Mold

Abstract

The present invention relates to a mold, which includes a mold core. The mold core includes a fixed seat and a demolding assembly. The demolding assembly is circumferentially installed around the fixed seat and is used to move relative to the workpiece for demolding. The mold further includes an upper mold assembly and a lower mold assembly. The lower mold assembly includes a lower middle mold and a lower mold, and the mold core is fixed to the lower mold. When demolding, the lower middle mold is fixed, and the lower mold is moved to make the mold core move with the lower mold. The demolding assembly can be unfolded or closed under the action of the abutting force between the demolding assembly and the workpiece to change the outer diameter of the mold core, and at the same time, by utilizing the elastic properties of the workpiece, the mold core can be automatically separated from the workpiece, without the need for manual pulling of the workpiece and prying the workpiece from the mold core, effectively reducing the probability of tire deformation or damage caused by human factors and improving the production efficiency and product quality.

Description

Technical Field

[0001] The present invention relates to the technical field of injection molding, and particularly to a mold. Background Art

[0002] A rubber injection mold is a commonly used device for manufacturing rubber products. Rubber raw materials are injected into the mold and vulcanized at high temperature to form rubber products according to the shape of the cavity in the mold. A tire is an annular elastic rubber product, which can be roughly divided into an inflated tire and a non-inflated tire. Generally, it is made by an injection molding process. A non-inflated tire is a tire that does not need to be inflated. Without relying on air, it only uses the materials and structure of the tire itself to achieve the performance of support and cushioning. During the manufacturing process of a non-inflated tire, a mold core is used. The main function of the mold core is to evacuate the inside of the tire from the inner side of the tire, and at the same time, reinforcing ribs and ribs need to be added inside to make the tire have better shock absorption performance and structural strength.

[0003] After the injection molding process is completed, the outer peripheral edge of the mold core is embedded in the internal space of the tire product. However, most of the existing mold cores are an integral annular structure. And due to the presence of reinforcing ribs and ribs inside the tire product, and due to the physical properties of the rubber material, it is difficult for the product to be separated from the mold core during demolding. The commonly used improvement method is to use components for assembly, inject glue after assembly until demolding from vulcanization, and finally disassemble the previously assembled components to achieve demolding. However, when disassembling, hitting the mold and pulling the product off are still likely to cause the product to deform, so the efficiency of this demolding method is still low, and it is easy to damage the processed product, resulting in great waste and making it difficult to ensure the quality of the product. Summary of the Invention

[0004] Based on this, in view of the problem that it is difficult to demold using the existing mold core during the demolding process, it is necessary to provide a mold that is easy to demold.

[0005] According to one aspect of the present application, a mold core is provided, including:

[0006] A fixed seat;

[0007] A demolding component, which is installed around the fixed seat in a circumferential direction;

[0008] The demolding component is configured to be able to expand or close under an external force to change the outer diameter size of the mold core.

[0009] In one embodiment, when the demolding component is in the expanded state, the demolding component has a first outer diameter; when the demolding component is in the closed state, the demolding component has a second outer diameter;

[0010] The first outer diameter is greater than the second outer diameter, and the second outer diameter is greater than the outer diameter of the fixed seat.

[0011] In one embodiment, the demolding assembly includes a plurality of blades, the plurality of blades being mounted on the fixed seat, and all the blades being capable of synchronously rotating relative to the fixed seat under an external force so that the demolding assembly is deployed or closed.

[0012] In one embodiment, the fixed seat has a plurality of mounting grooves, the plurality of mounting grooves being circumferentially spaced apart along the fixed seat; each blade is rotatably mounted in one of the mounting grooves.

[0013] In one embodiment, the fixed seat includes:

[0014] A chassis having a plurality of first grooves formed at one end, the plurality of first grooves being circumferentially spaced apart along the chassis;

[0015] A cover body mounted on a side of the chassis where the first grooves are formed, and having a plurality of second grooves penetrating through opposite ends in the axial direction of the cover body;

[0016] Each of the first grooves is disposed opposite to and communicated with one of the second grooves to jointly define one of the mounting grooves.

