Core-pulling mechanism for injection mold for making narrow inner-arc fold
The core-pulling mechanism, which combines wedge linkage and cylinder drive, solves the problem of unstable locking of chamfered cores in injection molds, enabling precise molding of injection molded parts and simplified assembly.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HANGZHOU FERDR PRECISION MOLD
- Filing Date
- 2025-09-04
- Publication Date
- 2026-06-09
AI Technical Summary
The existing injection molds lack an effective mechanical locking mechanism for the chamfered core, which leads to defects such as dimensional instability and flash during molding.
The mechanical self-locking and unlocking are achieved by using a wedge linkage, and the independent cylinder drive ensures the reliability of the core pulling action sequence. The ingenious cooperation between the inclined hole and the locking inclined rod achieves unlocking before core pulling and self-locking after mold closing.
This ensures that the inner core does not retract during the injection process, guarantees a reliable sequence of actions, simplifies the assembly process of the inner core, and enables precise molding of injection molded parts.
Smart Images
Figure CN224334924U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of mold technology, specifically to a core-pulling mechanism for injection molds used to manufacture narrow, inner-arc folded parts. Background Technology
[0002] Narrow, inwardly curved folded parts, as a typical structure in precision injection molding, are widely used in consumer electronics, medical devices, and automotive components. These components typically have complex internal geometric features and high dimensional accuracy requirements, and their molding quality directly affects the assembly performance and service life of the final product.
[0003] According to CN212603153U, an internal core-pulling mechanism for injection molds is disclosed. This technology discloses a technical solution including "a fixed mold and a moving mold, with a core one and a core two provided between the moving mold and the fixed mold. The end of the core two near the core one is columnar and has a radially extending sliding hole. A chamfered core that can slide back and forth along the sliding hole is embedded in the sliding hole. The outer end of the chamfered core has an annular chamfered surface. An inclined guide post one is fixed at the end of the core one. The chamfered core has a slide that can be adapted to the inclined guide post one. When the inclined guide post one moves left and right, it can drive the chamfered core to slide back and forth along the sliding hole by acting on the inner sidewall of the slide. When the core one and the core two abut against each other, the outer end of the chamfered core extends out of the sliding hole. When the inclined guide post one disengages from the slide, the outer end of the chamfered core retracts into the sliding hole."
[0004] The chamfered core in the above scheme lacks an effective mechanical locking mechanism to resist the melt pressure during the injection process. Relying solely on the static fit of the core structure itself makes it difficult to ensure that the chamfered core does not shift or retreat during molding, resulting in unstable product dimensions or defects such as flash. Utility Model Content
[0005] To address the shortcomings of existing technologies, this utility model provides a core-pulling mechanism for injection molds used to manufacture narrow, inwardly curved folded parts. It achieves mechanical self-locking and unlocking through wedge linkage, and the independent cylinder drive ensures reliable core-pulling sequence. It automatically locks to resist injection pressure during mold closing, and unlocks before side-pulling, ensuring precise action and controllable stroke.
[0006] To achieve the above objectives, this utility model provides the following technical solution: a core-pulling mechanism for an injection mold used to manufacture narrow, inwardly curved folded parts, comprising a lower mold and an upper mold, wherein a lower cavity and an upper cavity are respectively provided inside the lower mold and the upper mold, and an injection molded part is formed between the lower cavity and the upper cavity. The lower mold is provided with a core-pulling mechanism for core pulling and resetting / locking. The core-pulling mechanism includes:
[0007] The main component includes a mounting base fixed to the right side of the lower mold, with a cylinder mounted on the right end of the mounting base;
[0008] The actuator includes a slider that is slidably mounted inside the mounting base. Two inner cores are provided on the left end of the slider. A mounting plate is fixed to the left end of the slider and used to position the inner cores. A guide block is slidably mounted inside the slider. An oblique hole is opened inside the guide block. A connecting rod is fixed to the left end of the guide block and inserted into the inner core. Locking oblique rods are provided on both sides of the upper end of the slider. The lower end of the locking oblique rod is located inside the oblique hole. A locking groove is opened at the lower end of the slider. The locking groove is located below the lower end of the locking oblique rod.
