Secondary ejection mechanism for injection mold

Abstract

The utility model discloses a kind of secondary ejection mechanisms of injection mold, apply in injection mold technical field;Including mold base plate, the top of mold base plate is respectively equipped with ejector pin base plate and ejector pin panel, the inside bolt connection of ejector pin base plate has machine base, the inside sliding connection of machine base has movable block, the one side fixed connection of mold base plate top has respectively with the first buckle machine of the sliding connection of ejector pin panel and machine base.Through the mechanical locking and unlocking mechanism of first buckle machine and second buckle machine, accurate secondary ejection stroke control is realized, avoid the unstable problem of stroke caused by spring fatigue or hydraulic system leakage, especially suitable for high-precision injection molding product.Simultaneously adopt bolt connection and sliding fit, reduce the risk of shaft abrasion and deformation in lever mechanism, prolong the service life of mould.The trapezoidal groove design between buckle machine and movable block provides self-locking function, ensure that it will not be accidentally unlocked during ejection process.

Description

Technical Field

[0001] This utility model belongs to the field of injection mold technology, and specifically relates to a secondary ejection mechanism for injection molds. Background Technology

[0002] In the mass production of plastic products, molds are usually used to reduce costs, so an ejection mechanism is needed to eject and demold the injection molded products.

[0003] Currently, Chinese utility model patent CN218857603U discloses a secondary ejection mechanism for injection molds. Existing secondary ejection mechanisms for injection molds are generally classified into several types: single ejector plate combination, pneumatic / hydraulic, and lever type.

[0004] The secondary ejection mechanism of a single ejector plate assembly mainly relies on elastic elements such as springs for drive. When dealing with heavy injection molded products, the springs experience high demolding resistance and are prone to fatigue after long-term use, leading to a decrease in secondary ejection force and unstable stroke. Secondly, pneumatic / hydraulic secondary ejection mechanisms are expensive, and the seals are prone to aging in high-temperature mold environments, requiring frequent replacement; hydraulic systems also require regular hydraulic oil changes, making maintenance complex and affecting production continuity. Finally, lever-type secondary ejection mechanisms use levers as the core force-bearing component, which are subjected to mold opening impact and lever torque over a long period of time. Levers are prone to deformation and shaft wear, leading to jamming; and external levers require reserved installation and movement space on the outside of the mold, making them unsuitable for small molds or multi-cavity molds; internal levers compress the internal space of the mold base and restrict cavity layout, thus making them unsuitable for multi-variety, small-batch production. Utility Model Content

[0005] The purpose of this invention is to provide a secondary ejection mechanism for injection molds. Its advantage lies in using a locking and unlocking mechanism for the injection ejection control to complete the second ejection, thereby improving the accuracy and safety of the secondary ejection. This mechanism can be widely applied in various molds such as injection molds and die-casting molds, effectively reducing mold costs and simplifying maintenance and processing.

[0006] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a secondary ejection mechanism for an injection mold, comprising a mold base plate, an ejector base plate and an ejector panel respectively mounted on the top of the mold base plate, a base bolted inside the ejector base plate, a movable block slidably connected inside the base, a first fastener fixedly connected to the ejector panel and the base respectively on one side of the top of the mold base plate, a spring bolted to the base fixedly connected to the side of the movable block away from the first fastener, a second fastener bolted inside the ejector panel and slidably connected to the base and the movable block respectively, and an injection molding machine ejector roller bolted to the ejector panel slidably connected to the bottom of the mold base plate.

[0007] The above technical solution achieves precise secondary ejection stroke control through a mechanical locking and unlocking mechanism using a first and second locking mechanism. This avoids stroke instability caused by spring fatigue or hydraulic system leakage, making it particularly suitable for high-precision injection molded products. Simultaneously, the use of bolted connections and sliding fits reduces the risk of shaft wear and deformation in lever-type mechanisms, extending mold life. The trapezoidal groove design between the locking mechanism and the moving block provides a self-locking function, ensuring that it will not be accidentally unlocked during ejection. Furthermore, the mechanical locking mechanism avoids the risk of failure under heavy loads in traditional spring mechanisms, improving operational safety and reducing the possibility of mold damage and product defects. The structure is simple, requiring no complex hydraulic or pneumatic systems, reducing the need for seal replacement and hydraulic oil maintenance.

[0008] The present invention is further configured such that a first trapezoidal groove is provided on the side of the movable block away from the first buckle and on the side of the bottom of the second buckle away from the first buckle, and a second trapezoidal groove is provided between the first buckle and the movable block, and the second trapezoidal groove is provided between them.

[0009] The above technical solution is used to ensure smooth sliding and reliable locking between the first and second latches and the moving block.

