Mold structure

Abstract

The application discloses a mold structure and relates to the technical field of molds. The mold structure comprises a movable mold assembly and a fixed mold assembly which are oppositely arranged in a first direction, and the movable mold assembly is provided with a containing cavity. The movable mold assembly further comprises a plurality of sliding parts which are arranged in the containing cavity and are movable in the direction close to or away from the center of the containing cavity so as to have a matching position and a separation position. In the matching position, at least part of the plurality of sliding parts is attached to the inner side wall of the containing cavity, and in the separation position, the plurality of sliding parts are all away from the inner wall of the containing cavity. When the movable mold assembly and the fixed mold assembly are combined, the plurality of sliding parts are in the matching position. When the movable mold assembly and the fixed mold assembly are separated, the sliding parts are converted from the matching position to the separation position, so that the separation and avoidance of the product reverse buckling are realized, and the product reverse buckling and the cavity of the movable mold assembly are prevented from interfering when the movable mold assembly continues to move. The mold structure is suitable for narrow spaces and has good stability.

Description

Technical Field

[0001] This invention relates to the field of mold technology, and in particular to mold structure. Background Technology

[0002] Some plastic products are designed with undercut structures for assembly with other components. When demolding these undercut structures, it's necessary to consider avoidance issues to prevent damage. Currently, a slanted ejector mechanism is commonly used to facilitate demolding of undercut structures. However, this slanted ejector mechanism, because it penetrates the slanted surface of the mold core, is prone to generating flash during production. Furthermore, for some products with undercut structures on all four sides in confined spaces, the slanted ejector mechanism is limited by space constraints, resulting in smaller dimensions, insufficient strength, and susceptibility to damage. Summary of the Invention

[0003] The main objective of this invention is to propose a mold structure that enables smooth demolding in confined spaces.

[0004] To achieve the above objectives, the present invention proposes a mold structure for processing products with multiple undercuts, characterized in that the mold structure includes a moving mold assembly and a fixed mold assembly disposed opposite to each other in a first direction, and the moving mold assembly has a receiving cavity formed thereon;

[0005] The moving mold assembly further includes multiple sliding parts disposed within the receiving cavity. These sliding parts correspond to multiple undercuts on the product. The sliding parts move towards or away from the center of the receiving cavity, having a mating position and a withdrawn position. When the moving mold assembly and the fixed mold assembly are closed, the sliding parts are in the mating position, with at least a portion of each sliding part abutting against the inner wall of the receiving cavity to jointly define the undercut forming area of ​​the product. When the moving mold assembly and the fixed mold assembly are separated, the sliding parts are in the withdrawn position, with each sliding part moving away from the inner wall of the receiving cavity.

[0006] In one embodiment, the moving model assembly further includes:

[0007] A moving mold core, wherein the end face of the moving mold core facing the fixed mold assembly has a groove to form the receiving cavity; and,

[0008] The insert is fixed into the groove.

[0009] The plurality of sliding portions are arranged at circumferential intervals along the insert, and the plurality of sliding portions have a travel distance that moves closer to or further away from the insert so as to be able to switch between the withdrawn position and the engaged position.

[0010] In one embodiment, the inner sidewall of the groove is provided with a plurality of first mounting slots arranged at intervals along the circumference of the groove;

[0011] The plurality of sliding portions are provided with second mounting slots corresponding to the plurality of first mounting slots;

[0012] The moving mold assembly also includes multiple elastic elements, with the two ends of each elastic element located in a first mounting groove and a second mounting groove respectively, which are arranged opposite to each other.

[0013] In one embodiment, the mold structure further includes a locking block, one end of which is fixed to the fixed mold assembly in a first direction, and the other end of which tapers toward the moving mold assembly to form an annular guide surface;

[0014] Each of the sliding parts has a mating inclined surface formed on the sidewall facing the center of the receiving cavity;

[0015] The other end of the locking block can extend into the space between the plurality of sliding parts, and the annular guide surface is in contact with the plurality of mating inclined surfaces, so that the plurality of sliding parts are constrained at the mating position.

[0016] In one embodiment, the inner sidewall of the groove is provided with a plurality of first mounting grooves; the plurality of sliding parts are respectively provided with second mounting grooves; the first mounting grooves and the second mounting grooves arranged opposite to each other are provided for the two ends of the elastic member to accommodate;

[0017] The distance between the end face of the locking block facing away from the fixed mold assembly and the first mounting groove is h, where h ≥ 0.