[0017] In one embodiment, the demolding assembly further includes a plurality of connecting shafts, opposite ends of each connecting shaft being respectively limited between the chassis and the cover body, and each blade being sleeved on one of the connecting shafts and rotating relative to the fixed seat with the connecting shaft as the rotation center.

[0018] In one embodiment, the blade includes a connecting portion and a forming portion, the connecting portion being movably mounted in the mounting groove, and the forming portion being exposed outside the fixed seat and used for supporting a workpiece.

[0019] According to another aspect of the present application, there is provided a mold using the above-mentioned core, the mold further including an upper mold assembly and a lower mold assembly, the upper mold assembly having an upper mold cavity, the lower mold assembly having a lower mold cavity, and the upper mold cavity and the lower mold cavity jointly defining a mold cavity for accommodating a material to be injected to form a workpiece.

[0020] In some embodiments, the upper mold assembly includes an upper mold and an upper middle mold, opposite ends of the upper middle mold being communicated with each other, one end of the upper middle mold away from the lower mold assembly being abutted and mounted on one end of the upper mold, and the upper mold and the upper middle mold jointly defining the upper mold cavity;

[0021] The upper mold assembly further includes an elastic element capable of elastic deformation, mounted between the upper mold and the upper middle mold, and the upper mold and the upper middle mold being capable of separating from each other by means of the elastic deformation of the elastic element.

[0022] In some of these embodiments, the lower die assembly includes a lower middle die and a lower die. The opposite ends of the lower middle die communicate with each other. One end of the lower middle die away from the upper die assembly abuts and is installed on the lower die. The lower middle die and the lower die jointly define the lower die cavity.

[0023] The lower die assembly further includes a connecting member. The lower middle die is installed on the lower die through the connecting member. The die core is fixed on the lower die. The lower die can move relative to the lower middle die so that the die core is separated from the workpiece.

[0024] For the above-mentioned mold, by providing a fixing seat and a demolding assembly on the die core, and providing an installation groove on the fixing seat, the demolding assembly is movably installed in the installation groove. When demolding is required, an upper middle die and a lower middle die are arranged in the mold. The lower die moves downward relative to the lower middle die, and the abutting force between the demolding assembly and the workpiece causes relative movement between the demolding assembly and the fixing seat to change the outer diameter of the die core. And by utilizing the elastic performance of the workpiece, the demolding assembly can automatically separate from the workpiece, realizing automatic demolding without manually pulling the workpiece and prying the workpiece from the die core. This effectively reduces the probability of workpiece deformation or damage caused by human factors and improves production efficiency and product quality. Description of the Drawings

[0025] Figure 1 An exploded view of the mold according to the first embodiment provided by the present invention;

[0026] Figure 2 A cross-sectional view of the internal structure of the mold according to the first embodiment provided by the present invention;

[0027] Figure 3 An exploded view of the mold according to the second embodiment provided by the present invention;

[0028] Figure 4 A cross-sectional view of the internal structure of the mold according to the second embodiment provided by the present invention;

[0029] Figure 5 A schematic diagram of the blade in the die core provided by the present invention when it is in a horizontal state;

[0030] Figure 6 A schematic diagram of the blade in the die core provided by the present invention when it is in a flipped-up state;

[0031] Figure 7 A schematic diagram of the fixing seat provided by the present invention;

[0032] Figure 8 An exploded view of the die core provided by the present invention;

[0033] Figure 9An enlarged schematic diagram of the internal structure of the fixing seat in the mold core provided by the present invention;

[0034] Figure 10 A schematic diagram of the blade provided by the present invention. Specific embodiments

[0035] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe the specific embodiments of the present invention in detail with reference to the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0036] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be intermediate elements at the same time.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0038] The present invention provides a mold 10, including a mold core 300, which is used to inject materials into the cavity of the mold 10 during the injection molding process. After the materials solidify, they are formed into products with certain shapes both externally and internally, where the mold core 300 is used to form the internal structure of the products.

[0039] Next, taking the tire injection molding mold 10 as an example, the structure of the mold 10 in the present application will be described, including the structure of the mold core 300 in the mold 10. This embodiment is only used as an example for illustration and will not limit the technical scope of the present application. It can be understood that in other embodiments, the mold core 300 can also be used for the molding of other products, which is not limited herein.

