroke block 34 is activated, it begins to move the top plate 32 upward. The ejector pins 31 on the top plate 32 then eject, directly impacting the injection-molded product inside the mold base 7 and separating it from the mold base 7. This process ensures smooth ejection of the injection-molded product, effectively reducing defects such as whitening, penetration, or misalignment caused by improper ejection, thereby improving the product yield.
[0022] Please see Figure 1 as well as Figure 2In another embodiment, an auxiliary ejection mechanism 4 is also included, which includes a return needle 41 and a return needle insert 42. The return needle 41 is sequentially inserted through the rear mold template 1, the spring plate 22 and the ejector pin 31 plate, and the return needle insert 42 is disposed at the top of the return needle 41.
[0023] In the above embodiment, at this time, the return pin 41, as a key component connecting the rear mold template 1 and the ejector pin 31 plate, is still driven by the mold opening action of the injection molding machine and continues to move upward.
[0024] Since the return needle 41 passes sequentially through the rear mold plate 1, the stopped spring plate 22, and the ejector pin 31 plate, when the spring plate 22 stops, the return needle 41 will continue to rise, forcibly compelling the return needle insert 42 located at its top to retract relative to the spring plate 22 and the ejector pin 31 plate. During this process, although the return needle insert 42 is no longer directly pushed by the spring plate 22, it still rises along with the return needle 41, only with a certain retraction displacement relative to the spring plate 22.
[0025] As the ejector pin 41 continues to rise, the ejector pin 31 passes through the pre-drilled channel in the rear mold plate 1 and continues to eject the injection molded product. Finally, the force of the ejector pin 31 is sufficient to overcome the adhesion between the product and the mold base 7, completely ejecting the product from the mold base 7, thus completing the entire demolding process.
[0026] Please see Figure 1 as well as Figure 2 In another embodiment, a limiting post 5 is also included, which passes through the rear mold template 1 and the elastic plate 22.
[0027] In the above embodiments, during mold closing, the limiting post 5 acts as a support and guide structure, enabling the spring plate 22 and the rear mold plate 1 to move smoothly along a predetermined vertical direction, preventing tilting or offset caused by lateral forces or assembly errors. This vertical movement ensures precise alignment of the internal structure of the mold, providing a stable foundation for subsequent injection molding and ejection processes.
[0028] During the mold opening process, when the spring plate 22 moves upward under the push of the spring, the limiting post 5 continues to play its guiding role, ensuring that the spring plate 22 rises in the vertical direction, thus avoiding the risk of motion interference or damage to the mold structure caused by tilting.
[0029] Please see Figure 1 as well as Figure 2 In another embodiment, the portion of the ejector pin 31 that passes through the mold blank 7 is fitted with a guide sleeve 6.
[0030] In the above embodiment, firstly, the guide sleeve 6 provides precise guidance for the ejector pin 31. During the mold ejection process, the ejector pin 31 needs to move accurately along a certain path to ensure smooth ejection of the injection molded product. The presence of the guide sleeve 6 allows the ejector pin 31 to be effectively guided and constrained during movement, avoiding poor ejection or mold damage caused by offset or wobbling.
[0031] Please see Figure 1 as well as Figure 2 In another embodiment, the return pin 41 is threadedly locked to the top plate 32.
[0032] In the above embodiment, the threaded locking ensures a secure connection between the return pin 41 and the top plate 32. Through the tightening action of the thread, the return pin 41 is firmly fixed to the top plate 32, preventing motion interference or damage caused by loosening or detachment during mold opening, closing, or ejection. This robust connection method guarantees the stability and reliability of the mold structure.
[0033] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.
Claims
1. An injection mold with a secondary spring-opening structure for the rear mold blank, characterized in that, include: The rear mold template is equipped with limit slots and snap-fit points; The first ejection mechanism includes a limiting screw and a spring plate. One end of the limiting screw is disposed in the limiting groove, and the other end of the limiting screw is disposed in the spring plate. The second ejection mechanism includes an ejector pin, a top plate, a connecting plate, and a stroke block. One end of the ejector pin abuts against the mold blank, and the other end of the ejector pin is fixed to the top plate. One end of the connecting plate is provided with a slot, which is located at the snap-fit point. The stroke block is fixedly mounted on the top plate, and the other end of the connecting plate abuts against the stroke block.
2. The injection mold with a secondary spring-opening structure for the rear mold blank as described in claim 1, characterized in that: It also includes an auxiliary ejection mechanism, which includes a return needle and a return needle insert. The return needle passes through the rear mold plate, the spring plate and the ejector plate in sequence, and the return needle insert is located at the top of the return needle.
3. The injection mold with a secondary spring-opening structure for the rear mold blank as described in claim 1, characterized in that: It also includes a limiting post, which passes through the rear mold template and the elastic plate.
4. The injection mold with a secondary spring-opening structure for the rear mold blank as described in claim 1, characterized in that: A guide sleeve is fitted onto the part of the ejector pin that passes through the mold blank.
5. The injection mold with a secondary spring-opening structure for the rear mold blank as described in claim 2, characterized in that: The return thread is locked to the top plate.