[0010] The present invention is further configured such that the inclined angles of the first trapezoidal groove and the second trapezoidal groove are both 15° to 45° and the surfaces are coated with a wear-resistant coating.

[0011] The above technical solution improves wear resistance to ensure long-term stability and durability.

[0012] The present invention is further configured such that both sides of the top of the mold base plate are bolted with a central support that is slidably connected to the ejector base plate and the ejector panel respectively.

[0013] The above technical solution is used to guide the ejector base plate and ejector plate to move upward in a straight line when they are ejected, preventing them from tilting.

[0014] The present invention is further configured such that a blind hole is provided inside the base on the side near the spring, and the end of the spring away from the movable block is installed in the blind hole inside the base by a stop screw.

[0015] Using the above technical solution: the blind hole serves to position and guide the spring, and by loosening the stop screw, the spring can be popped out or easily removed under the preload of the spring, thus eliminating the need to disassemble the base or moving block, making it convenient to replace the spring.

[0016] In summary, this utility model has the following beneficial effects: 1. By employing a mechanical locking and unlocking mechanism with a first and second locking mechanism, precise secondary ejection stroke control is achieved, avoiding stroke instability caused by spring fatigue or hydraulic system leakage, making it particularly suitable for high-precision injection molded products. Simultaneously, the use of bolted connections and sliding fits reduces the risk of shaft wear and deformation in lever-type mechanisms, extending mold life. The trapezoidal groove design between the locking mechanism and the moving block provides a self-locking function, ensuring that it will not be accidentally unlocked during ejection.

[0017] 2. Simultaneously, the mechanical locking mechanism avoids the risk of failure under heavy loads associated with traditional spring mechanisms, improving operational safety and reducing the possibility of mold damage and product defects. Furthermore, its simple structure eliminates the need for complex hydraulic or pneumatic systems, reducing the need for seal replacement and hydraulic oil maintenance. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the overall structure of this utility model; Figure 2 This is a schematic diagram of the ejection state of this utility model; Figure 3 This is a partial structural schematic diagram of the present invention.

[0019] Reference numerals: 1. Mold base plate; 2. Ejector pin base plate; 3. Ejector pin panel; 4. Machine base; 5. Movable block; 6. First fastener; 7. Second fastener; 8. Spring; 9. Injection molding machine ejector roller; 10. First trapezoidal groove; 11. Second trapezoidal groove; 12. Center support. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings.

[0021] Example 1: refer to Figure 1 , Figure 2 , Figure 3A secondary ejection mechanism for an injection mold includes a mold base plate 1. An ejector base plate 2 and an ejector panel 3 are respectively mounted on the top of the mold base plate 1. A base 4 is bolted internally to the ejector base plate 2. A movable block 5 is slidably connected internally to the base 4. A first locking mechanism 6 is fixedly connected to one side of the top of the mold base plate 1, slidably connected to both the ejector panel 3 and the base 4. A spring 8, bolted to the base 4, is fixedly connected to the side of the movable block 5 away from the first locking mechanism 6. A second locking mechanism 7, slidably connected to both the base 4 and the movable block 5, is bolted internally to the ejector panel 3. An injection molding machine ejector roller 9, bolted to the ejector panel 3, is slidably connected to the bottom of the mold base plate 1. By employing a mechanical locking and unlocking mechanism of the first locking mechanism 6 and the second locking mechanism 7, precise control of the secondary ejection stroke is achieved, avoiding stroke instability caused by spring fatigue or hydraulic system leakage. This is particularly suitable for high-precision injection molded products. Simultaneously, the use of bolted connections and sliding fits reduces the risk of shaft wear and deformation in lever-type mechanisms, extending the mold's service life. The trapezoidal groove design between the latch and the moving block provides a self-locking function, ensuring that it will not be accidentally unlocked during ejection. At the same time, the mechanical latch locking avoids the risk of failure under heavy loads associated with traditional spring mechanisms, improving operational safety and reducing the possibility of mold damage and product defects. Furthermore, its simple structure eliminates the need for complex hydraulic or pneumatic systems, reducing the need for seal replacement and hydraulic oil maintenance.

[0022] refer to Figure 1 , Figure 3 The movable block 5 has a first trapezoidal groove 10 on the side away from the first latch 6 and the bottom of the second latch 7 on the side away from the first latch 6, both of which are slidably connected to each other. A second trapezoidal groove 11 is also provided between the first latch 6 and the movable block 5, both of which are slidably connected to each other. This ensures smooth sliding and reliable locking between the first latch 6, the second latch 7, and the movable block 5.