[0040] As Figures 1 to 2The mold 10 of the first embodiment shown includes an upper mold assembly 100, a lower mold assembly 500, and a mold core 300. The upper mold assembly 100 and the lower mold assembly 500 are both integral structures. The upper mold assembly 100 has an upper mold cavity 101 with the same outer shape as a part of the tire, and the lower mold 500 has a lower mold cavity 501 with the same outer shape as another part of the tire. One end of the upper mold assembly 100 abuts against one end of the lower mold assembly 500, forming a sealed space inside the mold 10. This sealed space is the mold cavity jointly defined by the upper mold cavity 101 and the lower mold cavity 501. The mold core 300 is coaxially installed in the lower mold assembly 500 and is received in the mold cavity.

[0041] In another embodiment, as Figure 3 and Figure 4 shown, different from the first embodiment of the mold 10, the upper mold assembly 100 and the lower mold assembly 500 in the mold 10 are split structures. The upper mold assembly 100 includes an upper mold 110 and an upper middle mold 120, and the lower mold assembly 500 is also a split structure. The lower mold assembly 500 includes a lower mold 520 and a lower middle mold 510.

[0042] The upper middle mold 120 has a cavity with the same outer shape as a part of the tire, and the opposite ends of the upper middle mold 120 communicate with each other. The opening at the end of the upper middle mold 120 far from the lower mold assembly 500 is smaller than the opening at the end of the upper middle mold 120 close to the lower mold assembly 500. The end of the upper middle mold 120 far from the lower mold assembly 500 is abutted and installed at one end of the upper mold 110. The upper mold 110 and the upper middle mold 120 jointly define the upper mold cavity 101.

[0043] Preferably, the upper mold 110 and the upper middle mold 120 are connected by a plurality of screws, and each screw is sleeved with an elastic element 130. In one embodiment, the elastic element 130 is preferably a large spring. In the normal state, the upper mold 110 and the upper middle mold 120 are abutted together, and the elastic element 130 is in a compressed state. When demolding after the molding work is completed, the upper mold 110 and the upper middle mold 120 are separated from each other by means of the elastic element 130 rebounding. The purpose of setting the elastic element 130 between the upper mold 110 and the upper middle mold 120 is to keep the distance between the upper mold 110 and the upper middle mold 120 consistent during the demolding process, so that the patterns on the upper and lower surfaces of the tire are consistent when demolding after molding is completed.

[0044] The lower middle mold 510 also has a cavity with the same shape as a part of the tire, and the opposite ends of the lower middle mold 510 communicate with each other. The opening at the end of the lower middle mold 510 away from the upper mold assembly 100 is smaller than the opening at the end of the lower middle mold 510 close to the upper mold assembly 100, and the end of the lower middle mold 510 away from the upper mold assembly 100 is abutted and installed on the lower mold 520. The lower middle mold 510 and the lower mold 520 jointly define the lower mold cavity 501. The lower mold 520 and the lower middle mold 510 are connected by a plurality of fixing members 530. The fixing members 530 are preferably screw rods and screw nuts. The screw rods pass through the mounting holes at the four corners of the lower middle mold 510 and the lower mold 520 to connect the lower mold 520 and the lower middle mold 510 together. The screw rods are also fixed and locked to the lower middle mold 510 through the screw nuts, but the screw rods do not lock the lower mold 520, so that the lower mold 520 can move relative to the lower middle mold 510 in the direction of approaching or departing from the lower middle mold 510. At the same time, the mold core 300 is fixed to the lower mold 520 and is coaxial with the lower mold 520. Thus, during demolding, when the tire is located in the lower mold cavity 501, the lower mold 520 is moved in the direction away from the lower middle mold 510, and the mold core 300 follows the lower mold 520 to move in the direction away from the lower middle mold 510, so that a relative movement occurs between the mold core 300 and the tire, thereby completing demolding.

[0045] In the mold 10 of the above two embodiments, a plurality of injection holes and exhaust holes (not shown in the figure) are further opened at the top of the upper mold assembly 100 for injecting liquid or semi-solid rubber material into the mold cavity. The upper mold cavity 101 and the lower mold cavity 501 are used for forming the external structure of the tire, the mold core 300 is used for forming the internal structure of the tire, and the exhaust holes are used for discharging the gas in the mold cavity, so that the rubber material can be tightly pressed into the mold cavity.

