Multi-material co-injection based automotive instrument panel forming system and method

Abstract

The application discloses a multi-material co-injection-based automobile instrument panel forming system and method, relates to the field of multi-material co-injection, and comprises a multi-station rotary die platform, a multi-material injection unit and an intelligent temperature control module. The application plans the collaborative work of the multi-station rotary die platform, the multi-material injection unit and the intelligent temperature control module, takes rotary station circulation as the core, material gradient forming as the path and precise temperature control as the guarantee, realizes the integrated forming of an automobile instrument panel from surface functional decoration to a structural framework, takes a rotary lifting driving device as a core transmission component, drives a core core die assembly to accurately switch among multiple injection stations, realizes the closing and separation of the core die assembly and each station core die assembly. The core die assembly is matched with the modular design of the core die assembly through a quick release structure, can complete the replacement of instrument panel molds of different vehicle models in a short time, and meets the production requirements of multiple varieties.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of multi-material co-injection molding, in particular to a multi-material co-injection molding based automobile instrument panel forming system and method. BACKGROUND

[0002] As a core component of automobile interior, the automobile instrument panel not only needs to meet the basic functions of structural support and safety protection, but also needs to have decorative, comfortable touch and intelligent interaction capabilities, such as integrated touch, atmosphere lamp and other functions. With the development of lightweight, integration and high-end of the automobile industry, the traditional instrument panel production process has gradually exposed many limitations, as follows:

[0003] The traditional automobile instrument panel production usually adopts a step-by-step forming and late assembly mode, involving 7-8 independent processes such as skeleton injection molding, surface decoration lamination, soft touch layer foaming, and functional component assembly, which has problems of low production efficiency, poor quality consistency, and low material utilization rate.

[0004] Although the existing multi-material co-injection molding technology has improved the integration, there are still key technical bottlenecks: the surface decoration process is limited: the mainstream adopts IMD film pre-pasting technology, which has problems of high film cost, wrinkling in complex surface lamination, and texture pattern switching requiring replacement of film mold; some technologies attempt in-mold spraying, but have defects such as poor coating uniformity and weak bonding with the base material;

[0005] The conductive layer and optical signal transmission layer need to be pasted or printed later, which not only increases the process, but also easily leads to functional failure due to poor interface bonding;

[0006] The traditional soft touch layer uses single component spraying or foaming, which is difficult to achieve hardness gradient adjustment in different areas, and the cell uniformity is poor, which is easy to collapse after long-term use;

[0007] In summary, it is urgent to develop a new multi-material co-injection molding forming system and method to realize integrated production from surface decoration, functional integration to structural forming and break through the bottleneck of traditional process. SUMMARY

[0008] In order to solve the above technical problems, the present application provides a multi-material co-injection molding based automobile instrument panel forming system and method. The following technical solutions are adopted:

[0009] The multi-material co-injection based automobile instrument panel forming system comprises a multi-station rotary die platform, a multi-material injection unit and an intelligent temperature control module. The multi-station rotary die platform comprises an injection platform, a plurality of injection stations, a plurality of die assemblies and a rotary core punch assembly. The plurality of injection stations are respectively installed on the injection platform. The plurality of die assemblies are respectively installed on the plurality of injection stations. The rotary core punch assembly comprises a rotary lifting driving device and a core punch assembly. The rotary lifting driving device is located above the injection platform. The core punch assembly is detachably installed on the rotary lifting part of the rotary lifting driving device.

[0010] The multi-material injection unit comprises a multifunctional surface forming device and a main injection device. The soft touch layer forming device is used for spraying a multifunctional decorative layer on the inner wall of the cavity of the die assembly and the core punch assembly before the injection action. The main injection device is connected with the core punch assembly. When the core punch assembly is connected with the die assembly, the injection action is performed.

[0011] The intelligent temperature control module controls the temperature of the die cavity formed after the core punch assembly is connected with the die assembly.

[0012] Optionally, the multifunctional surface forming device comprises a multi-modal adaptive printing assembly and a soft touch material precise coating assembly. The multi-modal adaptive printing assembly comprises a UV inkjet sub-module and a functional material extrusion sub-module. The UV inkjet sub-module is used for spraying a decorative texture on the inner wall of the cavity of the die assembly and the core punch assembly. The functional material extrusion sub-module is used for printing a functional layer. The functional layer comprises a conductive layer and an optical signal conduction layer. The soft touch material precise coating assembly sprays a TPO soft touch base material on the surface of the cavity after being sprayed by the UV inkjet sub-module by using an ultrasonic vibration atomizing nozzle.

[0013] Optionally, the multifunctional surface forming device further comprises a mechanical arm, a visual positioning module and a plasma surface activation assembly. The base of the mechanical arm is installed on one side of the multi-station rotary die platform. The nozzles of the multi-modal adaptive printing assembly and the soft touch material precise coating assembly are respectively installed on the movable end of the mechanical arm. The visual positioning module is installed on the movable end of the mechanical arm and is used for visually identifying and positioning the cavity position of the die assembly and the core punch assembly.

[0014] The multifunctional surface forming device further comprises a plasma surface activation assembly. The plasma surface activation assembly is installed on the movable end of the mechanical arm and is used for low-temperature plasma treatment on the cavity surface of the die assembly and the core punch assembly before the multi-modal adaptive printing assembly and the soft touch material precise coating assembly act.

[0015] Optionally, the main injection device comprises an injection molding machine, an injection outlet rotary joint, a conveying pipeline and a punch inlet rotary joint, one end of the conveying pipeline is communicated with the molten material outlet of the injection molding machine through the injection outlet rotary joint, and the other end is communicated with the injection port of the core punch assembly through the punch port rotary joint.

[0016] Optionally, the rotary lifting driving device comprises an electric turntable and a lifting electric cylinder, the base of the electric turntable is mounted on the support, the cylinder body of the lifting electric cylinder is detachably mounted on the rotating part of the electric turntable and rotates with the rotating part, the piston rod of the lifting electric cylinder faces the injection station, and the core punch assembly is detachably mounted on the end of the piston rod of the lifting electric cylinder, and the core punch assembly is clamped with the counter-connection by the action of the electric turntable and the lifting electric cylinder.

