Injection mold for demolding inner circumferential ring inverted buckle
The internal shrinkage demolding mechanism solves the problem of stable demolding of products with inverted inner circumference, achieving efficient production. It is suitable for products with smaller volume and improves product yield and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUANGDONG XIQIN PRECISION MOULD CO LTD
- Filing Date
- 2025-03-31
- Publication Date
- 2026-04-21
AI Technical Summary
Existing injection molds have difficulty achieving stable demolding on products with undercut inner circumferences, especially smaller products. Furthermore, the inward-curving, angled ejector structure is prone to breakage, resulting in poor stability and failing to meet production requirements.
The internal retraction demolding mechanism, including a pull rod, an internal retraction slider, and an inclined ejector block, is used to achieve product molding and smooth demolding through the cooperation of the pull rod, internal retraction slider, and inclined ejector block. It has a simple structure and high strength, and is suitable for products with small volume.
It improves product yield and production efficiency, ensures the stability and reliability of demolding, is suitable for smaller products, and reduces the number of parts and maintenance costs.
Smart Images
Figure CN224145229U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of mold technology, and in particular to an injection mold with an inner circumference undercut for demolding. Background Technology
[0002] Currently, in plastic mold development, many products have their inner circumference pressed against the injection mold, and they generally cannot be demolded directly. It is necessary to set up an internal shrinkage structure to enable the product to be smoothly demolded by pressing it against the mold.
[0003] In existing technologies, undercut demolding is generally achieved by segmented inward retraction. The inward retraction structure usually consists of several inward retraction angled ejectors. During demolding, these angled ejectors retract inward to detach from the product, thus achieving demolding.
[0004] However, because several inward-sloping ejectors are used, these ejectors are often machined to be quite slender, resulting in weak strength and a tendency to break, leading to poor stability. Furthermore, when producing small products, the space inside the product's undercut is also limited, leaving insufficient room to accommodate multiple inward-sloping ejectors. This not only makes it impossible to mold the product using inward-sloping ejectors, but also makes it impossible to demold using multiple inward-sloping ejectors in a segmented inward-sloping manner. Utility Model Content
[0005] The purpose of this invention is to provide an injection mold for demolding with an inner circumference undercut, which aims to solve or at least partially solve the shortcomings of the above-mentioned background technology. It can not only realize the molding and smooth demolding of products with an inner circumference undercut, but also has good stability and high reliability, which can improve product yield and production efficiency. In addition, it can be applied to the production of products with smaller volume.
[0006] This utility model provides an injection mold for undercut demolding of the inner circumference, including an upper mold plate and a lower mold plate. A lower mold push plate is movably disposed above the lower mold plate. A cavity for molding the product is provided between the upper mold plate and the lower mold push plate. The injection mold for undercut demolding of the inner circumference also includes an internal retraction demolding mechanism, which includes a pull rod, two internal retraction sliders and two inclined ejector blocks. The pull rod is disposed on the lower mold plate and passes through the lower mold push plate along the Z direction. The internal retraction sliders are slidably disposed on the lower mold push plate. The two internal retraction sliders are symmetrically disposed on opposite sides of the pull rod along the X direction and can reciprocate towards each other along the X direction. The inclined ejector blocks are movably disposed on the lower mold push plate. The two inclined ejector blocks are symmetrically disposed on opposite sides of the pull rod along the Y direction and are used to eject the product. In the mold closed state, the pull rod, internal retraction sliders and inclined ejector blocks are in contact with each other, and the pull rod, internal retraction sliders, inclined ejector blocks and upper mold plate together form the cavity.
[0007] Furthermore, the internal retraction demolding mechanism also includes two levers. One end of the lever is set on the lower mold plate, and the lever passes through the lower mold push plate along the Z direction. The other end of the lever is provided with an inclined guide post, which is inclined inward along the X direction and is movably connected to the internal retraction slider.
[0008] Furthermore, the inwardly retractable slider has an oblique hole that matches the oblique guide post, allowing the oblique guide post to move along the oblique hole.