[0018] In one embodiment, the dimension of the mating inclined surface in the first direction is H1, and the dimension of the sliding part in the first direction is H, wherein H1 / H ≥ 2 / 3.

[0019] In one embodiment, the insert has a relief groove in the middle and a plurality of guide holes communicating with the relief groove on its peripheral side.

[0020] The sliding parts are correspondingly and movably installed in the guide holes.

[0021] In one embodiment, the insert is fixed to the moving mold core by a locking member, a portion of which is located between the plurality of sliding portions to form a limiting portion;

[0022] At the withdrawn position, all of the sliding portions abut against the peripheral side surface of the limiting portion.

[0023] In one embodiment, at the mating position, the distance between each sliding part and the limiting part is S, wherein:

[0024] S-S1≥1mm, where S1 is the undercut dimension of the product; and / or,

[0025] The inner wall of the groove is provided with a plurality of first mounting grooves; the plurality of sliding parts are respectively provided with second mounting grooves; the first mounting grooves and the second mounting grooves arranged opposite to each other are provided for the two ends of the elastic element; the distance between the inner wall of the groove and the bottom wall of the second mounting groove is L, where L > S + 3mm.

[0026] In one embodiment, the distance between the inner sidewall of the groove and the bottom wall of the second mounting groove is L, and the distance between each sliding part and the limiting part is S, wherein 1 / 3L≤LS≤2 / 3L.

[0027] In the technical solution of this invention, the number of sliding parts matches the number of undercuts. When the mold structure is closed, the sliding parts are in the mating position, jointly defining the undercut forming area of ​​the product with the inner wall of the receiving cavity. This area corresponds to a part of the mold cavity. After the product is formed, the moving mold assembly moves away from the fixed mold assembly, and at the same time, the sliding parts change from the mating position to the withdrawing position, thereby achieving separation and avoidance from the undercuts of the product. This ensures that the undercuts of the product do not interfere with the core of the moving mold assembly while the moving mold assembly continues to move. The multiple sliding parts correspond to the inner side of the multiple undercuts, and the structural form of the multiple sliding parts can adapt to narrow spaces and has good stability. Attached Figure Description

[0028] 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 the structures shown in these drawings without creative effort.

[0029] Figure 1 A schematic diagram of the first embodiment of the mold structure provided by the present invention;

[0030] Figure 2 for Figure 1 Cross-sectional schematic diagram of the moving part assembly;

[0031] Figure 3 for Figure 1 A schematic diagram of the structure in which the sliding part mates with the product.

[0032] Figure 4 for Figure 3 A top view of the inlay.

[0033] Explanation of icon numbers:

[0034] 100. Mold structure; 1. Moving mold assembly; 10. Receiving cavity; 11. Sliding part; 111. Second mounting groove; 112. Mating inclined surface; 12. Moving mold core; 13. Insert; 131. Guide hole; 132. Clearance groove; 14. First mounting groove; 15. Elastic element; 16. Locking element; 2. Fixed mold assembly; 21. Locking block; 210. Annular guide surface.

[0035] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] It should be noted that if the embodiments of the present invention involve directional indication, the directional indication is only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0038] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0039] In the structural design of some plastic products, undercut structures are often introduced to facilitate assembly and connection with other components. However, special care must be taken to avoid deformation or damage to the undercut parts during the demolding process. For some products, undercut structures exist on all four sides in a confined space. These undercuts have the following structural characteristics: a small undercut amount; multiple undercuts arranged in a ring, resulting in a narrow space between them; and a through-hole between the multiple undercuts.

[0040] Currently, the industry commonly uses angled ejector structures to address the demolding requirements of undercut products. However, angled ejector structures often have the following drawbacks:

[0041] Because the angled ejector punches through the front mold, such punching can easily produce burrs during production.

[0042] Due to the limited installation space, the size of the inclined ejector structure is strictly limited and is often designed to be small, with some examples being only 8×8mm. When the mold is an inverted mold, the height of the inclined ejector structure will be relatively large, resulting in insufficient strength of the inclined ejector and easy wear or breakage during use.

[0043] If the angled ejector is damaged, the entire rear mold must be removed before it can be disassembled or reassembled, which is inconvenient and time-consuming.

[0044] Because of their small size, the inclined top structure makes it difficult to machine the inclined surfaces and grooves on the inclined top structure, resulting in higher mold costs.

