A demolding mechanism for a plastic product injection mold

Abstract

The utility model discloses a kind of demolding mechanisms for plastic product injection mould, apply in plastic processing technical field, the utility model can accurately adapt the ejection force threshold required by different products by adjustable pre-tightening force characteristics, fine adjustment mechanism ensures the long-term stability of parameter setting, while the flexible transmission characteristics of elasticity eliminates the product surface scratch risk easily caused by traditional rigid ejection, especially suitable for high-precision injection molding scene to the special structure product sensitive to ejection force;Adjusting ejection stroke makes the mould can quickly adapt the demolding demand of different specifications products, adjustable push rod structure effectively avoids the product residue or the mould damage problem caused by excessive stroke due to insufficient stroke of traditional fixed ejector rod, especially suitable for the scene of frequently changing products in multi-variety small batch production.

Description

Technical Field

[0001] This utility model belongs to the field of plastic processing technology, and specifically relates to a demolding mechanism for injection molds of plastic products. Background Technology

[0002] The ejection mechanism for injection molds of plastic products is a device in injection molding molds that ejects the molded plastic part from the cavity or core. It mainly consists of ejection elements (ejector rods, ejector tubes, etc.), reset elements (reset rods), and guide elements (guide pillars). Its power source covers manual, motorized, hydraulic, or pneumatic types. According to its structure, it can be divided into ejector type, ejector plate type, and combination type.

[0003] However, traditional ejection mechanisms for plastic injection molds, due to their rigid ejection design, are prone to causing irreversible mechanical damage to thin-walled or precision products during the ejection process. Furthermore, the lack of force adjustment functionality necessitates frequent replacement of mold components for different products. Fixed ejection systems cannot adapt to the force-sensitive characteristics of diverse products, often causing product deformation or surface indentations due to excessive impact force. Simultaneously, the fixed ejection stroke design cannot flexibly adapt to the demolding requirements of products with different specifications, leading to frequent replacement or adjustment of mold components during mold changes, significantly reducing production efficiency.

[0004] To address the problems mentioned in the background above, a demolding mechanism for injection molds of plastic products is proposed. Utility Model Content

[0005] The purpose of this utility model is to provide a demolding mechanism for injection molds of plastic products, which has the advantages of ejection buffer adjustment and ejection stroke adjustment.

[0006] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a demolding mechanism for injection molds of plastic products, including a housing, a cylinder embedded in the right side of the housing, a push plate 1 bolted to the left side of the cylinder, a screw rotatably connected to the left side of the push plate 1, a threaded sleeve connected to the surface of the screw, a push plate 2 fixedly sleeved on the surface of the threaded sleeve, a push rod 1 bolted to the top and bottom of the left side of the push plate 2, and the middle of the surface of the push rod 1 penetrates the left side of the housing and is slidably connected, a spring fixedly connected to the top and bottom of the left side of the inner wall of the housing and the top and bottom of the left side of the push plate 2, and the inside of the spring sleeved with the right side of the surface of the push rod 1, and an adjustment mechanism provided on the left side of the push rod 1.

[0007] The above technical solution is adopted as follows: By rotating the screw on the left side of push plate one, the screw and the threaded engagement of the screw and the threaded sleeve drive the threaded sleeve to move push plate two left and right along the screw axis. When push plate two moves to the left, the spring between the left side of the inner wall of the outer shell and the left side of push plate two is compressed, and the spring preload increases. When push plate two moves to the right, the spring relaxes, and the preload decreases. This adjustment process can match a suitable initial ejection buffer force according to the material or wall thickness of the product. The self-locking characteristic of the thread ensures that the position of push plate two is stable after adjustment. The cylinder extends to the left, driving push plate one to move to the left synchronously. Push plate one pushes push plate two to the left through the screw and the threaded sleeve. Push rod one on the left side of push plate two slides along the guide hole on the left side of the outer shell. Its left end extends out of the outer shell and pushes the product in the mold, so that the product is separated from the cavity. During this process, the spring is further compressed as the second pusher plate moves to the left, absorbing the initial impact load of ejection through elastic deformation. This prevents the rigid push of the first pusher rod from causing deformation or surface damage to the thin-walled product. After the product is demolded, the cylinder retracts and pushes the first pusher plate to the right. The first pusher plate pulls the second pusher plate to the right via the screw, and the first pusher rod retracts back to its original position with the second pusher plate. At the same time, the compressed spring releases its elastic force, assisting the second pusher plate to quickly reset and prepare for the next demolding. The adjustable preload characteristic can accurately adapt to the ejection force threshold required by different products. The fine-tuning mechanism ensures the long-term stability of parameter settings. Meanwhile, the flexible transmission characteristic of elasticity eliminates the risk of surface scratches on products that are easily caused by traditional rigid ejection. It is particularly suitable for special structural products that are sensitive to ejection force in high-precision injection molding scenarios.

