Buffering structure of ejector plate of injection mold

Abstract

The utility model relates to an injection mold ejector plate buffer structure which comprises a mold frame and a bottom plate, a guide rod is fixedly arranged between the mold frame and the bottom plate, an ejector mounting plate is connected to the guide rod in a sliding mode, an ejector extending into a mold frame cavity is arranged on the ejector mounting plate, and a fixing plate used for fixing the ejector is arranged on one side of the ejector mounting plate. A reset spring is arranged on the guide rod and located between the ejector pin mounting plate and the mold frame, a pressing plate is arranged on the guide rod and located on one side of the bottom plate in a sliding mode, a buffer spring is arranged on the guide rod and located between the pressing plate and the fixing plate, impact force is absorbed through the buffer spring in the ejection stage, and the ejector pin mounting plate is pushed to eject products at the buffer speed. And meanwhile, due to the synergistic effect of the buffer spring and the reset spring in the reset process, reset impact of the ejector pin mounting plate can be relieved, abrasion of mold parts is reduced, the service life is prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, and specifically to a buffer structure for an ejector plate of an injection mold. Background Technology

[0002] In the injection mold production process, the product ejection stage is a crucial step, and its operation directly affects the final product quality and production efficiency. Traditional injection mold ejection methods mostly involve the injection molding machine's ejector roller directly driving the ejector plate. While this method is simple and direct, it has significant drawbacks. When the ejector pins contact the product instantaneously, they exert a large impact force, easily leading to deformation of thin-walled products, dimensional deviations in precision plastic parts, or surface scratches. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a buffer structure for the ejector plate of injection mold.

[0004] The objective of this utility model can be achieved through the following technical solution: A buffer structure for an injection mold ejector plate includes a mold frame and a base plate. A guide rod is fixedly provided between the mold frame and the base plate. An ejector mounting plate is slidably connected to the guide rod. An ejector pin is provided on the ejector mounting plate, extending into the cavity of the mold frame. A fixing plate for fixing the ejector pin is provided on one side of the ejector mounting plate. A return spring is provided on the guide rod between the ejector mounting plate and the mold frame. A pressure plate is slidably provided on the guide rod on one side of the base plate. A buffer spring is provided on the guide rod between the pressure plate and the fixing plate.

[0005] Preferably, a limiting post is provided on the side of the pressure plate near the fixed plate.

[0006] Preferably, the base plate is provided with a flexible cushioning pad.

[0007] Preferably, the bottom of the buffer spring is provided with an adjustment component.

[0008] Preferably, the adjusting assembly includes a slide sleeve fixedly mounted on the pressure plate and slidably connected to the guide rod, and a spring seat is threadedly connected to the slide sleeve.

[0009] Preferably, a locking nut is threaded onto the bottom of the spring seat on the sliding sleeve.

[0010] The beneficial effects of this invention are as follows: By using a buffer spring to absorb impact force during the ejection stage and pushing the ejector plate to eject the product at a buffered speed, the risk of deformation of thin-walled parts, dimensional deviations in precision products, and surface scratches can be effectively reduced. Simultaneously, the synergistic effect of the buffer spring and the return spring during the reset process can mitigate the impact on the ejector plate during reset, reducing wear on mold components, extending service life, and lowering maintenance costs. It balances ejection smoothness and reset stability, thereby improving product qualification rate and mold operational reliability. Attached Figure Description

[0011] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the ejector plate buffer structure of an injection mold according to the present invention.

[0013] Figure 2 This is a schematic diagram of the adjustment component of the ejector plate buffer structure for an injection mold according to the present invention.

[0014] The labels in the diagram represent: 1. Mold frame; 2. Base plate; 3. Guide rod; 4. Ejector pin mounting plate; 5. Ejector pin; 6. Return spring; 7. Pressure plate; 8. Buffer spring; 9. Limiting post; 10. Flexible buffer pad; 11. Adjustment component; 1101. Sliding sleeve; 1102. Spring seat; 1103. Locking nut; 12. Fixing plate. Detailed Implementation

[0015] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0016] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0017] The technical solution of this utility model will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0018] See Figures 1 to 2As shown, the structure of this utility model is as follows: an ejector plate buffer structure for injection mold, including a mold frame 1 and a base plate 2. A guide rod 3 is fixedly provided between the mold frame 1 and the base plate 2. An ejector mounting plate 4 is slidably connected to the guide rod 3. An ejector pin 5 extending into the cavity of the mold frame 1 is provided on the ejector mounting plate 4. A fixing plate 12 for fixing the ejector pin 5 is provided on one side of the ejector mounting plate 4. A return spring 6 is provided on the guide rod 3 between the ejector mounting plate 4 and the mold frame 1. A pressure plate 7 is slidably provided on the guide rod 3 on one side of the base plate 2. A buffer spring 8 is provided on the guide rod 3 between the pressure plate 7 and the fixing plate 12.