[0009] Furthermore, the cross-section of the inclined guide post is rectangular, and the cross-section of the inclined hole is rectangular.
[0010] Furthermore, the pull rod is provided with a first inclined surface on each of its opposite sides along the X direction. The first inclined surface is inclined inward and fits against the inward sliding block. The inclination of the first inclined surface is consistent with the inclination of the inclined guide post.
[0011] Furthermore, the pull rod is provided with a second inclined surface on each of its opposite sides along the Y direction. The second inclined surface is inclined inward and fits against the inclined top block.
[0012] Furthermore, the inward sliding block has a third inclined surface on each of its opposite sides along the Y direction. The third inclined surface is on the same plane as the second inclined surface and is in contact with the inclined top block.
[0013] Furthermore, it also includes an ejector mechanism, which includes an ejector plate movably disposed below the lower template, and an inclined ejector block connected to the ejector plate via a connecting rod.
[0014] Furthermore, the lower mold push plate is embedded with a lower mold core, and an inward sliding slider is slidably provided on the lower mold core.
[0015] Furthermore, the inward sliding block is connected to a driving device, which is located on opposite sides of the injection mold along the X direction for the inner circumference undercut demolding.
[0016] This utility model provides an injection mold for demolding with an inner circumference undercut. Through the cooperation of an internal retraction demolding mechanism and an upper mold plate, it achieves the molding of a product with an inner circumference undercut. During demolding, the lower mold push plate moves upward along the Z-axis, causing the retraction rod to move downward relative to the product along the Z-axis to detach from the product. The retraction rod retracts to separate from the product. The angled ejector block adheres to the product and pushes it upward and inward along the retraction rod, thus achieving smooth demolding of the product with an inner circumference undercut. Furthermore, compared to the existing internal retraction angled ejector, the internal retraction demolding mechanism has higher strength, better stability, and higher reliability, which can improve product yield and production efficiency. The internal retraction demolding mechanism has a simple structure and fewer parts, thus requiring less space for the undercut of the product with an inner circumference undercut, making it suitable for producing smaller products. Attached Figure Description
[0017] Figure 1This is a cross-sectional view of the molded state of an injection mold with an inner circumference undercut demolding according to Embodiment 1 of this utility model.
[0018] Figure 2 This is a cross-section of an injection mold with an undercut inner circumference during demolding, according to Embodiment 1 of this utility model. Figure 1 .
[0019] Figure 3 This is a cross-section of an injection mold with an undercut inner circumference during demolding, according to Embodiment 1 of this utility model. Figure 2 .
[0020] Figure 4 This is a cross-sectional view of an injection mold with an inverted inner circumference for demolding, according to Embodiment 1 of this utility model, after demolding.
[0021] Figure 5 for Figure 1 The diagram shows a three-dimensional view of the inward-shrinking demolding structure.
[0022] Figure 6 for Figure 5 An exploded perspective view of the inward-shrinking demolding structure shown.
[0023] Figure 7 This is a cross-sectional view of the molded state of an injection mold with an inner circumference undercut demolding according to Embodiment 2 of this utility model. Detailed Implementation
[0024] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.
[0025] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and claims of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.
[0026] The directional terms such as "up," "down," "left," "right," "front," "back," "top," and "bottom" (if present) used in the specification and claims of this utility model are defined according to the position of the structures in the drawings and the relative positions of the structures, and are only for the purpose of clarity and convenience in expressing the technical solution. It should be understood that the use of directional terms should not limit the scope of protection claimed in this application.
[0027] Example 1:
[0028] Please see Figures 1-5 An injection mold for demolding with an inverted inner circumference includes an upper mold plate 10 and a lower mold plate 20. A lower mold push plate 21 is movably disposed above the lower mold plate 20. A cavity 50 for molding a product 100 is provided between the upper mold plate 10 and the lower mold push plate 21.
