Long-distance side core-pulling mechanism for gear and rack of injection mold

Abstract

A gear and rack long-distance side core-pulling mechanism 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, an ejection assembly is arranged on the lower compound plate between the mold feet, a movable mold plate is arranged on the mold feet, a mold cavity is formed between the movable mold plate and the fixed mold plate, and a plastic part is arranged in the mold cavity. More than two downward flanges are arranged on one side of the plastic part, corresponding through holes are formed in the flanges, a fixed seat is arranged on the movable mold plate, a sliding groove is formed in the fixed seat, a side core-pulling rack is arranged in the sliding groove, one end of the side core-pulling rack is matched with the through hole of the plastic part, and a gear is arranged in the fixed seat and located below the side core-pulling rack. One side of the gear is meshed with the bottom of the side core-pulling rack, a mold opening and closing rack is arranged below the fixed mold plate, corresponding insertion holes are formed in the fixed seat and the movable mold plate, and the mold opening and closing rack is inserted into the insertion holes to be meshed with one side of the gear.

Description

Technical Field

[0001] This invention relates to injection molds, and more particularly to a long-distance side core-pulling mechanism for gears and racks in injection molds. Background Technology

[0002] When producing plastic parts using injection molds, if a deep through hole is opened on one side of the plastic part, or if two or more flanges are set on one side of the plastic part and corresponding through holes are opened on each flange, the through holes need to be pulled before the mold is opened in order to eject the plastic part from the mold. Traditionally, a hydraulic cylinder is used to directly drive the side core-pulling slider to pull out the through hole, or a slanted guide rod is used in conjunction with the slanted guide hole of the side core-pulling slider to drive the slider out of the through hole. The disadvantages of this structure are: 1. Due to the depth of the through hole, the stroke of the side core-pulling slider is long. If a hydraulic cylinder is used to drive the slider, a cylinder with a long stroke is required. Long-stroke cylinders are large, occupying a significant amount of space outside the mold, increasing the lateral volume of the mold. Furthermore, the high cost of the cylinder increases the mold development cost. 2. If a slanted guide rod and slanted guide hole are used to drive the side core-pulling slider, making the angle of the slanted guide rod smaller increases the mold opening and closing distance. While making the angle of the slanted guide rod larger can reduce the mold opening and closing distance, the slanted guide rod is prone to bending and deformation, resulting in a short service life. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a long-distance side core-pulling mechanism for injection mold gears and racks that has a long core-pulling stroke, occupies less external space of the mold, has a simple structure, is easy to manufacture, and reduces mold development costs.

[0004] The technical solution of the long-distance side core-pulling mechanism for gear racks in injection molds of the present invention is as follows: It includes an upper plate and a lower plate. A fixed template is provided under the upper plate. A through hole is formed in the lower plate. Mold feet are provided on the lower plate. An ejector assembly is provided on the lower plate between the mold feet. The ejector rod of the injection molding machine passes through the through hole and cooperates with the ejector assembly. A movable template is provided on the mold feet. A mold cavity is formed between the movable template and the fixed template. A plastic part is injection molded in the mold cavity. Two or more downward-facing flanges are provided on one side of the plastic part. Each flange has a corresponding through hole. A fixed seat is provided on the movable template. A sliding groove is formed in the fixed seat. A side core-pulling rack is provided in the sliding groove. One end of the side core-pulling rack passes through the fixed seat and cooperates with the through hole of the plastic part. A gear is installed below the side core-pulling rack in the fixed base. The gear rotates and engages with the fixed base via a rotating shaft. One side of the gear meshes with the bottom of the side core-pulling rack. An opening and closing mold rack is installed below the fixed template. Corresponding insertion holes are opened in the fixed base and the moving template. The opening and closing mold rack is inserted into the insertion hole and meshes with one side of the gear. A locking rod is installed below the fixed template. A locking hole is opened in the fixed base. A locking groove is opened on the side core-pulling rack. The locking groove corresponds to the locking hole. The locking rod passes through the locking hole and engages with the locking groove. When the mold is opened, the opening and closing mold rack disengages from the insertion hole. The opening and closing mold rack drives the gear to rotate. The gear drives the side core-pulling rack to move to the right along the slide groove, so that one end of the side core-pulling rack is pulled out of the through hole in each flange of the plastic part.

[0005] Furthermore, a first positioning groove and a second positioning groove are provided under the side core-pulling rack, and an installation hole is provided in the fixed seat. A positioning pin, a spring and a plug are provided in the installation hole. The upper end of the positioning pin passes through the fixed seat and is positioned and engaged with the first positioning groove or the second positioning groove. The lower end of the positioning pin contacts the spring, and the lower end of the spring contacts the plug.

