A combined large and small inclined ejector mechanism for injection molds
By combining large and small angled ejectors, the problem of difficult demolding of plastic parts in injection molds is solved, achieving high yield and effective locking of barbs, thus preventing barb breakage.
Patent Information
- Application Number
- CN202522056581.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-24
- Publication Date
- 2026-11-06
- Estimated Expiration
- 2035-09-24
AI Technical Summary
In existing injection molds, the barb structure of plastic parts is prone to breakage during demolding, resulting in low yield and smaller barb size affecting the clamping ability.
It adopts a combination structure of large and small inclined ejectors. Through the cooperation of inclined guide holes and small inclined ejectors, the plastic parts can be demolded smoothly, while ensuring the locking ability of the barbs. The cooperation of springs and positioning pins ensures accurate ejection.
This enabled smooth demolding of plastic parts, improved yield, and maintained the locking ability of the barbs, avoiding problems such as barb size shrinkage and breakage.
Smart Images
Figure CN224940499U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to injection molds, and in particular to a combined large and small inclined ejector mechanism for injection molds. Background Technology
[0002] When producing plastic parts using injection molds, if the plastic part has downward-facing flanges on all four sides, and one side of the flange has a horizontal baffle and a barb on its inner wall, with the barb located below the baffle, the plastic part cannot be directly demolded. Existing technology typically involves arranging angled ejector pins on the upper and lower ejector plates. The upper end of the angled ejector pin passes through the moving mold plate and engages with the horizontal baffle. While the angled ejector pin pushes the plastic upwards, it also moves laterally to disengage from the horizontal baffle. However, because the barb is located below the baffle, it restricts the lateral movement of the angled ejector pin. Therefore, the barb is usually made smaller, utilizing the elastic deformation ability of the plastic material to forcefully disengage the angled ejector pin from the barb. However, this method results in a smaller barb, affecting the clamping ability of the plastic part, and forceful disengagement can easily cause breakage at the barb, leading to a low product yield. Summary of the Invention
[0003] The purpose of this utility model is to overcome the shortcomings of existing technologies and provide a simple structure that allows plastic parts to be easily demolded while ensuring the hook-locking ability of the plastic parts, resulting in a high yield.
[0004] The technical solution of this utility model for a combined large and small inclined ejector demolding mechanism for injection molds is as follows: It includes an upper platen and a lower platen. A fixed template is provided under the upper platen. A through hole is formed in the lower platen. Mold feet are provided on the lower platen. An ejector structure is provided on the lower platen between the mold feet. The ejector rod of the injection molding machine passes through the through hole and cooperates with the ejector structure. 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. The plastic part has downward-facing flanges around its perimeter, with one side of the flange having an inner wall... The ejector structure includes an upper ejector plate and a lower ejector plate, with a straight ejector rod and a slide block on each plate. The upper end of the straight ejector rod passes through the moving template and contacts the bottom of the plastic part. A slider is installed in the slide block, which is connected to a large inclined ejector via a fixed shaft. The lower end of the large inclined ejector is rotatably engaged with the fixed shaft, and the upper end of the large inclined ejector passes through the moving template and engages with the baffle on the inner wall of the flange. A slanted guide hole is formed in the large inclined ejector, and a small inclined ejector is installed in the guide hole. The small inclined ejector engages with the barb.
[0005] Furthermore, a groove is formed in the large inclined top, and a spring and a positioning post are set in the groove. One end of the spring contacts the bottom of the groove, and the other end of the spring contacts the positioning post. A positioning protrusion is set at the end of the positioning post away from the spring. A first positioning groove and a second positioning groove are set on the small inclined top, and the positioning protrusion cooperates with the first positioning groove or the second positioning groove.
[0006] Furthermore, an anti-slip positioning groove is provided at the upper end of the straight rod, and an anti-slip protrusion is provided on the lower part of the plastic part, the anti-slip protrusion cooperating with the anti-slip positioning groove.
[0007] Furthermore, there are two or more anti-slip positioning grooves and two or more corresponding anti-slip protrusions.
[0008] Furthermore, a guide post is provided between the lower cover plate and the moving template, and guide holes are opened in the upper ejector plate and the lower ejector plate, with the guide holes cooperating with the guide post.
