Automotive engine hood cover uniform foaming extrusion die

Abstract

The application discloses a uniform foaming extrusion die for a car engine cover, and relates to the technical field of plastic forming.The uniform foaming extrusion die comprises a die main body, a melt distribution structure and a flow adjusting device.The melt distribution structure is connected with an extruder through a flange type constant temperature interface in a main feeding channel, so that the melt is stably inputted;in a three-stage diffusion flow divider, a first-stage fan-shaped diffusion cavity preliminarily diffuses the melt and changes the flow direction, a second-stage flow guide fin guides the melt flow and adjusts the flow distribution, and a third-stage corrugated flow channel increases the melt flow path and the contact area;and the arc transition surfaces between the stages reduce the flow resistance and the turbulence intensity, so that the melt distribution is more uniform;and a PID control module dynamically adjusts the power of a spiral heating pipe and the flow speed of a spiral cooling pipe according to real-time temperature data, so that the temperature of a forming cavity is accurately controlled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastic forming, in particular to a uniform foaming extrusion die for an automobile engine cover. BACKGROUND

[0002] Under the promotion of automobile lightweighting and energy saving demand, plastic engine covers gradually become the mainstream solution due to their large forming freedom and significant weight reduction effect, which can be injection molded by a foaming extrusion die. The foaming extrusion die controls the bubble nucleation, expansion and solidification process in the plastic melt to achieve lightweighting and performance balance.

[0003] The existing foaming extrusion die has the following defects:

[0004] 1. Patent document US4797083A discloses an extrusion die for manufacturing foamed thermoplastic webs, but the device in the above document has the technical problem of uneven distribution of the melt during transportation and extrusion, resulting in poor movement effect of the melt;

[0005] 2. Patent document US06383425B1 discloses a method for extruding foamed polypropylene sheets with improved surface appearance, but the device in the above document has the technical problem of being unable to flexibly adjust the extrusion direction according to the needs of different products;

[0006] 3. Patent document US20150048535A1 discloses a foaming polymeric material cooling method and device, but the device in the above document has the technical problem of short service life of the flow channel during use;

[0007] 4. Patent document CN104385554A discloses a PVC foaming plate extrusion die, but the device in the above document has the technical problems of poor flexibility and easy leakage. SUMMARY

[0008] The present application aims to provide a uniform foaming extrusion die for an automobile engine cover to solve the technical problems raised in the background art.

[0009] To achieve the above-mentioned purpose, the present application provides the following technical solution: a uniform foaming extrusion die for an automobile engine cover, comprising a die body, a melt distribution structure and a flow adjusting device, the die body is internally provided with a melt distribution structure and a flow adjusting device, the die body comprises an upper die and a lower die, the front end of the top of the lower die is provided with a mounting groove, the inner wall of the mounting groove is movably connected with the upper die, and the lower die and the upper die are provided with a forming cavity matched with the profile of the automobile engine cover;

[0010] The melt distribution structure comprises a main feeding channel, a three-stage diffusion distributor and a gradient temperature control unit, and the main feeding channel is arranged in the middle of the back surface of the lower mold, the input end of the main feeding channel is connected with a flange type constant temperature interface through bolts, and the other end of the flange type constant temperature interface is connected with the input end of an extruder through bolts;

[0011] The three-stage diffusion distributor comprises a first-stage fan-shaped diffusion cavity, a second-stage flow guide fin and a third-stage corrugated flow channel, and arc transition surfaces are arranged between the first-stage fan-shaped diffusion cavity and the second-stage flow guide fin and between the second-stage flow guide fin and the third-stage corrugated flow channel, the first-stage fan-shaped diffusion cavity is used for preliminarily diffusing the melt and changing the flow direction, the second-stage flow guide fin is used for guiding the melt flow and adjusting the flow distribution, the third-stage corrugated flow channel is used for increasing the melt flow path and the contact area, and the arc transition surfaces are used for reducing the flow resistance and reducing the turbulence intensity;

[0012] The gradient temperature control unit is alternately provided with a spiral heating pipe and a spiral cooling pipe along the circumference of the forming cavity, the gradient temperature control unit comprises an embedded thermocouple array and a PID control module, the embedded thermocouple array is used for longitudinally arranging 3-5 groups of temperature measuring points along the forming cavity, and the PID control module is used for dynamically adjusting the power of the spiral heating pipe and the flow rate of the cooling liquid of the spiral cooling pipe according to real-time temperature data.

[0013] Preferably, the flow adjusting device comprises a multi-stage pressure buffer and an adjustable extrusion terminal, the multi-stage pressure buffer is arranged inside the main feeding channel, the multi-stage pressure buffer is composed of alternately connected tapered sections and expanded sections, a turbulence suppression ring is arranged at the connection position of the tapered sections and the expanded sections, an annular groove with a depth of 0.2-0.4 mm is arranged on the inner wall of the turbulence suppression ring, and a porous ceramic damping sheet is embedded and installed in the annular groove;

[0014] The adjustable extrusion terminal is arranged at the output end of the three-stage diffusion distributor, the output end of the adjustable extrusion terminal is provided with eight extrusion heads with independent angle adjusting mechanisms, each extrusion head is provided with a spherical hinge adjusting mechanism and a pressure compensation ring, and eight equalizing holes are arranged in the pressure compensation ring.

