Rubber injection rain boot mold

Abstract

The utility model requests protecting a kind of rubber injection rain boot mould, and its technical scheme main point is including base, left mould, right mould, inner last and upper die, inner last is equipped with inner electric heating tube, left mould is equipped with left electric heating tube, right mould is equipped with right electric heating tube, upper die is equipped with upper electric heating tube, inner electric heating tube, left electric heating tube, right electric heating tube and upper electric heating tube are electrically connected with temperature control electric box, the utility model is set by the independent electric heating tube and temperature control system of upper die, inner last, left mould and right mould, and the secondary heating of injection material is realized, to avoid the high-temperature vulcanization risk before injection molding, and shorten the mould heating time and vulcanization cycle, improve the capacity.

Description

Technical Field

[0001] This utility model relates to an injection mold, and more specifically, to a rubber injection mold for rain boots. Background Technology

[0002] Currently, patent application number CN200920185646.6 discloses a hinged PU warm rain boot / PU work boot mold, which includes a pressure plate, a bottom plate, a left side plate, a right side plate, and a boot mold. The pressure plate has left and right side connecting plates connected by hinges on both sides of the fixed base. The boot mold is fixedly set in the middle of the fixed base. The left and right side plates are fixedly set on the left and right side connecting plates, respectively. The left and right side plates are L-shaped and can wrap the boot mold when closed, with an injection gap that matches the boot mold. An injection hole is formed in the middle of the left and right side plates that are closed perpendicularly to the fixed base. The bottom plate is set on the sole part of the boot mold and on the left and right side panels. The advantages are: the hinged connection method is convenient to operate, the produced product quality is good, there are no air bubbles, and it is suitable for the production of rain boots and rain shoes.

[0003] However, in actual production, it was found that the rubber material tends to solidify prematurely due to high-temperature vulcanization before being injected into the mold cavity. However, the temperature inside the mold needs to be maintained at around 150 degrees Celsius. Therefore, a rubber injection mold for rain boots is needed. This device can inject the rubber material into the mold at a low temperature and then heat it to prevent the rubber material from vulcanizing prematurely before being injected into the mold cavity.

[0004] For the reasons mentioned above, the problem addressed in this application is how to inject rubber material into the mold at a low temperature and then heat it. Utility Model Content

[0005] To address the shortcomings of existing technologies, a rubber injection mold for rain boots is provided. This device can inject rubber material into the mold at a low temperature and then heat it to prevent the rubber material from vulcanizing prematurely before being injected into the mold cavity.

[0006] To achieve the above objectives, the following technical solution is provided: A rubber injection molding mold for rain boots includes a base, a left mold, a right mold, an inner last, and an upper mold. The left and right molds are hinged to the base on one side, and a connecting structure is provided on the other side of the left and right molds to achieve a locking and fixing mechanism. A left cavity and a right cavity are respectively provided on the facing sides of the left and right molds. The inner last is connected to the base and located between the left and right molds. An injection cavity for injection molding the rain boot shaft is formed between the left and right cavities and the outer surface of the inner last. The upper mold is used to fasten to the upper side of the injection cavity. A sole cavity is provided on the surface of the upper mold facing the injection cavity for injection molding the boot sole. The mold is characterized in that an inner heating element is installed inside the inner last, a left heating element is installed inside the left mold, a right heating element is installed inside the right mold, and an upper heating element is installed inside the upper mold. The inner heating element, left heating element, right heating element, and upper heating element are all electrically connected to a temperature control box.

[0007] Furthermore, there are multiple left and right heating tubes arranged in a vertical array. The left mold has a left heating tube hole that passes through both ends of the left mold and is horizontally positioned, with the left heating tube housed in the left heating tube hole. The right mold has a right heating tube hole that passes through both ends of the right mold and is horizontally positioned, with the right heating tube housed in the right heating tube hole.

[0008] Furthermore, the upper mold is provided with an upper heating tube hole, which passes through both ends of the upper mold and is in a horizontal position, and the upper heating tube is accommodated in the upper heating tube hole.

