Injection coating integrated mold, automobile plastic front hood forming system and process

Abstract

The application discloses a kind of injection coating integration mould, automobile plastic front hatch forming system and process, mould includes fixed mould and movable mould, fixed mould and movable mould form left and right injection moulds;The fixed mould and movable mould form a mold cavity between, mechanical hand is provided on fixed mould, for grabbing the thermoformed sheet and the front hatch after forming, and pouring system is arranged at the side of fixed mould, for pouring reinforcing rib on the sheet B face after moulding forming;The paint injection system is arranged at the side of movable mould, for spraying paint on the sheet A face after moulding forming;A circle sealing rubber strip is provided on the outer circle of mold cavity, for sealing mold cavity.

Description

Technical Field

[0001] This invention mainly relates to the field of molding of automotive plastic front hood outer panels, specifically to an integrated mold and molding process for automotive plastic front hood injection coating. Background Technology

[0002] Currently, the molds for the inner and outer panels of the car hood are mainly made of stamping molds, which involve complex processes. Even injection molds suffer from low mold integration, multiple parts bonding, and low precision. At the same time, the cost of molds and fixtures is high.

[0003] Existing new energy electric vehicles do not have an engine in the front compartment. The inner and outer panels of the front compartment cover are made of plastic composite materials, and the molding mold is an injection mold. The inner panel mold is formed separately, the outer panel mold is formed separately, and the inner and outer panel molds are bonded together with glue after being formed separately. This molding method has many processes, low integration, and low precision. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide an integrated mold and molding process for injection and coating. This device is highly integrated and practical, simplifying the production process.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] In a first aspect, embodiments of the present invention provide an integrated injection molding and coating mold, comprising a fixed mold and a moving mold, the fixed mold and the moving mold forming a left-right injection mold, rather than a traditional top-bottom molding structure; a mold cavity is formed between the fixed mold and the moving mold, a robotic arm is provided on the fixed mold for gripping the formed thermoformed sheet and the formed front hatch, and a gating system is provided on the side of the fixed mold for casting reinforcing ribs on the B side of the molded sheet; the painting system is provided on the side of the moving mold for spraying paint on the A side of the molded sheet; a sealing strip is provided on the outer ring of the mold cavity for sealing the mold cavity during painting.

[0007] As a further technical solution, a demolding mechanism is provided on the fixed mold.

[0008] As a further technical solution, the demolding mechanism includes an ejector plate, ejector pins, ejector blocks, and an ejection drive. One end of the ejector block and ejector pin is fixed to the ejector plate, and the other end passes through the fixed mold plate and the hot runner in sequence. The output end of the ejection drive is fixed to the ejector plate. By driving the ejector plate to move, the ejector block and ejector pin can be extended or retracted. When the ejector block and ejector pin are extended, the workpiece is demolded.

[0009] As a further technical solution, the demolding mechanism also includes a guide component.

[0010] As a further technical solution, the casting system includes a sprue sleeve, a hot runner manifold, a main hot runner plate, multiple manifolds, and multiple hot nozzles; the sprue sleeve is connected to the main flow channel on the main hot runner plate, the main hot runner plate is connected to the manifolds through the manifold plate, and each manifold is connected to the manifold plate at one end and to the hot nozzle at the other end.

[0011] As a further technical solution, a hot nozzle sleeve is provided on the outside of the hot nozzle. The hot nozzle sleeve includes a heat insulation layer, a cooling layer and an injection molding sealant layer arranged sequentially from the inside to the outside. A water flow space is formed between the cooling layer and the sealant layer.

[0012] As a further technical solution, the sealing layer has a first water passage hole and a second water passage hole on opposite sides, and the water flows through the first water passage hole and the second water passage hole to connect with the cooling pipe.

[0013] As a further technical solution, the front end of the hot nozzle passes through the heat insulation layer, the cooling layer, and the sealing layer in sequence.

[0014] As a further technical solution, a pre-embedded groove is provided on the fixed mold, and the sealing strip is pre-embedded in the pre-embedded groove.

[0015] Secondly, the present invention also proposes an automotive plastic hood molding system, including the aforementioned integrated mold structure for injection and coating.