[0009] Furthermore, a guide sleeve is provided in the guide hole, and the guide sleeve cooperates with the guide post.
[0010] The beneficial effects of this utility model of a combined large and small inclined ejector demolding mechanism for injection molds are as follows: by opening an inclined guide hole in the large inclined ejector and setting a small inclined ejector in the inclined guide hole, while the large inclined ejector pushes the plastic part out of the mold, the large inclined ejector moves inward to release the baffle. The inclined guide hole of the large inclined ejector cooperates with the small inclined ejector, driving the small inclined ejector to move upward to release the barb. Without having to make the barb size smaller, it ensures that the injection mold can smoothly release the baffle and barb structure of the plastic part, so that the plastic part can be smoothly demolded and the yield is high. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of the mold closing state structure of a combined large and small inclined ejector mechanism for injection molds according to this utility model; Figure 2 This is a schematic diagram of the mold opening state structure of a combined large and small inclined ejector mechanism for injection molds according to this utility model; Figure 3 This is a schematic diagram of the ejection state of a plastic part in a combined large and small inclined ejector mechanism for injection molds according to this utility model. Figure 4 yes Figure 3 A magnified view of part A; Figure 5 yes Figure 3 A magnified view of part B.
[0012] In the diagram, 1. Upper cover plate; 2. Lower cover plate; 3. Fixed template; 4. Perforation; 5. Mold foot; 6. Ejector rod; 7. Moving template; 8. Plastic part; 9. Flanged edge; 10. Baffle; 11. Barb; 12. Upper ejector plate; 13. Lower ejector plate; 14. Straight ejector rod; 15. Slide block; 16. Slider; 17. Fixed shaft; 18. Large angled ejector; 19. Angled guide hole; 20. Small angled ejector; 21. Groove; 22. Spring; 23. Positioning post; 24. Positioning protrusion; 25. First positioning groove; 26. Second positioning groove; 27. Anti-slip positioning groove; 28. Anti-slip protrusion; 29. Guide post; 30. Guide hole; 31. Guide sleeve. Detailed Implementation
[0013] To enable those skilled in the art to better understand the technical solution of this utility model, the preferred embodiments of this utility model 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 this utility model. 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 this utility model.
[0014] It should be noted that the terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this utility model 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 structure; 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 utility model according to the specific circumstances.
[0015] In the description of this utility model, it should be understood that the terms "upper," "lower," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for 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 limitations on this utility model. The terms "first" and "second" are also used only for the sake of brevity in description and do not indicate or imply relative importance.
[0016] To further illustrate the content, features, and effects of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and examples, but it should not be construed as a basis for limiting this utility model.
[0017] This utility model relates to a combined large and small inclined ejector mechanism for injection molds, such as... Figure 1 — Figure 5 As shown, the 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 4 is provided in the lower platen 2. Mold feet 5 are provided on the lower platen 2. An ejector structure is provided on the lower platen 2 between the mold feet 5. The ejector pin 6 of the injection molding machine passes through the through hole 4 and cooperates with the ejector structure. A movable template 7 is provided on the mold feet 5. A mold cavity is formed between the movable template 7 and the fixed template 3. A plastic part 8 is injection molded in the mold cavity. The plastic part 8 has downward flanges 9 around its perimeter. A transverse baffle 10 and a barb 11 are provided on the inner wall of one side of the flange 9. The ejector structure includes an upper ejector plate 1. 2 and lower ejector plate 13, straight ejector rod 14 and slide block 15 are provided on upper ejector plate 12 and lower ejector plate 13. The upper end of the straight ejector rod 14 passes through the moving template 7 and contacts the bottom of the plastic part 8. A slider 16 is provided in the slide block 15. The slider 16 is connected to the large inclined ejector 18 via the fixed shaft 17. The lower end of the large inclined ejector 18 is rotatably engaged with the fixed shaft 17. The upper end of the large inclined ejector 18 passes through the moving template 7 and engages with the baffle 10 on the inner wall of the flange 9. An inclined guide hole 19 is opened in the large inclined ejector 18. A small inclined ejector 20 is provided in the inclined guide hole 19. The small inclined ejector 20 engages with the barb 11.