[0045] To address the numerous problems associated with the aforementioned angled ejector structure, this invention proposes a mold structure that designs an undercut ejector structure to replace the angled ejector structure. This eliminates concerns about flash or burrs caused by the angled ejector structure colliding with the front mold, effectively improving product quality. Furthermore, for products with limited space and undercut structures on all four sides, this design is not limited by the confined installation space, optimizing the ejection solution for the undercut structure.

[0046] In this invention, the first direction is a relative direction. Depending on the different placement methods when the mold structure is used, the first direction can be up and down, left and right, or front and back.

[0047] Please refer to Figures 1 to 3 The mold structure 100 includes a moving mold assembly 1 and a fixed mold assembly 2 disposed opposite to each other in a first direction. A receiving cavity 10 is formed on the moving mold assembly 1. The moving mold assembly 1 also includes a plurality of sliding parts 11 disposed in the receiving cavity 10. The plurality of sliding parts 11 are used to correspond to a plurality of undercuts of the product. The plurality of sliding parts 11 move in a direction close to or away from the center of the receiving cavity 10 so as to have a mating position and a withdrawing position. When the moving mold assembly 1 and the fixed mold assembly 2 are closed, the plurality of sliding parts 11 are in the mating position, and at least a portion of the plurality of sliding parts 11 are in contact with the inner sidewall of the receiving cavity 10 so as to define the undercut forming area of ​​the product together with the receiving cavity 10. When the moving mold assembly 1 and the fixed mold assembly 2 are separated, the plurality of sliding parts 11 are in the withdrawing position, and the plurality of sliding parts 11 are all away from the inner wall of the receiving cavity 10.

[0048] It should be understood that the end face of the sliding part 11 facing the outside of the receiving cavity 10 should be provided with a recess and / or a protrusion that conforms to the shape of the product's undercut.

[0049] In the technical solution of this invention, multiple sliding parts 11 match the number of multiple undercuts on the product. When the mold structure 100 is closed, the multiple sliding parts 11 are in a mating position, jointly defining the undercut forming area of ​​the product with the inner wall of the receiving cavity 10. This area corresponds to a part of the mold cavity. After the product is formed, the moving mold assembly 1 moves away from the fixed mold assembly 2, and at the same time, the sliding parts 11 change from the mating position to the withdrawing position, thereby realizing the separation and avoidance of the undercuts of the product. This ensures that the undercuts of the product do not interfere with the core of the moving mold assembly 1 during the continued movement of the moving mold assembly 1. The multiple sliding parts 11 correspond to the inner side of the multiple undercuts, and the structural form of the multiple sliding parts 11 can adapt to narrow spaces and has good stability.

[0050] Multiple sliding portions 11 are arranged in a ring. To match the product's snap fasteners, in some embodiments, the multiple sliding portions 11 have the same circumferential size along the receiving cavity 10, and the spacing between each pair of adjacent sliding portions 11 is the same. In some embodiments, the multiple sliding portions 11 include multiple first sliding portions and multiple second sliding portions, the first sliding portions and the second sliding portions having different circumferential sizes along the receiving cavity 10, and the multiple first sliding portions and the multiple second sliding portions are alternately arranged. In some embodiments, each pair of adjacent sliding portions 11 forms a mating group, and the spacing between the two sliding portions 11 in at least some mating groups is different from that in other mating groups.

[0051] Furthermore, the moving mold assembly 1 also includes a moving mold core 12 and an insert 13. The moving mold core 12 has a groove on its end face facing the fixed mold assembly 2 to form a receiving cavity 10. The insert 13 is fixed to the groove. A plurality of sliding parts 11 are arranged at intervals along the circumference of the insert 13. The plurality of sliding parts 11 have a travel distance that moves closer to or further away from the insert 13, so that they can switch between a withdrawn position and a mating position. The insert 13 serves to support and position the mold, and is located in the middle area of ​​the groove.

[0052] Precise positioning of the sliding part 11 during movement can be achieved through the structural design of the insert 13. In some embodiments, one end face of the insert 13 in the first direction is fitted with the bottom wall of the groove, and multiple grooves are provided on the other end face, in which multiple sliding parts 11 are slidably installed. The extending direction of the groove is consistent with the moving direction of the sliding part 11. This design allows the sliding part 11 to move stably along a predetermined trajectory during movement, effectively preventing the sliding part 11 from deviating or getting stuck during movement. The groove can be set as a T-groove or a dovetail groove to define the orientation of the sliding part 11 in the first direction.

