Mold partition temperature control system based on gas film adjustable thermal resistance boundary

Abstract

The invention discloses a mold partition temperature control system based on an air film adjustable thermal resistance boundary, and belongs to the technical field of mold temperature control and thermal management. The system comprises a mold body, at least two temperature control subareas and gas film adjustable thermal resistance boundary units arranged between the adjacent temperature control subareas. The air film adjustable thermal resistance boundary unit comprises a boundary air cavity, an air injection micropore, an exhaust adjusting structure and an air supply unit. Gas enters the partition boundary area through the gas injection micropores and forms a gas film layer, and the thickness, continuity, stability and coverage range of the gas film layer are changed by adjusting the gas supply pressure, the gas supply flow and the exhaust resistance, so that the thermal coupling strength between the adjacent temperature control partitions is adjusted. The system is suitable for injection molding, pressure casting, hot pressing and composite material forming molds.

Description

Technical Field

[0001] This invention relates to the field of mold temperature control and thermal management technology, and in particular to a mold zone temperature control system that achieves zone thermal decoupling and adjustable boundary thermal resistance by constructing an adjustable thermal resistance boundary between adjacent temperature control zones. Background Technology

[0002] In molding processes such as injection molding, die casting, hot pressing, and composite material molding, the temperature field distribution of the mold directly affects melt flow behavior, filling uniformity, surface replicability, crystallization behavior, residual stress, dimensional stability, and demolding quality. For parts with significant differences in wall thickness, high requirements for local high gloss, or the presence of reinforcing ribs, thin-walled areas, insert areas, or defect-sensitive areas, it is usually necessary to implement differentiated temperature control for different areas of the mold to meet the thermal requirements of different areas during the molding process.

[0003] Existing mold temperature control technologies typically employ zoned heating, zoned cooling, or a combination of both to achieve localized temperature control. Although independent thermal control loops can be set up for different areas, significant heat conduction still occurs between adjacent temperature control zones due to the high thermal conductivity of the mold matrix material. This results in noticeable thermal crosstalk, blurred zone boundaries, and difficulty in maintaining a stable temperature gradient, thereby affecting the independence of zoned temperature control and the accuracy of process response.

[0004] To reduce thermal crosstalk, existing technologies have also improved the situation by increasing the density of cooling channels, optimizing the heating layout, creating heat insulation grooves, or embedding heat insulation materials. However, most of these methods are passive structural adjustments, and their thermal resistance is basically fixed after the mold is manufactured. It is difficult to dynamically adjust them according to the molding stage, and they cannot take into account the different requirements of the thermal coupling relationship of the partition boundaries in different stages such as filling, holding pressure, shaping, and cooling.

[0005] In addition, existing technologies involving gas participation in heat exchange are mostly used to enhance local heat exchange, assist cooling, or form insulation layers. However, they usually do not structurally design the boundary area between adjacent temperature control zones as an independent thermal resistance adjustment interface, nor do they integrate gas supply, exhaust, zone temperature control, and temperature feedback into a system. Therefore, it is difficult to achieve controllable adjustment of the thermal coupling strength between zones.

[0006] Therefore, it is necessary to provide a new mold partition temperature control system that makes the boundary area between adjacent temperature control partitions no longer just a geometric boundary, but a functional interface with adjustable thermal conductivity. By forming an air film and adjusting its state, the thermal coupling strength between partitions can be changed, thereby improving the partition independence, boundary temperature gradient control capability and overall temperature control accuracy. Summary of the Invention

[0007] To address the problems of significant thermal crosstalk between adjacent zones, difficulty in adjusting thermal coupling strength, fixed boundary thermal resistance, and inability to adapt to the temperature control requirements of different process stages in existing mold zone temperature control technologies, this invention provides a mold zone temperature control system based on an adjustable thermal resistance boundary of an air film. By forming an adjustable air film layer between adjacent temperature control zones, the zone boundary becomes an adjustable thermal resistance interface, thereby achieving zone thermal decoupling and controllable adjustment of boundary thermal resistance.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a mold partition temperature control system based on an adjustable thermal resistance boundary of a gas film, comprising a mold body, at least two temperature control partitions, and an adjustable thermal resistance boundary unit of a gas film disposed between adjacent temperature control partitions; the mold body includes a molding working part and a mold support part; the at least two temperature control partitions are correspondingly disposed in different areas of the molding working part, and each temperature control partition is provided with an independent heating unit and / or cooling unit; the adjustable thermal resistance boundary unit of a gas film includes a boundary air cavity disposed along the partition boundary and embedded inside the molding working part, a plurality of air jet micro-holes communicating with the boundary air cavity and opening toward the area near the partition boundary, an exhaust adjustment structure communicating with the partition boundary area, and an air supply unit communicating with the boundary air cavity.

[0009] The jet micro-orifice, in conjunction with the exhaust regulating structure, causes the gas medium to form an air film layer in the boundary region of the partition, and the air film layer constitutes an air film thermal resistance boundary between adjacent temperature control partitions. By adjusting the gas supply pressure, gas supply flow rate, gas supply on / off state output by the gas supply unit and the exhaust resistance of the exhaust regulating structure, the thickness, continuity, stability, and coverage of the air film layer can be changed to adjust the thermal coupling strength between adjacent temperature control partitions.