[0015] Preferably, the first-stage fan-shaped diffusion cavity, the inlet of which communicates with the outlet of the main feeding channel, has a diffusion intersection angle of 90-120°;

[0016] The second-stage flow guide fin is composed of radially distributed fins, and the interval between the fins decreases by 5-15% from the center to the edge;

[0017] The third-stage corrugated flow channel has a corrugated surface with an amplitude of 1-3 mm and a wavelength of 5-8 mm, forming a serpentine flow path;

[0018] The transition curvature radius R of the arc transition surface is 1.2-1.5 times the height of the cavity.

[0019] Preferably, the inner wall of the third-stage corrugated flow channel is provided with a nanoscale lyophobic coating for improving the service life of the flow channel wall and preventing damage caused by erosion of the melt.

[0020] Preferably, the porous ceramic damping sheet has a porosity of 45-65%, a pore size of 0.05-0.25 mm, and a honeycomb support framework embedded therein, the honeycomb support framework being made of silicon carbide material and having a wall thickness of 20-33% of the pore diameter to form a hierarchical filtering structure.

[0021] Preferably, a double-seal structure is provided at the joint surface of the upper die and the lower die, including a metal labyrinth seal ring on the outside and a silicon nitride ceramic seal strip on the inside, the metal labyrinth seal ring being provided with three layers of staggered sawtooth structures with a spacing of 0.8-1.2 mm between adjacent sawteeth to form a non-contact dynamic seal.

[0022] The top of the upper die is provided with a connecting mechanism for connecting a lifting device.

[0023] Preferably, the ball joint adjustment mechanism is integrated with a micro servo motor and an angle encoder, the micro servo motor drives the extrusion head to make a three-dimensional angle fine adjustment within a range of ±15° through a worm gear transmission mechanism, and the angle resolution is 0.1°, and the angle encoder forms a closed-loop feedback system with a PID control module.

[0024] Preferably, the ejection mechanism includes a hydraulic cylinder, and the outer wall of the hydraulic cylinder is fitted and installed in the interior of the lower die, and the inner bottom wall of the forming cavity is provided with a mounting chamber, and the inner wall of the mounting chamber is mounted to the outer wall of the hydraulic cylinder.

[0025] Preferably, the working steps of the uniform foaming extrusion die for the automobile engine cover are as follows:

[0026] S1, injecting the foaming material in a molten state into the main feeding channel through the flange constant temperature interface of the extruder;

[0027] S2, the embedded thermocouple array monitors the temperature in real time at 3-5 groups of temperature measuring points distributed longitudinally along the forming cavity, and the PID control module dynamically adjusts the power of the spiral heating pipe and the flow rate of the cooling liquid of the spiral cooling pipe according to the temperature data, to establish an alternating heating or cooling gradient field along the circumference of the forming cavity, and to ensure the flowability and uniformity of the melt;

[0028] S3, first-stage diffusion: the melt enters the first-stage fan-shaped diffusion cavity, preliminarily diffuses and changes the flow direction, and forms a uniform basic flow field;

[0029] Second-stage flow guiding: the melt is guided to flow directionally by the second-stage flow guiding fins, and the flow distribution is adjusted to different regions.

[0030] Third level path enhancement: melt into the third level corrugated runner, prolong the flow path and increase the contact area, promote the uniform dispersion of foaming agent;

[0031] S4, the multi-stage pressure buffer in the main feed channel balances the pressure fluctuation through alternating tapered sections and expanding sections, and the inner wall of the turbulence suppression ring is provided with an annular groove of 0.2-0.4 mm, and a porous ceramic damping sheet embedded in the groove further absorbs turbulent energy, stabilizing the melt flow state;

[0032] S5, the 8 extrusion heads of the adjustable extrusion terminal are adjusted by a spherical hinge adjustment mechanism, driven by a miniature servo motor to realize worm gear transmission, and an angle encoder and a PID control module form a closed loop feedback to adjust the extrusion direction in real time to match the complex profile of the engine cover;

[0033] S6, the upper mold and the lower mold are accurately closed through the installation slot to form a forming cavity matched with the profile of the engine cover, and the melt is uniformly foamed under the synergistic action of temperature gradient, flow optimization and pressure compensation, and the temperature, pressure and extrusion head angle parameters are monitored in real time, and dynamically adjusted through the PID control module to ensure the foaming density and size accuracy.

[0034] Preferably, in the S3, the following steps are further included:

[0035] S31, transition optimization: the arc-shaped transition surface between the two-stage structure reduces the turbulence intensity and reduces the flow resistance;

[0036] In the S5, the following steps are further included:

[0037] S51, each extrusion head is equipped with a pressure compensation ring, and the eight pressure equalization holes inside the ring balance the local pressure to ensure that the melt uniformly fills the forming cavity.