[0016] Thirdly, the present invention also proposes a process for molding automotive plastic hoods using the aforementioned integrated injection and coating mold, as follows:

[0017] The robotic arm grasps the formed thermoformed sheet and bakes it in a constant-temperature oven to soften it. Then, the robotic arm removes it and places it into the mold cavity. The moving mold closes, and the sheet is clamped and molded. The sealing strip is compressed under the pressure of the gating system and interferes with the pre-embedded groove. After the mold is locked with a certain clamping force, the injection device advances to make the nozzle fit with the mold. The molten material fills the mold cavity until it is full, and the screw maintains a certain pressure on the molten material. After the gate is sealed, the pressure holding process is canceled, and the sheet cools and solidifies naturally in the mold. At the same time, the gating system conveys granular plastic from the hopper forward for plasticization. After the pre-plasticizing metering and anti-delay process is completed, the moving mold retracts to the set position. After the mold is slightly opened, the sealing strip seals the mold cavity. The paint injection device begins to pour paint into the mold. After the front hatch is completely painted, the mold is opened and the front hatch is removed.

[0018] The beneficial effects of the above embodiments of the present invention are as follows:

[0019] 1. The integrated molding, injection and painting mold proposed in this invention can simultaneously realize three functions: molding, casting and painting. After the moving mold and fixed mold realize molding, the reinforcing ribs can be cast on the back of the workpiece. After the casting is completed, paint can be cast on the front of the workpiece. This mold can combine the production of the outer and inner panels of the front hatch in the prior art into one plate, which can have the functions of both the outer and inner panels. Therefore, this mold simplifies the production process of the front hatch, reduces tooling, lowers costs, increases integration and precision, and saves production space.

[0020] 2. This invention proposes to set a pre-embedded groove on the fixed mold, and set a sealing strip in the pre-embedded groove. After the B side of the workpiece is injected, the moving mold retracts to the set position. At this time, the mold is slightly opened. Since the sealing strip has a certain elasticity, the sealing strip can still seal the entire mold cavity. At this time, the paint injection begins. The setting of the sealing strip can prevent the paint from flowing out of the mold cavity.

[0021] 3. By rationally designing the gating system, the present invention performs injection molding on the B side of the sheet, reducing the pressure loss of the hot runner manifold and ensuring the strength of the reinforcing ribs on the B side, while also improving the quality of the injection molded parts.

[0022] 4. This invention achieves automatic sheet material gripping by designing a robotic arm on the mold, eliminating the need for manual gripping and improving work efficiency. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0024] Figure 1 A schematic diagram showing the state of the injection-molded parts of the front hood;

[0025] Figure 2 This is a schematic diagram of the injection mold structure in this invention, specifically a fixed mold.

[0026] Figure 3 This is a schematic diagram of the injection mold structure of the present invention, showing the second moving mold.

[0027] Figure 4 This is a view of the injection mold structure in this invention;

[0028] Figure 5 This is a view of the injection mold structure in this invention;

[0029] Figure 6 This is a cross-sectional view of the injection mold in this invention;

[0030] Figure 7This is a structural diagram of the gate hot nozzle and the hot nozzle sleeve in this invention;

[0031] Figure 8 This is a schematic diagram of the ejection device of the present invention;

[0032] Figure 9 This is a schematic diagram of the demolding mechanism of the present invention;

[0033] Figure 10 This is a schematic diagram of the cooling water channel structure in the mold according to the present invention;

[0034] Figure 11 This is a structural diagram of the robotic arm in the injection mold structure of the present invention;

[0035] Figure 12 This is a structural diagram showing the working state of the robotic arm in the injection mold structure of the present invention;

[0036] Figure 13(a) is a schematic diagram of the pre-embedded groove for the sealing strip;

[0037] Figure 13(b) is an enlarged schematic diagram of the pre-embedded groove for the sealing strip;

[0038] Figure 14 This is a schematic diagram of the sealing strip in the pre-embedded groove;

[0039] Figure 15 This is a schematic diagram of the casting system;

[0040] Explanation of reference numerals in the attached figures:

[0041] 1. Fixed mold plate; 2. Hot runner controller; 3. Sprue bushing; 4. Hot runner controller; 5. Hydraulic cylinder body; 6. Hydraulic cylinder base; 7. Moving mold core; 8. Mold foot; 9. Fixed mold core; 10. Square guide pillar; 11. Support pillar; 12. Moving mold plate; 13. Hot runner manifold plate; 14. Manifold heat insulation plate; 15. Ejector plate; 16. Fixed mold core; 17. Cooling water channel; 18. Sealing ring; 19. Fixed mold cavity; 20. Moving mold core; 22. Sealing layer; 23. Heat insulation layer; 24. Cooling layer; 25. Hot nozzle; 26. Hot nozzle bushing;