[0009] Furthermore, the upper mold is fixedly connected with an operating lever. The connection points between the operating lever and the upper mold and the injection cavity are respectively located on both sides of the upper mold and are diagonally arranged. The extension direction of the operating lever is perpendicular to the rotation direction of the upper mold.

[0010] Furthermore, a positioning component is fixedly connected to the base away from the inner last. A left positioning cavity is provided in the left cavity, and a right positioning cavity is provided in the right cavity. The left and right positioning cavities are combined to form a positioning groove for accommodating the positioning component.

[0011] Furthermore, the base is also provided with an inner heating tube lead-out cavity, the left mold is provided with a left heating tube lead-out cavity, the right mold is provided with a right heating tube lead-out cavity, the left heating tube lead-out cavity and the right heating tube lead-out cavity are combined to extend the length of the corresponding inner heating tube lead-out cavity, and the inner last is provided with a heating tube lead-out hole that communicates with the inner heating tube lead-out cavity, and the inner heating tube is accommodated in the heating tube lead-out hole.

[0012] Furthermore, the base is fixedly connected to a support shaft located outside the left and right molds, and both the left and right molds are movably connected to the support shaft.

[0013] Furthermore, the left mold is fixedly connected to a guide block located away from the support shaft, and the guide block and the left cavity are located on the same side. The right mold is provided with a guide groove located away from the support shaft, and the guide groove and the right cavity are located on the same side. The guide block is accommodated in the guide groove, and the guide surface of the guide block is inclined.

[0014] Furthermore, the right mold is movably connected to a mold cavity retainer located away from the support shaft, and the left mold is fixedly connected to a mold cavity latch located away from the support shaft. A compression spring is provided inside the mold cavity retainer. When the mold cavity retainer is tightly fastened to the mold cavity latch, the left mold and the right mold are in close contact, and the compression spring is in a relaxed state.

[0015] Furthermore, the positioning component is provided with slots on both sides, with a left snap fastener in the left positioning cavity that fits into the slot, and a right snap fastener in the right positioning cavity that fits into the slot.

[0016] In summary, the above technical solution has the following beneficial effects: This utility model achieves secondary heating of the injection material by setting independent electric heating tubes and temperature control systems in the upper mold, inner last, left mold and right mold, so as to avoid the risk of high temperature vulcanization before injection molding, and shorten the mold heating time and vulcanization cycle, thereby improving production capacity. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of a rubber injection mold for rain boots.

[0018] Figure 2 This is a three-dimensional structural diagram of the inner last part in this utility model.

[0019] Figure 3 This is a three-dimensional structural diagram of the present invention when it is opened.

[0020] Attached reference numerals: 1. Base; 2. Left mold; 3. Right mold; 4. Inner last; 5. Upper mold; 11. Positioning component; 12. Inner heating element lead-out cavity; 13. Support shaft; 14. Slot; 21. Left cavity; 22. Left heating element; 23. Left heating element hole; 24. Left positioning cavity; 25. Left heating element outlet cavity; 26. Guide block; 27. Mold cavity latch; 28. Left retaining tenon; 31. Right cavity; 32. Right heating element; 33. Right heating element hole; 34. Right positioning cavity; 35. Right heating element outlet cavity; 36. Guide groove; 37. Mold cavity retaining ring; 38. Right clamping tenon; 41. Internal heating element; 42. Heating element lead-out hole; 51. Shoe sole cavity; 52. Upper heating element; 53. Upper heating element hole; 54. Operating lever. Detailed Implementation

