Mold for injection molding of hollowed-out support

Abstract

The utility model relates to a mold for injection molding of a hollow support, which is provided with an upper mold and a lower mold, a mounting chamber is arranged between the upper mold and the lower mold, and the mounting chamber comprises an upper groove arranged in the upper mold and a lower groove arranged in the lower mold; a mold core is fixedly mounted in the mounting chamber, a cavity is formed in the mold core, and pre-deformation structures for providing shrinkage when a product is cooled are symmetrically arranged on the two sides of the cavity. The pre-deformation structures are symmetrically arranged on the two sides of the mold cavity, so that the shrinkage amount needed when a product is cooled is provided, and the design requirement is met.

Description

Technical Field

[0001] The utility model relates to the field of injection molds, and particularly to a mold for injecting a hollow bracket. Background Art

[0002] With the development of social economy, people have higher and higher requirements for plastic products. They not only require the actual size of the injection-molded products to meet the design size, but also require the appearance to be beautiful. The whole injection molding process is roughly divided into several steps: mold closing, injection, cooling and forming, and mold opening. Since the plastic product is at a relatively high temperature when the flowing plastic enters the cavity during the cooling and forming process. During the cooling and forming process, the flowing plastic cools into a solid product, so the whole will shrink during the cooling process. Therefore, when the injection-molded product is a flat surface, the traditional cavity design is adopted, and the size after cold cutting shrinkage is relatively close to the design size of the product, thus meeting the design requirements. However, when one surface of the product has a hollow design, such as Figure 6 as shown, the size after cold cutting shrinkage is quite different from the design size of the product, resulting in a large number of unqualified products. Since the product has a hollow design, the dimensional difference between two adjacent parts is relatively large, making the size of the product unstable.

[0003] For example, the Chinese patent with the publication number CN209616214U discloses a lightweight injection mold for the front frame of an automotive sunroof crossbeam based on pre-deformation compensation technology. The utility model sequentially includes a bottom plate, a movable template, a fixed template and an injection plate. The forming cavity is located between the movable template and the fixed template, and the injection product is located in the forming cavity. The injection plate has an injection port, and the injection port is communicated with the forming cavity. The forming cavity includes an outer frame body forming cavity recessed into the movable template. A crossbeam plate forming core protrudes from the surface of the movable template close to the fixed template. A pre-deformation forming core is fixedly connected to the edge of the crossbeam plate forming core close to the outer frame body forming cavity. The upper surface of the pre-deformation forming core is arc-shaped and is communicated with the outer frame body forming cavity. The utility model uses the injection mold to inject an injection product. Compared with the existing products made of high-strength steel, the weight is greatly reduced, thereby improving fuel economy, saving energy and reducing exhaust emissions. In the above technical solution, by fixedly connecting a pre-deformation forming core to the edge of the cavity, and the upper surface of the pre-deformation forming core is arc-shaped, it can solve the warping of the crossbeam plate generated during the cooling process during the injection process of the product, making the final injection product flatter. That is, an arc shape is set on the edge of the core, which is equivalent to adding a fixed part to the product during the injection process to prevent the product from warping. However, when one surface of the product is hollow-designed, the above problems will also occur. Summary of the Utility Model

[0004] To solve the above problems, the present utility model provides a mold for injection molding a hollow bracket. By symmetrically arranging pre-deformation structures on both sides of the cavity, the shrinkage amount required for the product during cooling is provided, so as to meet the design requirements.

[0005] To achieve the above object, the technical solution adopted by the present utility model is: a mold for injection molding a hollow bracket, which has an upper mold and a lower mold. There is an installation chamber between the upper mold and the lower mold. The installation chamber includes an upper groove provided in the upper mold and a lower groove provided in the lower mold; a mold core is fixedly installed in the installation chamber, and a cavity is provided in the mold core. Pre-deformation structures for providing shrinkage amount for the product during cooling are symmetrically provided in the cavity.

[0006] Preferably, the mold core includes a female mold fixed in the upper groove and a male mold fixed in the lower groove; side molds are provided on both sides of the male mold; the side molds are slidably installed in the lower mold.

[0007] Preferably, connection grooves communicating with the lower groove are provided on both sides of the lower groove; fixing platforms are integrally formed on both side walls of the connection grooves; a pressing plate is fixedly installed on the fixing platforms, and a sliding groove is formed between the pressing plate and the bottom surface of the connection groove; the side molds move in the sliding groove.

[0008] Preferably, an installation groove recessed downward is provided on the bottom surface of the connection groove, and a transition plate is fixedly installed in the installation groove, and the side mold abuts against the transition plate.