[0053] In some embodiments, please refer to Figure 4The insert 13 has a relief groove 132 in its center, and multiple guide holes 131 communicating with the relief groove 132 are provided on its peripheral side surface. Multiple sliding parts 11 are correspondingly and movably installed in the multiple guide holes 131. When the sliding part 11 is in the mating position, the end of the corresponding side wall of the receiving cavity 10 should be exposed outside the guide hole 131, thereby ensuring the fit between the sliding part 11 and the receiving cavity 10 and effectively reducing the flash generated in the inclined mating structure. When the sliding part 11 is in the withdrawn position, the sliding part 11 can be hidden in the guide hole 131, or the sliding part 11 can be partially located in the relief groove 132. The relief groove 132 is designed to facilitate the locking of the insert 13. Through holes or threaded holes can be opened in the bottom wall of the relief groove 132 for screws to pass through.

[0054] Furthermore, the clearance between the sliding part 11 and the guide hole 131 is controlled at 0.01 to 0.02 mm on one side. This ensures that the sliding part 11 moves smoothly within the guide hole 131, and effectively prevents the sliding part 11 from shaking or shifting during movement due to excessive clearance, thereby ensuring the stability of the product's undercut demolding.

[0055] The driving structure of the multiple sliding parts 11 is not limited. In some embodiments, a slanted rod matching the multiple sliding parts 11 is provided on the fixed mold assembly 2. The slanted rod and the sliding part 11 are engaged through a slanted groove. When the moving mold assembly 1 and the fixed mold assembly 2 separate, the slanted rod drives the sliding part 11 to the withdrawn position. During the mold closing process of the moving mold assembly 1 and the fixed mold assembly 2, the slanted rod can be reinserted into the slanted groove, thereby driving the sliding part 11 back to the engaged position. Because the size of the undercut of the product is small and the length of the slanted rod is small, even a narrow space can meet the design requirements.

[0056] In some embodiments, the inner wall of the groove is provided with a plurality of first mounting grooves 14 arranged at intervals along the circumference of the groove; a plurality of sliding parts 11 are respectively provided with second mounting grooves 111 corresponding to the wall surfaces of the plurality of first mounting grooves 14; the moving mold assembly 1 also includes a plurality of elastic members 15, the two ends of each elastic member 15 being located in the opposite first mounting grooves 14 and second mounting grooves 111 respectively. On the one hand, it can prevent the elastic members 15 from detaching, and on the other hand, it can accommodate the length requirements of the elastic members 15. When the fixed mold assembly 2 and the moving mold assembly 1 are separated, the plurality of sliding parts 11 can move towards the withdrawal position under the pushing force of the elastic members 15.

[0057] It should be understood that the primary function of the first mounting groove 14 is to position the elastic element 15. Therefore, the width of the first mounting groove 14 should match the outer diameter of the elastic element 15. The machining requirements for the second mounting groove 111 are lower, so the width of the second mounting groove 111 can be set to be greater than the width of the first mounting groove 14. It should be understood that during mold closing or opening, the elastic element 15 is always limited by the first mounting groove 14 and the second mounting groove 111.

[0058] Based on the above embodiments, the elastic element 15 can be combined with the inclined rod and the sliding part 11.

[0059] The elastic element 15 should correspond to the middle region of the sliding part 11 so that the sliding part 11 is subjected to balanced force.

[0060] Considering that the main function of the elastic element 15 is to drive the sliding part 11 to move automatically when the mold is opened, in order to ensure the smooth reset of the sliding part 11 during the mold closing process, the mold structure 100 also includes a locking block 21. One end of the locking block 21 is fixed to the fixed mold assembly 2 in the first direction, and the other end gradually tapers towards the moving mold assembly 1 to form an annular guide surface 210. Each sliding part 11 has a mating inclined surface 112 formed on the side wall facing the center of the receiving cavity 10. The corresponding end of the locking block 21 can extend into the gap between multiple sliding parts 11, and the annular guide surface 210 fits against multiple mating inclined surfaces 112 so that multiple sliding parts 11 are limited to the mating position. When the mold structure 100 is closed, the annular guide surface 210 is in contact with the mating inclined surfaces 112 on the multiple sliding parts 11. At this time, the elastic element 15 is compressed, and the sliding parts 11 are in contact with the inner wall of the receiving cavity 10. During the mold opening process, the locking block 21 separates from the sliding parts 11. At this time, the sliding parts 11 can move towards the center of the receiving cavity 10 under the action of the elastic element 15. After the mold is fully opened, even if the multiple sliding parts 11 come close to each other, the space formed by the mating inclined surfaces 112 of the multiple sliding parts 11 can allow the end of the locking block 21 to extend into it, ensuring that the locking block 21 and the sliding parts 11 are in contact again when the mold is closed.