[0029] The injection mold with undercut demolding of the inner circumference also includes an internal retraction demolding mechanism 30. The internal retraction demolding mechanism 30 includes a pull rod 31, two internal retraction sliders 32 and two inclined ejector blocks 33. The pull rod 31 is set on the lower mold plate 20 and passes through the lower mold push plate 21 along the Z direction. The internal retraction sliders 32 are slidably set on the lower mold push plate 21. The two internal retraction sliders 32 are symmetrically set on opposite sides of the pull rod 31 along the X direction and can move back and forth in opposite directions along the X direction. The inclined ejector blocks 33 are movably set on the lower mold push plate 21. The two inclined ejector blocks 33 are symmetrically set on opposite sides of the pull rod 31 along the Y direction and are used to eject the product 100.
[0030] In the mold-closed state, the pull rod 31, the inward sliding block 32, and the inclined ejector block 33 are in contact with each other, and the pull rod 31, the inward sliding block 32, the inclined ejector block 33, and the upper mold plate 10 together form the cavity 50.
[0031] As described above, the injection mold for inverted demolding of the inner circumference provided in this embodiment of the present invention achieves the forming of the product 100 with an inverted inner circumference through the cooperation of the inward demolding mechanism 30 and the upper template 10; through the cooperation of the pull rod 31, the inward sliding block 32, the lower mold push plate 21, and the inclined ejector block 33, during demolding, the lower mold push plate 21 moves upward along the Z direction, causing the pull rod 31 to move downward relative to the product 100 along the Z direction to detach from the product 100, the inward sliding block 32 retracts inward to detach from the product 100, and the inclined ejector block 33 adheres to and pushes the product 100 upward and inward along the pull rod 31, thus achieving smooth demolding of the product 100 with an inverted inner circumference. In addition, compared with the internal retraction inclined ejector in the prior art, the internal retraction demolding mechanism 30 has higher strength, better stability and higher reliability, which can improve product yield and production efficiency. The internal retraction demolding mechanism 30 has a simple structure and fewer parts, so it has a smaller requirement for the size of the undercut space of the product with the inner circumference undercut, and can be applied to the production of smaller products.
[0032] Please see Figures 1-3 , Figure 5 and Figure 6 In this embodiment, the inward retraction demolding mechanism 30 further includes two levers 34. One end of each lever 34 is mounted on the lower mold plate 20 and extends into the lower mold push plate 21 along the Z-direction. The other end of each lever 34 is provided with an inclined guide post 341, which is inclined inward along the X-direction and movably connected to the inward retraction slider 32. The two levers 34 are used to drive the two inward retraction sliders 32 to reciprocate in opposite directions along the X-direction, so that the two inward retraction sliders 32 retract and separate from the product 100 during demolding.
[0033] Furthermore, the inward-shrinking slider 32 has an oblique hole 321 that mates with the oblique guide post 341, and the oblique guide post 341 can move along the oblique hole 321. During demolding, the lower mold push plate 21 moves upward along the Z direction, the lever 34 moves downward relative to the inward-shrinking slider 32 along the Z direction, and the oblique guide post 341 pushes the inward-shrinking slider 32 to slide inward along the X direction through the oblique hole 321, thereby achieving inward shrinkage and separation from the product 100.
[0034] More specifically, the cross-section of the inclined guide post 341 is rectangular, and the cross-section of the inclined hole 321 is rectangular. This arrangement can prevent the movement trajectory of the inward sliding block 32 from deviating when the inclined guide post 341 moves along the inclined hole 321, so that it always slides back and forth in the X direction.
[0035] Please see Figure 2 , Figure 3 and Figure 6 The pull rod 31 has a first inclined surface 311 on each of its opposite sides along the X direction. The first inclined surface 311 is inclined inward and fits against the inward sliding block 32. The inclination of the first inclined surface 311 is consistent with the inclination of the inclined guide post 341.
[0036] Furthermore, the inwardly retractable slider 32 is provided with a fitting inclined surface 322 that fits against the first inclined surface 311, and the fitting inclined surface 322 fits against the first inclined surface 311.
[0037] During demolding, the lower mold push plate 21 moves upward along the Z direction, causing the pull rod 31 to move downward relative to the product 100 along the Z direction to detach from the product 100. Since the pull rod 31 is provided with a first inclined surface 311, during the process of the pull rod 31 moving downward, it gradually makes room in the X direction. Simultaneously, the lever 34 drives the inward sliding block 32 to move inward along the X direction, and the first inclined surface 311 and the fitting inclined surface 322 are always in contact.