[0009] Preferably, a driving component for driving the two side molds to move simultaneously towards the male mold when the upper mold and the lower mold are closed is provided on the upper mold; the two driving components are symmetrically arranged on both sides of the upper groove.

[0010] Preferably, the driving component includes an inclined jack provided in the upper mold, an inclined plug rod is in interference fit in the inclined jack, one end of the inclined plug rod passes through the inclined jack and extends from the bottom surface of the upper mold to the outside of the upper mold; a limit hole with a clearance fit with the inclined plug is provided on the side mold.

[0011] Preferably, the pre-deformation structure includes a first pre-deformation surface and a second pre-deformation surface symmetrically arranged on both sides of the cavity. The first pre-deformation surface and the second pre-deformation surface are both arcs of the same structure. The vertical distance H from the vertex of the first pre-deformation surface to both end points of the first pre-deformation surface is set to 0.08 MM - 0.5 MM.

[0012] Preferably, cooling pipes are provided on the male mold, female mold, and side molds. The water inlet and outlet of the cooling pipes in the male mold are arranged on both sides of the lower mold, and the water inlet and outlet of the cooling pipes in the female mold are arranged on both sides of the upper mold. The water inlet and outlet of the cooling pipes in one of the side molds are arranged on one side of the side mold, and the water inlet and outlet of the cooling pipes in the other side mold are arranged on both sides of the side mold and adjacent to the water inlet and outlet on the upper mold.

[0013] The beneficial effects of the present utility model are as follows: 1. After the flowing plastic enters the pre-deformation structure, the thickness of the uncooled plastic is greater than the actual thickness of the product. After the injection molding is completed, the plastic begins to cool, turning the flowing plastic into solid plastic. Therefore, during the cooling process, the plastic begins to shrink. Since the thickness during injection is greater than the thickness of the product, the size after solidification is within the tolerance range of the designed size of the product.

[0014] 2. Through the separate design of the mold core, during subsequent maintenance, the mold core and any side mold can be repaired or replaced individually, without the need to repair or replace the entire upper mold or lower mold. Compared with the design where both the mold core and the cavity are arranged on the upper mold or lower mold, the later maintenance cost is lower. Description of the Drawings

[0015] Figure 1 is an exploded three-dimensional schematic diagram of the present utility model.

[0016] Figure 2 is a three-dimensional schematic diagram of the lower mold of the present utility model.

[0017] Figure 3 is a bottom view of the upper mold of the present utility model.

[0018] Figure 4 is a cross-sectional view of the mold core of the present utility model.

[0019] Figure 5 is an enlarged view of part A of the present utility model.

[0020] Figure 6 is a three-dimensional schematic diagram of the product of the present utility model.

[0021] Explanation of the reference numerals in the drawings: 01. Upper mold, 02. Lower mold, 03. Upper groove, 04. Lower groove, 05. Connection groove, 06. Female mold, 07. Male mold, 08. Side mold, 09. Fixed table, 10. Pressure plate, 11. Sliding groove, 12. Installation groove, 13. Transition plate, 14. Oblique insertion hole, 15. Oblique insertion rod, 16. Limit hole, 17. Mold core, 18. Mold cavity, 19. Notch, 20. First pre-deformation surface, 21. Second pre-deformation surface, 22. Cooling pipe, 23. Water inlet, 24. Water outlet, 25. Glue inlet, 26. Glue outlet, 27. Cavity. Detailed implementation mode

[0022] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model.

[0023] Please refer to Figures 1-6 As shown, the present utility model relates to a mold for injection molding a hollow bracket, which has an upper mold 01 and a lower mold 02. An upper groove 03 is arranged in the upper mold 01. A lower groove 04 is arranged in the lower mold 02. After the mold is closed, the upper groove 03 and the lower groove 04 are combined into an installation chamber, and a mold core is fixedly installed in the installation chamber through fasteners. By separately manufacturing the mold core, it is convenient for the later maintenance of the mold.