[0038] Compared with the prior art, the beneficial effects of the present application are:

[0039] 1. Through the setting of the melt distribution structure and the flow adjusting device, the main feed channel in the melt distribution structure is connected with the extruder through a flange type constant temperature interface to ensure stable melt input, in the three-stage diffusion distributor, the first stage fan-shaped diffusion cavity preliminarily diffuses the melt and changes the flow direction, the second stage flow guide fin guides the melt flow and adjusts the flow distribution, the third stage corrugated runner increases the melt flow path and contact area, and the arc-shaped transition surface between the stages reduces the flow resistance and reduces the turbulence intensity, making the melt distribution more uniform, and through the setting of the spiral heating pipe and the spiral cooling pipe, the embedded thermocouple array is arranged as multiple temperature measuring points along the forming cavity, the PID control module dynamically adjusts the power of the spiral heating pipe and the flow rate of the cooling liquid of the spiral cooling pipe according to the real-time temperature data, realizing accurate control of the temperature of the forming cavity;

[0040] 2. The present application can ensure that the melt undergoes multiple changes in pressure and velocity during the flow process through the alternately connected tapered sections and expanding sections, thereby achieving the effect of uniformly distributing the melt pressure and flow, and the setting of the turbulence suppression ring can reduce the fluctuations of the melt flow, making the melt flow more stable, and the 8 extrusion heads with independent angle adjustment mechanisms set at the output end of the adjustable extrusion terminal, each of which is equipped with a ball joint adjustment mechanism and a pressure compensation ring, the ball joint adjustment mechanism can realize multi-angle adjustment of the extrusion head in three-dimensional space, and can flexibly adjust the extrusion direction according to the needs of different products, and the 8 equalizing holes in the pressure compensation ring can keep the melt pressure output by the extrusion head uniform through equalizing action when the extrusion head is subjected to different pressures, thereby avoiding the problems of inconsistent product thickness and uneven density caused by uneven pressure, and achieving the effects of improving the quality and stability of the extruded products;

[0041] 3. The design of the first-stage fan-shaped diffusion cavity can make the melt rapidly diffuse after entering the diffusion cavity, and preliminarily change the flow direction, the multiple tapered fins of the second-stage flow guide fin can guide the melt flow, and the decreasing design of the spacing helps to adjust the distribution of the flow, so that the melt is reasonably distributed at different positions, the serpentine flow path formed by the third-stage corrugated runner increases the flow path and contact area of the melt, which is beneficial to the full mixing and uniform heat dissipation of the melt, the arc transition surface can effectively reduce the flow resistance and the turbulence intensity, making the melt flow more stable, in addition, the nanoscale lyophobic coating provided on the inner wall of the third-stage corrugated runner is beneficial to improving the service life of the runner, thereby reducing the problems of melt leakage and product quality caused by runner damage, and ensuring the long-term stable operation of the melt distribution structure and the quality of the extruded products;

[0042] 4. The double-channel sealing structure at the joint surface of the upper die and the lower die, the metal labyrinth sealing ring on the outside is provided with 3 layers of staggered arrangement, and the spacing between adjacent sawteeth is 0.8-1.2mm, which can form a non-contact dynamic seal to achieve the effect of blocking the leakage of the melt, the silicon nitride ceramic sealing strip on the inside is beneficial to further enhancing the sealing effect, the ball joint adjustment mechanism integrates a micro servo motor and an angle encoder, the micro servo motor drives the extrusion head to make three-dimensional angle fine adjustment within ±15° through a worm and gear transmission mechanism, realizes high-precision angle adjustment, and the angle encoder and the PID control module form a closed-loop feedback system, which can feedback the angle information of the extrusion head in real time, thereby meeting the extrusion angle requirements of different products and improving the molding precision and consistency of the products. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 is a three-dimensional schematic view of the overall structure of the present application;

[0044] Figure 2 Fig. 9 is a schematic view of the top section of the overall structure of the present application;

[0045] Figure 3 Fig. 10 is a schematic view of the overall structure of the present application; Figure 2 Fig. 11 is a schematic view of the structure at point A in Fig. 10;

[0046] Figure 4 Fig. 12 is a schematic view of the overall structure of the present application; Figure 2 Fig. 13 is a schematic view of the structure at point B in Fig. 12;

[0047] Figure 5 Fig. 14 is a schematic view of the mounting groove structure of the present application;

[0048] Figure 6 Fig. 15 is a schematic view of the overall structure of the present application; Figure 5 Fig. 16 is a schematic view of the structure at point C in Fig. 15;

[0049] Figure 7 Fig. 17 is a schematic view of the nanoscale liquid-repellent coating structure of the present application;

[0050] Figure 8 Fig. 18 is a schematic view of the system flow of the present application;

[0051] Figure 9 Fig. 19 is a schematic view of the working flow of the present application.

[0052] In the figure: 1, mold body; 2, melt distribution structure; 3, flow regulating device; 4, upper mold; 5, lower mold; 6, mounting groove; 8, forming cavity; 9, main feed channel; 10, three-stage diffusion flow divider; 11, gradient temperature control unit; 13, first-stage fan-shaped diffusion cavity; 14, second-stage flow guide fin; 15, third-stage corrugated flow channel; 16, arc-shaped transition surface; 17, spiral heating pipe; 18, embedded thermocouple array; 19, PID control module; 20, multi-stage pressure buffer; 21, adjustable extrusion terminal; 22, tapered section; 23, gradually expanding section; 24, turbulence suppression ring; 25, annular groove; 26, porous ceramic damping sheet; 27, extrusion head; 28, ball joint adjustment mechanism; 29, pressure compensation ring; 30, pressure equalizing hole; 31, nanoscale liquid-repellent coating; 34, metal labyrinth seal ring; 35, silicon nitride ceramic sealing strip; 37, micro servo motor; 38, angle encoder; 39, worm gear transmission mechanism; 41, hydraulic cylinder; 42, spiral cooling pipe; 43, mounting chamber; 44, flange constant-temperature interface. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0054] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0055] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "provided with", "connection" and the like should be broadly understood, for example, "connection" can be fixed connection, can also be detachable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0056] Embodiment 1: please refer to Figure 1 、 Figure 2 、 Figure 7 and Figure 8 , the present application provides an embodiment: a uniform foaming extrusion die for automobile engine cover, comprising a die body 1, a melt distribution structure 2 and a flow regulating device 3, the die body 1 is internally provided with the melt distribution structure 2 and the flow regulating device 3, the die body 1 comprises an upper die 4 and a lower die 5, the top of the lower die 5 is provided with a mounting groove 6, the inner wall of the mounting groove 6 is movably connected with the upper die 4, and a forming cavity 8 matched with the profile of the automobile engine cover is arranged between the lower die 5 and the upper die 4;