[0009] Preferably, the execution component further includes slots on both sides of the left end of the connecting rod, and insertion holes are provided at both the upper and lower ends of the inner core. A card head is inserted into the insertion hole, and a T-shaped groove is provided at the inner end of the card head to cooperate with the slot.
[0010] Preferably, the angle between the axis of the oblique hole and the horizontal direction is 15°-25°, and the axis of the locking oblique rod is parallel to the axis of the oblique hole.
[0011] Preferably, the mounting plate and the slider are positioned by locating pins and fixedly connected by double-ended bolts.
[0012] Preferably, the main component further includes balance bars fixed at both ends inside the mounting base, and the cylinder is slidably mounted inside the mounting base via the balance bars.
[0013] Preferably, the mounting plate has a guide hole that matches the inner core. The inner core slides through the corresponding guide hole, and the cross-sectional shape of the inner core matches the shape of the guide hole to restrict the inner core from rotating within the guide hole.
[0014] Beneficial effects
[0015] This invention provides a core-pulling mechanism for injection molds used in manufacturing narrow, inwardly curved folded parts. Compared with existing technologies, it offers the following advantages:
[0016] 1. When the cylinder pulls the slider to the right, the lower end of the locking angled rod fixed on the slider slides relative to the inclined surface of the guide block's inclined hole, forcing the locking angled rod to lift upward and disengage from the locking groove, thus achieving mechanical unlocking. Continued movement then allows the inner core to be pulled out of the inner arc structure of the injection molded part. Conversely, when the cylinder pushes the slider to the left to reset, the lower end of the locking angled rod slides along the inclined hole and finally engages in the locking groove, forming a self-locking mechanism. This ensures that the inner core will not retract when subjected to cavity pressure during injection. The clever cooperation between the inclined hole and the locking angled rod achieves unlocking before core pulling and self-locking after mold closing. The action sequence is reliable and does not rely on the mold opening and closing stroke. Independent cylinder drive provides flexible control over the core pulling timing and stroke.
[0017] 2. When assembling the inner core, first insert the clip into the insertion hole of the inner core, and then push the connecting rod to the left into the inner core. At this time, the wedge-shaped grooves on both sides of the left end of the connecting rod are inserted into the T-shaped groove at the inner end of the clip. This realizes the quick positioning and reliable connection between the connecting rod and the inner core, which simplifies the assembly process when the inner core needs to be replaced. Attached Figure Description
[0018] Figure 1 This is a three-dimensional structural diagram of the present invention;
[0019] Figure 2 This is a schematic diagram of the core-pulling mechanism in this utility model;
[0020] Figure 3 This is a schematic diagram of the internal structure of the core-pulling mechanism in this utility model;
[0021] Figure 4 This is a cross-sectional structural diagram of the core-pulling mechanism in this utility model;
[0022] Figure 5 This is a schematic diagram of the inner core structure in this utility model.
[0023] In the diagram: 1. Lower mold; 2. Upper mold; 3. Lower cavity; 4. Upper cavity; 5. Injection part; 6. Core pulling mechanism; 61. Main component; 611. Mounting base; 612. Cylinder; 613. Balance bar; 62. Actuating component; 621. Slider; 622. Inner core; 623. Mounting plate; 624. Guide block; 625. Angled hole; 626. Connecting rod; 627. Locking angled rod; 628. Locking groove; 629. Wedge-shaped slot; 6210. Insertion hole; 6211. Clip; 6212. T-slot. Detailed Implementation
[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0025] Please see Figure 1 - Figure 5 This utility model provides a technical solution: a core-pulling mechanism for an injection mold used to manufacture narrow, inwardly curved folded parts, comprising a lower mold 1 and an upper mold 2, wherein a lower cavity 3 and an upper cavity 4 are respectively provided inside the lower mold 1 and the upper mold 2, and an injection molded part 5 is formed between the lower cavity 3 and the upper cavity 4. A core-pulling mechanism 6 is provided on the lower mold 1 for core pulling and resetting locking, and the core-pulling mechanism 6 includes:
[0026] The main component 61 includes a mounting base 611 fixed to the right side of the lower mold 1, and a cylinder 612 is mounted on the right end of the mounting base 611.