[0008] The present invention is further configured such that the adjusting mechanism includes a second push rod, which is slidably sleeved on the left side of the first push rod. The first push rod has insertion holes on the left side of its top and bottom, and the second push rod has threaded holes on the right side of its top and bottom. The threaded holes are internally threaded with a limit bolt, and the surface of the limit bolt penetrates the inside of the right insertion hole.

[0009] The above technical solution involves an adjustment mechanism. Loosening the limiting bolt and the limiting bolt on the surface of push rod two allows its end to exit the insertion hole on the left side of push rod one, releasing the lock on the relative position of push rod two and push rod one. Since push rod two is slidably sleeved on the left side of push rod one, it can move left and right along the axis of push rod one, changing the overlap length and thus adjusting the effective ejection length of push rod one and push rod two. After adjusting to the required length, align the limiting bolt with the corresponding insertion hole on push rod one and tighten the bolt so that its end is inserted through the insertion hole. The self-locking of the bolt and the threaded hole, along with the limiting action of the insertion hole, secures the push rod. The relative position of push rod 2 and push rod 1 ensures that the length remains unchanged during the ejection process. When the cylinder drives push rod 1 to eject to the left, push rod 2 moves synchronously with push rod 1. Its left end directly contacts the product and transmits the ejection force. Since the appropriate total length is set in advance by adjustment, it can ensure that push rod 2 accurately pushes the product to the target position. Adjusting the ejection stroke allows the mold to quickly adapt to the demolding requirements of products of different specifications. The adjustable push rod structure effectively avoids the problems of product residue caused by insufficient stroke or mold damage caused by excessive stroke in traditional fixed push rods. It is especially suitable for scenarios where products are frequently changed in multi-variety, small-batch production.

[0010] The present invention is further configured such that sliders are bolted to the top and bottom of the push plate two, and grooves are provided at the top and bottom of the inner shell, and the interior of the grooves is slidably connected to the surface of the sliders.

[0011] The above technical solution is adopted: by setting sliders and grooves, the movement of push plate two can be limited.

[0012] The present invention is further configured such that a locking nut is threadedly connected to the bottom of the surface of the limiting bolt.

[0013] The above technical solution involves setting a locking nut to limit the position of the limit bolt, preventing vibration from causing the limit bolt to fall off.

[0014] The present invention is further configured such that a push-out base plate is slidably sleeved through and connected to the left side of the second surface of the push rod.

[0015] The above technical solution allows for the installation of base films for various specifications of plastic products by setting up an ejector base plate.

[0016] The present invention is further configured such that a handle is fixedly sleeved on the left side of the screw.

[0017] The above technical solution allows for easy rotation of the screw by incorporating a handle.

[0018] The present invention is further configured such that a base is bolted to the bottom of the ejector plate and the outer shell.

[0019] The above technical solution utilizes a base to stabilize the mechanism.

[0020] The present invention is further configured such that a door is rotatably connected to the front of the outer casing via a hinge.

[0021] The above technical solution allows for easy opening of the door, adjustment of the screws inside the casing, and convenient maintenance.

[0022] In summary, this utility model has the following beneficial effects: 1. This utility model can accurately adapt to the ejection force threshold required by different products through adjustable preload characteristics. The fine-tuning mechanism ensures the long-term stability of parameter settings. At the same time, the elastic flexible transmission characteristics eliminate the risk of surface scratches on products that are easily caused by traditional rigid ejection. It is particularly suitable for special structural products that are sensitive to ejection force in high-precision injection molding scenarios. 2. This utility model enables the mold to quickly adapt to the demolding requirements of products of different specifications by adjusting the ejection stroke. The adjustable push rod structure effectively avoids the problems of product residue caused by insufficient stroke or mold damage caused by excessive stroke in traditional fixed push rods. It is especially suitable for scenarios where products are frequently changed in multi-variety, small-batch production. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a partial front sectional view of the structure of this utility model; Figure 3 This is a utility model Figure 2 An enlarged schematic diagram of the structure at point A in the middle.

