Lever type secondary ejection structure of injection mold

Abstract

A lever type secondary ejection structure of an injection mold comprises an upper compound plate and a lower compound plate, a fixed mold plate is arranged below the upper compound plate, mold feet are arranged on the lower compound plate, a movable mold plate is arranged on the mold feet, a movable mold insert and a stripper plate are arranged on the movable mold plate, a first upper ejector plate and a first lower ejector plate are arranged on the lower compound plate, and stripper ejector rods are arranged on the first upper ejector plate and the first lower ejector plate. A lever is arranged in the first lower ejector plate, a left lever arm and a right lever arm are arranged on the lever, the middle of the lever is rotationally connected with the first lower ejector plate through a rotating shaft, a mounting hole is formed in the first upper ejector plate, a second upper ejector plate and a second lower ejector plate are arranged in the mounting hole, and ejector pins are arranged on the second upper ejector plate and the second lower ejector plate. The ejector pin penetrates through the movable mold plate and the movable mold insert to be in contact with the plastic part, a positioning groove is formed in the inner wall of the side, located on the lever, of the mold foot, a left lever arm of the lever is matched with the positioning groove, and a right lever arm of the lever is in contact with the lower face of the second lower ejector pin plate.

Description

Technical Field

[0001] The utility model relates to an injection mold, in particular to a lever-type secondary ejection structure of an injection mold. Background Art

[0002] When producing plastic parts with an injection mold, if the plastic part has a hemming on its periphery, an outward flanging is made at the bottom of the hemming, and a protruding rib is made under the flanging. Due to the large clamping force of the hemming on the moving die insert, it is impossible to eject the plastic part from the mold directly with a ejector pin. The ejector pin is prone to deformation, and ejector pin marks are likely to be left on the plastic part. Therefore, people usually use a stripper plate. The stripper plate abuts against the bottom of the periphery of the plastic part, and the plastic part is ejected from the mold through the stripper plate. However, since a rib is made under the flanging of the plastic part, a corresponding rib groove needs to be made on the stripper plate, and the rib is stuck in the rib groove. After the stripper plate ejects the plastic part from the moving die insert, a secondary ejection structure is required to eject the plastic part from the stripper plate. An existing secondary ejection structure is like the Chinese utility model patent CN 205364434 U, with the patent name "Secondary ejection mechanism of an injection mold for an automobile door panel plug". An upper, a middle and a lower ejector pin plate are arranged on the lower platen. Secondary ejector pins are arranged on the upper and middle ejector pin plates and are in contact with the automobile door panel plug. Left and right reverse buckle ejector rods are arranged on the lower ejector pin plate and are in double reverse buckle cooperation with the automobile door panel plug. A secondary ejection separation device is arranged on the outer walls of the upper, middle and lower ejector pin plates and the backing plate. The secondary ejection separation device includes a fixed block, an upper insertion rod and a lower hook. The fixed block is fixed to the upper and middle ejector pin plates, the upper insertion rod is fixed to the backing plate, and the lower hook is fixed to the lower ejector pin plate. A slider is arranged in the fixed block, and an upper insertion rod groove and a lower hook groove are opened in the slider. The upper insertion rod passes through the upper insertion rod groove and is in cooperation with the slider, and the lower hook passes through the lower hook groove and is in cooperation with the slider. The disadvantages of this structure are that the secondary ejection separation device needs to be arranged on the outer walls of the ejector pin plate and the cushion block, which occupies the space outside the mold, resulting in an increase in the volume of the mold body. For some molds with a relatively compact structure, this structure cannot be applied. Summary of the Invention

[0003] The purpose of the utility model is to overcome the disadvantages of the existing technology, and provide a lever-type secondary ejection structure of an injection mold that does not occupy the space outside the mold, does not increase the volume of the mold, has a compact structure, and ensures that the plastic part can be smoothly ejected from the mold.