[0006] Furthermore, a limiting groove is provided under the side core-pulling rack, and a limiting block is provided on the outer wall of the fixed base, with the limiting block and the limiting groove engaging in a limiting fit.

[0007] Furthermore, the ejection assembly includes an upper ejector plate and a lower ejector plate. The ejector rod of the injection molding machine passes through the perforation and contacts the bottom of the lower ejector plate. Ejector pins are provided on the upper and lower ejector plates, and the ejector pins pass through the moving template to cooperate with the plastic part.

[0008] The beneficial effects of the long-distance side core-pulling mechanism of the gear rack and pinion of the injection mold of the present invention are as follows: the opening and closing rack on the fixed platen drives the gear in the fixed seat to rotate when the mold is opened. The gear then drives the side core-pulling rack that meshes with it to move laterally to achieve core pulling. The mold opening and closing motion is transformed into a long-distance core pulling motion of the side core-pulling rack. There is no need to use a long-stroke hydraulic cylinder, which greatly reduces the space occupied by the mold and effectively controls the lateral volume of the mold. As a result, a smaller tonnage injection molding machine can be used, reducing the mold development cost. In addition, compared with the traditional inclined guide rod structure, it avoids the bending deformation problem caused by excessive tilt angle, and there is no need to increase the opening and closing distance to ensure the stroke, making the operation more stable and reliable. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the mold closing state structure of the long-distance side core-pulling mechanism of the gear and rack of the injection mold of the present invention; Figure 2 This is a schematic diagram of the mold opening state structure of the long-distance side core-pulling mechanism for the gear and rack of the injection mold according to the present invention; Figure 3 This is a schematic diagram of the opening and closing rack side core-pulling state structure of the long-distance side core-pulling mechanism for injection mold gears and racks of the present invention; Figure 4 yes Figure 3 A magnified view of part A.

[0010] In the diagram, 1. Upper cover plate; 2. Lower cover plate; 3. Fixed template; 5. Through hole; 6. Mold foot; 7. Ejector rod; 8. Moving template; 9. Plastic part; 10. Flanged edge; 11. Through hole; 12. Fixed seat; 13. Slide groove; 14. Side core-pulling rack; 15. Gear; 16. Rotating shaft; 17. Opening and closing mold rack; 18. Insertion hole; 19. Mold locking rod; 20. Mold locking hole; 21. Mold locking groove; 22. First positioning groove; 23. Second positioning groove; 24. Mounting hole; 25. Positioning pin; 26. Spring; 27. Plug; 28. Limiting groove; 29. ​​Limiting block; 30. Upper ejector plate; 31. Lower ejector plate; 32. Ejector pin. Detailed Implementation

[0011] To enable those skilled in the art to better understand the technical solutions of the present invention, preferred embodiments of the present invention are described below in conjunction with specific examples. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote elements with the same or similar functions throughout. However, it should be understood that the drawings are for illustrative purposes only and should not be construed as limiting the present invention. To better illustrate this embodiment, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product size. It is understandable for those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting the present invention.

[0012] It should be noted that the terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion. The terms "set," "equipped with," "installed," "connected," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral construction; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two mechanisms, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0013] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the mechanism or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0014] To further illustrate the content, features, and effects of this invention, the invention will be described in detail below with reference to the accompanying drawings and examples, but this should not be construed as limiting the invention.

[0015] This invention relates to a long-distance side core-pulling mechanism for gears and racks in injection molds, such as... Figure 1 — Figure 4The system includes an upper platen 1 and a lower platen 2. A fixed template 3 is provided under the upper platen 1. A through hole 5 is formed in the lower platen 2. Mold feet 6 are provided on the lower platen 2. An ejector assembly is provided on the lower platen 2 between the mold feet 6. An ejector rod 7 of the injection molding machine passes through the through hole 5 and engages with the ejector assembly. A movable template 8 is provided on the mold feet 6. A mold cavity is formed between the movable template 8 and the fixed template 3. A plastic part 9 is injection molded in the mold cavity. Two or more downward-facing flanges 10 are provided on one side of the plastic part 9. Each flange 10 has a corresponding through hole 11. A fixed seat 12 is provided on the movable template 8. A groove 13 is formed in the fixed seat 12. A side core-pulling rack 14 is provided in the groove 13. One end of the side core-pulling rack 14 passes through the fixed seat 12 and engages with the through hole 11 of the plastic part 9. A gear 15 is provided in the fixed seat 12 below the side core-pulling rack 14. Gear 15 rotates with the fixed base 12 via the rotating shaft 16. One side of gear 15 meshes with the bottom of the side core-pulling rack 14. A mold-opening and closing rack 17 is provided under the fixed template 3. Corresponding insertion holes 18 are opened in the fixed base 12 and the moving template 8. The mold-opening and closing rack 17 is inserted into the insertion hole 18 and meshes with one side of gear 15. A mold-locking rod 19 is provided under the fixed template 3. A mold-locking hole 20 is opened in the fixed base 12. A mold-locking groove 21 is opened on the side core-pulling rack 14. The mold-locking groove 21 corresponds to the mold-locking hole 20. The mold-locking rod 19 passes through the mold-locking hole 20 and engages with the mold-locking groove 21. When the mold is opened, the mold-opening and closing rack 17 disengages from the insertion hole 18. The mold-opening and closing rack 17 drives gear 15 to rotate. Gear 15 drives the side core-pulling rack 14 to move to the right along the slide groove 13, so that one end of the side core-pulling rack 14 is pulled out of the through hole 11 in each flange 10 of the plastic part 9.

