An injection mold

Abstract

The embodiment of the present application discloses an injection mold, comprising a movable mold assembly and a fixed mold assembly, the movable mold assembly comprises a movable mold plate, a plurality of movable mold inserts, a plurality of pairs of inclined ejector blocks and a plurality of pairs of core rods, the plurality of movable mold inserts are arranged on the movable mold plate and arranged along the length direction of the plastic part, each movable mold insert corresponds to a reverse buckle on the plastic part, each pair of inclined ejector blocks is located outside the corresponding movable mold insert and connected with the corresponding movable mold insert along the opening direction, and each core rod is movably arranged on the movable mold plate and cooperates with the corresponding movable mold insert and the inclined ejector block to form the reverse buckle; during the opening process, each pair of inclined ejector blocks moves synchronously and drives the corresponding movable mold insert to move away from the movable mold plate, so that the core rod is separated from the inside of the reverse buckle. The present application provides an injection mold, which realizes the multi-core-pulling demolding of the core rod separated from the reverse buckle by synchronously driving each movable mold insert to move through the paired inclined ejector blocks during the opening, and still realizes the compact and reliable arrangement under the limited spacing.

Description

Technical Field

[0001] This invention relates to the field of injection mold technology, and more specifically, to an injection mold. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] like Figure 1 As shown in the figure, the plastic part has multiple undercut structures along its length on the inner side wall to achieve assembly or limiting functions, and these undercuts are usually distributed at different heights. For this type of plastic part, the mold design needs to consider both the undercut forming and demolding requirements to ensure that the plastic part can be smoothly released from the mold.

[0004] In existing technologies, a common approach is to use angled ejectors to form the outer contour of the undercut and utilize the elastic deformation of the plastic material itself for forced demolding. When multiple undercuts are located at different heights, the deformation generated by each undercut during demolding is inconsistent, leading to localized stress concentration in the plastic part. This can easily result in permanent deformation or even cracking, thus affecting product yield. Another approach is to add a straight ejector mechanism to the angled ejector mechanism, using straight ejector rods to drive the moving mold insert for core pulling, thereby reducing the degree of forced deformation of the plastic part. However, for multi-cavity mold structures, the internal space of the mold is relatively limited, and the installation spacing between adjacent angled ejectors is usually insufficient to accommodate two straight ejector rods. This results in the space constraints of this type of core pulling structure, making it difficult to meet practical application requirements. Summary of the Invention

[0005] The purpose of this invention is to provide an injection mold that solves the problems in the prior art when demolding plastic parts with multiple undercuts of different heights on the inner side wall. Forcing demolding with a slanted ejector can easily lead to product scrap due to deformation of the plastic part, while using a slanted ejector combined with a straight ejector for core pulling is limited by the limited internal space of a multi-cavity mold and the difficulty in arranging a straight ejector mechanism.

[0006] The technical solution adopted by this invention is as follows: An injection mold is provided, comprising a moving mold assembly and a fixed mold assembly. The moving mold assembly and the fixed mold assembly are closed to form at least two cavities for molding a pair of plastic parts. The moving mold assembly includes a moving template, multiple moving mold inserts, multiple pairs of angled ejector blocks, and multiple pairs of core rods. The multiple moving mold inserts are disposed on the moving template and arranged along the length of the plastic part. Each moving mold insert corresponds to an undercut on the plastic part. Each pair of angled ejector blocks is located outside the corresponding moving mold insert and connected to the corresponding moving mold insert along the mold opening direction. Each core rod is movably disposed on the moving template and cooperates with the corresponding moving mold insert and the angled ejector block to form the undercut. During mold opening, each pair of angled ejector blocks moves synchronously and drives the corresponding moving mold insert to move away from the moving template, so that the core rod disengages from the undercut.