[0038] Please see Figures 4-6 The pull rod 31 has a second inclined surface 312 on each of its opposite sides along the Y direction. The second inclined surface 312 is inclined inward and fits against the inclined ejector block 33. During demolding, the inclined ejector block 33 moves upward and inward along the second inclined surface 312, so that the two inclined ejector blocks 33 retract inward while ejecting the product 100.
[0039] Furthermore, the inward sliding block 32 is provided with a third inclined surface 323 on each of its opposite sides along the Y direction. The third inclined surface 323 is on the same plane as the second inclined surface 312. The third inclined surface 323 fits into the inclined ejector block 33, which not only achieves a tight fit between the inclined ejector block 33, the pull rod 31, and the inward sliding block 32 to ensure the molding quality of the product 100, but also makes the movement of the inclined ejector block 33 more stable during demolding.
[0040] Please see Figure 4The injection mold with an undercut inner circumference also includes an ejector mechanism. The ejector mechanism includes an ejector plate 40 movably disposed below the lower mold plate 20, and an inclined ejector block 33 connected to the ejector plate 40 via a connecting rod 331. The ejector plate 40 is used to drive the inclined ejector block 33 to rise or fall.
[0041] Please see Figures 4-7 The lower mold ejector plate 21 is fitted with a lower mold core 211, and an inwardly retractable slider 32 is slidably mounted on the lower mold core 211. A lever 34 passes through the lower mold core 211, and the inclined ejector pin 341 is movably connected to the inwardly retractable slider 32. The lower mold core 211 can reduce the wear of the lower mold ejector plate 21. When the lower mold core 211 is excessively worn, its disassembly and assembly are relatively simple, and the replacement cost is also low. The lower mold core 211 plays a role in reducing the wear of the lower mold ejector plate 21 and lowering maintenance costs.
[0042] The demolding process of the injection mold with inner circumference undercut demolding provided by this utility model is as follows:
[0043] (1) Please refer to Figure 2 The upper template 10 moves upward along the Z direction, and the upper template 10 separates from the product 100. At this time, the product 100 is inverted and placed on the inner shrinkage demolding mechanism 30.
[0044] (2) Please refer to Figure 3 As the lower mold push plate 21 moves upward along the Z-axis, the pull rod 31 moves downward relative to the product 100 along the Z-axis to disengage from the product 100. Simultaneously, the lever 34 drives the inward sliding block 32 to move inward along the X-axis, disengaging the inward sliding block 32 from the product 100. In addition, the ejector plate 40 moves upward along the Z-axis the same distance in sync with the lower mold push plate 21.
[0045] (3) Please refer to Figure 4 The lower mold push plate 21 stops moving, and the ejector plate 40 moves upward along the Z direction to drive the inclined ejector block 33 to move upward and inward along the second inclined surface 312, so that the two inclined ejector blocks 33 retract inward while ejecting the product 100, thus achieving smooth ejection of the product 100.
[0046] Example 2:
[0047] An injection mold for undercut demolding of the inner circumference is similar in structure to the injection mold for undercut demolding of the inner circumference in Example 1, except that:
[0048] Please see Figure 7The retractable slider 32 is connected to a driving device 60, which is located on opposite sides of the injection mold along the X-direction for undercut demolding. The driving device 60 drives the retractable slider 32 to slide back and forth along the X-direction on the lower mold push plate 21. During demolding, the lower mold push plate 21 moves upward along the Z-direction, and the pull rod 31 moves downward relative to the product 100 along the Z-direction to detach from the product 100. Simultaneously, the driving device 60 drives the retractable slider 32 to move inward along the X-direction, and the retractable slider 32 detaches from the product 100.
[0049] The advantages of the injection mold with undercut inner circumference demolding provided by this utility model include:
[0050] (1) It can achieve the molding of products with inverted inner circumference and smooth demolding.
[0051] (2) It has good stability and high reliability, which can improve product yield and production efficiency.