[0023] refer to Figure 3 The first trapezoidal groove 10 and the second trapezoidal groove 11 both have an inclined angle of 15° to 45° and are coated with a wear-resistant coating. This improves wear resistance and ensures the stability and durability of their long-term operation.

[0024] refer to Figure 1 , Figure 2 Both sides of the top of the mold base plate 1 are bolted with a central support 12 that slides through and is connected to the ejector base plate 2 and the ejector panel 3 respectively. This is used to guide the ejector base plate 2 and the ejector panel 3 to move upward in a straight line when they are ejected, preventing them from tilting.

[0025] refer to Figure 1A blind hole is provided inside the base 4 on the side near the spring 8. The end of the spring 8 away from the movable block 5 is installed in the blind hole inside the base 4 by a stop screw. The blind hole serves to position and guide the spring 8. At the same time, loosening the stop screw allows the spring 8 to pop out or be easily removed under the preload of the spring 8, thus eliminating the need to disassemble the base 4 or the movable block 5, making it convenient to replace the spring 8.

[0026] Brief description of the usage process: First, in the mold closed state, the ejector base plate 2 and ejector panel 3 are fixed to the mold base plate 1 by the central support 12. The movable block 5 is in the reset position under the action of the spring 8, and the first fastener 6 and the second fastener 7 are slidably connected to the movable block 5 and the base 4 respectively.

[0027] During the first ejection, when the injection molding machine's ejector roller 9 pushes the ejector plate 3, the ejector plate 3 moves upward along with the ejector base plate 2, achieving the first ejection. At this time, the first latch 6 is slidably connected to the second trapezoidal groove 11 of the movable block 5, but the second latch 7 is not yet in contact with the first trapezoidal groove 10 of the movable block 5, remaining in a locked state. When the ejection stroke reaches the predetermined position, the first latch 6 disengages from the second trapezoidal groove 11 of the movable block 5, while the second latch 7 begins to contact the first trapezoidal groove 10 of the movable block 5. Due to the inclined design of the trapezoidal groove, the second latch 7 pushes the movable block 5 to compress the spring 8, causing the movable block 5 to slide relative to the machine base 4, unlocking the ejector base plate 2.

[0028] During the second ejection, the ejector plate 2 moves independently under the continued pushing of the injection molding machine's ejector roller 9, achieving the second ejection and ensuring complete demolding of the injection molded product. After ejection is completed, the injection molding machine's ejector roller 9 retracts, the spring 8 pushes the movable block 5 to reset, the first latch 6 and the second latch 7 relock, and the mechanism returns to its initial state, ready for the next cycle.

[0029] It should be noted that parts have a lifespan and can be replaced during regular maintenance when they no longer meet performance requirements. Deterioration in performance due to prolonged use of parts is not a design defect of this application.

[0030] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

Claims

1. A secondary ejection mechanism for an injection mold, comprising a mold base plate (1), characterized in that: The top of the mold base plate (1) is respectively equipped with an ejector base plate (2) and an ejector panel (3). The ejector base plate (2) is bolted to a base (4). The base (4) is slidably connected to a movable block (5). A first fastener (6) is fixedly connected to one side of the top of the mold base plate (1) and is slidably connected to the ejector panel (3) and the base (4). A spring (8) is bolted to the base (4) on the side of the movable block (5) away from the first fastener (6). A second fastener (7) is bolted to the base (4) and is slidably connected to the movable block (5) on the inside of the ejector panel (3). An injection molding machine ejector roller (9) is slidably connected to the bottom of the mold base plate (1) and is bolted to the ejector panel (3).

2. The secondary ejection mechanism for an injection mold according to claim 1, characterized in that: The movable block (5) has a first trapezoidal groove (10) that is slidably connected to each other on the side away from the first buckle (6) and the bottom of the second buckle (7) is away from the first buckle (6). The first buckle (6) and the movable block (5) have a second trapezoidal groove (11) that is slidably connected to each other.

3. The secondary ejection mechanism for an injection mold according to claim 2, characterized in that: The first trapezoidal groove (10) and the second trapezoidal groove (11) both have an inclination angle of 15° to 45° and are coated with a wear-resistant coating.

4. The secondary ejection mechanism for an injection mold according to claim 1, characterized in that: Both sides of the top of the mold base plate (1) are bolted with a central support (12) that slides through and is connected to the ejector base plate (2) and the ejector panel (3) respectively.

5. The secondary ejection mechanism for an injection mold according to claim 1, characterized in that: A blind hole is provided inside the base (4) on the side near the spring (8). The end of the spring (8) away from the movable block (5) is installed in the blind hole inside the base (4) by a stop screw.

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