[0042] 27. Sloping top; 28. Graphite guide sleeve; 29. ​​Sloping top movable rod; 30. Sloping top movable rod fixing seat; 31. Sloping top universal base;

[0043] 32. Fixed mold slider structure; 33. Painting system; 34. Sealing strip; 35. Robot arm; 36. Embedded groove;

[0044] 37 Ejector plate, 38 Ejector pin, 39 Ejector drive component;

[0045] 40 Main hot runner; 41 Branch runner;

[0046] 42 Hot runner panel, 43 Pressure plate, 44 Spacer block. Detailed Implementation

[0047] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0048] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0049] For ease of description, the words "up," "down," "left," and "right" appearing in this invention only indicate that they are consistent with the up, down, left, and right directions of the accompanying drawings themselves, and do not limit the structure. They are merely for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0050] Terminology Explanation: In this invention, sheet B faces the back of the molded car hood, and sheet A faces the front of the molded car hood.

[0051] As described in the background section, because existing sheet metal parts cannot meet the requirements of new energy vehicles, new energy vehicles use plastic composite materials to make the hood (such as...). Figure 1 As shown in the diagram, existing front hood inner and outer panel molding molds are injection molds, with the inner panel mold and outer panel mold formed separately, and then bonded together with glue after the inner and outer panel molds are formed separately. This molding method involves many processes, has low integration, and low precision. To solve the above technical problems, this application proposes an integrated mold for injection molding and coating, as well as a molding method. This method has a simple structure, high integration, and is practical, simplifying the production process.

[0052] The technical solution adopted by the integrated molding and coating mold proposed in this embodiment is as follows: the inner and outer panels of the front hatch are integrally molded into a single plate, and are made of composite materials. After the composite material is molded by a complete set of molds, the reinforcing ribs are injected into the B side of the molded plate. After the reinforcing ribs are injected, the paint is poured into the A side of the plate, thus realizing the integration of the front hatch production.

[0053] The integrated injection molding and coating mold proposed in this embodiment includes a fixed mold and a moving mold, which form a left-right injection mold structure instead of a traditional top-bottom molding structure. A mold cavity is formed between the fixed mold and the moving mold. A robotic arm is installed on the fixed mold to grasp the thermoformed sheet and the formed front hatch. The gating system is located on the side of the fixed mold to cast reinforcing ribs on the B side of the molded sheet. The painting system is located on the side of the moving mold to spray paint the A side of the molded sheet.

[0054] Specifically, the structure of the fixed mold is as follows: Figure 2 As shown, the middle mold core corresponds to surface A of the sheet material; the structure of the moving mold is as follows. Figure 3 As shown, the middle mold core corresponds to side B of the sheet material;

[0055] The overall structure of the mold is as follows Figure 4 , Figure 5 , Figure 6 As shown, it includes a fixed plate 1 on the right and a fixed plate 12 on the left; wherein, a fixed mold is fixed on the fixed plate 1, and a movable mold is fixed on the fixed plate 12. The movable mold can move, and a locking mechanism is provided between the fixed mold and the movable mold; however, the locking mechanism is the same as the existing mold locking structure, and will not be described in detail here.

[0056] Furthermore, a gating system is provided on the fixed mold for casting reinforcing ribs on the B side of the sheet; the gating system includes a sprue sleeve 3, a hot runner controller 2, a hot runner controller 4, a hot runner manifold 13, a manifold heat insulation plate 14, a main hot runner plate 40, multiple manifolds 41 and multiple hot nozzles 25.

[0057] Among them, the sprue sleeve 3 is fixed on the fixed plate 1, the sprue sleeve 3 is connected to the main channel on the main hot runner plate, the main channel of the main hot runner plate 40 is connected to the branch channel of the hot runner branch plate 13, and multiple hot nozzles 25 are provided at the end of each branch channel.

[0058] Both the hot runner controller 2 and the hot runner controller 4 are installed on the side of the fixed mold, and their function is to control the hot runner injection process.

[0059] The aforementioned hot runner manifold 13 is disposed between the fixed plate 1 and the fixed template;

[0060] The main runner and the branch runners are converted by the manifold; one end of each branch runner is connected to the manifold, and the other end is connected to the hot runner nozzle 25; all hot runners are evenly distributed in the mold.