[0046] During the production process of the tire, it is necessary to reasonably control the space size of the mold cavity, so that the space of the mold cavity is reduced in a certain proportion according to the volume of the tire, so that the size of the tire in the mold cavity is smaller than the required size. When the tire is demolded, the tire uses the expansion performance of the rubber material itself to automatically supplement the size difference, so that the size of the demolded tire meets the required size range. In some embodiments, the space size of the mold cavity is 0.5 - 0.99 of the volume size of the tire.

[0047] It should be noted that the space size of the mold cavity and the volume size of the tire are reduced in equal proportion according to a ratio of 0.5 - 0.99, and the reduction ratio parameter of 0.5 - 0.99 is mainly determined according to the expansion coefficient of the injected rubber material.

[0048] In some embodiments, such as Figures 5 to 8As shown in the figure, the mold core 300 includes a fixed seat 310 and a demolding assembly 320. The demolding assembly 320 is installed on the fixed seat 310 along the circumferential direction of the fixed seat 310, and is used to support the inner surface of the tire and to form the internal structure of the tire. The demolding assembly 320 can be expanded or closed under the action of an external force to change the outer diameter of the mold core 300. When the demolding assembly 320 is in the expanded state, the demolding assembly 320 has a first outer diameter; when the demolding assembly 320 is in the closed state, the demolding assembly 320 has a second outer diameter; wherein the first outer diameter is greater than the second outer diameter, and the second outer diameter is greater than the outer diameter of the fixed seat 310, so that during demolding, relative movement is generated between the demolding assembly 320 and the workpiece to enable the workpiece to be detached from the mold core 300.

[0049] In a preferred embodiment, the fixed seat 310 is a cylindrical structure. One end of the fixed seat 310 is provided with a plurality of mounting grooves 313 distributed at intervals along the circumferential direction. Each mounting groove 313 extends from the outer peripheral surface of the fixed seat 310 along the radial direction of the fixed seat 310 towards the central axis direction of the fixed seat 310. In some of these embodiments, the fixed seat 310 further includes a plurality of mounting holes 314. The plurality of mounting holes 314 are distributed at intervals along the circumferential direction of the fixed seat 310. Opposite ends of each mounting hole 314 communicate with two adjacent mounting grooves 313.

[0050] In some embodiments, the demolding assembly 320 includes a plurality of blades 321 and a plurality of connecting shafts 322. The plurality of blades 321 are respectively partially embedded and installed in the plurality of mounting grooves 313 along the circumferential direction of the fixed seat 310, and the remaining parts are exposed outside the fixed seat 310 and support the inner surface of the tire. The plurality of connecting shafts 322 are distributed at intervals along the circumferential direction of the fixed seat 310. Opposite ends of each connecting shaft 322 in the length direction are respectively limited in two adjacent mounting holes 314. Each blade 321 is correspondingly sleeved on a connecting shaft 322, so that each blade 321 can rotate relative to the fixed seat 310 around a connecting shaft 322.

[0051] In this way, the plurality of blades 321 can rotate simultaneously around the plurality of connecting shafts 322 under the action of gravity. Therefore, when the mold core 300 is moved downward for demolding, all the blades 321 can rotate synchronously relative to the fixed seat 310 under the action of an external force to expand or close the demolding assembly 320, so that the outer diameter of the mold core 300 changes. By utilizing the recoverable elastic deformation of the tire, while the plurality of blades 321 rotate synchronously relative to the fixed seat 310, they also move relative to the tire, prompting the tire to automatically detach from the mold core 300, thus realizing automatic demolding.

[0052] Specifically, in some embodiments, such as Figure 7 and Figure 8As shown, the fixed seat 310 includes a chassis 311 and a cover 312. The chassis 311 is preferably disc-shaped. At one end of the chassis 311 facing the cover 312, a plurality of first grooves 3111 with a certain depth are formed at intervals along the circumferential direction of the chassis 311. The length direction of each first groove 3111 is consistent with the radial direction of the chassis 311, and each first groove 3111 extends from the circumferential surface of the chassis 311 along the radial direction of the chassis 311 towards the central axis direction of the chassis 311.