[0017] Optionally, the intelligent temperature control module comprises multiple sets of circulating liquid temperature control devices, a temperature detection module and a temperature controller, the multiple core punch assemblies and the core punch assembly are provided with temperature control flow channels, the circulating liquid inlets and outlets of the multiple sets of circulating liquid devices are respectively communicated with the temperature control flow channels of the multiple core punch assemblies and the core punch assembly, the temperature detection module respectively collects the temperatures in the multiple core punch assemblies and the core punch assembly, the temperature controller is in communication connection with the temperature detection module, and the execution actions of the multiple sets of circulating liquid temperature control devices are respectively controlled based on the temperature detection data and the set temperature control data.

[0018] Optionally, it further comprises an industrial control computer, which controls the execution actions of the multiple-station rotary mold platform, the multiple-material injection unit and the intelligent temperature control module.

[0019] The automobile instrument panel forming method based on multi-material co-injection is performed by using the automobile instrument panel forming system based on multi-material co-injection, and comprises the following steps:

[0020] Step 1, spraying argon and carbon dioxide mixed plasma on the inner wall of the cavity;

[0021] Step 2, inkjet printing is performed on the cavity surface of the core punch assembly, and hidden texture is printed on the corresponding area of the core punch assembly at the same time;

[0022] Step 3, extruding conductive paste to form a conductive layer and extruding optical conductive material to form an optical signal conductive layer in the core punch assembly;

[0023] Step 4, spraying two-component TPO soft touch material on the surface of the decorative texture and the functional layer;

[0024] Step 5, the core punch assembly is transferred to the second injection station;

[0025] Step 6, the multiple-material injection unit is used for injection to obtain an automobile instrument panel product.

[0026] Optionally, the following detailed steps are included:

[0027] Step 1, the industrial control computer controls the electric rotating disc to rotate, moves the core mold assembly to the first injection molding station, drives the core mold assembly to descend by the lifting electric cylinder, and the visual positioning module photographs the inner wall of the cavity to feed the position deviation to the mechanical arm;

[0028] Step 2, the mechanical arm carries the plasma surface activation assembly into the cavity between the core mold assembly and the core mold assembly, sprays the mixed plasma of argon and carbon dioxide, and performs global scanning processing on the inner wall of the cavity;

[0029] Step 3, switch to the UV inkjet sub-module, perform inkjet printing on the cavity surface of the core mold assembly according to the preset pattern, print the hidden texture on the corresponding area of the core mold assembly at the same time, after completion, the mechanical arm carries the UV lamp to cure the texture;

[0030] Step 4, the mechanical arm switches to the functional material extrusion sub-module, extrudes the conductive paste to form a conductive layer in the designed area of the core mold assembly, and extrudes the optical conductive material to form an optical signal conductive layer in the edge area of the instrument panel;

[0031] Step 5, the mechanical arm switches to the soft touch material precise coating assembly, sprays the two-component TPO soft touch material on the surface of the decorative texture and the functional layer;

[0032] Step 6, the lifting electric cylinder drives the core mold assembly to ascend, and the electric rotating disc rotates to move the core mold assembly to the second injection molding station;

[0033] Step 7, the lifting electric cylinder drives the core mold assembly to close with the core mold assembly, and the multi-material injection molding unit and the intelligent temperature control module act to perform injection molding to obtain the finished product of the automobile instrument panel.

[0034] Optionally, the Z-axis micro compensation mechanism is additionally installed at the end of the mechanical arm, according to the cavity depth deviation of the core mold assembly fed back by the visual positioning module, the distance between the extrusion head and the cavity surface is dynamically adjusted, and the specific method of dynamic adjustment is: based on the filtered deviation value, the extrusion head distance to be adjusted is calculated, and a compensation coefficient is introduced to avoid overshoot:

[0035] ;

[0036] Wherein is the distance between the extrusion head and the cavity surface after dynamic adjustment, is the target distance between the extrusion head and the cavity surface, is a correction coefficient for balancing the adjustment sensitivity and stability, is the average value of the cavity depth deviation of the core mold assembly fed back by the visual positioning module for n times.

[0037] Optionally, in step 7, injection molding includes the following sub-steps:

[0038] Step 71, the injection molding machine starts plasticizing, heats the injection material to melt, injects the melt into the tree-shaped shunt flow channel of the core mold assembly through the conveying pipeline, and finally fills the mold cavity from multiple shunt ports in a radial manner;

[0039] Step 72, after the melt fills the cavity, the injection molding machine switches to the pressure maintaining mode, and the intelligent temperature control module maintains the core mold assembly and the cavity mold assembly at the set temperature for a certain time;

[0040] Step 73, after the heat preservation and pressure maintaining is completed, the industrial control computer instructs the intelligent temperature control module to switch to the cooling mode, and after cooling, the lifting cylinder drives the core mold assembly to rise and separate from the cavity mold assembly, and the automobile instrument panel product is taken out.

[0041] In summary, the present application includes at least one of the following beneficial technical effects:

[0042] The present application can provide a multi-material co-injection based automobile instrument panel forming system and method, which coordinates the collaborative work of a multi-station rotary mold platform, a multi-material injection molding unit and an intelligent temperature control module, takes rotary station circulation as the core, material gradient forming as the path, and precise temperature control as the guarantee, realizes the integrated forming of automobile instrument panels from surface functional decoration to structural framework, and takes the rotary lifting drive device as the core transmission component to drive the core mold assembly to accurately switch between multiple injection molding stations and realize the closing and separation with the cavity mold assemblies. The core mold assembly can complete the replacement of different vehicle instrument panel molds in a short time through the quick release structure cooperating with the modular design of the cavity mold assembly, meeting the production needs of multiple varieties.

[0043] The soft touch layer forming device of the multi-material injection molding unit is used to spray a multifunctional decorative layer on the inner wall of the cavity of the core mold assembly before the injection molding action, and the main injection molding device performs the injection molding action after the spraying of the multifunctional decorative layer is completed; through multi-station rotary continuous operation, the production cycle of a single instrument panel is greatly shortened; the 7-8 discrete processes such as pretreatment, decoration, functional layer forming, injection molding, cooling, etc. are integrated into an integrated system, saving material transfer time and reducing equipment floor space. The quick release structure of the core mold assembly greatly shortens the mold replacement time and can be compatible with multiple vehicle instrument panel production; it fully breaks through the efficiency, quality and flexibility bottleneck of traditional automobile instrument panel production, and provides an industrializable technical solution for the high-end and intelligent production of automobile interiors. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 is the structural principle schematic diagram of the automobile instrument panel forming system based on multi-material co-injection of the present application;

[0045] Figure 2Fig. 1 is a schematic diagram of a component connection principle of a multi-material co-injection automobile instrument panel forming system according to the present application.