[0024] Reference numerals: 1. Outer shell; 2. Cylinder; 3. Push plate one; 4. Push plate two; 5. Screw; 6. Screw sleeve; 7. Push rod one; 8. Push rod two; 9. Spring; 10. Insertion hole; 11. Threaded hole; 12. Limit bolt; 13. Slider; 14. Slide groove; 15. Locking nut; 16. Ejector base plate; 17. Handle; 18. Base; 19. Door. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings.

[0026] Example 1: refer to Figure 1 , Figure 2A demolding mechanism for injection molds of plastic products includes a housing 1. A cylinder 2 is embedded in the right side of the housing 1. The cylinder 2 is model SC63×100, with a working pressure of 0.4-0.6MPa and a maximum thrust of 1500N. A push plate 3 is bolted to the left side of the cylinder 2. A screw 5 is rotatably connected to the left side of the push plate 3. The screw 5 has a diameter of 12mm, a pitch of 2mm, a fine-tuning accuracy of 0.1mm / turn, and is made of 45 steel tempered HB220-250. A threaded sleeve 6 is threaded onto the surface of the screw 5. A second push plate 4 is fixedly fitted onto the surface of the threaded sleeve 6. A push rod 7 is bolted to the top and bottom of the left side of the push plate 4, and the middle of the push rod 7 passes through the left side of the housing 1 and is slidably connected. The push rod 7 has a diameter of 10mm, a length of 150mm, and is made of 45 steel. The steel is quenched to HRC40-45. The clearance between the spring and push rod 8 is 0.1-0.2mm. Springs 9 are fixedly connected to the top and bottom of the left side of the inner wall of outer shell 1 and the top and bottom of the left side of push plate 4. The inside of spring 9 is sleeved with the right side of the surface of push rod 7. Spring 9 is made of 65Mn steel, with a diameter of 8mm, a wire diameter of 1mm, and a free length of 50mm. The preload adjustment range is 50-300N, corresponding to a compression amount of 5-25mm, ensuring compatibility with products of different wall thicknesses. 50N is used for thin-walled products, and 300N for thick-walled products. An adjustment mechanism is provided on the left side of push rod 7. By rotating the screw 5 on the left side of push plate 3, the screw 5 and the screw sleeve 6 are threaded together, driving the screw sleeve 6 to move push plate 4 left and right along the axis of screw 5. When push plate 4 moves to the left, spring 9 between the left side of the inner wall of outer shell 1 and the left side of push plate 4 is compressed, increasing the preload of spring 9. When push plate 4 moves to the right, spring 9 relaxes, decreasing the preload. This adjustment process can match the appropriate initial ejection buffer force according to the material or wall thickness of the product. The self-locking characteristic of the thread ensures that the position of the second ejector plate 4 is stable after adjustment. The cylinder 2 extends to the left, driving the first ejector plate 3 to move to the left in sync. The first ejector plate 3 pushes the second ejector plate 4 to the left through the screw 5 and the screw sleeve 6. The push rod 7 on the left side of the second ejector plate 4 slides along the guide hole on the left side of the outer shell 1. Its left end extends out of the outer shell 1 and pushes the product in the mold, so that the product is separated from the cavity. During this process, the spring 9 is further compressed as the second ejector plate 4 moves to the left. It absorbs the impact load of the initial ejection through elastic deformation, avoiding the deformation or surface damage of the thin-walled product caused by the rigid push of the push rod 7. After the product is demolded, the cylinder 2 vents and retracts, driving the first ejector plate 3 to reset to the right. The first ejector plate 3 pulls the second ejector plate 4 to the right through the screw 5. The push rod 7 retracts back to its original position with the second ejector plate 4. At the same time, the compressed spring 9 releases its elastic force to assist the second ejector plate 4 to reset quickly, preparing for the next demolding.