[0021] Reference Figure 1-3 As shown, a rubber injection molding mold for rain boots includes a base 1, a left mold 2, a right mold 3, an inner last 4, and an upper mold 5. The left mold 2 and the right mold 3 are hinged to the base 1 on the same side. The other side of the left mold 2 and the right mold 3 is provided with a connecting structure for fastening and fixing the left mold 2 and the right mold 3. A left cavity 21 and a right cavity 31 are respectively provided on the facing sides of the left mold 2 and the right mold 3. The inner last 4 is connected to the base 1 and is located between the left mold 2 and the right mold 3. The left cavity 21 and the right cavity 31 are connected to the inner last. An injection cavity for injection molding the boot shaft is formed between the outer surfaces of the mold 4; the upper mold 5 is used to fasten to the upper side of the injection cavity, and the upper mold 5 has a sole cavity 51 on the surface facing the injection cavity. The sole cavity 51 is used for injection molding the boot sole. An inner heating tube 41 is installed in the inner last 4, a left heating tube 22 is installed in the left mold 2, a right heating tube 32 is installed in the right mold 3, and an upper heating tube 52 is installed in the upper mold 5. The inner heating tube 41, the left heating tube 22, the right heating tube 32 and the upper heating tube 52 are all electrically connected to the temperature control box.

[0022] Low-temperature injection and high-temperature vulcanization are the core of the entire process. When the rubber material is injected at around 50°C (low temperature), the rubber molecular chains have good fluidity, easily filling the complex cavity and ensuring the integrity of the boot shaft injection. At this time, vulcanization reaction basically does not occur. After the rubber material is injected into the mold, the various heating elements inside the mold begin to heat up, maintaining the mold temperature at around 150°C, providing the necessary environment for the rubber vulcanization reaction.

[0023] The left mold 2, right mold 3, inner last 4, and upper mold 5 are all equipped with independent heating elements. This allows the temperature of each part of the mold to be maintained uniformly at 150°C, ensuring that the vulcanization speed is consistent for different thicknesses and parts during the production of rain boots, and avoiding the risk of under-vulcanization or over-vulcanization due to temperature differences.

[0024] During the production process, an additional color-separating mold is installed. This color-separating mold is an extra mold that matches the injection cavity, and its shape is similar to the upper mold 5. It is usually placed in the original position of the upper mold 5 during use, thereby dividing the originally uniform boot shaft injection cavity into two independent areas: the shaft body and the sole, within the complete injection cavity formed by the original upper mold 5, inner last 4, left mold 2, and right mold 3. This way, after the color-separating mold is removed and the upper mold 5 is reinstalled, the sole, which is a different color from the shaft body, can continue to be injection molded.

[0025] The following process flow can typically be used when employing this device: 1. Start the temperature control box to heat and maintain the vulcanization temperature of the left mold 2, right mold 3, and inner last 4 at approximately 150°C. At this time, the upper mold 5 can be preheated or heated simultaneously and maintained at approximately 150°C. Close and lock the left mold 2 and right mold 3, install the color-separating mold, and form the sealed cavity of the first color.

[0026] 2. The first color of natural rubber compound is injected through the barrel into the first cavity defined by the color-separating mold at a low temperature of about 50°C.

[0027] 3. The injected low-temperature rubber compound comes into contact with the 150°C high-temperature mold, begins to absorb heat and undergoes a vulcanization reaction. Since rubber is a poor conductor of heat, it takes time for the entire component to fully vulcanize. At this stage, the first color of the boot shaft undergoes initial vulcanization and shaping.

[0028] 4. Briefly open the color separation mold and remove it from the first color rubber part that has been initially vulcanized.

[0029] 5. Close and lock the upper mold 5 to prepare for the second color injection.

[0030] 6. Inject the second color of natural rubber into the newly formed cavity, usually the cavity inside the upper mold 5, at a low temperature of approximately 50°C. At this point, the second color of rubber will come into contact with the first color of rubber, which has already undergone preliminary vulcanization but still retains some surface activity.

[0031] 7. At a mold temperature of 150°C, the second-color rubber begins to vulcanize. At the same time, at the interface between the second-color rubber and the first-color rubber, due to high temperature and pressure, the molecular chains of the two rubbers diffuse and cross-link with each other, forming a strong chemical bond (co-vulcanization).

[0032] 8. After the entire product is fully vulcanized, open the left and right molds 3 and the upper mold 5, and remove the molded rain boots from the inner last 4.