[0046] BRIEF DESCRIPTION OF DRAWINGS: 11, injection platform; 12, injection station; 13, cavity mold assembly; 14, rotating core mold assembly; 141, core mold assembly; 142, electric turntable; 143, lifting electric cylinder; 21, multifunctional surface forming device; 211, multimodal adaptive printing assembly; 212, soft touch material precision coating assembly; 213, mechanical arm; 214, visual positioning module; 215, plasma surface activation assembly; 22, main injection device; 221, injection molding machine; 222, injection outlet rotary joint; 223, conveying pipeline; 224, core mold inlet rotary joint; 4, industrial control computer; 100, support. DETAILED DESCRIPTION

[0047] The present application will be further described in detail below with reference to the accompanying drawings.

[0048] The present application discloses a multi-material co-injection automobile instrument panel forming system and method.

[0049] REFERENCE Figure 1 and Figure 2 Embodiment 1, a multi-material co-injection automobile instrument panel forming system, comprises a multi-station rotary mold platform, a multi-material injection unit and an intelligent temperature control module, the multi-station rotary mold platform comprises an injection platform 11, a plurality of injection stations 12, a plurality of cavity mold assemblies 13 and a rotating core mold assembly 14, the plurality of injection stations 12 are respectively installed on the injection platform 11, the plurality of cavity mold assemblies 13 are respectively installed on the plurality of injection stations 12, and the rotating core mold assembly 14 comprises a rotating lifting driving device and a core mold assembly 141, the rotating lifting driving device is located above the injection platform 11, and the core mold assembly 141 is detachably installed on the rotating lifting part of the rotating lifting driving device;

[0050] The multi-material injection unit comprises a multifunctional surface forming device 21 and a main injection device 22, the soft touch layer forming device 22 is used for spraying a multifunctional decorative layer on the inner wall of the cavity of the cavity mold assembly 13 and the core mold assembly 141 before the injection action, and the main injection device 22 is connected with the core mold assembly 141, and the injection action is performed after the core mold assembly 141 is connected with the cavity mold assembly 13;

[0051] The intelligent temperature control module controls the temperature of the mold cavity formed after the core mold assembly 141 is connected with the cavity mold assembly 13.

[0052] By adopting the above technical scheme, through the collaborative work of the industrial control computer 4, the multi-station rotary mold platform, the multi-material injection molding unit and the intelligent temperature control module, the rotation station circulation is taken as the core, the material gradient forming is taken as the path, and the precise temperature control is taken as the guarantee, the integrated forming of the automobile instrument panel from the surface functional decoration to the structural framework is realized, and the specific operation mechanism is as follows:

[0053] The rotary lifting driving device is a core transmission component, drives the core mold assembly 141 to realize 360° intermittent rotation and lifting, can accurately switch between multiple injection molding stations 12, realize closing and separation with each station mold assembly 13, and is typically provided with four stations, which are respectively a pretreatment / decoration station, a functional layer forming station, a main injection molding station and a cooling and taking station, to realize closing and separation with each station mold assembly 13.

[0054] The core mold assembly 141 is connected with the lifting electric cylinder 143 through a quick release structure, such as a positioning pin plus an electromagnetic lock, and cooperates with the modular design of the mold assembly 13, so that the mold for different vehicle instrument panels can be replaced in a short time to meet the production demand of multiple varieties.

[0055] The soft touch layer forming device 22 of the multi-material injection molding unit is used to spray a multifunctional decorative layer on the inner wall of the cavity of the mold assembly 13 and the core mold assembly 141 before the injection molding action, and the main injection molding device 22 performs the injection molding action after the spraying of the multifunctional decorative layer is completed;

[0056] The plurality of mold assemblies 13 and the core mold assembly 141 are provided with independent temperature control channels, and the intelligent temperature control module realizes differential adjustment.

[0057] In the pretreatment / decoration stage, the temperature of the mold and the mold is controlled at 80±5℃, so as to ensure sufficient UV curing and stability of the soft touch material pre-coating;

[0058] In the main injection molding stage, the temperature of the mold is increased to 150±5℃ (to reduce the melt flow resistance), and the temperature of the mold is adjusted according to the region to avoid weld marks;

[0059] In the cooling stage, through 25℃ cold water circulation, the temperature of the cavity is reduced to 40±3℃ within 10 seconds to ensure the dimensional stability of the framework.

[0060] Through multi-station rotary continuous operation, the production cycle of a single instrument panel is shortened from the traditional 120-180 seconds to 45-60 seconds, and the beat is increased by 67%-75%;

[0061] The 7-8 discrete processes such as pretreatment, decoration, functional layer forming, injection molding, cooling and the like are integrated into an integrated system, the material transfer time is saved, and the equipment occupies an area is reduced.

[0062] The quick release structure of the core punch assembly 141 shortens the mold changing time from more than 30 minutes to less than 15 minutes, and is compatible with 5-8 vehicle instrument panel production;

[0063] The above technical solutions comprehensively break through the efficiency, quality and flexibility bottlenecks of traditional automobile instrument panel production, and provide an industrializable technical solution for high-end and intelligent production of automobile interiors.

[0064] In embodiment 2, the multifunctional surface forming device 21 includes a multi-modal adaptive printing assembly 211 and a soft touch material precision coating assembly 212. The multi-modal adaptive printing assembly 211 includes a UV inkjet sub-module and a functional material extrusion sub-module. The UV inkjet sub-module is used for spraying decorative texture on the inner wall of the cavity of the core punch assembly 141 and the concave die assembly 13. The functional material extrusion sub-module is used for printing a functional layer, which includes a conductive layer and an optical signal conduction layer. The soft touch material precision coating assembly 212 sprays TPO soft touch base material on the cavity surface after being sprayed by the UV inkjet sub-module.

