Bottom plate ejector pin structure for preventing sticking

Abstract

The utility model relates to a bottom plate ejector pin structure preventing sticking mold belongs to the technical field of injection mold, including die holder, the lower end of die holder is equipped with die bottom plate, a plurality of with die holder are inserted and embedded and are connected to the movable die of die holder, the periphery of movable die and die holder is equipped with injection molding insert, movable die and die bottom plate are equipped with ejector pin assembly. The ejector pin assembly includes inner extraction base, a plurality of pattern inner extractions extending out of the inner extraction base are arranged in the inner extraction base. It has the characteristics of simple structure, high efficiency and good running stability. The risk of product sticking mold in the production process is avoided. The cost of producing unqualified products is avoided, and the qualified rate of products is improved.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, specifically to a base plate spring pin structure for preventing mold sticking. Background Technology

[0002] To better meet consumer aesthetic demands, some plastic parts now feature increasingly diverse and complex surface patterns, with some patterns completely encasing the mold insert. During molding, the cooling and shrinkage of the product, combined with the tightness of the product encasing the insert, causes it to stick to the mold. However, most of these products are transparent, thick-walled parts with a large visible surface area. Due to the high product requirements, there isn't enough space for the patterned attachments to eject the product, making demolding difficult and affecting the product yield.

[0003] In traditional mold design, to address products with this risk of sticking to the mold, designers typically choose to design inserts within the pattern, utilizing a spring plate structure. Before mold opening, the spring plate mold is used to open the mold first, followed by ejection. Due to the mold's movement characteristics, the inserts encased in the product are first pulled out, and then ejected. This structure adds a third plate to the moving mold side in addition to the B plate, along with other corresponding accessories, which leads to a significant increase in mold costs.

[0004] In modern mold design, due to the small movement distance of such inserts, typically between 3mm and 5mm, and considering mold cost, the patterned insert is directly fixed to the base plate. A spring is set between the square iron and the B plate, omitting the third plate and its accessories in the traditional mold. The spring plate structure is simplified and optimized. During the product molding process, the B plate is directly ejected and the patterned insert is extracted by utilizing the mold opening sequence, thus eliminating the risk of sticking to the mold in advance. Summary of the Invention

[0005] This invention primarily addresses the shortcomings of existing technologies by providing a base plate spring pin structure to prevent product sticking to the mold. This structure is characterized by its simple structure, high efficiency, and good operational stability. It effectively mitigates the risk of product sticking to the mold during production, avoids producing defective products that increase costs, and improves the product qualification rate.

[0006] The above-mentioned technical problems of this utility model are mainly solved by the following technical solutions: A base plate spring pin structure for preventing mold sticking includes a mold base, a mold base plate at the lower end of the mold base, a plurality of movable mold cores that are inserted and connected to the mold base, injection molding inserts between the periphery of the movable mold cores and the mold base, and a spring pin assembly between the movable mold cores and the mold base plate. The spring pin assembly includes an inner drawer base, and a plurality of patterned inner drawers extending out of the inner drawer base are provided within the inner drawer base.

[0007] Preferably, a top plate is provided between the inner mold core and the moving mold core.

[0008] Preferably, the mold base plate and the mold seat are provided with an ejector pin base plate that is sleeved with the spring pin assembly. The upper end of the ejector pin base plate is provided with an ejector pin moving plate. The ejector pin base plate is provided with a plurality of ejector pins that penetrate through the mold seat, the ejector pin moving plate and to the lower end of the injection molding insert.

[0009] Preferably, square irons are provided on all four corners of the mold base plate.

[0010] Preferably, the upper end of the square iron and the mold base are both provided with springs that are plugged into and guided by the square iron.

[0011] This invention can achieve the following effects: This invention provides a base plate spring pin structure to prevent product sticking to the mold. Compared with existing technologies, it features a simple structure, high efficiency, and good operational stability. It avoids the risk of product sticking to the mold during production, prevents the production of defective products that increase costs, and improves the product qualification rate.

[0012] Effectively prevents sticking to the mold: This is the biggest advantage. Through the "pre-ejection" action of the spring pin assembly, it powerfully separates the areas with the strongest adhesion (such as patterns and deep cavities), fundamentally solving the problem of products sticking to the moving mold core.

[0013] Protecting product surface quality: For products with fine patterns, logos, or easily damaged surfaces, this instantaneous and uniform elastic force is more effective than the slow pushing force of traditional ejector pins in protecting product features from being pulled or deformed.

[0014] Improved production stability: Avoids downtime for cleaning, mold damage and production interruption caused by sticking to the mold, significantly improving the efficiency and yield of automated production.

[0015] Ingenious structure and reliable operation: It achieves complex sequential actions by combining a simple spring and a standard ejector pin system. The structure is compact and highly reliable. Attached Figure Description

[0016] Figure 1 This is a top view of the structure of this utility model.

[0017] Figure 2 This is a front view of the structural cross-section of this utility model.

[0018] Figure 3 This is a side view of the structural cross-section of this utility model.

[0019] Figure 4 This is a schematic diagram of the spring pin assembly in this utility model.