[0053] The cover 312 is preferably disc-shaped, and its diameter is equal to that of the chassis 311. The cover 312 is provided with a plurality of second grooves 3121 that penetrate through the opposite ends in the axial direction of the cover 312. The plurality of second grooves 3121 are distributed at intervals along the circumferential direction of the cover 312. The length direction of each second groove 3121 is parallel to that of one of the first grooves 3111, and each second groove 3121 extends from the circumferential surface of the cover 312 along the radial direction of the cover 312 towards the central axis direction of the cover 312.

[0054] The cover 312 is fixedly connected to one side on the axis of the chassis 311. Specifically, in a preferred embodiment, one end of the cover 312 fits against one end of the chassis 311 where the first grooves 3111 are formed, and each second groove 3121 of the cover 312 is arranged opposite to one first groove 3111 of the chassis 311, so that one first groove 3111 and one second groove 3121 communicate with each other. At the same time, the cover 312 and the chassis 311 are fixedly connected by screws and there is no relative movement between them.

[0055] In this way, each first groove 3111 and one second groove 3121 jointly define an installation groove 313, so that the fixed seat 310 has a plurality of installation grooves 313 distributed at intervals along the circumferential direction. At the same time, the installation groove 313 has a certain depth and length. One end of the installation groove 313 in the depth direction communicates with one end face close to the lower die 500, and one end of the installation groove 313 in the length direction communicates with the circumferential surface of the fixed seat 310.

[0056] Specifically, in some of these embodiments, the chassis 311 further has a plurality of third grooves 3112 spaced apart circumferentially on the end face provided with the first groove 3111, and opposite ends of each third groove 3112 in the length direction communicate with two adjacent first grooves 3111. The cover 312 is provided with a plurality of fourth grooves 3122 spaced apart circumferentially on the end face fitting with the chassis 311, and opposite ends of each fourth groove 3122 in the length direction communicate with two adjacent second grooves 3121, and the length direction of each fourth groove 3122 is parallel to one third groove 3112. When the cover 312 is fixedly connected to the chassis 311, one end face of the cover 312 provided with the fourth groove 3122 fits against the end face of the chassis 311 provided with the third groove 3112. Since there is no relative movement between the cover 312 and the chassis 311 after the cover 312 is fixedly connected to the chassis 311, each third groove 3112 and a fourth groove 3122 together define an installation hole 314.

[0057] Thus, as Figure 9 shown, the blade 321 is sleeved outside the connecting shaft 322, and then opposite ends of the connecting shaft 322 are respectively limited to one end of two adjacent installation holes 314, and the blade 321 can rotate relative to the fixed seat 310 with the connecting shaft 322 as the rotation axis.

[0058] In some of these embodiments, as Figure 5 and Figure 6 shown, the blade 321 is a plate-like structure with a certain thickness, and the thickness of the blade 321 is slightly smaller than the width of the installation groove 313. The purpose is to have a certain gap between the blade 321 and the installation groove 313 so that the blade 321 can move flexibly in the installation groove 313, facilitating the separation of the mold core 300 from the tire during demolding.

[0059] In a preferred embodiment, as Figure 10 shown, the blade 321 is an integrally processed and formed structure, including an integrally formed connecting portion 3211 and a forming portion 3212. The connecting portion 3211 is used to connect with the fixed seat 310, and the forming portion 3212 is used to form the reinforcing ribs and ribs on the inner surface of the tire. The length of the blade 321 is greater than the length of the installation groove 313, and the length of the connecting portion 3211 is slightly equal to the length of the installation groove 313. When the blade 321 is placed in the installation groove 313 and installed with the fixed seat 310, the connecting portion 3211 of the blade 321 is completely embedded in the installation groove 313. Since the length of the blade 321 is greater than the length of the installation groove 313, the forming portion 3212 is exposed outside the fixed seat 310. Two adjacent blades 321 and the circumferential surface of the fixed seat 310 together define a forming gap, and each forming gap communicates with two opposite end faces of the mold core 300, so that a plurality of forming gaps are formed in the circumferential direction of the mold core 300, and this gap is used to form the reinforcing ribs inside the tire.