[0057] The melt distribution structure 2 comprises a main feeding channel 9, a three-stage diffusion distributor 10 and a gradient temperature control unit 11, and the main feeding channel 9 is arranged at the middle of the back surface of the lower die 5, the input end of the main feeding channel 9 is connected with a flange type constant temperature interface 44 through bolts, and the other end of the flange type constant temperature interface 44 is connected with the input end of the extruder through bolts;

[0058] The three-stage diffusion flow distributor 10 comprises a first-stage fan-shaped diffusion cavity 13, a second-stage flow guide fin 14 and a third-stage corrugated flow channel 15, and arc-shaped transition surfaces 16 are arranged between the first-stage fan-shaped diffusion cavity 13 and the second-stage flow guide fin 14 and between the second-stage flow guide fin 14 and the third-stage corrugated flow channel 15, the first-stage fan-shaped diffusion cavity 13 is used for preliminarily diffusing the melt and changing the flow direction, the second-stage flow guide fin 14 is used for guiding the melt flow and adjusting the flow distribution, the third-stage corrugated flow channel 15 is used for increasing the melt flow path and contact area, and the arc-shaped transition surfaces 16 are used for reducing the flow resistance and lowering the turbulence intensity;

[0059] The gradient temperature control unit 11 is circumferentially alternately provided with a spiral heating pipe 17 and a spiral cooling pipe 42 along the forming cavity 8, the gradient temperature control unit 11 comprises an embedded thermocouple array 18 and a PID control module 19, the embedded thermocouple array 18 is used for longitudinally arranging 3-5 groups of temperature measuring points along the forming cavity 8, and the PID control module 19 is used for dynamically adjusting the power of the spiral heating pipe 17 and the flow rate of the cooling liquid of the spiral cooling pipe 42 according to real-time temperature data;

[0060] Further, through the arrangement of the melt distribution structure 2 and the flow adjusting device 3, the main feeding channel 9 in the melt distribution structure 2 is connected with the extruder through a flange type constant temperature interface 44, so that the melt is stably input, in the three-stage diffusion flow distributor 10, the first-stage fan-shaped diffusion cavity 13 preliminarily diffuses the melt and changes the flow direction, the second-stage flow guide fin 14 guides the melt flow and adjusts the flow distribution, the third-stage corrugated flow channel 15 increases the melt flow path and contact area, and the arc-shaped transition surfaces 16 between the stages reduce the flow resistance and lower the turbulence intensity, so that the melt distribution is more uniform, and through the arrangement of the spiral heating pipe 17 and the spiral cooling pipe 42, the embedded thermocouple array 18 longitudinally arranges multiple groups of temperature measuring points along the forming cavity 8, and the PID control module 19 dynamically adjusts the power of the spiral heating pipe 17 and the flow rate of the cooling liquid of the spiral cooling pipe according to real-time temperature data, so that the temperature of the forming cavity 8 is accurately controlled.

[0061] Embodiment 2: please refer to Figure 2 and Figure 4 An embodiment provided by the application: the flow adjusting device 3 comprises a multi-stage pressure buffer 20 and an adjustable extrusion terminal 21, the multi-stage pressure buffer 20 is arranged inside the main feeding channel 9, the multi-stage pressure buffer 20 is composed of alternately connected tapered sections 22 and expanded sections 23, a turbulence suppression ring 24 is arranged at the connection position of the tapered sections 22 and the expanded sections 23, an annular groove 25 with a depth of 0.2-0.4 mm is arranged on the inner wall of the turbulence suppression ring 24, and a porous ceramic damping sheet 26 is embedded and installed in the annular groove 25;

[0062] The adjustable extrusion terminal 21 is arranged at the output end of the three-stage diffusion flow divider 10, and the output end of the adjustable extrusion terminal 21 is provided with eight extrusion heads 27 with independent angle adjustment mechanisms, and each extrusion head 27 is provided with a spherical hinge adjustment mechanism 28 and a pressure compensation ring 29, and eight pressure equalizing holes 30 are arranged in the pressure compensation ring 29;

[0063] The porosity of the porous ceramic damping sheet 26 is 45-65%, the pore size is 0.05-0.25 mm, and a honeycomb support framework is embedded in the porous ceramic damping sheet 26, the honeycomb support framework is made of silicon carbide material, the wall thickness of the honeycomb support framework is 20-33% of the pore diameter, and a hierarchical filtering structure is formed;

[0064] Further, through the alternating connection of the tapering section 22 and the expanding section 23, the melt can experience multiple changes in pressure and velocity during the flow process, thereby achieving the effect of uniformly distributing the melt pressure and flow. The setting of the turbulence suppression ring 24 can reduce the fluctuation of the melt flow, making the melt flow more stable. The eight extrusion heads 27 with independent angle adjustment mechanisms arranged at the output end of the adjustable extrusion terminal 21, and each extrusion head 27 is provided with a spherical hinge adjustment mechanism 28 and a pressure compensation ring 29. The spherical hinge adjustment mechanism 28 can realize multi-angle adjustment of the extrusion head 27 in three-dimensional space, and can flexibly adjust the extrusion direction according to the needs of different products. The eight pressure equalizing holes 30 in the pressure compensation ring 29 can keep the melt pressure output by the extrusion head 27 uniform through pressure equalization when the extrusion head 27 is subjected to different pressures, thereby avoiding the problem of inconsistent thickness and uneven density of the extruded product caused by uneven pressure, and achieving the effect of improving the quality and stability of the extruded product.