[0024] Please refer to Figures 1-3 As shown, on both sides of the lower groove 04, there are connecting grooves 05 that are perpendicular to and communicate with the lower groove 04. A female mold 06 is fixedly installed in the upper groove 03 through fasteners. A male mold 07 is fixedly installed in the lower groove 04 through fasteners. A side mold 08 is slidably installed in the connecting groove 05. On the upper mold 02, there is a driving component that drives the two side molds 08 to move simultaneously towards the male mold 07 when the upper mold 01 and the lower mold 02 are closed. The two driving components are symmetrically arranged on both sides of the upper groove 03. After the upper mold 01 and the lower mold 02 are closed, a complete mold core is formed by the male mold 07, the female mold 06, and the two side molds 08. Then, through the injection component arranged in the upper mold 01, glue is injected into the mold core, the product is cooled and formed in the mold core, and the formed product is taken out of the mold core by demolding to complete the production of the product. On both side walls of the connecting groove 05, there is an integrally formed fixing platform 09. The top surface of the fixing platform 09 and the side surface of the connecting groove 05 form a step. A pressing plate 10 is fixedly installed on the step through fasteners. One side of the pressing plate 10 is located on the step, while the other side is located outside the step and extends into the connecting groove 05. Thus, a sliding groove 11 is formed between the pressing plate 10 and the bottom surface of the connecting groove 05. The side mold 08 moves in the sliding groove 11.

[0025] Please refer to Figure 2 As shown, since the side mold 08 moves in the connecting groove 05, the service life of the connecting groove 05 is further improved. On the bottom surface of the connecting groove 05, there is a downwardly concave installation groove 12, and a transition plate 13 is fixedly installed in the installation groove 12 through fasteners. The transition plate 13 is made of high manganese steel, chromium alloy, cobalt-based alloy, stainless steel, tungsten carbide alloy, nickel-tungsten alloy, titanium alloy, aluminum bronze, carburized steel, HT200 cast iron, and other wear-resistant materials. When the side mold 08 moves in the sliding groove 11, the side mold 08 is in direct contact with the transition plate 13. The effect of improving the service life of the connecting groove 05 is achieved. At the same time, by arranging the transition plate 13, it is convenient to adjust the height of the side mold 08. So that all the side molds 08 are at the same height.

[0026] Please refer to Figure 3As shown in the figure, an inclined jacking hole 14 is disposed inside the upper mold 01 in an inclined manner. The inclined jacking hole 14 inclines from the top surface of the upper mold 01 towards the outer side surface of the upper mold 01. A fixing hole that is connected in communication with the inclined jacking hole 14 is provided on the top surface of the upper mold 01. A fixing plate is fixedly installed in the fixing hole through a fastener. An inclined inserting rod 15 is in interference fit inside the inclined jacking hole. The interference fit method is adopted to prevent the inclined inserting rod 15 from moving along the inclined jacking hole 14 during the mold closing process, thereby improving the stability of the inclined inserting rod 15. One end of the inclined inserting rod 15 abuts against the fixing plate, and the stability of the inclined inserting rod 15 is further improved through the arrangement of the fixing plate. The other end passes through the inclined jacking hole 14 and extends from the bottom surface of the upper mold 01 to the outside of the upper mold 01. A limiting hole 16 that is in clearance fit with the inclined inserting rod is provided on the side mold 08. The clearance fit method is adopted to ensure that the inclined inserting rod 15 can be taken out of the limiting hole 16 without the need to contact external force after being inserted into the limiting hole 16. Since the inclined inserting rod 15 is inclined, during the mold closing process, when the inclined inserting rod 15 is inserted into the limiting hole 16, a thrust force towards the male mold 07 is generated on the side mold 08. Thereby, the side mold 08 moves towards the male mold 07 along the sliding groove 11. On the contrary, during the mold opening process, when the inclined inserting rod 15 is taken out of the limiting hole 16, the side mold 08 is driven to move in the opposite direction of the male mold 07 in the sliding groove 11.

[0027] Please refer to Figures 4-5 As shown in the figure, a convex mold core 17 is provided on the center of the male mold 07, and a concave mold cavity 18 is provided inside the female mold 06. Notches 19 for accommodating the side mold 08 are provided on both sides of the male mold 07 and the female mold 06. After the mold is closed, the template on the side mold 08 is located inside the notch 19, so that a mold cavity 27 is formed between the mold core 17 and the side wall of the mold cavity 18 and the side mold 08. When the injection device inside the upper mold 01 injects flowing plastic into the mold cavity 27. After the injection is completed, the flowing plastic cools and solidifies inside the mold cavity 27.

[0028] To ensure that the size of the product is stable after cooling when injecting hollow products, an arc-shaped first pre-deformation surface 20 that is recessed towards the inside of the mold core 17 is provided on the outer surface of the mold core 17. Arc-shaped second pre-deformation surfaces 21 that are the same as the first pre-deformation surface 20 are provided on the side wall of the mold cavity 18 and the side mold 08. The first pre-deformation surface 20 and the second pre-deformation surface 21 are symmetrically arranged on both sides inside the mold cavity 27. Through the pre-deformation structure composed of the first pre-deformation surface 20 and the second pre-deformation surface 21. During use, due to the arrangement of the pre-deformation structure, when injecting plastic into the mold cavity 27, when the flowing plastic enters the pre-deformation structure, the thickness of the uncooled plastic is greater than the actual thickness of the product. After the injection is completed, the plastic starts to cool, turning the flowing plastic into solid plastic. Therefore, during the cooling process, the plastic starts to shrink. Since the thickness is greater than the thickness of the product during injection, the size after solidifying is within the tolerance range of the designed size of the product.