[0061] like Figure 15As shown, the gating system also includes a hot runner panel 42, a pressure plate 43, and multiple spacers 44; the hot runner panel 42 is located between the hot runner manifold 13 and the ejector plate 37, the pressure plate 43 is located between the hot runner panel 42 and the ejector plate 37, and the spacers 44 are evenly distributed among the multiple manifolds 41. The screw holes of the spacers 44 are through holes, and the spacers 44 are connected to the manifolds 41. The panel of the ejector plate 37 is located between the manifolds and the fixed mold panel. The hot runner panel, the pressure plate, and the spacers ensure the strength of the hot runner system on the mold after the glue is injected.

[0062] The mold also includes a demolding mechanism, such as... Figure 9 , Figure 6 As shown, the device includes an ejector plate 37, ejector pins 38, and an ejector drive 39. The ejector plate 37 is located on the right side of the hot runner manifold. The ejector pins 38 include several of them. One end of the ejector pin 38 is fixed to the ejector plate 37, and its movable part passes through the fixed template and the hot runner in sequence. The output end of the ejector drive 39 is fixed to the ejector plate 37, driving the ejector plate 37 to eject the workpiece together with the ejector pins 38.

[0063] Furthermore, the demolding mechanism also includes multiple guide components, each of which includes a guide post 10, and the guide post 10 is designed with a guide sleeve structure; the two ends of the guide post 10 are respectively connected to the pressure plate and the fixed mold fixing plate; the ejection fixing plate 15 and the ejector block are both fixed to the guide component fixing seat.

[0064] like Figure 8 As shown, the demolding mechanism of the fixed mold also includes an ejection device, which includes an inclined ejector 27. The bottom of the inclined ejector 27 is connected to two movable rods 29. Each movable rod 29 is provided with a graphite guide sleeve 28. At the bottom of the movable rod 29 is a universal base 30. The universal base 30 is connected to a fixed seat 31, which is fixed on the ejector plate 37.

[0065] This invention incorporates cooling water channels in the fixed mold, moving mold, and hot runner, primarily to dissipate excess heat from the mold to the outside. Specifically, as shown below... Figure 10 As shown.

[0066] like Figure 7 As shown, in this embodiment, the hot nozzle position of the casting system is also provided with a hot nozzle sleeve 26. The hot nozzle sleeve 26 includes a heat insulation layer 23, a cooling layer 24, and an injection molding sealing layer 22 arranged sequentially from the inside to the outside. The heat insulation layer 23 is inside the hot nozzle and plays a certain role in heat insulation. The cooling layer 24 is outside the heat insulation layer 23, and the sealing layer 22 is outside the cooling layer. A water flow space is formed between the cooling layer 24 and the sealing layer 22. A first water passage hole and a second water passage hole are respectively opened on opposite sides of the sealing layer 22. The water flow is connected to the cooling pipe through the first water passage hole and the second water passage hole to achieve cooling of the hot nozzle. The front end of the hot nozzle passes through the heat insulation layer 23, the cooling layer 24, and the sealing layer 22 in sequence.

[0067] The mold of this application also has a single-arm robot 35 (e.g., on the upper end of the fixed mold side) arranged. Figure 11 As shown), the main function of the robotic arm 35 is to grasp the thermoformed sheet and the finally formed plastic front hatch, such as... Figure 12 The diagram shown illustrates the gripping state of the robotic arm.

[0068] Compared with the prior art, the mold of this application is changed from the original sheet metal stamping mold to an injection mold. Compared with the existing injection mold technology, the mold of this application has a single-arm robot arranged on the upper end of the fixed mold side to grab the formed thermoformed sheet, bake it in a constant temperature oven to soften the sheet, and then the robot takes it out and fixes the sheet in the mold through positioning. Through the design of multiple gates in the hot runner, injection molding is performed on the B side of the sheet. Through the design of the gating system, the pressure loss of the hot runner manifold is reduced, ensuring the strength of the B side reinforcing ribs, while also improving the quality of the injection molded parts.