[0007] By employing the above technical solution, each undercut is correspondingly positioned on the moving mold insert, and paired ejector blocks synchronously drive the corresponding moving mold insert to move during mold opening, causing the core rod to disengage from the undercut, thus achieving core pulling and demolding of multiple undercuts. This method completes the core pulling action through the action relationship between the ejector blocks and the moving mold insert, allowing the core pulling process to be directly achieved by the ejector drive mechanism inside the mold. This reduces reliance on additional independent core pulling drive structures, simplifying the overall mold structure and reducing mechanism complexity. Furthermore, since each moving mold insert is driven by a corresponding ejector block, the core pulling actions can be spatially distributed and coordinated by multiple paired ejector blocks, resulting in a more compact and rational structural arrangement between the core pulling units. This ensures reliable driving of the moving mold insert even when the spacing between a pair of ejector blocks is limited, avoiding the problem of difficult core pulling mechanism arrangement due to insufficient local space.

[0008] Furthermore, the above structure enables the stable realization of multiple undercut cores of different heights within a limited mold space, reducing local stress concentration and deformation of the plastic part caused by forced demolding, and improving the smoothness of the demolding process and the molding quality of the plastic part.

[0009] According to one embodiment of the present invention, the inclined ejector block has a connecting portion on the side facing the moving mold insert, and the moving mold insert has a connecting groove corresponding to the connecting portion, with the connecting portion embedded in the connecting groove. Through the cooperation of the connecting portion and the connecting groove, a reliable connection between the inclined ejector block and the moving mold insert is achieved, facilitating the synchronous movement of the moving mold insert by the inclined ejector block.

[0010] According to one embodiment of the present invention, in the mold-closed state, the bottom surface of the inclined ejector block abuts against the top surface of the moving mold insert. The mutual abutment between the inclined ejector block and the moving mold insert ensures stable support in the mold-closed state, which helps to guarantee the positioning accuracy of the cavity and improve the molding quality of the plastic part.

[0011] According to one embodiment of the present invention, in the mold-closed state, the bottom surface of the connecting part contacts the bottom of the connecting groove, and a gap X is reserved between the top surface of the connecting part and the top of the connecting groove; when the mold opens, after the inclined ejector block moves a distance corresponding to the gap X relative to the moving mold insert, the connecting part abuts against the connecting groove and drives the moving mold insert to move synchronously. By setting the gap X, the inclined ejector block completes a predetermined stroke in the initial stage of mold opening, and drives the moving mold insert to move after a delay, which helps to optimize the demolding action sequence, reduce the demolding resistance of the plastic part, and improve demolding stability.

[0012] According to one embodiment of the present invention, a spring is provided between the moving mold insert and the moving mold platen. The spring is used to apply an elastic force to the moving mold insert toward the inclined ejector block, so that the moving mold insert and the inclined ejector block remain in contact when the mold is closed. By continuously providing an elastic preload by the spring, the moving mold insert always maintains a reliable fit with the inclined ejector block, avoiding positioning deviations due to gaps and improving the stability of mold operation.

[0013] According to one embodiment of the present invention, the moving mold insert is provided with a guide rod extending along the mold opening direction, and the moving mold plate is correspondingly provided with a guide sleeve. The guide rod is inserted into the guide sleeve and guides the guide sleeve. Through the guiding cooperation between the guide rod and the guide sleeve, the movement process of the moving mold insert is guided, preventing the moving mold insert from deviating and improving the motion accuracy.

[0014] According to one embodiment of the present invention, the moving template is provided with a guide seat, and the core rod is movably inserted through the guide seat and slidably connected to the guide seat. The guide seat guides and supports the core rod, enabling it to move stably along a predetermined trajectory and improving the reliability of the core rod extraction process.

[0015] According to one embodiment of the present invention, one end of the core rod is provided with a forming end for forming the inside of the undercut, and the other end is provided with a guide groove. By providing the guide groove, a guiding and mating position is provided for the movement of the core rod, making the movement of the core rod more stable.