[0029] In order to control the size of the plastic more accurately and precisely during the shrinkage process, the vertical distance H from the vertex of the first pre-deformation surface 20 to the two end points of the first pre-deformation surface 20 is set to 0.08 MM - 0.5 MM.

[0030] For example, when the length of the hollow part of the product on one surface is less than 100 MM, the vertical distance H is set between 0.08 MM - 0.1 MM. Preferably 0.09 MM.

[0031] For example, when the length of the hollow part of the product on one surface is 100 MM - 150 MM, the vertical distance H is set between 0.1 MM - 0.16 MM. Preferably 0.12 MM.

[0032] For example, when the length of the hollow part of the product on one surface is 150 MM - 200 MM, the vertical distance H is set between 0.16 MM - 0.2 MM. Preferably 0.175 MM.

[0033] For example, when the length of the hollow part of the product on one surface is 200 MM - 250 MM, the vertical distance H is set between 0.21 MM - 0.24 MM. Preferably 0.23 MM.

[0034] For example, when the length of the hollow part of the product on one surface is 250 MM - 300 MM, the vertical distance H is set between 0.25 MM - 0.29 MM. Preferably 0.27 MM.

[0035] For example, when the length of the hollow part of the product on one surface is 300 MM - 350 MM, the vertical distance H is set between 0.3 MM - 0.36 MM. Preferably 0.35 MM.

[0036] When the length of the hollow part of the product on one surface is greater than 350 MM. The maximum value of the vertical distance H cannot exceed 0.5 MM. If H exceeds 0.5 MM. The actual size of the product after the plastic cools and shrinks is greater than the designed size of the product, and the size requirement cannot be met.

[0037] In the actual production process, different vertical distances H are selected according to the length of the hollow surface. In the actual production process, the difference between the actual size of the product after shrinkage and the designed size of the product is between 0.01 MM - 0.045 MM, which meets the tolerance requirements of the product design.

[0038] Please refer to Figure 1As shown in the figure, in order to enable the plastic to be quickly cooled and formed in the cavity 27, cooling pipes 22 are provided on the male mold 07, female mold 06 and side molds. The water inlet 23 and water outlet 24 of the cooling pipe 22 located in the male mold 07 are arranged on both sides of the lower mold 02, and the water inlet 23 and water outlet 24 of the cooling pipe 22 in the female mold 06 are arranged on both sides of the upper mold 01. The water inlet 23 and water outlet 24 of the cooling pipe 22 in one of the side molds 08 are arranged on one side of the side mold 08, and the water inlet 23 and water outlet 24 of the cooling pipe 22 in the other side mold 08 are arranged on both sides of the side mold and are adjacent to the water inlet 23 and water outlet 24 on the upper mold 01. By arranging the water inlets and outlets on both sides of the upper and lower molds and arranging the water inlets and outlets on one side of the side mold 08. It is equivalent to arranging the water inlets and outlets in three directions of the mold. Such a layout facilitates the user to observe the flow of the cooling water at all times. Instead of the user having to go around to the back of the mold to observe the flow of the cooling water. At the same time, cooling pipes are provided on the male mold, female mold and two side molds, which speeds up the cooling and forming speed of the flowing plastic in the cavity 27. Thereby improving the production efficiency from the side.

[0039] Please refer to Figure 1 As shown in the figure, the injection component includes a glue inlet 25 provided in the upper mold 01 and a plurality of glue outlets 26 located in the mold cavity 18. The glue inlet 25 and the glue outlets 26 are connected through a connecting pipe. The plurality of glue outlets are arranged on the diagonal of the mold cavity 18. The design of the glue outlet 26 using the diagonal line is more efficient in injecting glue compared to the traditional straight layout or only using one glue outlet 26. Most importantly, the plastic enters the cavity 27 more evenly and stably. There will be no glue blockage in the cavity 27. Thus avoiding the situation where the flowing plastic cannot reach all corners of the cavity 27.