[0061] It should be understood that the locking block 21 mainly serves to limit the multiple sliding parts 11 to the mating position. In this embodiment, by combining the locking block 21 with multiple elastic elements 15, the undercut demolding process can be automatically completed during the mold opening process without the need to add a separate pause cycle and waiting time.

[0062] In other embodiments, the locking block 21 can also cooperate with other structures to realize the active driving and position locking of the sliding part 11, and the present invention does not limit this.

[0063] Since the mold closing height is fixed, the length of the portion of the locking block 21 that mates with the sliding part 11 in the first direction is limited. To ensure stable mating, the length of the annular guide surface 210 in the first direction is the same as the length of the mating inclined surface 112 in the first direction. In other embodiments, the length of the mating inclined surface 112 in the first direction may also be greater than the length of the annular guide surface 210 in the first direction.

[0064] Please refer to Figure 1 When locking block 21 and multiple elastic elements 15 are simultaneously provided, during mold closing, the distance between the end face of locking block 21 facing away from fixed mold assembly 2 and the first mounting groove 14 is h, where h ≥ 0. Taking the first direction as the up-down direction as an example, the distance between the lower end face of locking block 21 and the lower wall of the first mounting groove 14 is h. When h = 0, the lower end face of locking block 21 is flush with the lower wall of the first mounting groove 14; when h > 0, locking block 21 protrudes downward from the first mounting groove 14. This arrangement ensures that the lower end face of locking block 21 is located below the elastic element 15, ensuring that the force direction of locking block 21 during mold closing and reset is parallel to the extension direction of elastic element 15, making the transition process of sliding part 11 from the withdrawn position to the mating position smoother.

[0065] Please refer to Figure 2 The dimension of the mating inclined surface 112 in the first direction is H1, and the dimension of the sliding part 11 in the first direction is H, where H1 / H ≥ 2 / 3. By reasonably setting the length of the mating inclined surface 112 in the first direction, its effective contact length with the locking block 21 is ensured. Furthermore, when the value of H1 / H meets the above conditions, the interaction force between the locking block 21 and the sliding part 11 is more evenly distributed during the mold closing and opening process. This not only effectively reduces wear caused by local stress concentration but also improves the overall service life of the mold. Moreover, this dimensional ratio design also ensures that the mold maintains relatively stable fitting accuracy after repeated use, ensuring the molding quality of the product.

[0066] The withdrawal position of the sliding part 11 can be limited by the support of the elastic member 15. In some embodiments, multiple elastic members 15 support multiple sliding parts 11. When the multiple sliding parts 11 are in contact with each other on the side facing the center of the receiving cavity 10, the multiple sliding parts 11 cannot continue to move, thereby reaching the withdrawal position. In this embodiment, the insert 13 is fixed to the moving mold core 12 by the locking member 16. A portion of the locking member 16 is located between the multiple sliding parts 11 to form a limiting part. In the withdrawal position, the multiple sliding parts 11 all abut against the peripheral side surface of the limiting part. The locking member 16 has two functions: on the one hand, it can lock the insert 13 and the moving mold core 12; on the other hand, it can limit the movement stroke of the sliding parts 11.

[0067] In this embodiment, the locking element 16 is a bolt. After the locking element 16 is assembled, the nut of the locking element 16 is exposed to the outside, thus forming a limiting part. Since the nut abuts against the inner surfaces of the multiple sliding parts 11, the sliding parts 11 can be accurately positioned when they are held by the elastic element 15 and cannot continue to move outward. This limits the travel of the sliding parts 11 and ensures the positional stability of the multiple sliding parts 11 in the withdrawn state. Moreover, this design, which uses a bolt as the locking element 16 and its nut to form a limiting part, is simple in structure and easy to implement. During the assembly and maintenance of the mold, operators can easily install and disassemble the locking element 16, greatly improving the assembly efficiency and maintenance convenience of the mold. At the same time, bolts, as common standard parts, have various specifications and low cost, which can effectively reduce the manufacturing cost of the mold.