[0060] Specifically, in some embodiments, each blade 321 is provided with a through hole 3213 at the end face of the connecting portion 3211. The through hole 3213 communicates with the two end faces of the blade 321 in the thickness direction. The connecting shaft 322 of the fixing seat 310 passes through the through hole 3213, so that the blade 321 is sleeved outside the connecting shaft 322 and can rotate around the connecting shaft 322. One end of the forming portion 3212 of each blade 321 away from the fixing seat 310 in the length direction further has a fifth groove 3214. The fifth groove 3214 penetrates through the opposite ends of the forming portion 3212 in the thickness direction and is used for forming the ribs inside the tire. The shape of the fifth groove 3214 is determined according to the shape of the ribs inside the tire and can be arc-shaped, square, triangular or other irregular shapes.

[0061] When the above-mentioned mold core 300 is specifically installed, first place the chassis 311 on a plane; then pass the connecting shaft 322 through the through hole 3213 of the blade 321 so that the blade 321 is sleeved outside the connecting shaft 322; then embed a part of the connecting portion 3211 of the blade 321 into the first groove 3111, and place a plurality of connecting shafts 322 in the third groove 3112 of the chassis 311. The opposite ends of each connecting shaft 322 in the length direction are respectively placed at one end of two adjacent third grooves 3112, so that the two ends of each connecting shaft 322 are lapped on two adjacent third grooves 3112. At this time, a part of the connecting portion 3211 and the forming portion 3212 of the blade 321 are exposed outside the chassis 311; finally, place the cover body 312 on the end face of the chassis 311 provided with the first groove 3111 and the third groove 3112, so that the second groove 3121 of the cover body 312 is placed opposite to the first groove 3111 of the chassis 311, and at the same time, the fourth groove 3122 of the cover body 312 is placed opposite to the third groove 3112 of the chassis 311, so that the part of the connecting portion 3211 exposed outside the chassis 311 is embedded in the second groove 3121 of the cover body 312, and the opposite ends of the connecting shaft 322 are covered by the fourth groove 3122 of the cover body 312, and then use screws to fix the cover body 312 and the chassis 311 so that there is no relative movement between the cover body 312 and the chassis 311. In this way, the opposite ends of the connecting shaft 322 are received in the mounting hole 314 formed by the third groove 3112 and the fourth groove 3122, and the forming portion 3212 of the blade 321 is exposed outside the fixing seat 310 and can rotate around the connecting shaft 322 and turn up relative to the fixing seat 310.

[0062] When installing the mold 10, first fix the lower mold assembly 500 on a plane; then place the mold core 300 into the lower mold cavity 501 of the lower mold assembly 500. The chassis 311 of the mold core 300 has mounting holes, and install the mold core 300 with the lower mold assembly 500 so that the central axis of the mold core 300 is coaxially arranged with the central axis of the lower mold cavity 501; then abut the upper mold assembly 100 against one end face of the lower mold assembly 500 close to the upper mold 100, so that the upper mold cavity 101, the mold core 300 and the lower mold cavity 501 are all coaxially arranged. In this way, the installation of the mold 10 is completed.

[0063] When producing tires, first inject the rubber material into the mold cavity from the injection hole of the upper mold assembly 100, and at the same time use the exhaust hole to discharge the gas in the mold cavity, so that the rubber material fills and tightly presses into the mold cavity. Specifically, the injected rubber material is rubber foam material. Since the structure design of the cavity is consistent with the shape of the tire, and the structure of the mold core 300 is also designed according to the shape of the internal reinforcing ribs and ribs of the tire, after injecting the rubber material into the mold cavity, an internally hollow structure will be formed corresponding to the inside of the tire formed in the mold cavity. After the rubber material solidifies and cools, the rubber material solidifies into a tire with internal reinforcing ribs and ribs.

[0064] Next, the demolding process begins. The purpose of demolding is to remove the tire from the cavity of the mold 10 and separate it from the mold core 300. The demolding process will be described by taking the mold 10 with the structure of the second embodiment as an example. As Figure 3 shown, the arrow direction in the figure is the demolding direction.