[0033] This invention achieves secondary heating of the injection material through independent electric heating tubes and temperature control systems installed in the upper mold 5, inner last 4, left mold 2, and right mold 3, thereby avoiding the risk of high-temperature vulcanization before injection molding, shortening the mold heating time and vulcanization cycle, and improving production capacity.

[0034] Multiple left heating elements 22 and multiple right heating elements 32 are arranged in a vertical array. The left mold 2 has a left heating element hole 23 that extends through both ends of the left mold 2 and is horizontally positioned. The left heating element 22 is housed within the left heating element hole 23. The right mold 3 has a right heating element hole 33 that extends through both ends of the right mold 3 and is horizontally positioned. The right heating element 32 is housed within the right heating element hole 33. The upper mold 5 has an upper heating element hole 53 that extends through both ends of the upper mold 5 and is horizontally positioned. The upper heating element 52 is housed within the upper heating element hole 53.

[0035] Rain boots are typically injection molded with a tall, vertical structure. If heating elements are only placed outside the mold, heat cannot be evenly distributed across the entire boot shaft, leading to uneven temperatures and inconsistent rubber vulcanization. Therefore, this invention segments the heating source both vertically and horizontally, with each heating element responsible for heating its corresponding horizontal area. This multi-point distribution creates a uniformly distributed heat field along the boot shaft's height. Furthermore, the simultaneous operation of multiple heat sources shortens the time required for mold preheating and temperature maintenance, improving production efficiency.

[0036] From a functional perspective, the color-separating mold is usually used to close the injection cavity, so it does not significantly increase the size of the injection space formed. Therefore, it does not need to be equipped with a heating tube inside. On the other hand, the upper mold 5 also needs to be equipped with a heating tube to maintain the temperature.

[0037] An operating lever 54 is fixedly connected to the upper mold 5. The connection points between the operating lever and the upper mold 5 and the injection cavity are respectively located on both sides of the upper mold 5, and are diagonally arranged. The extension direction of the operating lever is perpendicular to the rotation direction of the upper mold 5. This utilizes the lever principle to achieve smooth opening and closing and accurate positioning of the upper mold 5 with minimal operating force, while avoiding interference. Furthermore, the diagonal arrangement ensures uniform mold closing force, improving sealing performance and product quality.

[0038] A positioning element 11 is fixedly connected to the base 1, positioned away from the inner last 4. A left positioning cavity 24 is provided within the left cavity 21, and a right positioning cavity 34 is provided within the right cavity 31. The left and right positioning cavities 24 and 34 combine to form a positioning groove for accommodating the positioning element 11. Typically, due to cost considerations, the connection and fit between the left mold 2 and the right mold 3 have a lower precision, and a certain amount of space is required. Therefore, during mold closing, active radial positioning is necessary to prevent misalignment of the left and right molds 2 and 3 when closing, thereby ensuring the uniformity of the boot shaft wall thickness and the dimensional accuracy of the product. The fit between the positioning element 11 and the positioning groove creates an action similar to a pin inserting into a socket, forcibly guiding the left and right molds 2 and 3 to the correct position, reducing the possibility of radial misalignment. Simultaneously, positioning the positioning element 11 away from the mold center (inner last 4) utilizes the lever principle to generate a greater corrective effect from a smaller positioning action.

[0039] The base 1 also has an internal heating tube outlet cavity 12, the left mold 2 has a left heating tube outlet cavity 25, and the right mold 3 has a right heating tube outlet cavity 35. The left heating tube outlet cavity 25 and the right heating tube outlet cavity 35 are combined to extend the length of the corresponding internal heating tube outlet cavity 12. The inner last 4 has a heating tube outlet hole 42 that communicates with the internal heating tube outlet cavity 12, and the internal heating tube 41 is accommodated in the heating tube outlet hole 42. The power cords of the internal heating tube 41, the left heating tube 22, and the right heating tube 32 need to be connected from inside the mold to the external temperature control box. The left heating tube 22 and the right heating tube 32 can be directly connected to the outside, while the internal heating tube 41 needs to pass through the part formed by the combination of the base 1 and the left and right molds. Therefore, a dedicated channel needs to be set up to reduce safety hazards.