[0016] According to one embodiment of the present invention, the guide seat is provided with a guide block, which extends into the guide groove and slides in a limiting manner with the guide groove. The limiting sliding engagement between the guide block and the guide groove constrains the movement direction of the core rod, improving the movement accuracy of the core rod and preventing it from swaying.

[0017] According to one embodiment of the present invention, the moving mold insert is provided with an obliquely oriented mating groove extending vertically, and the core rod passes through the obliquely oriented mating groove and slides within the groove. The obliquely oriented mating groove guides the core rod, enabling it to complete the core-pulling movement along a predetermined trajectory, further ensuring smooth demolding. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a perspective view of the plastic part in an embodiment of the present invention.

[0020] Figure 2 This is a perspective view of the moving mold assembly in an embodiment of the present invention.

[0021] Figure 3 This is a perspective view of the inclined ejector block and the moving mold insert during mold closing in an embodiment of the present invention.

[0022] Figure 4 This is a cross-sectional view of the inclined ejector block and the moving mold insert during mold closing in an embodiment of the present invention.

[0023] Figure 5 for Figure 4 A magnified view of a portion of point A in the middle.

[0024] Figure 6 This is a perspective view of the inclined ejector block and the moving mold insert during mold opening in an embodiment of the present invention.

[0025] Figure 7 This is a perspective view of the core rod and guide seat in an embodiment of the present invention.

[0026] Explanation of the labels in the diagram: 10. Plastic parts; 20. Moving mold components; 11. Top wall; 12. Side wall; 13. Inverted; 21. Moving mold plate; 22. Moving mold insert; 23. Top plate; 24. Angled ejector block; 25. Guide rod; 26. Guide seat; 27. Core rod; 28. Spring; 29. ​​Guide sleeve; 221. Angled mating groove; 222. Connecting groove; 241. Connecting part; 242. Inclined guide rod; 243. Sliding block; 244. Sliding seat; 261. Guide block; 271. Forming end; 272. Guide groove. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0028] This injection mold is used to mold plastic part 10, combined with Figure 1 As shown, the plastic part 10 includes a top wall 11 and a side wall 12. Seven undercuts 13 are provided on the inner side of the side wall 12, and the undercuts 13 are located at the lower part of the top wall 11. To clearly illustrate the relative positional relationship of each technical feature, the orientation is explained using the mold-closed state as a reference state and the plane where the moving mold plate 21 is located as the reference plane. Wherein, "mold opening direction" refers to the direction perpendicular to the moving mold plate 21 and pointing away from it; "along the mold opening direction" refers to the extension or arrangement along this direction perpendicular to the moving mold plate 21 and pointing away from it; "inner side" refers to the direction of the undercuts 13 relative to the interior of the plastic part 10 body; "outer side" refers to the peripheral area extending outward relative to the moving mold insert 22; "top surface" refers to the surface of the inclined ejector block 24 or the moving mold insert 22 facing the mold opening direction, and "bottom surface" refers to the surface in the opposite direction; "up and down" refers to the relative positional relationship along the mold opening direction, where "up" points to the mold opening direction and "down" points to the moving mold plate 21.

[0029] like Figure 2-7 As shown, this embodiment discloses an injection mold, including a moving mold assembly 20 and a fixed mold assembly (not shown in the figure). The moving mold assembly 20 and the fixed mold assembly are closed to form at least two cavities, each cavity for molding a pair of plastic parts 10. The core structure of the moving mold assembly 20 includes a moving mold plate 21, a plurality of moving mold inserts 22, a plurality of pairs of inclined ejector blocks 24, and a plurality of pairs of mandrels 27. Given that the inner sidewall 12 of the plastic part 10 is provided with seven undercuts 13, correspondingly, each cavity in the moving mold assembly 20 is provided with seven moving mold inserts 22. These seven moving mold inserts 22 are disposed on the moving mold plate 21 and arranged along the length direction of the plastic part 10. Each moving mold insert 22 corresponds to one undercut 13 on the plastic part 10 and is used to cooperate with the mandrels 27 to form the cavity shape of the undercut 13.