[0004] The technical solution of the lever-type secondary ejection structure of the injection mold of the present utility model is as follows: It includes an upper clamping plate and a lower clamping plate. A fixed mold plate is arranged below the upper clamping plate. A perforation is made in the lower clamping plate. A mold base is arranged on the lower clamping plate. A movable mold plate is arranged on the mold base. A movable mold insert and a stripper plate are arranged on the movable mold plate. There is a plastic part formed by injection molding between the fixed mold plate, the movable mold insert, and the stripper plate. A wrap-around edge is made around the plastic part. The inner wall of the wrap-around edge is tightly fitted with the movable mold insert. A flanging is made at the bottom of the wrap-around edge. A rib is made under the flanging. The rib is matched with the stripper plate. A first upper ejector pin plate and a first lower ejector pin plate are arranged on the lower clamping plate. The first upper ejector pin plate and the first lower ejector pin plate are fixedly connected by fasteners. The ejector rod of the injection machine passes through the perforation and is matched with the first lower ejector pin plate. Stripping ejector rods are arranged on the first upper ejector pin plate and the first lower ejector pin plate. The upper head of the stripping ejector rod passes through the movable mold plate and is fixedly connected with the stripper plate. A lever is arranged in the first lower ejector pin plate. A left rod arm and a right rod arm are arranged on the lever. The middle part of the lever is rotatably connected with the first lower ejector pin plate through a rotating shaft. An installation hole is opened in the first upper ejector pin plate. A second upper ejector pin plate and a second lower ejector pin plate are arranged in the installation hole. The second upper ejector pin plate and the second lower ejector pin plate are fixedly connected by fasteners. Ejector pins are arranged on the second upper ejector pin plate and the second lower ejector pin plate. The ejector pins pass through the movable mold plate and the movable mold insert and are in contact with the plastic part. A positioning groove is made on the inner wall of one side of the mold base where the mold base is located on the lever. The left rod arm of the lever is matched with the positioning groove. The right rod arm of the lever is in contact with the lower surface of the second lower ejector pin plate.

[0005] Further, the lever is in a V shape or an arc shape.

[0006] Further, there are two groups of levers on the left and right, and the corresponding positioning grooves are two on the left and right.

[0007] Further, a spring is arranged on the outer wall of the ejector pin. One end of the spring is in contact with the movable mold plate, and the other end of the spring is in contact with the second upper ejector pin plate.

[0008] The beneficial effect of the lever-type secondary ejection structure of the injection mold of the present utility model is as follows: When the first upper ejector pin plate and the first lower ejector pin plate drive the lever to move upward, the left rod arm of the lever is matched with the positioning groove, accelerating the upward rotation of the right rod arm of the lever, thereby driving the second upper ejector pin plate, the second lower ejector pin plate, and the ejector pins to accelerate upward movement, ejecting the plastic part from the stripper plate. The ejection action is reliable, ensuring that the plastic part can be smoothly ejected and demolded. The lever and the positioning groove structure are arranged inside the mold. Especially, the positioning groove is opened on the inner wall of the mold base. On the premise of ensuring the structural strength of the mold base, the internal space of the mold is fully utilized, without occupying the external space of the mold and without increasing the volume of the mold. It is especially suitable for injection molds with a compact structure. Description of the Drawings

[0009] Figure 1 It is a schematic diagram of the closed mold state structure of the lever-type secondary ejection structure of the injection mold of the present utility model;

[0010] Figure 2 is a schematic structural diagram of the open mold state of the lever - type secondary ejection structure of the injection mold of the present utility model;

[0011] Figure 3 is a schematic structural diagram of the first ejection state of the lever - type secondary ejection structure of the injection mold of the present utility model;

[0012] Figure 4 is a schematic structural diagram of the second ejection state of the lever - type secondary ejection structure of the injection mold of the present utility model. Specific embodiments