[0027] The execution component 62 includes a slider 621 that is slidably installed inside the mounting base 611. Two inner cores 622 are provided at the left end of the slider 621. A mounting plate 623 is fixed at the left end of the slider 621 and used to position the inner cores 622. A guide block 624 is slidably installed inside the slider 621. An oblique hole 625 is opened inside the guide block 624. A connecting rod 626 is fixed at the left end of the guide block 624 and inserted into the inner core 622. Locking oblique rods 627 are provided on both sides of the upper end of the slider 621, and the lower end of the locking oblique rod 627 is located inside the oblique hole 625. A locking groove 628 is opened at the lower end of the slider 621, and the locking groove 628 is located below the lower end of the locking oblique rod 627.
[0028] In this embodiment, when the cylinder 612 pulls the slider 621 to the right, the lower end of the locking angle rod 627 fixed on the slider 621 slides relative to the inclined surface of the inclined hole 625 of the guide block 624, forcing the locking angle rod 627 to lift upward and disengage from the locking groove 628, thus achieving mechanical unlocking. Then, the continued movement can drive the inner core 622 to be pulled out from the inner arc structure of the injection molded part 5. Conversely, when the cylinder 612 pushes the slider 621 to the left to reset, the lower end of the locking angle rod 627 slides along the inclined hole 625 and finally locks into the locking groove 628, forming a self-locking mechanism to ensure that the inner core 622 will not move backward when subjected to cavity pressure during injection. The clever cooperation between the inclined hole 625 and the locking angle rod 627 achieves unlocking before core pulling and self-locking after mold closing. The action sequence is reliable and does not depend on the mold opening and closing stroke. The independent drive of the cylinder 612 provides flexible control of the core pulling timing and stroke.
[0029] Specifically, the execution component 62 also includes slots 629 on both sides of the left end of the connecting rod 626, and insertion holes 6210 are provided at both the upper and lower ends of the inner core 622. A card head 6211 is inserted into the insertion hole 6210, and a T-shaped groove 6212 is provided at the inner end of the card head 6211 to cooperate with the slot 629.
[0030] In this embodiment, when assembling the inner core 622, the clip 6211 is first inserted into the insertion hole 6210 of the inner core 622, and then the connecting rod 626 is pushed to the left into the inner core 622. At this time, the wedge-shaped slots 629 on both sides of the left end of the connecting rod 626 are inserted into the T-shaped slot 6212 at the inner end of the clip 6211. This achieves quick positioning and reliable connection between the connecting rod 626 and the inner core 622, which simplifies the assembly process when the inner core 622 needs to be replaced.
[0031] Specifically, the angle between the axis of the inclined hole 625 and the horizontal direction is 15°-25°, and the axis of the locking rod 627 is parallel to the axis of the inclined hole 625.
[0032] In this embodiment, the inclined angle design of the inclined hole 625 enables the locking rod 627 to generate a certain displacement ratio when it moves within the inclined hole 625. When the slider 621 moves laterally, the lower end of the locking rod 627 slides along the inclined surface of the inclined hole 625, converting the horizontal movement into the vertical movement of the locking rod 627, thereby realizing the functional conversion between mechanical locking and unlocking.
[0033] Specifically, the mounting plate 623 and the slider 621 are positioned by locating pins and fixedly connected by double-headed bolts.
[0034] In this embodiment, the positioning pin first ensures that the mounting plate 623 is in an accurate preset position relative to the slider 621, eliminating the cumulative error during the assembly process. Then, the double-ended bolts apply uniform preload from both sides simultaneously, firmly connecting the mounting plate 623 and the slider 621 into a whole.
[0035] Specifically, the main component 61 also includes balance bars 613 fixed at both ends inside the mounting base 611, and the cylinder 612 is slidably mounted inside the mounting base 611 via the balance bars 613.
[0036] In this embodiment, when the piston rod of cylinder 612 pushes or pulls slider 621, the cylinder body itself will be subjected to a reverse force. At this time, balance bar 613 provides precise axial guidance and radial support for cylinder body, ensuring that cylinder 612 always moves smoothly along a straight line and avoiding off-center load.
[0037] Specifically, the mounting plate 623 has a guide hole that matches the inner core 622. The inner core 622 slides through the corresponding guide hole, and the cross-sectional shape of the inner core 622 matches the shape of the guide hole to restrict the inner core 622 from rotating within the guide hole.