[0018] Furthermore, a groove 21 is formed in the large inclined top 18, and a spring 22 and a positioning post 23 are arranged in the groove 21. One end of the spring 22 contacts the bottom of the groove 21, and the other end of the spring 22 contacts the positioning post 23. A positioning protrusion 24 is provided at the end of the positioning post 23 away from the spring 22. A first positioning groove 25 and a second positioning groove 26 are provided on the small inclined top 20. The positioning protrusion 24 cooperates with the first positioning groove 25 or the second positioning groove 26. In the mold-closed state, the positioning protrusion 24 under the positioning post 23 is positioned and engaged with the first positioning groove 25 on the small inclined ejector 20. When the large inclined ejector 18 is ejected, as the large inclined ejector 18 moves, the large inclined ejector 18 drives the small inclined ejector 20 to move accordingly, causing the positioning protrusion 24 to disengage from the first positioning groove 25. After the large inclined ejector 18 and the small inclined ejector 20 are in place, under the elastic force of the spring 22, the positioning protrusion 24 of the positioning post 23 is pushed into the second positioning groove 26. With the cooperation of the positioning protrusion 24 and the first and second positioning grooves 25 and 26, the ejection and resetting actions of the large inclined ejector 18 and the small inclined ejector 20 are more precise.
[0019] Furthermore, an anti-slip positioning groove 27 is provided at the upper end of the straight push rod 14, and an anti-slip protrusion 28 is provided below the plastic part 8. The anti-slip protrusion 28 cooperates with the anti-slip positioning groove 27. Since the large inclined push rod 18 has a large clamping force on the baffle 10, when the large inclined push rod 18 moves inward, it can easily drive the baffle 10 and the entire plastic part 8 to move laterally, causing it to be unable to disengage from the baffle 10 structure. With the cooperation of the anti-slip positioning groove 27 and the anti-slip protrusion 28, the plastic part 8 can be positioned to prevent it from moving laterally, ensuring that the large inclined push rod 18 can smoothly disengage from the baffle 10.
[0020] Furthermore, there are two or more anti-slip positioning grooves 27 and two or more corresponding anti-slip protrusions 28. The number of anti-slip positioning grooves 27 and anti-slip protrusions 28 can be set according to the clamping force of the large inclined top 18 on the baffle 10. If the number of anti-slip positioning grooves 27 and anti-slip protrusions 28 increases, the width of the straight top rod 14 will also increase accordingly.
[0021] Furthermore, a guide post 29 is provided between the lower cover plate 2 and the moving template 7, and guide holes 30 are provided in the upper ejector plate 12 and the lower ejector plate 13, which cooperate with the guide post 29. With the guide post 29 and the guide hole 30, the movement of the upper and lower ejector plates 12 and 13 can be guided, ensuring that their operation is more accurate and reliable.
[0022] Furthermore, a guide sleeve 31 is provided in the guide hole 30, and the guide sleeve 31 cooperates with the guide post 29. The guide sleeve 31 increases its wear resistance and ensures its service life.
[0023] This utility model discloses a combined large and small inclined ejector demolding mechanism for injection molds. After the plastic part is injection molded, the injection molding machine drives the lower platen 2 to move downwards. The lower platen 2 drives the mold feet 5, the ejector structure, the moving platen 7, and the plastic part 8 to move downwards together, while the upper platen 1 and the fixed platen 3 remain stationary, allowing the mold to gradually open from the fixed platen 3 and the moving platen 7. When the lower ejector platen 13 of the ejector structure moves downwards to the position of the ejector rod 6 of the injection molding machine, the ejector rod 6 stops the downward movement of the lower ejector platen 13, the upper ejector plate 12, the straight ejector rod 14, and the slide block 15. The slide block 15 then drives the large inclined ejector 18 and the small inclined ejector 20 to stop moving downwards through the slider 16 and the fixed shaft 17. The large inclined ejector 18 and the straight ejector rod 14 stop the downward movement of the plastic part 8. Meanwhile, the lower platen 2, mold foot 5, and moving platen 7 continue to move downwards. Under the cooperation of the inclined hole inside the moving platen 7 (which is the hole through which the large inclined ejector passes in the moving platen) and the large inclined ejector 18, the large inclined ejector 18 gradually slides inwards. The lower part of the large inclined ejector 18 slides along the slide block 15 via the fixed shaft 17 and the slider 16, causing the upper part of the large inclined ejector 18 to disengage from the baffle 10 on the inner wall of the flange 9 on one side of the plastic part 8. At the same time as the large inclined ejector 18 slides inwards, the inclined guide hole 19 in the large inclined ejector 18 cooperates with the small inclined ejector 20, causing the small inclined ejector 19 to gradually move upwards along the inclined direction of the inclined guide hole 19, causing the small inclined ejector 20 to disengage from the barb 11 of the plastic part 8, so that each part of the plastic part 8 completes the core-pulling action, and finally the plastic part 8 can be removed and demolded.