[0016] Furthermore, the side core-pulling rack 14 has a first positioning groove 22 and a second positioning groove 23, and a mounting hole 24 is provided in the fixed base 12. The mounting hole 24 is provided with a positioning pin 25, a spring 26 and a plug 27. The upper end of the positioning pin 25 passes through the fixed base 12 and is positioned and engaged with the first positioning groove 22 or the second positioning groove 23. The lower end of the positioning pin 24 contacts the spring 26, and the lower end of the spring 26 contacts the plug 27. The upper end of the positioning pin 25 is arc-shaped, and the first positioning groove 22 and the second positioning groove 23 are also arc-shaped. During mold closing, the positioning pin 25 and the second positioning groove 23 are positioned and engaged. When the gear 15 drives the side core-pulling rack 14 to move to the right, under the squeezing action of the arc-shaped second positioning groove 23, the positioning pin 25 is pushed downward into the mounting hole 24. The lower end of the positioning pin 25 squeezes the spring 26. When the side core-pulling rack 14 moves to the right until the first positioning groove 22 corresponds to the positioning pin 25, the spring 26 pushes the positioning pin 25 upward under the action of the restoring force, so that the upper end of the positioning pin 25 is engaged in the first positioning groove 22. With the positioning pin 25 and the first positioning groove 22 or the second positioning groove 23 in a positioning engagement, the side core-pulling rack 14 can be positioned after it moves outward and inward to reset, preventing it from shaking after core pulling or reset, and ensuring the accuracy and stability of the core pulling and reset actions.

[0017] Furthermore, a limiting groove 28 is provided under the side core-pulling rack 14, and a limiting block 29 is provided on the outer wall of the fixed base 12. The limiting block 29 is engaged with the limiting groove 28. With the limiting groove 28 and the limiting block 29, the movement stroke of the side core-pulling rack 14 can be limited, preventing it from disengaging from the gear 15 due to excessive movement, thereby improving the safety and reliability of the mechanism operation.

[0018] Furthermore, the ejection assembly includes an upper ejector plate 30 and a lower ejector plate 31. The ejector rod 7 of the injection molding machine passes through the through hole 5 and contacts the bottom of the lower ejector plate 31. Ejector pins 32 are provided on the upper ejector plate 30 and the lower ejector plate 31. The ejector pins 32 pass through the moving template 8 and cooperate with the plastic part 9. After the plastic part 9 completes the side core pulling, the ejector rod 7 of the injection molding machine pushes the upper and lower ejector plates 30 and 31 to move upward. The upper and lower ejector plates 30 and 31 drive the ejector pins 32 to move upward. The ejector pins 32 eject the plastic part 9 upward and demold it. When the mold is closed, the ejector pins 32 can contact the lower end of the fixed template 3 to push the ejector pins 32 and the upper and lower ejector plates 30 and 31 to reset.

[0019] This invention discloses a long-distance side core-pulling mechanism for a gear and rack in an injection mold. After the plastic part 9 is injection molded, the lower cover plate 2 is moved downward by the injection molding machine. The lower cover plate 2 moves the mold feet 6, ejector assembly, moving mold plate 8, plastic part 9, fixed seat 12, side core-pulling rack 14, gear 15, and other components on the moving mold side downward together, while the upper cover plate 1, fixed mold plate 3, mold opening and closing rack 17, and other components on the fixed mold side remain stationary. This allows the mold to gradually open from the fixed mold plate 3 and moving mold plate 8. At the same time as the mold opens, the mold opening and closing rack 17 gradually disengages from the insertion hole 18. The mold opening and closing rack 17 drives the gear 15 to rotate clockwise, and the gear 15 drives the side core-pulling rack 14 to move to the right along the slide groove 13, so that one end of the side core-pulling rack 14 is pulled out from each flange 10 of the plastic part 9. Through hole 11, the ejector assembly is finally driven by the ejector rod 7 of the injection molding machine. The ejector assembly ejects the plastic part 9 that has completed the core pulling upwards for demolding. When the mold gradually closes, the part on the moving mold side closes upwards, the ejector assembly resets downwards, the mold opening and closing rack 17 is inserted into the insertion hole 18, the mold opening and closing rack 17 drives the gear 15 to rotate counterclockwise, the gear 15 drives the side core pulling rack 14 to move to the left along the slide groove 13 and insert into the moving platen 8. When the moving platen 8 and the fixed platen 3 complete the mold closing, the side core pulling rack 14 also completes the reset and is ready for the next injection. At the same time, the mold locking rod 19 passes through the mold locking hole 20 and is inserted into the mold locking groove 21, which can lock and position the side core pulling rack 14 to prevent the side core pulling rack 14 from moving due to excessive injection pressure during mold closing injection.