[0040] Normally, the inner heating element 41 and the heating element lead-out hole 42 vertically penetrate the inner last 4, while the inner heating element lead-out cavity 12 horizontally penetrates the base 1. The inner heating element 41 can also be installed inside the inner heating element lead-out cavity 12, but due to the presence of the left heating element 22 and the right heating element 32, the inner heating element 41 is usually not installed inside the inner heating element lead-out cavity 12 to reduce costs; only the inner heating element 41 vertically penetrating the inner last 4 is retained to maintain uniform temperature distribution. When the mold is closed, the two lead-out cavities on the left mold 2 and the right mold 3 combine and precisely align with the inner heating element lead-out cavity 12 on the base 1, forming a complete inner heating element lead-out cavity 12. This cavity is directly used to lead the wire of the inner heating element 41 to the outside and isolate it from the surrounding moving mold components. This not only improves equipment safety but also facilitates subsequent maintenance.

[0041] The base 1 is fixedly connected to a support shaft 13 located outside the left mold 2 and the right mold 3. Both the left mold 2 and the right mold 3 are movably connected to the support shaft 13. For large molds, under the long-term action of gravity or injection pressure, the mold may sag slightly or warp outward. Thus, placing the support shaft 13 in the common vertical direction will affect it and cause deformation after long-term use. In this utility model, the base 1 is set as a supporting structure, and the support shaft 13 provides an auxiliary support point on the outside of the mold. The combination of the mold cavity buckle 37 and the mold cavity snap 27 forms a two-point support, which greatly enhances the overall rigidity of the mold.

[0042] The left mold 2 is fixedly connected to a guide block 26 located away from the support shaft 13. The guide block 26 and the left cavity 21 are located on the same side. The right mold 3 is provided with a guide groove 36 located away from the support shaft 13. The guide groove 36 and the right cavity 31 are located on the same side. The guide block 26 is accommodated in the guide groove 36, and the guide surface of the guide block 26 is inclined. The inclined guide surface generates a self-correcting force when the mold is closed, forcing the left mold 2 and the right mold 3 to be precisely aligned to the final closed position, achieving precise positioning.

[0043] During mold closing, as the left mold 2 and right mold 3 are about to contact, the guide block 26 enters the guide groove 36 before the main cavity body. Because the guide surfaces are inclined, when the two inclined surfaces contact, the vertical closing force is decomposed into a horizontal component. This horizontal force pushes the left mold 2 and right mold 3 to make minor adjustments in their horizontal positions. Furthermore, the inclined guide surfaces ensure that the mold contact is a gradual process, avoiding direct, hard impact between the cavities of the left and right molds 3, thus extending the mold's lifespan.

[0044] The right mold 3 is movably connected to a cavity retaining ring 37 located away from the support shaft 13, while the left mold 2 is fixedly connected to a cavity latch 27 located away from the support shaft 13. A compression spring is installed inside the cavity retaining ring 37. When the cavity retaining ring 37 is tightly fastened to the cavity latch 27, the left mold 2 and right mold 3 are in close contact, and the compression spring is in a relaxed state. Utilizing the spring-assisted over-center locking principle, a reliable and self-locking mold locking state is achieved, ensuring that the left mold 2 and right mold 3 are tightly fitted under high injection pressure, preventing them from being forced apart.

[0045] The positioning component 11 is also provided with slots 14 on both sides. The left positioning cavity 24 is provided with a left tenon 28 that fits into the slot 14, and the right positioning cavity 34 is provided with a right tenon 38 that fits into the slot 14. In this way, the large-area sliding friction between the positioning component 11 and the positioning slot can be transformed into a small-area embedded engagement between the tenon and the slot 14, thereby greatly reducing wear, improving positioning accuracy, and distributing the clamping force.