[0030] like Figure 2 As shown, in this embodiment, there are seven pairs of inclined ejector blocks 24. Each pair of inclined ejector blocks 24 cooperates with a corresponding moving mold insert 22. The inclined ejector blocks 24 are located on both sides of the corresponding moving mold insert 22, that is, on the outer side extending outward relative to the moving mold insert 22 along the width direction of the plastic part 10. The main function of the inclined ejector blocks 24 is to lift the top wall 11 of the plastic part 10 upward and pull the moving mold insert 22 to move. The inclined ejector blocks 24 and the corresponding moving mold insert 22 are connected along the mold opening direction, so that the two can interact during the mold opening process.

[0031] like Figure 3 As shown, the core rods 27 are arranged in pairs, with each pair corresponding to a moving mold insert 22. They are movably mounted on the moving mold plate 21, meaning the core rods 27 can move relative to the moving mold plate 21 rather than being fixedly connected. Each core rod 27, in conjunction with its corresponding moving mold insert 22 and the ejector block 24, forms the inner and outer contours of the undercut 13. After injection molding, the pairs of ejector blocks 24 move synchronously during mold opening. Due to the engagement mechanism between the ejector blocks 24 and the moving mold insert 22, the initial movement of the ejector blocks 24 causes the corresponding moving mold insert 22 to move away from the moving mold plate 21. Subsequently, the ejector blocks 24 lift the plastic part 10, causing the core rods 27 to gradually detach from the undercut 13, i.e., move away from the moving mold plate 21 along the mold opening direction, ensuring complete separation of the undercut 13 from the core rods 27.

[0032] Specifically, such as Figure 6 As shown, the internal structure of the inclined ejector block 24 includes an inclined guide rod 242, a sliding block 243, and a sliding seat 244. The upper end of the inclined guide rod 242 is connected to the inclined ejector block 24, and the lower end of the inclined guide rod 242 is provided with a sliding block 243, which slides within the sliding seat 244. "Sliding fit" means that the sliding block 243 can move relative to the sliding seat 244 along its axial direction. The lower part of the moving template 21 is provided with a top plate 23, and the sliding seat 244 is fixedly installed on the top plate 23. The top plate 23 lifts the sliding seat 244, and the sliding seat 244, through the inclined guide rod 242, lifts the inclined ejector block 24 upwards, pushing the inclined ejector block 24 to move along the mold opening direction, thereby achieving the demolding purpose of the aforementioned undercut 13.

[0033] Combination Figure 3-4 As shown, the side of the ejector block 24 facing the moving mold insert 22 refers to the side where the ejector block 24 and the moving mold insert 22 are in adjacent contact. Specifically, a connecting portion 241 is provided on the side opposite the moving mold insert 22 along the width direction of the plastic part 10. This connecting portion 241 is a protrusion extending towards the moving mold insert 22. The moving mold insert 22 has a connecting groove 222 at the position corresponding to the connecting portion 241. The connecting portion 241 is embedded in the connecting groove 222, forming a reliable mating mechanism between the ejector block 24 and the moving mold insert 22. "Embedded" means that the connecting portion 241 enters the connecting groove 222 to form a relatively tight fit. In the mold-closed state, the bottom surface of the ejector block 24 abuts against the top surface of the moving mold insert 22, forming a tight contact. Simultaneously, the bottom surface of the connecting portion 241 contacts the bottom of the connecting groove 222, indicating that they are in the tightest mating state. However, a gap X is reserved between the top surface of the connecting part 241 and the top of the connecting groove 222. The gap X refers to the distance difference between the top surface of the connecting part 241 and the top of the connecting groove 222 along the mold opening direction.