[0065] During demolding, the upper mold assembly 100 is stationary and fixed in the initial state; first, move the lower mold 520 in the lower mold assembly 500 downward in a direction away from the upper mold assembly 100. After moving a certain distance, a certain gap is generated between the upper middle mold 120 and the lower middle mold 510 under the action of the demolding force. At this time, a gap is also generated between the upper middle mold 120 in the upper mold assembly 100 and the upper mold 110 under the action of the demolding force. The elastic element 130 installed between the upper mold 110 and the upper middle mold 120 returns to the normal state from the compressed state by means of the elastic force, so that the upper mold 110 and the upper middle mold 120 bounce apart, and the upper mold assembly 100 turns up relative to the lower mold assembly 500, and the angle with the lower mold assembly 500 changes from 0 degree to 90 degrees. At this time, the tire is separated from the upper mold assembly 100, and the upper half of the tire is exposed.

[0066] Then continue to move the lower mold 520 downward, exposing the lower half of the tire and the mold core 300. At this time, the molding portion 3212 of the mold core 300 supports the inner surface of the tire. Since the mold core 300 is fixedly arranged on the lower mold 520, the mold core 300 also moves downward with the lower mold 520. Generally, the blades 321 of the mold core 300 cannot move relative to the fixing portion. At this time, if demolding is required, it is necessary to manually pry the inner periphery of the tire from the mold core 300 along the circumferential direction of the tire to separate the tire from the mold core 300, and then take away the mold core 300 to complete demolding. However, the blades 321 in the mold core 300 of the present application can rotate relative to the fixed seat 310. Since the tire is located in the lower mold cavity 501, and the opening at the end of the lower middle mold 510 far from the upper mold assembly 100 is smaller than the opening at the end of the lower middle mold 510 close to the upper mold assembly 100, when the mold core 300 moves downward together with the lower mold 520, the tire is held and cannot move downward. Therefore, during demolding, under the action of the holding force of the tire on the blades 321, the multiple blades 321 will simultaneously rotate and turn upward relative to the fixed seat 310 around the connecting shaft 322. Since the rubber material of the tire has a certain elasticity, it can undergo recoverable deformation under the action of an external force. Under the action of the blades 321, the inner periphery of the tire can be pried open by the blades 321, causing relative movement between the blades 321 and the tire, so that the mold core 300 is separated from the tire. After the tire is separated from the mold core 300, the elastic deformation caused by the action of the blades 321 immediately recovers. At this time, the tire is located in the lower mold cavity 501 and has no other constraints. At this time, the tire can be taken away manually to obtain the final finished product.

[0067] If the mold 10 of the first embodiment is used for demolding, after the molding process is completed, the upper mold assembly 110 is taken out, and the lower mold assembly 510 bounces the mold core 300 and the tire upward. At this time, it is still necessary to manually lift the mold core 300 and the tire together with other tools, and then use the relative movement between the blades 321 and the fixed seat 310 to cause relative movement between the blades 321 and the tire for demolding. Compared with using the mold 10 of the first embodiment, when using the mold 10 of the second embodiment for demolding, automatic demolding can be completed without manual intervention throughout the process.

[0068] In addition, as described above, the size of the mold cavity in the present application is set by reducing the volume of the tire in equal proportion according to a preset ratio, so that the volume of the rubber material in the mold cavity is smaller than the actual volume of the tire. When the tire is separated from the cavity, by using the expansion performance of the rubber material itself, the volume of the rubber material expands, so that the volume of the final tire finished product can reach the size required by the user. At the same time, the expanded tire will also be separated from the mold core to a certain extent, making the demolding of the tire more efficient and convenient.

[0069] The above-mentioned mold 10 is designed such that the mold core 300 is divided into two parts, namely a fixed seat 310 and a demolding assembly 320. An installation groove 313 is provided in the fixed seat 310, enabling the demolding assembly 320 to be movably installed in the installation groove 313. When demolding is required, the upper middle mold 120 and the lower middle mold 510 are arranged in the mold. The mold core 300 is fixed to the lower mold 520. The lower mold 520 and the mold core 300 move downward relative to the lower middle mold 510. By using the abutting force between the demolding assembly 320 and the workpiece, relative movement is generated between the demolding assembly 320 and the fixed seat 310 to change the outer diameter of the mold core 300. Moreover, by utilizing the elastic property of the workpiece, the demolding assembly 320 can automatically separate from the tire, eliminating the need for manual pulling and prying of the tire from the mold core 300. This effectively reduces the probability of tire deformation or damage caused by human factors, and improves production efficiency and product quality.