[0065] In embodiment 3, the multifunctional surface forming device 21 further includes a mechanical arm 213 and a visual positioning module 214. The base of the mechanical arm 213 is installed on one side of the multi-station rotary die platform. The spray heads of the multi-modal adaptive printing assembly 211 and the soft touch material precision coating assembly 212 are respectively installed on the movable end of the mechanical arm 213. The visual positioning module 214 is installed on the movable end of the mechanical arm 213, and is used for visually identifying and positioning the cavity position of the core punch assembly 141 and the concave die assembly 13.

[0066] In embodiment 4, the multifunctional surface forming device 21 further includes a plasma surface activation assembly 215. The plasma surface activation assembly 215 is installed on the movable end of the mechanical arm 213, and performs low-temperature plasma treatment on the cavity surface of the core punch assembly 141 and the concave die assembly 13 before the multi-modal adaptive printing assembly 211 and the soft touch material precision coating assembly 212 act.

[0067] By adopting the above technical solutions, the multifunctional surface forming device 21 takes the mechanical arm 213 as a motion carrier, integrates the plasma surface activation assembly 215, the multi-modal adaptive printing assembly 211, the UV inkjet sub-module, the functional material extrusion sub-module, and the soft touch material precision coating assembly 212, and realizes precise operation of the cavity surface through the visual positioning module 214. Each assembly is linked according to a preset time sequence to complete the whole process from surface activation to functional layer and soft touch layer forming, and finally provides a substrate with decorative, functional and comfortable touch for subsequent injection molding.

[0068] When the core punch assembly 141 and the die assembly 13 reach the designated station, the visual positioning module 214, composed of two sets of industrial cameras and laser profile sensors, performs 3D scanning on the inner wall of the cavity, obtains the deviation between the actual profile and the theoretical model, and transmits the data to the control system of the mechanical arm 213.

[0069] The mechanical arm 213 corrects the motion trajectory in real time according to the visual positioning results, ensuring that the distance and angle of each working component to the surface of the cavity remain consistent, avoiding working deviations caused by mold installation errors or thermal deformation.

[0070] The mechanical arm 213 carries the plasma surface activation assembly 215 into the cavity, sprays Ar and CO2 mixed gas to form low-temperature plasma, removes surface impurities such as oil and oxidation layer through high-energy particle bombardment, greatly improves cleanliness, and introduces hydroxyl (-OH) and carboxyl (-COOH) polar groups to increase surface energy from 30 mN / m to more than 70 mN / m, significantly enhancing the adhesion of the subsequent coating. The mechanical arm 213 drives the plasma nozzle to scan the entire cavity along an S-shaped path at a speed of 50-100 mm / s, ensuring that each surface treatment time is greater than 1 s, achieving uniform activation.

[0071] High-precision inkjet and curing: The UV inkjet sub-module uses a piezoelectric nozzle to spray UV curing ink according to the pre-set pattern onto the activated cavity surface, forming a 0.02-0.05 mm thick texture layer; simultaneously equipped with a UV-LED lamp to irradiate and cure immediately after inkjetting, avoiding ink dripping.

[0072] For the inner cavity of the core punch assembly 141, the UV inkjet sub-module synchronously prints hidden textures, realizing differentiated decoration on both sides of the instrument panel.

[0073] Using a screw-type micro-extrusion head, silver nanoparticle conductive paste is extruded according to the circuit pattern to form a 0.1 mm thick conductive layer, meeting the touch sensing requirements;

[0074] For the atmosphere lamp light guide area, transparent silicone is extruded to form a 0.2 mm thick conductive layer, and the mechanical arm precisely controls the path to ensure uniform light transmission;

[0075] The extrusion temperature is adjusted according to the material properties (conductive paste 80°C, silicone 120°C) to avoid high-temperature damage to the already cured UV texture layer.

[0076] The soft-touch material precision coating assembly 212 uses an ultrasonic vibration atomization nozzle to atomize two-component TPO soft-touch base material (A component: hydroxyl-terminated TPO; B component: isocyanate curing agent, ratio 10:1) into 5-10 μm fine droplets, which are uniformly sprayed onto the surface of the decorative layer and functional layer through compressed air.

[0077] The whole process is linked with the intelligent temperature control module through the industrial control computer 4, so as to ensure that the cavity temperature is stabilized at 80±5℃, and to provide the best environment for the curing and adhesion of each coating.

[0078] The multifunctional surface forming device 21 realizes the integrated forming of decoration, function and soft touch layer, and lays a core foundation for the high-quality and multifunctional production of the automobile instrument panel.

[0079] In the embodiment 5, the main injection molding device 22 comprises an injection molding machine 221, an injection molding outlet rotary joint 222, a conveying pipeline 223 and a core mold inlet rotary joint 224. One end of the conveying pipeline 223 is communicated with the molten material outlet of the injection molding machine 221 through the injection molding outlet rotary joint 222, and the other end is communicated with the injection molding port of the core mold assembly 141 through the core mold inlet rotary joint 224.

[0080] By adopting the above technical scheme, the double mechanical sealing structure of the injection molding outlet rotary joint 222 and the core mold inlet rotary joint 224 can adapt to the 360° rotation and lifting action of the core mold assembly 141, ensure that there is no leakage in the molten material conveying process, and solve the sealing failure problem of the traditional fixed connection under the rotating working condition.

[0081] The combination of the conveying pipeline 223 and the rotary joint realizes the synchronous movement of the molten material conveying path with the core mold, guarantees the continuity of injection molding during multi-station rotation switching, and meets the multi-station integrated production demand.

[0082] The quick docking design of the core mold inlet rotary joint 224 and the core mold assembly 141, combined with the detachable structure of the core mold, eliminates the need to disassemble the molten material conveying pipeline during mold replacement, shortens the mold replacement time to within 15 minutes, and improves the production flexibility of multiple varieties.

[0083] In the embodiment 6, the rotary lifting driving device comprises an electric turntable 142 and a lifting electric cylinder 143. The base of the electric turntable 142 is mounted on the support 100, the cylinder body of the lifting electric cylinder 143 is detachably mounted on the rotating part of the electric turntable 142 and rotates with the rotating part, the piston rod of the lifting electric cylinder 143 faces the injection molding station 12, and the core mold assembly 141 is detachably mounted on the end of the piston rod of the lifting electric cylinder 143. When the electric turntable 142 and the lifting electric cylinder 143 act to dock the core mold assembly 141 with the female mold assembly 13, the mold is closed.