[0065] The turbulence suppression ring 24 is provided with an annular groove 25 with a depth of 0.2-0.4 mm on the inner wall, and a porous ceramic damping sheet 26 is embedded and installed in the annular groove 25, which can effectively reduce the turbulence intensity of the melt flow.

[0066] Example 3: please refer to Figure 2 and Figure 7 An embodiment provided by the present application: the first-stage fan-shaped diffusion cavity 13, the inlet of which is in communication with the outlet of the main feed channel 9, and the diffusion intersection angle is 90-120°;

[0067] The second-stage flow guide fin 14 is composed of radially distributed fins, and the fin spacing decreases by 5-15% from the center to the edge;

[0068] The third-stage corrugated flow channel 15 has a surface corrugation amplitude of 1-3 mm and a wavelength of 5-8 mm, forming a serpentine flow path;

[0069] The transition curvature radius R of the arc-shaped transition surface 16 is 1.2-1.5 times the height of the cavity.

[0070] The inner wall of the third-stage corrugated flow channel 15 is provided with a nanoscale liquid-repellent coating 31 for improving the service life of the flow channel wall and preventing damage due to erosion of the melt;

[0071] Further, the design of the first-stage fan-shaped diffusion cavity 13 can make the melt rapidly diffuse after entering the diffusion cavity, preliminarily change the flow direction, the plurality of tapered fins of the second-stage flow guide fin 14 can guide the melt flow, and the decreasing design of the spacing helps to adjust the distribution of the flow, so that the melt is reasonably distributed at different positions. The serpentine flow path formed by the third-stage corrugated flow channel 15 increases the flow path and contact area of the melt, which is beneficial to the full mixing and uniform heat dissipation of the melt. The arc transition surface 16 can effectively reduce the flow resistance and the turbulence intensity, so that the melt flows more smoothly. In addition, the nanoscale liquid-repellent coating 31 provided on the inner wall of the third-stage corrugated flow channel 15 is beneficial to improving the service life of the flow channel, thereby reducing the melt leakage and product quality problems caused by damage to the flow channel, and ensuring the long-term stable operation of the melt distribution structure 2 and the quality of the extruded product.

[0072] Embodiment 4: please refer to Figure 2 、 Figure 3 、 Figure 5 and Figure 6 An embodiment provided by the present application: a double-seal structure is arranged at the joint surface of the upper die 4 and the lower die 5, which includes a metal labyrinth seal ring 34 on the outside and a silicon nitride ceramic seal strip 35 on the inside. The metal labyrinth seal ring 34 is provided with three layers of staggered sawtooth structures, and the spacing between adjacent sawteeth is 0.8-1.2 mm, forming a non-contact dynamic seal.

[0073] The ball hinge adjustment mechanism 28 is integrated with a micro servo motor 37 and an angle encoder 38. The micro servo motor 37 drives the extrusion head 27 to make three-dimensional angle fine adjustment within a range of ±15° through a worm gear transmission mechanism 39, and the angle resolution is 0.1°. The angle encoder 38 forms a closed-loop feedback system with the PID control module 19.

[0074] The ejection mechanism is provided at the bottom of the forming cavity 8, and the ejection mechanism includes a hydraulic cylinder 41, and the outer wall of the hydraulic cylinder 41 is embeddedly installed in the inside of the lower die 5. The inner bottom wall of the forming cavity 8 is provided with a mounting chamber 43, and the inner wall of the mounting chamber 43 is installed on the outer wall of the hydraulic cylinder 41.

[0075] Further, through the double-channel sealing structure at the joint surface of the upper mold 4 and the lower mold 5, the metal labyrinth sealing ring 34 on the outer side is provided with three layers of staggered arrangement, and the spacing between adjacent sawteeth is 0.8-1.2 mm, which can form a non-contact dynamic seal, achieve the effect of blocking the leakage of the melt, and the silicon nitride ceramic sealing strip 35 on the inner side is beneficial to further enhance the sealing effect, the ball hinge adjustment mechanism 28 integrates a micro servo motor 37 and an angle encoder 38, the micro servo motor 37 drives the extrusion head 27 to perform three-dimensional angle fine adjustment within a range of ±15° through a worm gear transmission mechanism 39, realizes high-precision angle adjustment, and the angle encoder 38 and the PID control module 19 form a closed-loop feedback system, which can realize real-time feedback of the angle information of the extrusion head 27, thereby meeting the extrusion angle requirements of different products and improving the forming precision and consistency of the products.

[0076] The ejection mechanism arranged at the bottom of the forming cavity 8 is used for ejecting the processed material.