[0027] refer to Figure 2The top and bottom of the push plate 2 4 are bolted with sliders 13. The top and bottom of the housing 1 are provided with slide grooves 14, and the inside of the slide grooves 14 is slidably connected to the surface of the sliders 13. By setting sliders 13 and slide grooves 14, the movement of push plate 2 4 can be limited. The sliders 13 are 20mm long × 15mm wide × 10mm high and are made of polytetrafluoroethylene. The slide grooves 14 are corresponding to the size + 0.05mm gap and are coated with MoS2 wear-resistant coating on the inner wall.

[0028] refer to Figure 2 A handle 17 is fixedly sleeved on the left side of the screw 5, which allows the screw 5 to be rotated easily.

[0029] refer to Figure 1 The front of the outer casing 1 is connected to a door 19 by a hinge. The door 19 can be easily opened to adjust the screw 5 inside the outer casing 1 and facilitate maintenance.

[0030] Example 2: refer to Figure 1 , Figure 2 , Figure 3 A demolding mechanism for injection molds of plastic products includes an adjusting mechanism comprising a second push rod 8, which is slidably sleeved on the left side of a first push rod 7. The second push rod 8 has a diameter of 8mm, an adjustable length range of 100-150mm, and is made of the same material as the first push rod, with a 0.05mm chrome plating. The first push rod 7 has insertion holes 10 on its top and bottom left sides, with one insertion hole 10 every 5mm along the axial direction of the first push rod 7. The holes are 6mm in diameter and accommodate M6 bolts. The second push rod 8 has threaded holes 11 on its top and bottom right sides. A limit bolt 12 is threaded into the threaded hole 11, and its surface penetrates the inside of the right-side insertion hole 10. The limit bolt 12 is M6×20mm, 8.8 grade high strength. Loosening the limit bolt 12 loosens the end of the second push rod 8 from the insertion hole 10 on the left side of the first push rod 7. Exiting from position 0 releases the lock on the relative position of push rod 28 and push rod 17. Since push rod 28 is slidably sleeved on the left side of push rod 17, it can move left and right along the axis of push rod 17 to change the overlap length of the two, thereby adjusting the effective ejection length of push rod 17 and push rod 28. After adjusting to the required length, align the limiting bolt 12 with the corresponding insertion hole 10 of push rod 17 and tighten the bolt so that its end is inserted into the insertion hole 10. Through the self-locking of the bolt and the threaded hole 11 and the limiting effect of the insertion hole 10, the relative position of push rod 28 and push rod 17 is fixed to ensure that the length remains unchanged during ejection. When cylinder 2 drives push rod 17 to eject to the left, push rod 28 moves synchronously with push rod 17. Its left end directly contacts the product and transmits the ejection force. Since the appropriate total length is set in advance by adjustment, it can be ensured that push rod 28 accurately pushes the product to the target position.

[0031] refer to Figure 1, Figure 2 , Figure 3 The bottom of the limit bolt 12 is threaded with a locking nut 15. By setting the locking nut 15, the limit bolt 12 can be limited to prevent vibration from causing the limit bolt 12 to fall off. The material is nylon insert anti-loosening nut DIN985.

[0032] refer to Figure 1 , Figure 2 The push rod 8 has a push-out base plate 16 that slides through and is fitted onto the left side of its surface. By setting the push-out base plate 16, base films of various specifications of plastic products can be installed.

[0033] refer to Figure 1 , Figure 2 A base 18 is bolted to the bottom of the ejector base plate 16 and the outer casing 1. The mechanism can be stabilized by setting the base 18.