[0068] In other embodiments, an annular protrusion may be provided at the end of the locking member 16, the annular protrusion being exposed to the outside to form a limiting portion.

[0069] Due to the limited space design, the dimensional constraints during component assembly can affect the overall stability of the module. In this embodiment, the distance between each sliding part 11 and the limiting part at the mating position is S. S is the travel distance of the sliding part 11.

[0070] The travel distance of the sliding part 11 should be greater than the undercut dimension S1 of the product to avoid mold opening interference. However, how to set the dimensional allowance in a confined space is a key consideration for designers. Specifically, S-S1≥1mm, where S1 is the undercut dimension of the product; in this embodiment, 1mm≤S-S1≤2mm. This dimensional range setting ensures that the sliding part 11 has sufficient travel space to avoid mold opening interference, while also making reasonable use of the dimensional allowance in a confined space, preventing the layout of other mold components and the overall structural compactness from being affected by excessive size.

[0071] In some embodiments, the distance between the inner wall of the groove and the bottom wall of the second mounting groove 111 is L, where L > S + 3mm. L is the guide distance of the sliding part 11. By limiting the guide distance to be at least 3mm larger than the active stroke of the sliding part 11, it is ensured that the sliding part 11 has sufficient guiding length during the guiding process, which can effectively avoid the sliding part 11 from deviating or jamming during the movement, and ensure the smoothness and accuracy of the movement of the sliding part 11. Moreover, this reasonable limitation of the guide distance can also reduce the noise caused by the unstable movement of the sliding part 11 during the mold opening and closing process to a certain extent, and improve the overall operation quality of the mold.

[0072] Furthermore, the distance between the inner wall of the groove and the bottom wall of the second mounting groove 111 is L, and the distance between each sliding part 11 and the limiting part is S, wherein 1 / 3L≤LS≤2 / 3L. This ensures smooth return of the sliding part 11, avoids shaking of the sliding part 11 due to excessive spacing or jamming due to insufficient spacing, and effectively improves the stability and accuracy of the mold opening and closing process.

[0073] In addition, considering the installation and fit between the insert 13 and the sliding part 11, multiple process holes are provided on the end face of the insert 13 facing the fixed mold assembly 2, based on Figure 1 In this embodiment, the installation sequence of the relevant components is as follows: Insert 13 into the moving mold core 12. Elastic member 15 and sliding block are installed respectively. After installing one sliding part 11, a pin needs to be installed through the process hole to limit the sliding part 11, so that the next sliding part 11 can be installed. This is because after the elastic member 15 is installed, the elastic force will cause the sliding part 11 to pop out, affecting the installation of the next sliding part 11. Therefore, the pin is inserted through the process hole to pre-limit the position of the sliding part 11. After installing all the sliding parts 11 in sequence, the locking member 16 is installed. Then, the pins in each process hole are removed. The sliding part 11 can be tightly engaged with the locking member 16 under the action of the elastic force. At this time, the process hole is covered and hidden by the sliding part 11. Demolding is performed by reversing the operation.

[0074] To ensure the stability of the sliding part 11, an arc-shaped recess is provided on the inner side of the sliding part 11 to match the limiting part.

[0075] It should be noted that the side of the sliding part 11 facing the center of the receiving cavity 10 is the inner side, and the side of the sliding part 11 facing the edge of the receiving cavity 10 is the outer side.

[0076] In one specific embodiment, the product's undercut S1 = 0.85 mm, the stroke of the sliding part 11 S = 2.2 mm, and the guide distance L = 5.5 mm. The elastic element 15 is a rectangular helical spring with a diameter of 8 mm and a spring length of 15.0 mm. The depth of the space formed by the combination of the first mounting groove 14 and the second mounting groove 111 is 9.5 mm. The spring compression is 15 - 9.5 = 6.5 mm. After the sliding part 11 reaches the withdrawal position, the spring preload is 15 - 9.5 - 2.2 = 4.3 mm, and the spring constant is 10.5 N / mm. According to the spring load calculation method: load N = spring constant N / mm × compression F, the initial withdrawal force of the sliding part 11 is calculated to be 10.5 × 6.5 = 68.25 N, approximately equal to 6.825 kgf. After the sliding part 11 withdraws, the preload is 10.5 × 4.3 = 45.15 N, approximately equal to 4.515 kgf.