[0084] By adopting the above technical scheme, the electric turntable 142 is driven by a servo motor, drives the lifting electric cylinder 143 and the core mold assembly 141 to realize 360° intermittent rotation, and can accurately switch between multiple injection molding stations 12. The lifting electric cylinder 143 drives the core mold assembly 141 to lift, so as to realize the closing and separation with each station female mold assembly 13.

[0085] In the embodiment 7, the intelligent temperature control module comprises a plurality of circulating liquid temperature control devices, a temperature detection module and a temperature controller, the plurality of recessed die assemblies 13 and the core male die assembly 141 are respectively provided with temperature control flow channels, the circulating liquid inlets and outlets of the plurality of circulating liquid devices are respectively communicated with the temperature control flow channels of the plurality of recessed die assemblies 13 and the core male die assembly 141, the temperature detection module respectively collects the temperatures in the plurality of recessed die assemblies 13 and the core male die assembly 141, the temperature controller is in communication connection with the temperature detection module, and the execution actions of the plurality of circulating liquid temperature control devices are respectively controlled based on the temperature detection data and the set temperature control data.

[0086] The industrial control computer 4 is further included, and the industrial control computer 4 respectively controls the execution actions of the plurality of multi-station rotary die platforms, the plurality of multi-material injection molding units and the intelligent temperature control module.

[0087] Through the above technical scheme, the plurality of circulating liquid temperature control devices are one-to-one corresponding to the independent temperature control flow channels of the recessed die assemblies 13 and the core male die assembly 141, and the temperature requirements of different stations can be differentiated and adjusted.

[0088] In the pretreatment stage, the temperatures of the recessed die and the male die are synchronously and stably kept at 80±5℃, so that the UV curing is fully ensured, the soft touch material is uniformly coated, and the dripping caused by low temperature or the early curing caused by high temperature is avoided.

[0089] In the injection molding stage, the temperature of the male die is independently increased to 150±5℃, so that the melt flow resistance is reduced, and the recessed die is provided with 140℃ (edge) and 120℃ (center) according to regions, so that the weld mark is reduced and the filling fullness is improved.

[0090] In the cooling stage, the temperature of the cavity is rapidly reduced to 40±3℃ through the 25℃ cold water circulation, so that the size stability of the framework is ensured.

[0091] Compared with the traditional unified temperature control mode, the interface combination and molding requirements of the multi-materials are met.

[0092] The temperature detection module can collect the cavity temperature in real time based on the detection forms of the PT100 sensor and the infrared temperature detector, and the temperature controller dynamically adjusts the circulating liquid flow through the PID algorithm.

[0093] When the local temperature deviation is detected to be more than 3℃, the circulating liquid temperature or flow is corrected within 3 seconds, so that the defects caused by temperature fluctuation are avoided.

[0094] For the complex surface of the large instrument panel, the temperature difference of each region of the cavity is controlled to be within 5℃ through the flow channel flow distribution optimization, and the product consistency is improved.

[0095] In the embodiment 8, the automobile instrument panel molding method based on the multi-material co-injection molding is used to perform the automobile instrument panel injection molding by using the automobile instrument panel molding system based on the multi-material co-injection molding, and comprises the following steps:

[0096] Step 1, spray argon and carbon dioxide mixed plasma on the inner wall of the cavity;

[0097] Step 2, inkjet printing on the surface of the cavity of the female mold assembly 13, and synchronously printing hidden texture on the corresponding area of the core male mold assembly 141;

[0098] Step 3, extruding conductive paste to form a conductive layer and extruding optical conductive material to form an optical signal conductive layer on the female mold assembly 13;

[0099] Step 4, spraying two-component TPO soft touch material on the surface of the decorative texture and functional layer;

[0100] Step 5, the core male mold assembly 141 is transferred to the second injection molding station;

[0101] Step 6, multi-material injection molding unit for injection molding to obtain the finished product of the automobile instrument panel.

[0102] The above method is implemented by the following specific operations:

[0103] The core male mold assembly 141 is lowered, and the visual positioning module 214 feeds back the position deviation to the mechanical arm 213;

[0104] The plasma surface activation assembly 215 sprays argon and carbon dioxide mixed plasma on the inner wall of the cavity;

[0105] The UV inkjet sub-module performs inkjet printing on the surface of the cavity of the female mold assembly 13 according to the preset pattern, and synchronously prints hidden texture on the corresponding area of the core male mold assembly 141;

[0106] The functional material extrusion sub-module extrudes conductive paste to form a conductive layer and extrudes optical conductive material to form an optical signal conductive layer on the female mold assembly 13;

[0107] The soft touch material precise coating assembly 212 sprays two-component TPO soft touch material on the surface of the decorative texture and functional layer;

[0108] The core male mold assembly 141 is transferred to the second injection molding station;

[0109] The core male mold assembly 141 is closed with the female mold assembly 13, and the multi-material injection molding unit is used for injection molding to obtain the finished product of the automobile instrument panel.

[0110] Embodiment 9 includes the following detailed steps:

[0111] Step 1, the industrial control computer 4 controls the electric rotating disc 142 to rotate, moves the core male mold assembly 141 to the first injection molding station, drives the core male mold assembly 141 to lower by the lifting electric cylinder 143, and the visual positioning module 214 photographs the inner wall of the cavity and feeds back the position deviation to the mechanical arm 213;

[0112] Step 2, the mechanical arm 213 carries the plasma surface activation assembly 215 into the cavity between the core mold assembly 141 and the core mold assembly 13, sprays argon and carbon dioxide mixed plasma, and performs global scanning processing on the inner wall of the cavity;

[0113] Step 3, switch to the UV inkjet sub-module, and perform inkjet printing on the surface of the cavity of the core mold assembly 13 according to the preset pattern, and simultaneously print hidden textures on the corresponding area of the core mold assembly 141, after completion, the mechanical arm 213 carries the UV lamp to cure the textures;

[0114] Step 4, the mechanical arm 213 switches to the functional material extrusion sub-module, and extrudes conductive paste to form a conductive layer in the designed area of the core mold assembly 13; and extrudes optical conductive material to form an optical signal conductive layer in the edge area of the instrument panel;

[0115] Step 5, the mechanical arm 213 switches to the soft touch material precise coating assembly 212, and sprays two-component TPO soft touch material on the surface of the decorative texture and the functional layer;

[0116] Step 6, the lifting cylinder 143 drives the core mold assembly 141 to rise, and the electric rotating disc 142 rotates, so that the core mold assembly 141 is transferred to the second injection molding station;

[0117] Step 7, the lifting cylinder 143 drives the core mold assembly 141 to close with the core mold assembly 13, and the multi-material injection molding unit and the intelligent temperature control module act to perform injection molding to obtain the finished product of the automobile instrument panel.