[0038] In this embodiment, the special cross-sectional shape of the inner core 622 forms a precise geometric fit with the non-circular hole of the guide hole of the mounting plate 623. During the core pulling and resetting movements, this fit effectively restricts the rotational freedom of the inner core 622 around its axis, allowing it to only move linearly along the axial direction.
[0039] The working principle and usage process of this utility model are as follows: First, when the cylinder 612 pulls the slider 621 to the right, the lower end of the locking angle rod 627 fixed on the slider 621 slides relative to the inclined surface of the inclined hole 625 of the guide block 624, forcing the locking angle rod 627 to lift up and disengage from the locking groove 628, thus achieving mechanical unlocking. Then, the continued movement can drive the inner core 622 to be pulled out from the inner arc structure of the injection molded part 5. Conversely, when the cylinder 612 pushes the slider 621 to the left to reset, the lower end of the locking angle rod 627 slides along the inclined hole 625 and finally locks into the locking groove 628, forming a self-locking mechanism to ensure that the inner core 622 will not move backward when subjected to cavity pressure during injection. The clever cooperation between the inclined hole 625 and the locking angle rod 627 achieves unlocking before core pulling and self-locking after mold closing. The action sequence is reliable and does not depend on the mold opening and closing stroke. The independent drive of the cylinder 612 provides flexible control of the core pulling timing and stroke.
[0040] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0041] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A core-pulling mechanism for an injection mold used to manufacture narrow, inwardly curved folded parts, comprising a lower mold (1) and an upper mold (2), wherein a lower cavity (3) and an upper cavity (4) are respectively provided inside the lower mold (1) and the upper mold (2), and an injection molded part (5) is formed between the lower cavity (3) and the upper cavity (4), characterized in that: The lower mold (1) is provided with a core-pulling mechanism (6) for core pulling and resetting locking. The core-pulling mechanism (6) includes: The main component (61) includes a mounting base (611) fixed on the right side of the lower mold (1), and a cylinder (612) is mounted on the right end of the mounting base (611); The execution component (62) includes a slider (621) that is slidably installed inside the mounting base (611). Two inner cores (622) are provided on the left end of the slider (621). A mounting plate (623) is fixed on the left end of the slider (621) and used to position the inner cores (622). A guide block (624) is slidably installed inside the slider (621). An oblique hole (625) is opened inside the guide block (624). A connecting rod (626) is fixed on the left end of the guide block (624) and inserted into the inner core (622). Locking oblique rods (627) are provided on both sides of the upper end of the slider (621), and the lower end of the locking oblique rod (627) is located inside the oblique hole (625). A locking groove (628) is opened at the lower end of the slider (621), and the locking groove (628) is located below the lower end of the locking oblique rod (627).
2. The injection mold core-pulling mechanism for manufacturing narrow, inwardly curved folded parts according to claim 1, characterized in that: The execution component (62) also includes slots (629) on both sides of the left end of the connecting rod (626). The inner core (622) has insertion holes (6210) at both the upper and lower ends. A card head (6211) is inserted into the insertion hole (6210). The inner end of the card head (6211) has a T-shaped groove (6212) that cooperates with the slot (629).
3. The injection mold core-pulling mechanism for manufacturing narrow, inwardly curved folded parts according to claim 1, characterized in that: The angle between the axis of the inclined hole (625) and the horizontal direction is 15°-25°, and the axis of the locking rod (627) is parallel to the axis of the inclined hole (625).
4. The injection mold core-pulling mechanism for manufacturing narrow, inwardly curved folded parts according to claim 1, characterized in that: The mounting plate (623) and the slider (621) are positioned by locating pins and fixedly connected by double-headed bolts.
5. The injection mold core-pulling mechanism for manufacturing narrow, inwardly curved folded parts according to claim 1, characterized in that: The main component (61) also includes a balance bar (613) fixed at both ends inside the mounting base (611), and the cylinder (612) is slidably mounted inside the mounting base (611) via the balance bar (613).
6. The injection mold core-pulling mechanism for manufacturing narrow, inwardly curved folded parts according to claim 1, characterized in that: The mounting plate (623) has a guide hole that matches the inner core (622). The inner core (622) slides through the corresponding guide hole, and the cross-sectional shape of the inner core (622) matches the hole shape of the guide hole to restrict the inner core (622) from rotating in the guide hole.