[0077] Embodiment 5: please refer to Figure 9 An embodiment provided by the application: the working steps of the uniform foaming extrusion mold for the automobile engine cover are as follows:

[0078] S1, the foaming material in a molten state is injected into the main feeding channel 9 through the flange constant-temperature interface 44 by the extruder;

[0079] S2, the embedded thermocouple array 18 realizes real-time monitoring of 3-5 groups of temperature measuring points distributed longitudinally along the forming cavity 8, and the PID control module 19 dynamically adjusts the power of the spiral heating pipe 17 and the flow rate of the cooling liquid of the spiral cooling pipe 42 according to the temperature data, so as to establish an alternating heating or cooling gradient field along the circumference of the forming cavity 8, and ensure the flowability and foaming uniformity of the melt;

[0080] S3, first-stage diffusion: the melt enters the first-stage fan-shaped diffusion cavity 13, is preliminarily diffused and changes the flow direction, and forms a uniform basic flow field;

[0081] Second-stage flow guiding: the melt is guided to flow directionally through the second-stage flow guiding fin 14, and the flow distribution is adjusted to different regions;

[0082] Third-stage path enhancement: the melt enters the third-stage corrugated runner 15, the flow path is lengthened and the contact area is increased, and the uniform dispersion of the foaming agent is promoted;

[0083] S4, the multi-stage pressure buffer 20 in the main feeding channel 9 balances the pressure fluctuation through the alternating tapered section 22 and the gradually expanded section 23, and the inner wall of the turbulent flow suppression ring 24 is provided with a 0.2-0.4 mm annular groove 25, and the porous ceramic damping sheet 26 embedded in the groove further absorbs turbulent flow energy, and stabilizes the flow state of the melt;

[0084] S5、8 extrusion heads 27 of the adjustable extrusion terminal 21 are finely adjusted in three dimensions by ball hinge joint adjustment mechanism 28, driven by micro servo motor 37 to realize worm gear transmission mechanism 39, and angle encoder 38 forms a closed loop feedback with PID control module 19, real-time adjustment of the extrusion direction to match the complex profile of the engine cover;

[0085] S6、The upper die 4 and the lower die 5 are precisely closed by the installation slot 6, forming a forming cavity 8 matched with the profile of the engine cover, and the melt is uniformly foamed under the synergistic effect of temperature gradient, flow optimization and pressure compensation, and the temperature, pressure and angle parameters of the extrusion head 27 are monitored in real time, and dynamically adjusted by the PID control module 19 to ensure the foaming density and size accuracy.

[0086] In S3, the following steps are also included:

[0087] S31、Transition optimization: The arc-shaped transition surface 16 between the two-stage structure reduces the turbulence intensity and reduces the flow resistance;

[0088] In S5, the following steps are also included:

[0089] S51、Each extrusion head 27 is equipped with a pressure compensation ring 29, and 8 internal pressure equalizing holes 30 balance the local pressure to ensure uniform filling of the melt in the forming cavity 8;

[0090] In S6, the following steps are also included:

[0091] S61、The 3-layer staggered serration structure of the metal labyrinth seal ring 34 with a spacing of 0.8-1.2mm forms a non-contact dynamic seal, preventing melt leakage, and the silicon nitride ceramic sealing strip 35 provides high temperature resistance to ensure that the forming cavity 8 is completely sealed.

[0092] The working principle is that through the arrangement of the melt distribution structure 2 and the flow regulating device 3, the main feeding channel 9 in the melt distribution structure 2 is connected with the extruder through the flange constant temperature interface 44, which ensures stable melt input. In the three-stage diffusion distributor 10, the first-stage fan-shaped diffusion cavity 13 preliminarily diffuses the melt and changes the flow direction, the second-stage flow guide fin 14 guides the melt flow and adjusts the flow distribution, the third-stage corrugated flow channel 15 increases the melt flow path and contact area, and the arc transition surface 16 between each stage reduces the flow resistance and the turbulence intensity, so that the melt distribution is more uniform. Then, through the arrangement of the spiral heating pipe 17 and the spiral cooling pipe 42, the embedded thermocouple array 18 is arranged in multiple groups of temperature measurement points along the forming cavity 8, the PID control module 19 dynamically adjusts the power of the spiral heating pipe 17 and the flow rate of the cooling liquid of the spiral cooling pipe according to the real-time temperature data, and the temperature of the forming cavity 8 is accurately controlled. Through the alternately connected tapered section 22 and expanding section 23, the melt can experience multiple changes in pressure and velocity during the flow process, thereby achieving the effect of uniformly distributing the melt pressure and flow. The arrangement of the turbulence suppression ring 24 can reduce the fluctuation of the melt flow, making the melt flow more stable. Then, through the arrangement of the 8 extrusion heads 27 with independent angle adjusting mechanisms on the output end of the adjustable extrusion terminal 21, and each extrusion head 27 is equipped with a ball hinge adjusting mechanism 28 and a pressure compensation ring 29, the ball hinge adjusting mechanism 28 can realize multi-angle adjustment of the extrusion head 27 in three-dimensional space, and can flexibly adjust the extrusion direction according to the needs of different products. The 8 equalizing holes 30 in the pressure compensation ring 29 can maintain the uniformity of the melt pressure output by the extrusion head 27 when the extrusion head 27 is subjected to different pressures through the equalizing effect, thereby avoiding the problems of inconsistent product thickness and uneven density caused by uneven pressure, and achieving the effects of improving the quality and stability of the extruded products. The turbulence suppression ring 24 is arranged on the inner wall with a depth of 0.2-0.4mm annular groove 25, and the porous ceramic damping sheet 26 embedded in the annular groove 25, can effectively reduce the turbulence intensity of the melt flow, and the design of the first-stage fan-shaped diffusion cavity 13 can make the melt rapidly diffuse after entering the diffusion cavity, preliminarily change the flow direction, the multiple tapered fins of the second-stage flow guide fin 14 can guide the melt flow, and the decreasing design of the spacing helps to adjust the distribution of the flow, so that the melt is reasonably distributed at different positions, the serpentine flow path formed by the third-stage corrugated flow channel 15 increases the flow path and contact area of the melt, which is beneficial to the full mixing and uniform heat dissipation of the melt, and the arc transition surface 16 can effectively reduce the flow resistance and the turbulence intensity, so that the melt flow is more stable. In addition, the nanoscale lyophobic coating 31 provided on the inner wall of the third-stage corrugated flow channel 15 is beneficial to improving the service life of the flow channel, thereby reducing the melt leakage and product quality problems caused by flow channel damage, ensuring the long-term stable operation of the melt distribution structure 2 and the quality of the extruded product. Through the double-seal structure at the joint surface of the upper die 4 and the lower die 5, the metal labyrinth seal ring 34 on the outside is provided with three layers of staggered arrangement, and the spacing between adjacent sawteeth is 0.8-1.2mm, which can form a non-contact dynamic seal to block the leakage of the melt. The silicon nitride ceramic sealing strip 35 on the inside is beneficial to further enhancing the sealing effect. The ball hinge adjustment mechanism 28 integrates a micro servo motor 37 and an angle encoder 38. The micro servo motor 37 drives the extrusion head 27 to make three-dimensional angle fine adjustment within ±15° through a worm gear transmission mechanism 39, realizes high-precision angle adjustment, and the angle encoder 38 forms a closed-loop feedback system with the PID control module 19, which can feedback the angle information of the extrusion head 27 in real time, thereby meeting the extrusion angle requirements of different products and improving the forming precision and consistency of the products.