[0034] Brief description of the operation: By rotating the screw 5 on the left side of push plate 3, the screw 5 and the screw sleeve 6 are engaged, driving the screw sleeve 6 to move push plate 4 left and right along the axis of screw 5. When push plate 4 moves to the left, the spring 9 between the left side of the inner wall of the outer shell 1 and the left side of push plate 4 is compressed, and the preload of spring 9 increases. When push plate 4 moves to the right, spring 9 relaxes, and the preload decreases. This adjustment process can match a suitable initial ejection buffer force according to the material or wall thickness of the product. The self-locking characteristic of the thread ensures that the position of push plate 4 is stable after adjustment. Cylinder 2 extends to the left, driving... Push plate 3 moves synchronously to the left, pushing push plate 4 to the left via screw 5 and screw sleeve 6. Push rod 7 on the left side of push plate 4 slides along the guide hole on the left side of outer shell 1, with its left end extending out of outer shell 1 and pushing the product inside the mold, separating the product from the cavity. During this process, spring 9 is further compressed as push plate 4 moves to the left, absorbing the initial impact load of ejection through elastic deformation, avoiding deformation or surface damage to thin-walled products caused by rigid pushing of push rod 7. After the product is demolded, cylinder 2 retracts after ventilation, driving push plate 3 to reset to the right. Push plate 3 pulls push plate 4 via screw 5. As push plate 24 moves to the right, push rod 7 retracts back to its original position. Simultaneously, the compressed spring 9 releases its elasticity, assisting push plate 24 in quickly resetting and preparing for the next demolding. Loosen the limiting bolt 12 and the limiting bolt 12 on the surface of push rod 28, allowing its end to exit from the insertion hole 10 on the left side of push rod 17. This releases the locking of the relative position between push rod 28 and push rod 17. Since push rod 28 is slidably sleeved on the left side of push rod 17, it can move left and right along the axis of push rod 17, changing the overlap length between the two, thereby adjusting the effective ejection length of push rod 17 and push rod 28 as a whole. After adjusting to the required length, align the limiting bolt 12 with the corresponding insertion hole 10 of push rod 7, and tighten the bolt so that its end is inserted into the insertion hole 10. Through the self-locking of the bolt and the threaded hole 11 and the limiting effect of the insertion hole 10, the relative position of push rod 8 and push rod 7 is fixed, ensuring that the length remains unchanged during the ejection process. When the cylinder 2 drives push rod 7 to push to the left, push rod 8 moves synchronously with push rod 7. Its left end directly contacts the product and transmits the ejection force. Since the appropriate total length is set in advance by adjustment, it can be ensured that push rod 8 accurately pushes the product to the target position.

[0035] 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.

[0036] 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 demolding mechanism for injection molds of plastic products, comprising a housing (1), characterized in that: A cylinder (2) is embedded in the right side of the inner shell (1). A push plate (3) is bolted to the left side of the cylinder (2). A screw (5) is rotatably connected to the left side of the push plate (3). A screw sleeve (6) is threaded onto the surface of the screw (5). A push plate (4) is fixedly sleeved onto the surface of the screw sleeve (6). A push rod (7) is bolted to the top and bottom of the left side of the push plate (4). The middle of the surface of the push rod (7) passes through the left side of the outer shell (1) and is slidably connected. A spring (9) is fixedly connected to the top and bottom of the left side of the inner wall of the outer shell (1) and the top and bottom of the left side of the push plate (4). The inside of the spring (9) is sleeved with the right side of the surface of the push rod (7). An adjustment mechanism is provided on the left side of the push rod (7).

2. The demolding mechanism for a plastic product injection mold according to claim 1, characterized in that: The adjustment mechanism includes a second push rod (8), which is slidably sleeved on the left side of the first push rod (7). The first push rod (7) has insertion holes (10) on the left side of its top and bottom, and threaded holes (11) are provided on the right side of the top and bottom of the second push rod (8). The threaded hole (11) is connected to a limit bolt (12) with its internal thread, and the surface of the limit bolt (12) penetrates the inside of the insertion hole (10) on the right side.

3. The demolding mechanism for injection molds of plastic products according to claim 1, characterized in that: The top and bottom of the push plate 2 (4) are bolted with sliders (13), and the top and bottom of the outer shell (1) are provided with grooves (14), and the inside of the grooves (14) is slidably connected to the surface of the sliders (13).

4. The demolding mechanism for a plastic product injection mold according to claim 2, characterized in that: The bottom of the limiting bolt (12) is threaded with a locking nut (15).

5. The demolding mechanism for a plastic product injection mold according to claim 2, characterized in that: The push rod 2 (8) has a push-out base plate (16) that extends through and slides onto the left side of its surface.

6. The demolding mechanism for a plastic product injection mold according to claim 1, characterized in that: A handle (17) is fixedly sleeved on the left side of the screw (5).

7. The demolding mechanism for a plastic product injection mold according to claim 5, characterized in that: The bottom of the ejector plate (16) and the outer shell (1) are bolted with a base (18).

8. The demolding mechanism for a plastic product injection mold according to claim 1, characterized in that: The front of the outer casing (1) is connected to a door (19) by a hinge.

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