[0020] Although the embodiments of this application disclose the above-described methods, the content is merely an implementation method adopted for ease of understanding. Any person skilled in the art should understand that any modifications and changes in the form and details of the implementation can be made without departing from the spirit and scope of the present invention. However, the scope of patent protection of the present invention shall still be determined by the scope defined in the appended claims.

Claims

1. A long-distance side core-pulling mechanism for a gear and rack in an injection mold, comprising an upper platen (1) and a lower platen (2), wherein a fixed template (3) is provided under the upper platen (1), a through hole (5) is provided in the lower platen (2), a mold foot (6) is provided on the lower platen (2), an ejector assembly is provided on the lower platen (2) between the mold feet (6), an ejector rod (7) of an injection molding machine passes through the through hole (5) and cooperates with the ejector assembly, a movable template (8) is provided on the mold foot (6), a mold cavity is formed between the movable template (8) and the fixed template (3), a plastic part (9) is injection molded in the mold cavity, and two or more downward flanges (10) are provided on one side of the plastic part (9), each flange (10) having a corresponding through hole (11), characterized in that: A fixed seat (12) is provided on the moving template (8). A sliding groove (13) is opened in the fixed seat (12). A side core-pulling rack (14) is provided in the sliding groove (13). One end of the side core-pulling rack (14) passes through the fixed seat (12) and engages with the through hole (11) of the plastic part (9). A gear (15) is provided in the fixed seat (12) below the side core-pulling rack (14). The gear (15) is rotated and engaged with the fixed seat (12) via a rotating shaft (16). One side of the gear (15) meshes with the bottom of the side core-pulling rack (14). An opening and closing mold rack (17) is provided under the fixed template (3). Corresponding insertion holes (18) are opened in the fixed seat (12) and the moving template (8). The opening and closing mold rack (17) is inserted into the mold. The insertion hole (18) meshes with one side of the gear (15). A locking rod (19) is provided under the fixed template (3). A locking hole (20) is opened in the fixed seat (12). A locking groove (21) is opened on the side core-pulling rack (14). The locking groove (21) corresponds to the locking hole (20). The locking rod (19) passes through the locking hole (20) and engages with the locking groove (21). When the mold is opened, the opening and closing rack (17) disengages from the insertion hole (18). The opening and closing rack (17) drives the gear (15) to rotate. The gear (15) drives the side core-pulling rack (14) to move to the right along the slide (13), so that one end of the side core-pulling rack (14) is pulled out of the through hole (11) in each flange (10) of the plastic part (9).

2. The injection mold gear and rack long-distance side core-pulling mechanism as described in claim 1, characterized in that: The side core-pulling rack (14) has a first positioning groove (22) and a second positioning groove (23) on its underside. An installation hole (24) is provided in the fixed seat (12). A positioning pin (25), a spring (26) and a plug (27) are provided in the installation hole (24). The upper end of the positioning pin (25) passes through the fixed seat (12) and is positioned and engaged with the first positioning groove (22) or the second positioning groove (23). The lower end of the positioning pin (24) is in contact with the spring (26), and the lower end of the spring (26) is in contact with the plug (27).

3. The injection mold gear and rack long-distance side core-pulling mechanism as described in claim 1, characterized in that: The side core-pulling rack (14) has a limiting groove (28) on its underside, and a limiting block (29) is provided on the outer wall of the fixed seat (12). The limiting block (29) and the limiting groove (28) are in a limiting fit.

4. The injection mold gear and rack long-distance side core-pulling mechanism as described in claim 1, characterized in that: The ejector assembly includes an upper ejector plate (30) and a lower ejector plate (31). The ejector rod (7) of the injection molding machine passes through the through hole (5) and contacts the bottom of the lower ejector plate (31). Ejector pins (32) are provided on the upper ejector plate (30) and the lower ejector plate (31). The ejector pins (32) pass through the moving template (8) and cooperate with the plastic part (9).

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