[0093] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A uniform foaming extrusion mold for an automobile engine cover, comprising a mold body (1), a melt distribution structure (2), and a flow regulating device (3), characterized in that: The mold body (1) is provided with a melt distribution structure (2) and a flow adjustment device (3) inside. The mold body (1) includes an upper mold (4) and a lower mold (5). The front end of the top of the lower mold (5) is provided with an installation groove (6). The inner wall of the installation groove (6) is movably connected to the upper mold (4). A forming cavity (8) matching the outline of the car engine cover is provided between the lower mold (5) and the upper mold (4). The melt distribution structure (2) includes a main feed channel (9), a three-stage diffuser (10) and a gradient temperature control unit (11). The main feed channel (9) is located in the middle of the back of the lower die (5). The input end of the main feed channel (9) is connected to a flange-type thermostatic interface (44) by bolts. The other end of the flange-type thermostatic interface (44) is connected to the input end of the extruder by bolts. The three-stage diffuser (10) includes a first-stage fan-shaped diffuser cavity (13), a second-stage guide fin (14), and a third-stage corrugated flow channel (15). Arc-shaped transition surfaces (16) are provided between the first-stage fan-shaped diffuser cavity (13) and the second-stage guide fin (14), and between the second-stage guide fin (14) and the third-stage corrugated flow channel (15). The first-stage fan-shaped diffuser cavity (13) is used to initially diffuse the melt and change the flow direction. The second-stage guide fin (14) is used to guide the melt flow and adjust the flow distribution. The third-stage corrugated flow channel (15) is used to increase the melt flow path and contact area. The arc-shaped transition surface (16) is used to reduce flow resistance and reduce turbulence intensity. The gradient temperature control unit (11) is provided with alternating spiral heating tubes (17) and spiral cooling tubes (42) along the circumference of the molding cavity (8). The gradient temperature control unit (11) includes an embedded thermocouple array (18) and a PID control module (19). The embedded thermocouple array (18) is used to arrange 3-5 sets of temperature measuring points along the longitudinal direction of the molding cavity (8). The PID control module (19) is used to dynamically adjust the power of the spiral heating tube (17) and the coolant flow rate of the spiral cooling tube (42) according to the real-time temperature data.

2. The uniform foaming extrusion mold for an automobile engine cover according to claim 1, characterized in that: The flow regulating device (3) includes a multi-stage pressure buffer (20) and an adjustable extrusion terminal (21). The multi-stage pressure buffer (20) is located inside the main feed channel (9). The multi-stage pressure buffer (20) is composed of alternating converging sections (22) and expanding sections (23). A turbulence suppression ring (24) is provided at the connection between the converging section (22) and the expanding section (23). An annular groove (25) with a depth of 0.2-0.4 mm is provided on the inner wall of the turbulence suppression ring (24). A porous ceramic damping sheet (26) is fitted inside the annular groove (25). An adjustable extrusion terminal (21) is located at the output end of the three-stage diffuser (10). The output end of the adjustable extrusion terminal (21) is provided with eight extrusion heads (27) with independent angle adjustment mechanisms. Each extrusion head (27) is equipped with a ball joint adjustment mechanism (28) and a pressure compensation ring (29). The pressure compensation ring (29) is provided with eight pressure equalization holes (30).