[0118] In embodiment 10, the end of the mechanical arm 213 is additionally provided with a Z-axis micro compensation mechanism, which dynamically adjusts the distance between the extrusion head and the surface of the cavity according to the depth deviation of the cavity of the core mold assembly 13 fed back by the visual positioning module. The specific method of dynamic adjustment is as follows: based on the filtered deviation value, the distance of the extrusion head to be adjusted is calculated, and a compensation coefficient is introduced to avoid overshoot:

[0119] ;

[0120] Wherein is the distance between the extrusion head and the surface of the cavity after dynamic adjustment, is the target distance between the extrusion head and the surface of the cavity, is a correction coefficient for balancing the adjustment sensitivity and stability, is the average value of the depth deviation of the cavity of the core mold assembly 13 fed back by the visual positioning module for n times.

[0121] By adopting the above technical scheme, combined with the K value anti-overshoot design, the final extrusion head distance fluctuation is controlled within ±0.005mm, the corresponding conductive layer thickness deviation is less than 0.03mm, and the surface resistance uniformity error is less than 3%, meeting the conductive function requirements of the automobile instrument panel;

[0122] The optical signal transmission layer is stable in distance, the material flow rate is uniform during extrusion, the light transmittance is high, and the thickness deviation is less than 0.02mm, ensuring that the optical signal is transmitted without attenuation at the edge of the instrument panel.

[0123] Avoiding the accumulation of slurry due to too close distance or the lack of slurry due to too far distance, the one-time forming qualified rate of the functional layer is greatly improved.

[0124] In step 7 of embodiment 11, injection molding includes the following sub-steps:

[0125] Step 71, the injection molding machine 221 starts plasticizing, heats the injection molding raw material to melting, injects the melt into the tree-shaped shunt flow channel of the core mold assembly 141 through the conveying pipeline 223, and finally fills the mold cavity from multiple shunt ports in a radial manner;

[0126] Step 72, after the melt fills the cavity, the injection molding machine 221 switches to the pressure maintaining mode, and the intelligent temperature control module keeps the core mold assembly 141 and the concave mold assembly 13 at the set temperature for a certain time;

[0127] Step 73, after the heat preservation and pressure maintaining ends, the industrial control computer 4 instructs the intelligent temperature control module to switch to the cooling mode, and after cooling, the lifting cylinder 143 drives the core mold assembly 141 to rise and separate from the concave mold assembly 13, and the automobile instrument panel product is taken out.

[0128] The following specific embodiments are used to illustrate the implementation principle of the present application:

[0129] A certain new energy automobile center control instrument panel needs to integrate carbon fiber decorative texture, touch sensing function, atmosphere lamp light guide strip and partition soft touch layer, and adopts a multi-material co-injection based automobile instrument panel forming system for automobile instrument panel injection molding, and the specific parameters and processes are as follows:

[0130] System composition and initialization:

[0131] Multi-station rotary mold platform:

[0132] Containing 4 injection molding stations: pretreatment / decoration station, functional layer forming station, main injection molding station, cooling and taking station, evenly distributed along the injection molding platform 11 (interval 90°).

[0133] Die assembly 13: Made of P20 mold steel, with a cavity surface roughness of Ra0.8μm and built-in partitioned temperature control flow channel; Core punch assembly 141 is made of 718H mold steel with chrome plating, and is connected to lifting electric cylinder 143 through a positioning pin + electromagnetic locking quick-release structure.

[0134] Rotary lifting drive device: electric turntable 142, lifting electric cylinder 143 with a stroke of 150mm.

[0135] Multi-material injection molding unit:

[0136] Multifunctional surface forming device 21: robotic arm 213, equipped with vision positioning module 214, two 5-megapixel industrial cameras and laser contour sensor; plasma surface activation component 215; UV inkjet sub-module; functional material extrusion sub-module; soft touch material precision coating component 212.

[0137] Main injection unit 22: injection molding machine 221; conveying pipe 223; injection outlet / punch inlet rotary joint.

[0138] Four sets of circulating fluid temperature control devices (flow rate 0-50L / min, temperature control range 20-200℃); temperature detection module (PT100 sensor + infrared thermometer, accuracy ±0.1℃); temperature controller (PID regulation, response time <1s).

[0139] Industrial control computer 4 communicates with each module via Ethernet and is pre-installed with a process management system.

[0140] II. Molding process:

[0141] Step 1: System Initialization:

[0142] The industrial control computer 4 completes a self-test within 30 seconds of startup, confirming that all modules are fault-free; it then calls the process parameter package for the new energy vehicle dashboard, including:

[0143] Pretreatment temperature: Die / Punch 80±5℃;

[0144] Injection molding parameters: PP-LGF30 melt temperature 240℃, injection pressure 90bar, holding time 6s; Soft contact layer parameters: A / B component ratio 10:1 (master area) / 11:1 (passenger area), coating thickness 0.6mm / 0.8mm.

[0145] Step 2: Plasma activation:

[0146] The electric turntable 142 rotates the core punch assembly 141 to the work station, and the lifting electric cylinder 143 drives it to descend to a distance of 13-150mm from the die assembly; the vision positioning module 214 scans the cavity, provides feedback on the position deviation, and the robotic arm 213 automatically compensates for it.

[0147] Plasma surface activation assembly 215 starts: power 600W, scanning speed 80mm / s, processing the whole cavity for 1.5s; after processing, the surface oil removal rate is 99%, and the surface energy reaches 75mN / m.