Claims

1. A rubber injection molding mold for rain boots, comprising a base, a left mold, a right mold, an inner last, and an upper mold; the left and right molds are hinged to the base on one side; the other side of the left and right molds is provided with a connecting structure for fastening and fixing the left and right molds; the left and right molds have a left cavity and a right cavity respectively on their facing sides; the inner last is connected to the base and located between the left and right molds; the left and right cavities and the outer surface of the inner last form an injection cavity for injection molding the rain boot shaft; the upper mold is used to fasten to the upper side of the injection cavity; the surface of the upper mold facing the injection cavity has a sole cavity for injection molding the boot sole, characterized in that... An inner heating element is installed inside the inner mold, a left heating element is installed inside the left mold, a right heating element is installed inside the right mold, and an upper heating element is installed inside the upper mold. The inner heating element, left heating element, right heating element, and upper heating element are all electrically connected to the temperature control box.

2. The rubber injection mold for rain boots according to claim 1, characterized in that, The left and right heating tubes are provided in multiples and arranged in a vertical array. The left mold has a left heating tube hole that passes through both ends of the left mold and is horizontally positioned. The left heating tube is accommodated in the left heating tube hole. The right mold has a right heating tube hole that passes through both ends of the right mold and is horizontally positioned. The right heating tube is accommodated in the right heating tube hole.

3. The rubber injection mold for rain boots according to claim 1, characterized in that, The upper mold is provided with an upper heating tube hole, which passes through both ends of the upper mold and is horizontally positioned, and the upper heating tube is accommodated in the upper heating tube hole.

4. The rubber injection mold for rain boots according to claim 1, characterized in that, The upper mold is fixedly connected to an operating lever. The connection points between the operating lever and the upper mold and the injection cavity are respectively located on both sides of the upper mold and are diagonally arranged. The extension direction of the operating lever is perpendicular to the rotation direction of the upper mold.

5. The rubber injection mold for rain boots according to any one of claims 1-4, characterized in that, A positioning component is fixedly connected to the base, which is located away from the inner last. A left positioning cavity is provided in the left cavity, and a right positioning cavity is provided in the right cavity. The left and right positioning cavities are combined to form a positioning groove for accommodating the positioning component.

6. The rubber injection mold for rain boots according to claim 5, characterized in that, The base is also provided with an inner heating tube lead-out cavity. The left mold is provided with a left heating tube lead-out cavity, and the right mold is provided with a right heating tube lead-out cavity. The left heating tube lead-out cavity and the right heating tube lead-out cavity are combined to extend the length of the corresponding inner heating tube lead-out cavity. The inner last is provided with a heating tube lead-out hole that communicates with the inner heating tube lead-out cavity, and the inner heating tube is accommodated in the heating tube lead-out hole.

7. The rubber injection mold for rain boots according to claim 5, characterized in that, The base is fixedly connected to a support shaft located outside the left and right molds, and both the left and right molds are movably connected to the support shaft.

8. The rubber injection mold for rain boots according to claim 7, characterized in that, The left mold is fixedly connected to a guide block located away from the support shaft. The guide block and the left cavity are located on the same side. The right mold is provided with a guide groove located away from the support shaft. The guide groove and the right cavity are located on the same side. The guide block is accommodated in the guide groove, and the guide surface of the guide block is inclined.

9. The rubber injection mold for rain boots according to claim 7, characterized in that, The right mold is movably connected to a mold cavity buckle located away from the support shaft, and the left mold is fixedly connected to a mold cavity latch located away from the support shaft. A compression spring is provided inside the mold cavity buckle. When the mold cavity buckle is tightly fastened to the mold cavity latch, the left mold and the right mold are in close contact, and the compression spring is in a relaxed state.

10. The rubber injection mold for rain boots according to claim 5, characterized in that, The positioning component is also provided with slots on both sides, with a left locking tenon that fits into the slot in the left positioning cavity and a right locking tenon that fits into the slot in the right positioning cavity.

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