[0034] When opening the mold, combine Figure 6As shown, the top plate 23 moves upward, pushing the sliding seat 244 and the inclined guide rod 242 upward. Driven by the top plate 23, the inclined ejector block 24 begins to move obliquely along the mold opening direction. Due to the existence of the gap X, in the initial stage of mold opening, the inclined ejector block 24 moves a distance corresponding to the gap X relative to the moving mold insert 22. During this process, the inclined ejector block 24 and the moving mold insert 22 maintain a relatively independent motion state; that is, the movement of the inclined ejector block 24 has not yet driven the moving mold insert 22 to move synchronously. In this stage, the inclined ejector block 24 first applies an ejection action to the plastic part 10, causing the plastic part 10 to gradually break free from the cavity fit constraint and have a gap with the moving mold insert 22. Because of the gap, the moving mold insert 22 cannot apply an ejection action to the plastic part 10, thus avoiding the plastic part 10 being simultaneously subjected to ejection interference forces from the moving mold insert 22 during the initial demolding process. By delaying the movement of the moving mold insert 22 as described above, the possibility of stress concentration and deformation at the lower edge of the side wall 12 of the plastic part 10 due to the superposition of ejection forces is reduced. When the inclined ejector block 24 moves a distance equal to the gap X, the connecting part 241 abuts against the top of the connecting groove 222. Afterward, the inclined ejector block 24 and the moving mold insert 22 form a rigid connection. The continued movement of the inclined ejector block 24 drives the moving mold insert 22 to move synchronously. This causes the moving mold insert 22 and the inclined rod to move relative to each other, completely disengaging the core rod 27 from the undercut 13. "Synchronous movement" means that the moving mold insert 22 and the inclined ejector block 24 subsequently move at the same speed and in the same direction.

[0035] Furthermore, such as Figure 6 As shown, in this embodiment, a spring 28 is provided between the moving mold insert 22 and the moving mold plate 21. The spring 28 is used to apply an elastic force to the moving mold insert 22 toward the inclined ejector block 24, where "towards the inclined ejector block 24" refers to the force along the mold opening direction, pointing in the direction of the inclined ejector block 24. In the mold closed state, the elastic action of the spring 28 keeps the moving mold insert 22 and the inclined ejector block 24 abutting each other, that is, the bottom surface and the top surface remain in contact.

[0036] Furthermore, the moving mold insert 22 is provided with a guide rod 25 extending along the mold opening direction. The guide rod 25 refers to a rod-shaped structure that protrudes and extends from the moving mold insert 22 in the mold opening direction. A guide sleeve 29 is provided at a corresponding position on the moving mold plate 21, and this guide sleeve 29 is matched with the guide rod 25. Here, "corresponding position" refers to the position corresponding to the guide rod 25 when arranged along the mold opening direction. The guide rod 25 is inserted into the guide sleeve 29. This guiding structure constrains the movement direction of the moving mold insert 22 during the mold opening process, prevents displacement of the moving mold insert 22 in a plane perpendicular to the mold opening direction, and ensures the stability of the demolding process.

[0037] Combination Figure 4As shown, the moving template 21 is provided with a guide seat 26. One end of each core rod 27 is slidably connected to the guide seat 26, where "slidable connection" refers to a connection method that allows relative movement. The structure of each core rod 27 further includes: one end is provided with a forming end 271 for forming the inside of the undercut 13, the outer contour of the forming end 271 corresponding to the inner contour of the undercut 13; the other end is provided with a guide groove 272, which is a T-shaped groove structure. The guide seat 26 is provided with a guide block 261, which is a T-shaped block structure. The guide block 261 extends into the guide groove 272 of the core rod 27 and is in a limiting sliding fit with the guide groove 272. This fit allows the core rod 27 to slide laterally relative to the guide seat 26, and also constrains the position of the core rod 27 in a direction perpendicular to the axial direction of the core rod 27.