[0148] Step 3: UV decorative texture printing:

[0149] The UV inkjet sub-module adopts black polyurethane UV ink to print carbon fiber texture on the surface of the concave mold assembly 13-1, with a thickness of 0.03mm; at the same time, model identification is printed on the inside of the core convex mold assembly 141.

[0150] UV-LED lamp irradiation for 2s, energy density 900mJ / cm², texture curing degree greater than 95%, no sagging. Step 4: functional layer forming:

[0151] The electric turntable 142 is indexed to the work station, and the mechanical arm 213 is switched to the functional material extrusion sub-module: conductive layer: in the steering wheel corresponding area of the concave mold assembly 13-2, extrude silver nano paste (, forming a 0.1mm thick conductive circuit;

[0152] Optical transmission layer: extrude transparent silicone at the edge of the instrument panel to form a 0.2mm thick light guide strip; extrusion temperature 120℃ to avoid damaging the UV texture.

[0153] Step 5: soft touch layer coating:

[0154] The mechanical arm 213 is switched to the soft touch material precise coating assembly 212:

[0155] Main driver area: spray two-component TPO at a ratio of 10:1, thickness 0.6mm;

[0156] Co-pilot area: spray at a ratio of 11:1, thickness 0.8mm;

[0157] Ultrasonic atomization pressure 0.3MPa, coating speed 40mm / s, infrared preheating 60℃ to ensure uniform spreading. Step 6: indexing to injection molding station:

[0158] The lifting cylinder 143 drives the core convex mold assembly 141 to rise 100mm, the electric turntable 142 rotates 90° to the work station, and the concave mold assembly 13-3 has been preheated to 120℃.

[0159] Step 7: mold closing and injection molding:

[0160] The lifting cylinder 143 drives the core convex mold assembly 141 to descend and close the mold, and the convex mold inlet rotary joint 224 is sealed and connected with the core convex mold injection port.

[0161] Sub-step 71: The injection molding machine 221 heats the PP-LGF 30 to 240°C, injects it into the core mold tree runner through the delivery pipe 223, and fills the cavity by radiation.

[0162] Sub-step 72: After the melt is filled, the pressure is maintained for 6s, the intelligent temperature control module maintains the temperature of the core mold at 150°C, the temperature of the edge of the cavity mold at 140°C, and the temperature of the center at 120°C.

[0163] Sub-step 73: After the pressure holding is completed, the circulating liquid temperature control device is connected to 25°C cold water, and the cavity temperature is reduced to 40°C within 10s; the lifting cylinder 143 drives the core mold to rise, and the robot takes the part.

[0164] Step 8: Cooling and detection:

[0165] The product is transferred to the station, and the 3D visual inspection shows:

[0166] The decorative texture clarity is 1200 dpi, and there is no defect;

[0167] The thickness deviation of the soft touch layer is ±0.02mm, and the hardness meets the standard;

[0168] The conductive layer has good conductivity, and the brightness deviation of the light guide strip is less than 3%.

[0169] Production efficiency: single cycle 52s, 65% higher than traditional process (150s), equipment area reduced by 40%. Product quality: appearance defect rate 0.3%, soft touch layer bonding force 9N / cm, skeleton bending strength 85MPa, warpage 0.4mm / m.

[0170] Material cost: save IMD film and glue, cost reduction 18%, corner scrap recovery rate 92%.

[0171] Flexible production: mold changing time 12min, compatible with 8 vehicle models instrument panel production.

[0172] This embodiment verifies the feasibility of the technical scheme in the production of complex functional instrument panels, and realizes efficient, high-quality and low-cost integrated molding.

[0173] The above are preferred embodiments of the present application, but do not limit the protection scope of the present application, therefore: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A multi-material co-injection molding system for automotive dashboards, characterized in that: The system includes a multi-station rotary mold platform, a multi-material injection unit, and an intelligent temperature control module. The multi-station rotary mold platform includes an injection platform (11), multiple injection stations (12), multiple cavity mold assemblies (13), and a rotating core punch assembly (14). The multiple injection stations (12) are respectively installed on the injection platform (11), and the multiple cavity mold assemblies (13) are respectively installed on the multiple injection stations (12). The rotating core punch assembly (14) includes a rotary lifting drive device and a core punch assembly (141). The rotary lifting drive device is located above the injection platform (11), and the core punch assembly (141) is detachably installed on the rotary lifting part of the rotary lifting drive device. The multi-material injection molding unit includes a multi-functional surface molding device (21) and a main injection molding device (22). The multi-functional surface molding device (21) is used to spray a multi-functional decorative layer on the inner wall of the cavity of the cavity assembly (13) and the core punch assembly (141) before the injection molding action. The main injection molding device (22) is connected to the core punch assembly (141). The injection molding action is performed after the core punch assembly (141) is docked with the cavity assembly (13). The intelligent temperature control module controls the temperature of the mold cavity formed after the core punch assembly (141) and the die assembly (13) are docked; The multi-functional surface forming device (21) includes a multi-modal adaptive printing component (211) and a soft-touch material precision coating component (212). The multi-modal adaptive printing component (211) includes a UV inkjet sub-module and a functional material extrusion sub-module. The UV inkjet sub-module is used to spray decorative textures on the inner walls of the cavity of the die component (13) and the core punch component (141). The functional material extrusion sub-module is used to print functional layers, including conductive layers and optical signal transmission layers. The soft-touch material precision coating component (212) uses an ultrasonic vibration atomizing nozzle to spray TPO soft-touch base material onto the cavity surface after being sprayed by the UV inkjet sub-module. The multifunctional surface forming device (21) also includes a robotic arm (213), a vision positioning module (214), and a plasma surface activation component (215). The base of the robotic arm (213) is installed on one side of the multi-station rotary mold platform. The nozzles of the modal adaptive printing component (211) and the soft-touch material precision coating component (212) are respectively installed on the movable end of the robotic arm (213). The vision positioning module (214) is installed on the movable end of the robotic arm (213) and is used to visually identify and position the cavity position of the concave mold component (13) and the core punch component (141). The plasma surface activation component (215) is installed at the movable end of the robotic arm (213) and performs low-temperature plasma treatment on the cavity surfaces of the die assembly (13) and the core punch assembly (141) before the modal adaptive printing component (211) and the soft-touch material precision coating component (212) move.