[0019] Specifically, during the injection molding process, when the injection molding machine starts working, the ejector roller extends and presses against the pressure plate 7. The pressure plate 7 moves along the guide rod 3, at which point the buffer spring 8 begins to compress. In this stage, the buffer spring 8 plays a crucial role, absorbing the enormous impact force generated at the moment of ejection. When the buffer spring 8 is compressed to a certain extent, it releases its stored elastic potential energy, pushing the fixed plate 12 forward at a buffer speed. The ejector pins 5 on the ejector pin mounting plate 4 then smoothly eject the product from the mold cavity, avoiding the problem of excessive impact force on the product in traditional ejection methods. This effectively reduces deformation of thin-walled products, dimensional deviations in precision products, and surface scratches, significantly improving product yield and quality. After the product is ejected, the ejector roller of the injection molding machine retracts and resets, and the buffer spring 8 relaxes, pushing the pressure plate 7 back to its initial position. Immediately afterwards, the ejector plate 4 begins to reset under the elastic force of the reset spring 6. During the reset process, the buffer spring 8 also buffers the impact of the ejector plate 4 during reset, ensuring the smoothness of the reset process. Because the buffer spring 8 reduces the impact force during the ejection and reset process of the ejector plate 4, it reduces the wear between various parts of the mold, extends the service life of the mold, and reduces the maintenance and replacement costs of the mold.

[0020] like Figure 1 As shown, a limiting post 9 is provided on the side of the pressure plate 7 near the fixed plate 12. Specifically, after the buffer spring 8 is compressed to a certain extent, the limiting post 9 contacts the ejector mounting plate 4, causing the ejector mounting plate 4 to become rigidly ejected. In the initial stage of ejection, the buffer spring 8 plays a buffering role, reducing the impact force on the product and avoiding problems such as deformation, dimensional deviation or surface scratches in thin-walled and precision products. When it becomes rigidly ejected, it can provide sufficient ejection force to ensure that the product, especially the product with complex shape or large demolding resistance, can be completely ejected from the mold cavity. At the same time, it can prevent the buffer spring 8 from being over-compressed, prevent the buffer spring 8 from exceeding its elastic limit and being damaged, and extend the service life of the buffer spring 8.

[0021] like Figure 1As shown, the base plate 2 is provided with a flexible buffer pad 10, which is used to absorb the impact when the pressure plate 7 is reset, and at the same time avoids the direct collision of metal parts to generate noise, wear or deformation, and extends the service life of the mold.

[0022] like Figure 1 As shown, the bottom of the buffer spring 8 is provided with an adjustment component 11. The adjustment component 11 is used to adjust the preload of the buffer spring 8. By changing the initial compression of the spring, the timing of switching between the buffer force and rigid ejection at the initial ejection stage can be precisely controlled. On the one hand, it can be adapted to the product material, such as thin-walled plastic parts requiring low preload to reduce impact or demolding resistance, and high-adhesion plastic parts requiring high preload to enhance buffering flexibility, significantly reducing the risk of product deformation and scratches. On the other hand, it can avoid poor demolding caused by spring overload failure or insufficient ejection force, taking into account both product quality and production efficiency.