[0069] The specific molding process for the plastic hood using the above-mentioned mold is as follows:

[0070] A single-arm robotic arm is positioned on the upper end of the fixed mold side to grip the formed thermoformed sheet (the original sheet of the plastic front hatch). The sheet is then baked in a constant-temperature oven to soften it before being removed by the robotic arm. Pressure oil in the mold-closing cylinder drives the locking mechanism, causing the moving platen to move and close the mold. The sheet is fixed inside the mold cavity and clamped and molded following the mold's closing action. At this time, the sealing strip 34 fixed to the mold is compressed under the pressure of the injection molding machine, interfering with the fit in the pre-embedded groove 36 (as shown in Figures 13(a) and 13(b)). The pre-embedded groove 36 has dimensions of 5mm*7mm. After the mold is locked with a certain clamping force, the injection device advances to bring the nozzle into contact with the mold. After the molten material is opened through the hot runner valve needle, it fills the mold cavity until it is full. The screw maintains a certain pressure on the molten material to prevent backflow in the mold. After the gate is sealed, the pressure holding process is cancelled, and the product cools and solidifies naturally within the mold. Simultaneously, the injection molding machine drives the pre-plasticizing oil motor to rotate the screw, conveying the granular plastic from the hopper forward for plasticization. After the pre-plasticizing metering and anti-stretching processes are completed, the moving mold retracts to a set position of 0.5mm, and the mold slightly opens. Figure 14 The sealing strip 34 in the middle seals the cavity, and then the paint injection device starts to pour paint into the mold. The mold is sealed by the sealing strip 34 in the figure. After the plastic front cover is completely painted, the mold is opened and the plastic front cover is taken out by the robot.

[0071] Finally, it should be noted that relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An integrated injection molding and coating mold, characterized in that, The system includes a fixed mold and a moving mold, which together form left and right injection molds. A mold cavity is formed between the fixed mold and the moving mold. A robotic arm is mounted on the fixed mold for gripping the thermoformed sheet and the formed front hatch. A gating system is located on the side of the fixed mold for casting reinforcing ribs on side B of the molded sheet. A painting system is located on the side of the moving mold for painting side A of the molded sheet. A sealing strip is provided around the outer ring of the mold cavity for sealing the cavity. A demolding mechanism is provided on the fixed mold. The casting system includes a sprue bushing, a hot runner manifold, a main hot runner plate, multiple manifolds, and multiple hot nozzles. The sprue bushing is connected to the main runner on the main hot runner plate, and the main hot runner plate is connected to the manifolds via manifold plates. Each manifold is connected to the manifold plate at one end and to the hot nozzle at the other end. A hot nozzle bushing is also provided on the outside of the hot nozzle. The hot nozzle bushing includes a heat insulation layer, a cooling layer, and an injection sealing layer arranged sequentially from the inside to the outside. A water flow space is formed between the cooling layer and the sealing layer. A pre-embedded groove is provided on the fixed mold, and the sealing strip is pre-embedded in the pre-embedded groove. The sealing layer has a first water passage hole and a second water passage hole on opposite sides, and the water flows through the first water passage hole and the second water passage hole to connect with the cooling pipe. The tip of the hot nozzle passes through the heat insulation layer, the cooling layer, and the sealing layer in sequence.

2. The integrated molding and coating mold as described in claim 1, characterized in that, The demolding mechanism includes an ejector plate, ejector pins, ejector blocks, and an ejector drive. One end of the ejector block and ejector pin is fixed to the ejector plate, and the other end passes through the fixed mold plate and the hot runner in sequence. The output end of the ejector drive is fixed to the ejector plate. By driving the ejector plate to move, the ejector block and ejector pin can be extended or retracted. When the ejector block and ejector pin are extended, the workpiece is demolded.

3. The integrated molding and coating mold as described in claim 1, characterized in that, The demolding mechanism also includes guide components.

4. A molding system for automotive plastic hoods, comprising an integrated injection and coating mold as described in any one of claims 1-3.

5. The process for molding an automotive plastic hood using an integrated injection and coating mold as described in any one of claims 1-3, characterized in that, The robotic arm grasps the formed thermoformed sheet and bakes it in a constant-temperature oven to soften it. Then, the robotic arm removes it and places it into the fixed mold. The injection molding machine closes the moving mold, clamping and molding the sheet. The sealing strip is compressed under the pressure of the gating system and interferes with the pre-embedded groove. After the mold is locked with a certain clamping force, the injection device advances to make the nozzle and the mold fit together. The molten material fills the mold cavity until it is full, and the screw maintains a certain pressure on the molten material. After the gate is sealed, the pressure holding process is canceled, and the sheet cools and solidifies naturally in the mold. At the same time, the gating system conveys granular plastic from the hopper forward for plasticization. After the pre-plasticizing metering and anti-delay process is completed, the moving mold retracts to the set position. After the mold is slightly opened, the sealing strip seals the mold cavity. The paint injection device begins to pour paint into the mold. After the front hatch is completely painted, the mold is opened and the front hatch is removed.

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