[0038] Furthermore, the moving mold insert 22 is provided with a vertically extending oblique fitting groove 221. This groove extends obliquely from the upper surface to the lower surface of the moving mold insert 22, forming a through channel. "Oblique" refers to a direction at an angle relative to the mold opening direction, specifically the angle between the oblique fitting groove 221 and the mold opening direction. The core rod 27 passes through this oblique fitting groove 221, meaning it passes along the direction of the groove and enters the groove, engaging in a sliding fit with it. This sliding fit between the core rod 27 and the oblique fitting groove 221 allows the core rod 27 to move relative to the moving mold insert 22 during the mold opening process.

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 invention and simplifying the description, and are not intended to indicate or imply that the device 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 invention.

[0040] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An injection mold comprising a moving mold assembly (20) and a fixed mold assembly, wherein the moving mold assembly (20) and the fixed mold assembly are closed to form at least two cavities for molding a pair of plastic parts (10), characterized in that: The moving mold assembly (20) includes a moving mold plate (21), multiple moving mold inserts (22), multiple pairs of inclined ejector blocks (24), and multiple pairs of core rods (27). The multiple moving mold inserts (22) are disposed on the moving mold plate (21) and arranged along the length of the plastic part (10). Each moving mold insert (22) corresponds to an undercut (13) on the plastic part (10). Each pair of inclined ejector blocks (24) is located on the outside of the corresponding moving mold insert (22). The core rods (27) are connected to the corresponding moving mold inserts (22) along the mold opening direction. Each core rod (27) is movably set on the moving template (21) and cooperates with the corresponding moving mold inserts (22) and the inclined ejector blocks (24) to form the undercut (13). During the mold opening process, each pair of inclined ejector blocks (24) moves synchronously and drives the corresponding moving mold inserts (22) to move away from the moving template (21) so that the core rods (27) are disengaged from the undercut (13).

2. The injection mold according to claim 1, characterized in that: The inclined top block (24) has a connecting part (241) on the side facing the moving mold insert (22), and the moving mold insert (22) has a connecting groove (222) corresponding to the connecting part (241), and the connecting part (241) is embedded in the connecting groove (222).

3. The injection mold according to claim 2, characterized in that: In the mold-closed state, the bottom surface of the inclined ejector block (24) abuts against the top surface of the moving mold insert (22).

4. The injection mold according to claim 3, characterized in that: In the mold-closed state, the bottom surface of the connecting part (241) is in contact with the bottom of the connecting groove (222), and a gap X is reserved between the top surface of the connecting part (241) and the top of the connecting groove (222); when the mold is opened, after the inclined ejector block (24) moves relative to the moving mold insert (22) by the distance corresponding to the gap X, the connecting part (241) abuts against the connecting groove (222) and drives the moving mold insert (22) to move synchronously.

5. The injection mold according to claim 3, characterized in that: A spring (28) is provided between the moving mold insert (22) and the moving mold plate (21). The spring (28) is used to apply an elastic force toward the inclined ejector block (24) to the moving mold insert (22) so that the moving mold insert (22) and the inclined ejector block (24) remain in contact in the mold closing state.

6. The injection mold according to claim 5, characterized in that: The moving mold insert (22) is provided with a guide rod (25) extending along the mold opening direction, and the moving mold plate (21) is provided with a guide sleeve (29). The guide rod (25) is inserted into the guide sleeve (29) and is guided and cooperated with the guide sleeve (29).

7. The injection mold according to claim 1, characterized in that: The moving template (21) is provided with a guide seat (26), and the core rod (27) is movably inserted through the guide seat (26) and slidably connected with the guide seat (26).

8. The injection mold according to claim 7, characterized in that: One end of the core rod (27) is provided with a forming end (271) for forming the inside of the buckle (13), and the other end is provided with a guide groove (272).

9. The injection mold according to claim 8, characterized in that: The guide seat (26) is provided with a guide block (261), which extends into the guide groove (272) and slides in a limiting manner with the guide groove (272).

10. The injection mold according to claim 1, characterized in that: The moving mold insert (22) is provided with an oblique mating groove (221) that runs through the top and bottom. The core rod (27) passes through the oblique mating groove (221) and slides in cooperation with the oblique mating groove (221).

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