[0070] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0071] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A mold, characterized in that, It includes a core, an upper die assembly and a lower die assembly. The upper die assembly has an upper die cavity, and the lower die assembly has a lower die cavity. The upper die cavity and the lower die cavity jointly define a mold cavity for accommodating the material to be injected to form a workpiece. Among them, the lower die assembly includes a lower middle die and a lower die. The opposite ends of the lower middle die are interconnected. One end of the lower middle die away from the upper die assembly is abutted and installed on the lower die. The lower middle die and the lower die jointly define the lower die cavity. The opening at one end of the lower middle die away from the upper die assembly is smaller than the opening at one end of the lower middle die close to the upper die assembly. The lower die can move relative to the lower middle die. The core includes: A fixed seat fixedly arranged on the lower die; A demolding assembly circumferentially installed around the fixed seat. The demolding assembly includes a plurality of blades and a plurality of connecting shafts. The plurality of connecting shafts are installed on the fixed seat along the circumferential direction of the fixed seat, and each blade is sleeved on one connecting shaft. When the demolding assembly is in the unfolded state, the demolding assembly has a first outer diameter; when the demolding assembly is in the closed state, the demolding assembly has a second outer diameter. The first outer diameter is greater than the second outer diameter, and the second outer diameter is greater than the outer diameter of the fixed seat. When the lower die moves relative to the lower middle die, each blade rotates relative to the fixed seat with the connecting shaft as the rotation center and turns up relative to the fixed seat, so that the demolding assembly changes from the unfolded state to the closed state; so that during demolding, relative movement is generated between the blade and the workpiece to separate the workpiece from the core.

2. The mold according to claim 1, characterized in that, The fixed seat has a plurality of mounting grooves, and the plurality of mounting grooves are circumferentially spaced apart along the fixed seat; each blade is rotatably installed in one mounting groove.

3. The mold according to claim 2, characterized in that, The fixed seat includes: A chassis with a plurality of first grooves opened at one end, and the first grooves are circumferentially spaced apart along the chassis; A cover body installed on the side of the chassis where the first grooves are opened, and having a plurality of second grooves penetrating through the opposite ends in the axial direction of the cover body; Each first groove is oppositely arranged and communicated with a second groove to jointly define a mounting groove.

4. The mold according to claim 3, characterized in that, Opposite ends of each connecting shaft are respectively limited between the chassis and the cover body.

5. The mold according to claim 3, characterized in that, The chassis also has a plurality of third grooves circumferentially spaced apart on the end face where the first grooves are opened. Opposite ends in the length direction of each third groove communicate two adjacent first grooves; the cover body has a plurality of fourth grooves circumferentially spaced apart on the end face attached to the chassis. Opposite ends in the length direction of each fourth groove communicate two adjacent second grooves. The length direction of each fourth groove is parallel to one third groove. Each third groove and one fourth groove jointly define a mounting hole, and opposite ends of the connecting shaft are respectively limited at one end of two adjacent mounting holes.

6. The mold according to claim 2, wherein The blade includes a connecting portion and a forming portion. The connecting portion is movably installed in the installation groove, and the forming portion is exposed outside the fixing seat and is used to support the workpiece.

7. The mold according to claim 6, characterized in that, One end of the forming portion of each blade, which is away from the fixing seat along the length direction, further has a fifth groove, and the fifth groove penetrates through the opposite ends of the forming portion in the thickness direction.

8. The mold according to claim 1, characterized in that, The upper die assembly includes an upper die and an upper middle die. The opposite ends of the upper middle die communicate with each other. One end of the upper middle die, which is away from the lower die assembly, abuts and is installed at one end of the upper die. The upper die and the upper middle die jointly define the upper die cavity.

9. The mold according to claim 8, characterized in that, The upper die assembly further includes an elastic element that can undergo elastic deformation, and is installed between the upper die and the upper middle die. The upper die and the upper middle die can be separated from each other by means of the elastic deformation of the elastic element.

10. The mold according to claim 8, characterized in that, The lower die assembly further includes a connecting member, and the lower middle die is installed on the lower die through the connecting member.

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