[0013] The present utility model relates to a lever - type secondary ejection structure of an injection mold. As Figure 1 — Figure 4 shown, it includes an upper platen 1 and a lower platen 2. A fixed mold plate 3 is arranged under the upper platen 1. A perforation 4 is made in the lower platen 2. A mold foot 5 is arranged on the lower platen 2. A moving mold plate 6 is arranged on the mold foot 5. A moving mold insert 7 and a stripper plate 8 are arranged on the moving mold plate 6. There is a plastic part 9 formed by injection molding between the fixed mold plate 3, the moving mold insert 7, and the stripper plate 8. A wrap - around edge 10 is made around the plastic part 9. The inner wall of the wrap - around edge 10 is tightly fitted with the moving mold insert 7. A flanging 11 is made at the bottom of the wrap - around edge 10. A rib 12 is made under the flanging 11. The rib 12 is matched with the stripper plate 8. A first upper ejector plate 13 and a first lower ejector plate 14 are arranged on the lower platen 2. The first upper ejector plate 13 and the first lower ejector plate 14 are fixedly connected by fasteners. The ejector rod 30 of the injection machine passes through the perforation 4 and is matched with the first lower ejector plate 14. A stripper ejector rod 15 is arranged on the first upper ejector plate 13 and the first lower ejector plate 14. The upper end of the stripper ejector rod 15 passes through the moving mold plate 6 and is fixedly connected with the stripper plate 8. A lever 16 is arranged in the first lower ejector plate 14. A left lever arm 17 and a right lever arm 18 are arranged on the lever 16. The middle part of the lever 16 is rotatably connected with the first lower ejector plate 14 through a rotating shaft 19. An installation hole is opened in the first upper ejector plate 13. A second upper ejector plate 20 and a second lower ejector plate 21 are arranged in the installation hole. The second upper ejector plate 20 and the second lower ejector plate 21 are fixedly connected by fasteners. A ejector pin 22 is arranged on the second upper ejector plate 20 and the second lower ejector plate 21. The ejector pin 22 passes through the moving mold plate 6 and the moving mold insert 7 and contacts the plastic part 9. A positioning groove 23 is made on the inner wall of one side of the mold foot 5 where the lever 16 is located. The left lever arm 17 of the lever 16 is matched with the positioning groove 23. The right lever arm 18 of the lever 16 contacts the lower surface of the second lower ejector plate 21.

[0014] Furthermore, the lever 16 is in a V - shape or an arc shape.

[0015] Further, there are two sets of levers 16 on the left and right, and correspondingly, there are two positioning grooves 23 on the left and right. The two sets of levers 16 push the second upper ejector plate 20 and the second lower ejector plate 21 synchronously from the left and right sides, ensuring that the upward movement of the second upper ejector plate 20 and the second lower ejector plate 21 is more stable and reliable, without tilting, and ensuring that the plastic part 9 can be ejected smoothly.

[0016] Further, a spring 24 is arranged on the outer wall of the ejector pin 22. One end of the spring 24 is in contact with the moving template 6, and the other end of the spring 24 is in contact with the second upper ejector plate 20. With the spring 24, when the injection mold is closed, the spring 24 pushes the second upper ejector plate 20 and the second lower ejector plate 21 to reset downward. The second upper ejector plate 20 and the second lower ejector plate 21 drive the first upper ejector plate 13 and the first lower ejector plate 14 to reset downward, and drive the lever 16 to rotate and reset, which is beneficial to the next ejection action.

[0017] The utility model discloses a lever-type secondary ejection structure for an injection mold. After the plastic part 9 is injection-molded, the lower clamping plate 2 drives the mold feet 5, the moving template 6, the moving die insert 7, the stripping plate 8, the plastic part 9, the first upper ejector plate 13, the first lower ejector plate 14, the stripping ejector rod 15, the lever 16, the second upper ejector plate 20, the second lower ejector plate 21, and the ejector pin 22 (i.e., all components on the moving die side) to move downward together, while the upper clamping plate 1 and the fixed template 3 (i.e., all components on the fixed die side) remain stationary, so that the mold is opened at the fixed template 3 and the moving template 6. When the first upper ejector plate 13 and the first lower ejector plate 14 move downward to the position of the injection machine ejector rod 30, the injection machine ejector rod 30 presses against the first lower ejector plate 14, causing the first upper ejector plate 13 and the first lower ejector plate 14 to move upward. The first upper ejector plate 13 and the first lower ejector plate 14 drive the stripping ejector rod 15, the stripping plate 8, the lever 16, the second upper ejector plate 20, the second lower ejector plate 21, and the ejector pin 22 to move upward together. The stripping plate 8 pushes the flange 11 of the plastic part 9 upward, causing the plastic part 9 to be ejected upward from the moving die insert 7. At this time, the rib 12 under the flange 11 of the plastic part 9 is still stuck in the rib groove of the stripping plate 8. When the first upper ejector plate 13 and the first lower ejector plate 14 drive the left lever arm 17 of the lever 16 to move upward to contact the upper end of the positioning groove 23, the lever 16 continues to move upward. Under the action of the positioning groove 23, the left lever arm 17 of the lever 16 is driven to rotate reversely downward around the rotating shaft 19, and the right lever arm 18 of the lever 16 rotates upward around the rotating shaft 19 at an accelerated speed. The right lever arm 18 accelerates the upward movement of the second upper ejector plate 20 and the second lower ejector plate 21. The second upper ejector plate 20 and the second lower ejector plate 21 drive the ejector pin 22 to move upward at an accelerated speed, causing the plastic part 9 to be ejected upward from the rib groove of the stripping plate 8, completing the demolding. In the lever-type secondary ejection structure of this injection mold, during the upward movement of the first upper ejector plate 13 and the first lower ejector plate 14 driving the lever 16, the left lever arm 17 of the lever 16 is matched with the positioning groove 23, accelerating the upward rotation of the right lever arm 18 of the lever 16, thereby driving the second upper ejector plate 20, the second lower ejector plate 21, and the ejector pin 22 to move upward at an accelerated speed, ejecting the plastic part 9 out of the stripping plate 8. The ejection action is reliable, ensuring that the plastic part 9 can be smoothly ejected and demolded. The lever 16 and the positioning groove 23 structure are arranged inside the mold. Especially, the positioning groove 23 is opened on the inner wall of the mold feet 5. On the premise of ensuring the structural strength of the mold feet 5, the internal space of the mold is fully utilized, without occupying the external space of the mold, and without increasing the volume of the mold, which is particularly suitable for injection molds with a compact structure.