2. The automotive dashboard molding system based on multi-material co-injection molding according to claim 1, characterized in that: The main injection molding device (22) includes an injection molding machine (221), an injection outlet rotary joint (222), a conveying pipe (223), and a punch inlet rotary joint (224). One end of the conveying pipe (223) is connected to the molten material outlet of the injection molding machine (221) through the injection outlet rotary joint (222), and the other end is connected to the injection port of the core punch assembly (141) through the punch inlet rotary joint (224).

3. The automotive dashboard molding system based on multi-material co-injection molding according to claim 2, characterized in that: The rotary lifting drive device includes an electric turntable (142) and a lifting cylinder (143). The base of the electric turntable (142) is mounted on a bracket (100). The cylinder body of the lifting cylinder (143) is detachably mounted on the rotating part of the electric turntable (142) and rotates with the rotating part. The piston rod of the lifting cylinder (143) faces the injection molding station (12). The core punch assembly (141) is detachably mounted on the end of the piston rod of the lifting cylinder (143). When the electric turntable (142) and the lifting cylinder (143) move, the core punch assembly (141) is docked to achieve mold closing.

4. The automotive dashboard molding system based on multi-material co-injection molding according to claim 3, characterized in that: The intelligent temperature control module includes multiple sets of circulating fluid temperature control devices, a temperature detection module, and a temperature controller. The multiple concave mold components (13) and the core punch component (141) are all provided with temperature control channels. The circulating fluid inlets and outlets of the multiple sets of circulating fluid devices are respectively connected to the temperature control channels of the multiple concave mold components (13) and the core punch component (141). The temperature detection module collects the internal temperature of the multiple concave mold components (13) and the core punch component (141). The temperature controller is communicatively connected to the temperature detection module and controls the execution actions of the multiple sets of circulating fluid temperature control devices based on the temperature monitoring data and the set temperature control data. It also includes an industrial control computer (4), which controls the execution actions of each actuator of the multi-station rotary mold platform, the multi-material injection molding unit and the intelligent temperature control module.

5. A method for molding automotive dashboards based on multi-material co-injection molding, characterized in that: The automotive dashboard injection molding process using the multi-material co-injection molding system described in claim 4 includes the following steps: Step 1: Inject a mixed plasma of argon and carbon dioxide into the inner wall of the cavity; Step 2: Inkjet printing is performed on the cavity surface of the die assembly (13), and hidden textures are simultaneously printed in the corresponding area of ​​the core punch assembly (141). Step 3: Extruding conductive slurry to form a conductive layer and extruding optical conductive material to form an optical signal transmission layer in the die assembly (13); Step 4: Spray a two-component TPO soft touch material onto the decorative texture and functional layer surfaces; Step 5: The core punch assembly (141) is transferred to the second injection molding station; Step 6: The multi-material injection molding unit performs injection molding to obtain the finished car dashboard.

6. The automotive dashboard molding method based on multi-material co-injection molding according to claim 5, characterized in that, The following detailed steps are included: Step 1: The industrial control computer (4) controls the electric turntable (142) to rotate and transfer the core punch assembly (141) to the first injection station. The lifting electric cylinder (143) drives the core punch assembly (141) to descend. The vision positioning module (214) takes pictures of the inner wall of the cavity and feeds back the position deviation to the robotic arm (213). Step 2: The robotic arm (213) carries the plasma surface activation component (215) into the cavity between the concave mold component (13) and the core punch component (141), and sprays a mixed plasma of argon and carbon dioxide to perform a full-area scanning process on the inner wall of the cavity. Step 3: Switch to the UV inkjet sub-module and perform inkjet printing on the cavity surface of the concave mold assembly (13) according to the preset pattern. Simultaneously, print hidden textures in the corresponding area of ​​the core convex mold assembly (141). After completion, the robotic arm (213) is equipped with a UV lamp to cure the texture. Step 4: The robotic arm (213) switches to the functional material extrusion submodule, extrudes conductive slurry in the design area of ​​the die assembly (13) to form a conductive layer; and extrudes optical conductive material in the edge area of ​​the dashboard to form an optical signal conductive layer. Step 5, the robotic arm (213) switches to the soft touch material precision coating assembly (212) to spray a two-component TPO soft touch material onto the decorative texture and functional layer surfaces; Step 6: The lifting electric cylinder (143) drives the core punch assembly (141) to rise, and the electric turntable (142) rotates to transfer the core punch assembly (141) to the second injection molding station. Step 7: The lifting electric cylinder (143) drives the core punch assembly (141) and the die assembly (13) to close, and the multi-material injection molding unit and the intelligent temperature control module perform injection molding to obtain the finished car dashboard.

7. The automotive dashboard molding method based on multi-material co-injection molding according to claim 6, characterized in that, A Z-axis micro-compensation mechanism is added to the end of the robotic arm (213). Based on the depth deviation of the concave mold cavity fed back by the vision positioning module, the distance between the extrusion head and the surface of the cavity is dynamically adjusted. The specific method of dynamic adjustment is as follows: based on the filtered deviation value, the distance of the extrusion head to be adjusted is calculated, and a compensation coefficient is introduced to avoid overshoot. ； in It is the distance between the extruder head and the cavity surface that is dynamically adjusted. It is the target distance between the extruder head and the cavity surface. It is a correction factor used to balance sensitivity and stability. It is the average value of the depth deviation of the concave model cavity reported by the visual positioning module in the last n times.

8. The automotive dashboard molding method based on multi-material co-injection molding according to claim 7, characterized in that: Step 7, injection molding includes the following sub-steps: Step 71: The injection molding machine (221) starts plasticizing, heats the injection molding material to melt, and injects the melt into the tree-shaped distribution channel of the core punch assembly (141) through the delivery pipe (223), and finally fills the mold cavity radially from multiple distribution ports. Step 72: After the melt fills the cavity, the injection molding machine (221) switches to the holding pressure mode and continues for a set time. The intelligent temperature control module keeps the core punch assembly (141) and the die assembly (13) at the set temperature. Step 73: After the heat preservation and pressure preservation are completed, the industrial control computer (4) instructs the intelligent temperature control module to switch to the cooling mode. After cooling, the lifting electric cylinder (143) drives the core punch assembly (141) to rise and separate from the die assembly (13) to remove the finished car dashboard.

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