[0077] The technical solution of this invention combines the relationship between workpiece movement clearance and frictional force to optimize the structural solution of four-sided undercut demolding of the product, thereby achieving the effect of solving the problem of smooth demolding of the product in a narrow space and optimizing the mold structure.

[0078] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A mold structure for processing a product having a plurality of undercuts, the plurality of undercuts being arranged in a ring, characterized in that, The mold structure comprises a movable mold assembly and a fixed mold assembly oppositely arranged in a first direction, and a containing cavity is formed on the movable mold assembly; The movable mold assembly further comprises a plurality of sliding parts arranged in the containing cavity, the plurality of sliding parts are used for corresponding to a plurality of reverse buckles of a product, and the plurality of sliding parts are movable in a direction close to or away from the center of the containing cavity to have a matching position and a disengaging position; when the movable mold assembly and the fixed mold assembly are combined, the plurality of sliding parts are in the matching position, at least part of the plurality of sliding parts is attached to the inner side wall of the containing cavity to jointly define a product reverse buckle forming area with the containing cavity; when the movable mold assembly and the fixed mold assembly are separated, the plurality of sliding parts are in the disengaging position, and the plurality of sliding parts are all away from the inner wall of the containing cavity; An end face of the sliding part towards the outside of the containing cavity is provided with a concave part and / or a convex part shaped according to the product reverse buckle; the number of the plurality of sliding parts matches the number of the plurality of reverse buckles on the product; The movable mold assembly further comprises: a movable mold core, an end face of the movable mold core towards the fixed mold assembly is provided with a groove to form the containing cavity; and an insert fixed in the groove; The plurality of sliding parts are arranged along the circumference of the insert, and the plurality of sliding parts have a movable stroke close to or away from the insert to be able to switch between the disengaging position and the matching position; A middle part of the insert is provided with an avoiding groove, and a circumferential side face of the insert is provided with a plurality of guide holes communicating with the avoiding groove; The plurality of sliding parts are correspondingly movably arranged in the plurality of guide holes; The insert is fixed on the movable mold core by a locking part, and part of the locking part is between the plurality of sliding parts to form a limiting part; In the disengaging position, the plurality of sliding parts are all in contact with the circumferential side face of the limiting part; In the matching position, the distance between each sliding part and the limiting part is S, the inner side wall of the groove is provided with a plurality of first mounting grooves, each sliding part is provided with a second mounting groove, and the oppositely arranged first mounting grooves and second mounting grooves accommodate two ends of an elastic part, the distance between the inner side wall of the groove and the bottom wall of the second mounting groove is L, and the distance between each sliding part and the limiting part is S, wherein 1 / 3L≤L-S≤2 / 3L.

2. The mold structure of claim 1, wherein The inner side wall of the groove is provided with a plurality of first mounting grooves arranged along the circumference of the groove; Each of the plurality of sliding parts is provided with a second mounting groove corresponding to the plurality of first mounting grooves; The movable mold assembly further comprises a plurality of elastic parts, and two ends of each elastic part are respectively located in the oppositely arranged first mounting grooves and second mounting grooves.

3. The mold structure of claim 2, wherein The mold structure further comprises a locking block, one end of the locking block is fixed to the fixed mold assembly in the first direction, and the other end is tapered towards the movable mold assembly to form an annular guide surface; Each sliding part is formed with a matching inclined surface towards the side wall of the center of the containing cavity; The other end of the locking block can extend into between the plurality of sliding parts, and the annular guide surface is attached to the plurality of matching inclined surfaces to limit the plurality of sliding parts in the matching position.

4. The mold structure of claim 3, wherein Inner side walls of the recesses are provided with a plurality of first mounting grooves; a plurality of the sliding portions are respectively provided with second mounting grooves; the oppositely arranged first mounting grooves and the second mounting grooves are used for accommodating two ends of an elastic member; A distance between an end face of the locking block facing away from the mold assembly and the first mounting groove is h, and h≥0.

5. The mold structure of claim 4, wherein A size of the matching inclined surface in a first direction is H1, and a size of the sliding portion in the first direction is H, wherein H1 / H≥2 / 3.

6. The mold structure of claim 1, wherein S-S1≥1mm, S1 is a back-off size of the product; and / or, L>S+3mm.

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