Claims

1. A lever-type secondary ejection structure for an injection mold, comprising an upper composite plate (1) and a lower composite plate (2), wherein a fixed mold plate (3) is arranged below the upper composite plate (1), a perforation (4) is formed in the lower composite plate (2), a mold foot (5) is arranged on the lower composite plate (2), a movable mold plate (6) is arranged on the mold foot (5), a movable mold insert (7) and a stripper plate (8) are arranged on the movable mold plate (6), an injection-molded plastic part (9) is arranged between the fixed mold plate (3), the movable mold insert (7) and the stripper plate (8), a rim (10) is formed around the plastic part (9), an inner wall of the rim (10) is tightly fitted with the movable mold insert (7), a flange (11) is formed at the bottom of the flange (10), a convex rib (12) is formed below the flange (11), and the convex rib (12) cooperates with the stripper plate (8), characterized in that: A first upper ejector plate (13) and a first lower ejector plate (14) are arranged on the lower composite plate (2), and the first upper ejector plate (13) and the first lower ejector plate (14) are fixedly connected via fasteners. The ejector rod (30) of the injection molding machine passes through the through hole (4) and cooperates with the first lower ejector plate (14). A stripping ejector rod (15) is arranged on the first upper ejector plate (13) and the first lower ejector plate (14), and the upper head of the stripping ejector rod (15) passes through the movable template (6) and is fixedly connected to the stripping plate (8). A lever (16) is arranged in the first lower ejector plate (14), and a left lever arm (17) and a right lever arm (18) are arranged on the lever (16). The middle part of the lever (16) is rotatably connected to the first lower ejector plate (14) via a rotating shaft (19). The first upper ejector plate (13) is provided with a mounting hole, in which a second upper ejector plate (20) and a second lower ejector plate (21) are arranged, the second upper ejector plate (20) and the second lower ejector plate (21) are fixedly connected via fasteners, ejectors (22) are arranged on the second upper ejector plate (20) and the second lower ejector plate (21), the ejector pins (22) pass through the movable mold plate (6) and the movable mold insert (7) and contact the plastic part (9), the mold foot (5) is located on one side of the lever (16) and has a positioning groove (23) formed on the inner wall, the left lever arm (17) of the lever (16) cooperates with the positioning groove (23), and the right lever arm (18) of the lever (16) contacts the bottom of the second lower ejector plate (21).

2. The lever-type secondary ejection structure of the injection mold according to claim 1, characterized in that: The lever (16) is V-shaped or arc-shaped.

3. The lever-type secondary ejection structure of the injection mold according to claim 1, characterized in that: The levers (16) are divided into two groups, one on the left and one on the right, and the corresponding positioning grooves (23) are divided into two groups, one on the left and one on the right.

4. The lever-type secondary ejection structure of the injection mold according to claim 1, characterized in that: A spring (24) is arranged on the outer wall of the ejector pin (22), one end of the spring (24) contacts the movable plate (6), and the other end of the spring (24) contacts the second upper ejector pin plate (20).

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