[0052] (3) The internal shrinkage demolding mechanism has a simple structure and fewer parts, making it suitable for producing products with smaller volume.
[0053] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.
Claims
1. An injection mold for inner circumferential undercut demolding, comprising an upper mold plate (10) and a lower mold plate (20), wherein a lower mold push plate (21) is movably disposed above the lower mold plate (20), and a cavity (50) for molding a product (100) is provided between the upper mold plate (10) and the lower mold push plate (21), characterized in that, The injection mold for the inner circumference undercut demolding also includes an internal shrinkage demolding mechanism (30). The internal shrinkage demolding mechanism (30) includes a pull rod (31), two internal shrinkage sliders (32) and two inclined ejector blocks (33). The pull rod (31) is disposed on the lower mold plate (20) and passes through the lower mold push plate (21) along the Z direction. The internal shrinkage sliders (32) are slidably disposed on the lower mold push plate (21). The two internal shrinkage sliders (32) are symmetrically disposed on opposite sides of the pull rod (31) along the X direction and can reciprocate in opposite directions along the X direction. The inclined ejector blocks (33) are movably disposed on the lower mold push plate (21). The two inclined ejector blocks (33) are symmetrically disposed on opposite sides of the pull rod (31) along the Y direction and the inclined ejector blocks (33) are used to eject the product (100). In the mold-closed state, the pull rod (31), the inward sliding block (32), and the inclined ejector block (33) are in contact with each other, and the pull rod (31), the inward sliding block (32), the inclined ejector block (33), and the upper mold plate (10) together form the cavity (50).
2. The inner peripheral band undercut demolding injection mold according to claim 1, wherein The internal shrinkage demolding mechanism (30) also includes two levers (34). One end of the lever (34) is set on the lower template (20). The lever (34) passes through the lower mold push plate (21) along the Z direction. The other end of the lever (34) is provided with an inclined guide post (341). The inclined guide post (341) is inclined inward along the X direction and is movably connected to the internal shrinkage slider (32).
3. An inner peripheral band undercut demolding injection mold according to claim 2, characterized in that, The inward sliding block (32) has an oblique hole (321) that cooperates with the oblique guide post (341), and the oblique guide post (341) can move along the oblique hole (321).
4. An inner peripheral band undercut demolding injection mold according to claim 3, characterized in that, The oblique guide post (341) has a rectangular cross-section, and the oblique hole (321) has a rectangular cross-section.
5. An inner peripheral band undercut demolding injection mold according to claim 3, wherein The pull rod (31) has a first inclined surface (311) on each of its opposite sides along the X direction. The first inclined surface (311) is inclined inward and fits against the inward sliding block (32). The inclination of the first inclined surface (311) is consistent with the inclination of the inclined guide post (341).
6. The injection mold for undercut demolding of the inner circumference as described in claim 1, characterized in that, The pull rod (31) has a second inclined surface (312) on each of its opposite sides along the Y direction. The second inclined surface (312) is inclined inward and fits against the inclined top block (33).
7. An inner peripheral band undercut demolding injection mold according to claim 6, characterized in that, The inward sliding block (32) has a third inclined surface (323) on each of its opposite sides along the Y direction. The third inclined surface (323) and the second inclined surface (312) are on the same plane. The third inclined surface (323) is in contact with the inclined top block (33).
8. The inner peripheral band undercut demolding injection mold according to claim 1, wherein It also includes a ejector mechanism, which includes an ejector plate (40) movably disposed below the lower template (20), and the inclined ejector block (33) is connected to the ejector plate (40) via a connecting rod (331).
9. The inner peripheral band undercut demolding injection mold according to claim 1, wherein The lower mold push plate (21) is embedded with a lower mold core (211), and the inner sliding block (32) is slidably disposed on the lower mold core (211).
10. The inner peripheral band undercut demolding injection mold according to claim 1, wherein The inner shrinkage slider (32) is connected with a driving device (60), and the driving device (60) is arranged on the opposite sides of the injection mold along the X direction of the inner periphery circle reverse draw demolding.