[0024] 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 disclosed in this utility model. However, the patent protection scope of this utility model shall still be determined by the scope defined in the appended claims.
Claims
1. A combined large and small inclined ejector demolding mechanism for injection molds, 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 (4) is provided in the lower platen (2), mold feet (5) are provided on the lower platen (2), and an ejector structure is provided on the lower platen (2) between the mold feet (5), an ejector rod (6) of an injection molding machine passes through the through hole (4) and cooperates with the ejector structure, a movable template (7) is provided on the mold feet (5), and a mold cavity is formed between the movable template (7) and the fixed template (3), wherein a plastic part (8) is injection molded in the mold cavity, and downward flanges (9) are provided around the plastic part (8), wherein a transverse baffle (10) and a barb (11) are provided on the inner wall of one side of the flange (9), characterized in that: The ejection structure includes an upper ejector plate (12) and a lower ejector plate (13). A straight ejector rod (14) and a slide block (15) are provided on the upper ejector plate (12) and the lower ejector plate (13). The upper end of the straight ejector rod (14) passes through the moving template (7) and contacts the bottom of the plastic part (8). A slider (16) is provided in the slide block (15). The slider (16) is connected to the large inclined ejector (18) via a fixed shaft (17). The lower end of the large inclined ejector (18) is rotatably engaged with the fixed shaft (17). The upper end of the large inclined ejector (18) passes through the moving template (7) and engages with the baffle (10) on the inner wall of the flange (9). An inclined guide hole (19) is opened in the large inclined ejector (18). A small inclined ejector (20) is provided in the inclined guide hole (19). The small inclined ejector (20) engages with the barb (11).
2. The injection mold large and small inclined ejector combined demolding mechanism as described in claim 1, characterized in that: The large inclined top (18) has a groove (21) in which a spring (22) and a positioning post (23) are provided. One end of the spring (22) is in contact with the bottom of the groove (21), and the other end of the spring (22) is in contact with the positioning post (23). The positioning post (23) has a positioning protrusion (24) at the end away from the spring (22). The small inclined top (20) has a first positioning groove (25) and a second positioning groove (26). The positioning protrusion (24) cooperates with the first positioning groove (25) or the second positioning groove (26).
3. The injection mold large and small inclined ejector combined demolding mechanism as described in claim 1, characterized in that: The upper end of the straight rod (14) is provided with an anti-slip positioning groove (27), and an anti-slip protrusion (28) is provided under the plastic part (8). The anti-slip protrusion (28) cooperates with the anti-slip positioning groove (27).
4. The injection mold large and small inclined ejector combined demolding mechanism as described in claim 3, characterized in that: There are two or more anti-slip positioning grooves (27) and two or more corresponding anti-slip protrusions (28).
5. The injection mold large and small inclined ejector combined demolding mechanism as described in claim 1, characterized in that: A guide post (29) is provided between the lower cover plate (2) and the moving template (7), and a guide hole (30) is opened in the upper ejector plate (12) and the lower ejector plate (13), and the guide hole (30) cooperates with the guide post (29).
6. The injection mold large and small inclined ejector combined demolding mechanism as described in claim 5, characterized in that: A guide sleeve (31) is provided in the guide hole (30), and the guide sleeve (31) cooperates with the guide post (29).