[0023] like Figure 2 As shown, the adjusting assembly 11 includes a sliding sleeve 1101 fixedly mounted on the pressure plate 7 and slidably connected to the guide rod 3. A spring seat 1102 is threadedly connected to the sliding sleeve 1101. Specifically, the sliding sleeve 1101 is fixed on the pressure plate 7 and can slide freely on the guide rod 3, providing stable guidance and support for the entire adjusting structure. The sliding sleeve 1101 is threaded, and the spring seat 1102 is installed on the sliding sleeve 1101 by a threaded connection. When it is necessary to adjust the preload of the buffer spring 8, the operator can rotate the spring seat 1102. Since the spring seat 1102 is threadedly connected to the sliding sleeve 1101, rotating the spring seat 1102 will cause it to move along the sliding sleeve 1101. When the spring seat 1102 moves towards the ejector mounting plate 4, it will further compress the buffer spring 8, thereby increasing the preload of the buffer spring 8; conversely, if the spring seat 1102 moves away from the ejector mounting plate 4, the buffer spring 8 will be relaxed to a certain extent, and the preload will decrease accordingly.

[0024] like Figure 2 As shown, a locking nut 1103 is threadedly connected to the bottom of the spring seat 1102 on the sliding sleeve 1101. Specifically, the locking nut 1103, through its thread engagement with the sliding sleeve 1101, can firmly fix the spring seat 1102 onto the sliding sleeve 1101 after the spring seat 1102 is adjusted to the required preload position. After the operator rotates the spring seat 1102 to complete the preload adjustment, tightening the locking nut 1103 eliminates the thread gap between the spring seat 1102 and the sliding sleeve 1101, preventing the spring seat 1102 from rotating unexpectedly due to high-frequency vibration during injection molding, thus changing the preload. This ensures that the buffer spring 8 always maintains the set elastic modulus, thereby stably controlling the buffer stroke and rigid ejection switching timing of the ejector pin 5 plate, improving the reliability of mold operation and the consistency of product quality.

[0025] In practical use, during the injection molding process, when the injection molding machine starts working, the ejector roller extends and presses against the pressure plate 7. The pressure plate 7 moves along the guide rod 3, at which point the buffer spring 8 begins to compress. During this stage, the buffer spring 8 plays a crucial role, absorbing the enormous impact force generated at the moment of ejection. When the buffer spring 8 is compressed to a certain extent, it releases its stored elastic potential energy, pushing the fixed plate 12 forward at a buffered speed. The ejector pins 5 on the ejector pin mounting plate 4 then smoothly eject the product from the mold cavity. After the product is ejected, the ejector roller of the injection molding machine retracts and resets, and the buffer spring 8 relaxes, pushing the pressure plate 7 back to its initial position. Immediately afterwards, the ejector pin mounting plate 4 begins to reset under the elastic force of the reset spring 6. During the reset process, the buffer spring 8 also buffers the impact of the reset of the ejector pin mounting plate 4, ensuring the smoothness of the reset process.

[0026] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the substance and scope of the present invention. Various modifications made by those skilled in the art to the above embodiments after reading this specification are all within the scope of protection of the present invention.

Claims

1. A buffer structure for an ejector plate in an injection mold, characterized in that: The mold includes a mold frame (1) and a base plate (2). A guide rod (3) is fixed between the mold frame (1) and the base plate (2). A pin mounting plate (4) is slidably connected to the guide rod (3). A pin (5) is provided on the pin mounting plate (4) and extends into the cavity of the mold frame (1). A fixing plate (12) for fixing the pin (5) is provided on one side of the pin mounting plate (4). A return spring (6) is provided on the guide rod (3) between the pin mounting plate (4) and the mold frame (1). A pressure plate (7) is slidably provided on the guide rod (3) on one side of the base plate (2). A buffer spring (8) is provided on the guide rod (3) between the pressure plate (7) and the fixing plate (12).

2. The ejector plate buffer structure for injection molds according to claim 1, characterized in that: The pressure plate (7) is provided with a limiting post (9) on the side near the fixing plate (12).

3. The ejector plate buffer structure for injection molds according to claim 1, characterized in that: The base plate (2) is provided with a flexible buffer pad (10).

4. The ejector plate buffer structure for injection molds according to claim 1, characterized in that: The bottom of the buffer spring (8) is provided with an adjustment component (11).

5. The ejector plate buffer structure for injection molds according to claim 4, characterized in that: The adjustment assembly (11) includes a slide sleeve (1101) fixedly mounted on the pressure plate (7) and slidably connected to the guide rod (3), and a spring seat (1102) is threaded onto the slide sleeve (1101).

6. The ejector plate buffer structure for injection molds according to claim 5, characterized in that: A locking nut (1103) is threaded onto the bottom of the spring seat (1102) on the sliding sleeve (1101).

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