3. The uniform foaming extrusion mold for an automobile engine cover according to claim 1, characterized in that: The first-stage fan-shaped diffusion cavity (13) has its inlet connected to the outlet of the main feed channel (9), and the diffusion cross-section is 90-120°. The second-stage guide fins (14) are composed of radially distributed fins, with the spacing between each fin decreasing by 5-15% from the center to the edge; The third-stage corrugated flow channel (15) has a surface corrugation amplitude of 1-3 mm and a wavelength of 5-8 mm, forming a serpentine flow path; The transition curvature radius R of the arc transition surface (16) is 1.2-1.5 times the height of the cavity.

4. The uniform foaming extrusion mold for an automobile engine cover according to claim 1, characterized in that: The inner wall of the third-stage corrugated flow channel (15) is provided with a nano-level hydrophobic coating (31). The nano-level hydrophobic coating (31) is used to improve the service life of the flow channel wall and prevent damage caused by the scouring of the melt.

5. The uniform foaming extrusion mold for an automobile engine cover according to claim 2, characterized in that: The porous ceramic damping sheet (26) has a porosity of 45-65% and a pore size of 0.05-0.25mm. It is also embedded with a honeycomb support skeleton, which is made of silicon carbide material and has a wall thickness of 20-33% of the pore diameter, forming a graded filtration structure.

6. The uniform foaming extrusion mold for an automobile engine cover according to claim 1, characterized in that: The upper mold (4) and the lower mold (5) are provided with a double sealing structure, including an outer metal labyrinth sealing ring (34) and an inner silicon nitride ceramic sealing strip (35). The metal labyrinth sealing ring (34) is provided with a 3-layer staggered sawtooth structure with an adjacent sawtooth spacing of 0.8-1.2mm, forming a non-contact dynamic seal.

7. The uniform foaming extrusion mold for an automobile engine cover according to claim 2, characterized in that: The ball joint adjustment mechanism (28) integrates a micro servo motor (37) and an angle encoder (38). The micro servo motor (37) drives the extruder (27) to perform three-dimensional angle fine adjustment within a range of ±15° through a worm gear transmission mechanism (39), with an angle resolution of 0.1°. The angle encoder (38) and the PID control module (19) form a closed-loop feedback system.

8. The uniform foaming extrusion mold for an automobile engine cover according to claim 1, characterized in that: The bottom of the molding cavity (8) is provided with an ejection mechanism, which includes a hydraulic cylinder (41). The outer wall of the hydraulic cylinder (41) is fitted into the interior of the lower mold (5). The inner bottom wall of the molding cavity (8) is provided with an installation chamber (43), and the inner wall of the installation chamber (43) is installed on the outer wall of the hydraulic cylinder (41).

9. The method of using a uniform foaming extrusion mold for an automobile engine cover according to claim 7, characterized in that, The working steps of the uniform foaming extrusion mold for the car engine cover are as follows: S1. Molten foamed material is injected into the main feed channel (9) through the flange-type thermostatic interface (44) via an extruder. S2. Embedded thermocouple array (18) has 3-5 sets of temperature measuring points distributed longitudinally along the molding cavity (8) to monitor the temperature in real time. PID control module (19) dynamically adjusts the power of spiral heating tube (17) and the flow rate of coolant in spiral cooling tube (42) according to the temperature data, and establishes an alternating heating or cooling gradient field along the circumference of the molding cavity (8) to ensure melt flowability and foaming uniformity. S3, First-stage diffusion: The melt enters the first-stage fan-shaped diffusion cavity (13), initially diffuses and changes the flow direction to form a uniform basic flow field; Second-stage flow guide: The melt is guided to flow in a directional manner through the second-stage flow guide fins (14), and the flow rate is adjusted to distribute to different areas; Third-level path enhancement: The melt enters the third-level corrugated flow channel (15), which extends the flow path and increases the contact area, promoting the uniform dispersion of the foaming agent; S4. The multi-stage pressure buffer (20) in the main feed channel (9) balances pressure fluctuations through alternating converging sections (22) and expanding sections (23). At the same time, the inner wall of the turbulence suppression ring (24) is provided with a 0.2-0.4mm annular groove (25), and the porous ceramic damping sheet (26) embedded in the groove further absorbs turbulent energy and stabilizes the melt flow state. S5. The eight extrusion heads (27) of the adjustable extrusion terminal (21) are finely adjusted in three dimensions through the ball joint adjustment mechanism (28), which is driven by the micro servo motor (37) and the worm gear transmission mechanism (39). The angle encoder (38) and the PID control module (19) form a closed-loop feedback to adjust the extrusion direction in real time to match the complex contour of the engine cover. S6. The upper mold (4) and the lower mold (5) are precisely closed through the mounting groove (6) to form a molding cavity (8) that matches the contour of the engine cover. The melt foams uniformly under the synergistic effect of temperature gradient, flow optimization and pressure compensation. The temperature, pressure and extruder (27) angle parameters are monitored in real time and dynamically adjusted through the PID control module (19) to ensure foam density and dimensional accuracy.

10. The method of using a uniform foaming extrusion mold for an automobile engine cover according to claim 9, characterized in that, The S3 process also includes the following steps: S31, Transition Optimization: The arc-shaped transition surface (16) between the two-stage structures reduces turbulence intensity and lowers flow resistance; The S5 also includes the following steps: S51. Each extrusion head (27) is equipped with a pressure compensation ring (29) with 8 pressure equalization holes (30) inside to balance local pressure and ensure that the melt fills the molding cavity (8) evenly.

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