[0020] In the diagram: 1. Mold base; 2. Moving mold core; 3. Injection insert; 4. Spring pin assembly; 5. Ejector pin; 6. Ejector pin moving plate; 7. Ejector pin base plate; 8. Mold base plate; 9. Square iron; 10. Spring; 11. Ejector plate; 12. Patterned inner drawer; 13. Inner drawer base. Detailed Implementation

[0021] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0022] Example: Figure 1-4 As shown, a base plate spring pin structure for preventing mold sticking includes a mold base 1, a mold base plate 8 at the lower end of the mold base 1, square irons 9 at each of the four corners of the mold base plate 8, and springs 10 that are inserted and guided between the upper ends of the square irons 9 and the mold base 1. The mold base 1 has four movable mold cores 2 that are inserted and connected to the mold base 1. An injection molding insert 3 is provided between the periphery of the movable mold cores 2 and the mold base 1. An ejector base plate 7, which is sleeved with a spring pin assembly 4, is provided between the mold base plate 8 and the mold base 1. An ejector movable plate 6 is provided at the upper end of the ejector base plate 7, and four ejector pins 5 that penetrate the mold base 1, the ejector movable plate 6, and reach the lower end of the injection molding insert 3. A spring pin assembly 4 is provided between the movable mold cores 2 and the mold base plate 8. The spring pin assembly 4 includes an inner draw base 13, and a plurality of patterned inner drawers 12 extending out of the inner draw base 13 are provided inside the inner draw base 13. A top plate 11 is provided between the patterned inner drawers 12 and the moving mold core 2.

[0023] The workflow is as follows: Step 1: Mold closing and injection molding The mold closes, and molten plastic is injected into the cavity, filling the space formed by the moving mold core 2 and the injection insert 3.

[0024] When the product cools and solidifies, it shrinks and tightly wraps around the moving mold core 2, especially the bottom patterned area, which has a very strong bond with the moving mold core 2.

[0025] Step 2: Mold making The injection molding machine moves the moving mold part backward, the mold opens, and the product remains on the moving mold side.

[0026] Step 3: Pre-ejection stage (core action to prevent sticking) The ejector pin of the injection molding machine begins to move forward, pushing the ejector base plate 7 and the ejector moving plate 6 upward.

[0027] Since the top of the ejector pin 5 acts on the injection insert 3, and the spring pin assembly 4 is independent of the ejector plate, at the moment the ejector plate moves upward, the ejector pin 5 will first push the entire mold base 1 (along with the moving mold core 2 and the injection insert 3) to move upward together.

[0028] When mold base 1 moves upward, it will compress spring 10.

[0029] When the spring 10 is compressed to a certain extent, its accumulated elastic force will exceed the adhesion force between the product and the moving mold core 2. At this time, the strong reaction force of the spring 10, through the mold base 1, pushes the top plate 11 and the patterned inner pull 12, instantly and forcefully "bounces" the product away from the moving mold core 2 a short distance.

[0030] Result: The adhesion between the product and the moving mold core 2 (especially the patterned part) is broken. The product is now in a "suspended" state, having detached from the moving mold core 2, but still partially inside the injection insert 3.

[0031] Step 4: Main Top-Off Phase After the pre-ejection is completed, the ejector rod of the injection molding machine continues to push the ejector base plate 7 and the ejector moving plate 6 upward.

[0032] At this point, since the product has separated from the moving mold core 2, the resistance is greatly reduced. The ejector pin 5 begins to play its role, smoothly ejecting the "loosened" product from the injection insert 3.

[0033] Finally, the product is completely removed from the mold and can be taken out by a robotic arm or manually.

[0034] Step 5: Reset When the ejector pin of the injection molding machine retracts, the ejector plate 6 and the ejector base plate 7 return to their initial positions under the action of the spring 10 (or the mold reset rod).

[0035] The mold is closed, and the cycle begins.

[0036] In summary, this anti-sticking base plate spring pin structure features simple structure, high efficiency, and good operational stability. It effectively avoids the risk of product sticking to the mold during production, preventing the production of defective products, reducing costs, and improving the product qualification rate.

[0037] It will be apparent to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0038] In summary, the above description is only a specific embodiment of the present utility model, but the structural features of the present utility model are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present utility model are covered by the patent scope of the present utility model.

Claims

1. A base plate spring pin structure for preventing mold sticking, characterized in that: The mold base (1) includes a mold base plate (8) at the lower end of the mold base (1), and a plurality of movable mold cores (2) that are inserted and connected to the mold base (1) are provided on the mold base (1). An injection molding insert (3) is provided between the outer periphery of the movable mold core (2) and the mold base (1). A spring needle assembly (4) is provided between the movable mold core (2) and the mold base plate (8). The spring needle assembly (4) includes an inner drawer base (13), and a plurality of patterned inner drawers (12) extending out of the inner drawer base (13) are provided inside the inner drawer base (13).

2. The base plate spring pin structure for preventing mold sticking according to claim 1, characterized in that: A top plate (11) is provided between the inner mold (12) and the moving mold core (2).

3. The base plate spring pin structure for preventing mold sticking according to claim 1, characterized in that: The mold base plate (8) and the mold base (1) are provided with an ejector base plate (7) that is sleeved with the spring pin assembly (4). The upper end of the ejector base plate (7) is provided with an ejector moving plate (6). The ejector base plate (7) is provided with a plurality of ejector pins (5) that penetrate through the mold base (1), the ejector moving plate (6) to the lower end of the injection molding insert (3).

4. The base plate spring pin structure for preventing mold sticking according to claim 1, characterized in that: The mold base plate (8) is provided with square iron (9) on all four corners.

5. The base plate spring pin structure for preventing mold sticking according to claim 4, characterized in that: The upper end of the square iron (9) and the mold base (1) are provided with springs (10) that are plugged into the square iron (9) for guiding connection.

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