[0040] It should be noted that for the sake of clear description, the fasteners described in this application are any one of screws, bolts and screws. At the same time, the "water inlets" installed in different positions are identified with the same reference numeral "23", and the "water outlets" installed in different positions are identified with the same reference numeral "24"; the "cooling pipes" installed in different positions are identified with the same reference numeral "22".

[0041] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inner", "front", "center", "both ends", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0042] In the present utility model, unless otherwise clearly stipulated and defined, terms such as "installation", "setting", "connection", "fixation", "rotary connection" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. Unless otherwise clearly defined, for those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0043] The above embodiments are only descriptions of the preferred embodiments of the present utility model, and do not limit the scope of the present utility model. Without departing from the design spirit of the present utility model, various deformations and improvements made by those of ordinary engineering and technical personnel in the art to the technical solutions of the present utility model shall fall within the protection scope determined by the claims of the present utility model.

Claims

1. A mold for injection molding a hollow bracket, comprising an upper mold and a lower mold, characterized in that: An installation chamber is provided between the upper mold and the lower mold, and the installation chamber includes an upper groove arranged in the upper mold and a lower groove arranged in the lower mold; a mold core is fixedly installed in the installation chamber, a cavity is arranged in the mold core, and a pre-deformation structure is symmetrically provided in the mold cavity to provide shrinkage for the product when cooling.

2. The mold for injection molding a hollow bracket according to claim 1, characterized in that: The mold core comprises a female mold fixed in the upper groove and a male mold fixed in the lower groove; side molds are arranged on both sides of the male mold; and the side molds are slidably installed in the lower mold.

3. The mold for injection molding a hollow bracket according to claim 2, characterized in that: The two sides of the lower groove are provided with connecting grooves which are interpenetrating with the lower groove; a fixing platform is integrally formed on the two side walls of the connecting groove; a pressing plate is fixedly installed on the fixing platform, and a sliding groove is formed between the pressing plate and the bottom surface of the connecting groove; the side mold moves in the sliding groove.

4. The mold for injection molding a hollow bracket according to claim 3, characterized in that: A downwardly recessed installation groove is provided on the bottom surface of the connecting groove, a transition plate is fixedly installed in the installation groove, and the side mold is in contact with the transition plate.

5. The mold for injection molding a hollow bracket according to claim 4, characterized in that: The upper die is provided with a driving component for driving the two side dies to move simultaneously toward the male die when the upper die and the lower die are closed; the two driving components are symmetrically arranged on both sides of the upper groove.

6. The mold for injection molding a hollow bracket according to claim 5, characterized in that: The driving component includes an oblique insertion hole obliquely arranged in the upper mold, an oblique insertion rod is interference fit in the oblique insertion hole, one end of the oblique insertion rod passes through the oblique insertion hole and extends from the bottom surface of the upper mold to the outside of the upper mold; a limiting hole is provided on the side mold to match the oblique insertion gap.

7. The mold for injection molding a hollow bracket according to claim 1, characterized in that: The pre-deformation structure includes a first pre-deformation surface and a second pre-deformation surface symmetrically arranged on both sides of the cavity, the first pre-deformation surface and the second pre-deformation surface are both arcs of the same structure, and the vertical distance H from the vertex of the first pre-deformation surface to the two end points of the first pre-deformation surface is set to 0.08MM-0.5MM.

8. The mold for injection molding a hollow bracket according to claim 2, characterized in that: The male mold, female mold and side molds are all provided with cooling pipes; the water inlet and water outlet of the cooling pipe in the male mold are arranged on both sides of the lower mold, and the water inlet and water outlet of the cooling pipe in the female mold are arranged on both sides of the upper mold; the water inlet and water outlet of the cooling pipe in one of the side molds are arranged on one side of the side mold, and the water inlet and water outlet of the cooling pipe in the other side mold are arranged on both sides of the side mold and are adjacent to the water inlet and water outlet on the upper mold.

9. The mold for injection molding a hollow bracket according to claim 2, characterized in that: The center of the male mold is provided with an outwardly protruding mold core, and the female mold is provided with an inwardly recessed mold cavity; notches for accommodating the side molds are provided on both sides of the male mold and the female mold; after the molds are closed, the template on the side mold is located in the notch, and a cavity is formed between the mold core, the side wall of the mold cavity and the side mold.

10. The mold for injection molding a hollow bracket according to claim 9, characterized in that: The upper mold is provided with a glue injection component for injecting plastic into the mold cavity. The glue injection component includes a glue inlet arranged in the upper mold and a plurality of glue outlets located in the mold cavity. The glue inlet and the glue outlets are connected through a connecting pipe; the plurality of glue outlets are arranged on the diagonal line of the mold cavity.

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