[0010] Preferably, the boundary air chamber is continuously or intermittently arranged along the partition boundary to form a continuous or segmented air film thermal resistance boundary; the jet micro-orifices are an array of micro-orifices arranged along the partition boundary, with an aperture of 0.02 mm to 1.00 mm and a spacing of 0.10 mm to 5.00 mm between adjacent jet micro-orifices; the boundary air chamber is arranged at a depth of 0.5 mm to 20 mm from the forming working surface, with an equivalent width of 0.2 mm to 10 mm and an equivalent height of 0.2 mm to 8 mm; the air supply unit outputs an air pressure of 0.01 MPa to 0.80 MPa and an air flow rate of 0.1 L / min to 50 L / min to form a thickness of 0.01 mm to 1.00 mm in the partition boundary region. The system comprises a continuous or pulsed air film layer of mm; the exhaust regulating structure is a throttle orifice, a throttle valve, a variable cross-section exhaust channel, or a combination thereof, used to regulate the exhaust resistance in the partition boundary area to control the spreading state and residence stability of the air film layer; the gas medium is air, nitrogen, argon, or a mixture thereof; the mold partition temperature control system further includes a control unit and a temperature acquisition unit, the temperature acquisition unit including partition temperature sensors installed inside each temperature control partition and boundary temperature sensors installed near the partition boundary, the control unit being connected to the gas supply unit, the exhaust regulating structure, the heating unit, the cooling unit, and the temperature acquisition unit respectively, and is used to adjust the gas supply parameters, exhaust parameters, and partition heating or cooling intensity in a coordinated manner according to the temperature information of each temperature control partition and the temperature state of the partition boundary area.

[0011] In this invention, the boundary between adjacent temperature control zones is no longer merely a geometric dividing line, but is constructed as a functional interface with adjustable thermal conductivity. By setting boundary air cavities inside the zone boundaries and supplying gas medium to the boundary region through jet micro-holes, an air film layer is formed in the boundary region, thereby transforming the heat flow from the original continuous solid heat conduction path of the mold substrate into a composite heat transfer path that crosses the air film layer.

[0012] Since the thermal conductivity of the gas layer is lower than that of the mold matrix material, the formation of a gas film layer at the boundary of the zones can significantly increase the interfacial thermal resistance and weaken the thermal conduction coupling between adjacent temperature control zones. Furthermore, by adjusting the gas supply pressure, gas supply flow rate, and exhaust resistance, the thickness, continuity, coverage, and stability of the gas film layer can be varied, thereby achieving continuous or graded changes in the interfacial thermal conductivity. This transforms the thermal coupling relationship between zones from an inherent structural property into an adjustable controllable variable.

[0013] Compared with existing technologies, this invention has the following advantages: By constructing an adjustable thermal resistance boundary for the gas film between adjacent temperature control zones, the heat conduction path between zones can be effectively suppressed, thermal crosstalk reduced, and zone thermal decoupling achieved. Simultaneously, by adjusting the gas supply parameters and exhaust resistance to change the state of the gas film layer, the thermal resistance of the zone boundary can be flexibly adjusted between different levels, significantly improving the controllability and independence of the temperature control boundary. This solution can be seamlessly integrated with existing mold heating, cooling, and sensing feedback systems, improving temperature control performance without changing the overall mold working logic. This is beneficial for maintaining a stable boundary temperature gradient during the molding process of complex parts, reducing the risk of defects such as local overheating, underheating, shrinkage marks, warping, poor welding, or inconsistent surface quality. Furthermore, this invention is applicable to injection molds, die-casting molds, hot-pressing molds, and composite material molding molds, possessing good engineering applicability and promotional value. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of a mold according to one embodiment of the present invention.

[0015] Figure 2 This is a schematic diagram of the temperature control zone and zone boundary according to one embodiment of the present invention.

[0016] Figure 3 This is a schematic diagram of the arrangement structure of the air-film adjustable thermal resistance boundary unit in the mold according to one embodiment of the present invention.

[0017] Figure 4 for Figure 3 A magnified schematic diagram of the partition boundary at point A in the middle.

[0018] Figure 5 This is a schematic diagram of the connection of a mold partition temperature control system according to one embodiment of the present invention.

[0019] Figure 6 The diagrams are as follows: (a) is a schematic diagram of the thermal coupling change between adjacent temperature control zones when there is no air film thermal resistance boundary in one embodiment of the present invention; (b) is a schematic diagram of the thermal coupling change between adjacent temperature control zones after the air film thermal resistance boundary is formed in one embodiment of the present invention.

[0020] 100. Mold body; 110. Molding working part; 120. Mold support part; 130. Cavity; 200. Temperature control zone; 210. First temperature control zone; 220. Second temperature control zone; 230. Zone boundary; 300. Adjustable thermal resistance boundary unit; 310. Boundary air cavity; 320. Air jet micro-hole; 330. Exhaust adjustment structure; 340. Air film layer; 350. Boundary heat exchange area; 400. Control unit; 410. Heating unit; 420. Cooling unit; 430. Air supply unit; 500. Temperature acquisition unit; 510. Zone temperature sensor; 520. Boundary temperature sensor. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0022] See Figure 1 This embodiment provides a mold zone temperature control system based on an adjustable thermal resistance boundary of an air film, including a mold body 100. The mold body 100 includes a molding working part 110 located at the upper part and a mold support part 120 located at the lower part. The surface of the molding working part 110 forms a cavity 130 for molding parts.

[0023] See Figure 2 Multiple temperature control zones 200 are formed in different areas corresponding to the molding work section 110. For ease of explanation, this embodiment shows a first temperature control zone 210 and a second temperature control zone 220 arranged adjacent to each other, with a zone boundary 230 between them. The first temperature control zone 210 and the second temperature control zone 220 can correspond to different heating targets, cooling targets or process temperature requirements, and each is equipped with an independent thermal control loop to achieve localized differentiated temperature control.

[0024] See Figure 3 An adjustable thermal resistance boundary unit 300 is provided between the first temperature control zone 210 and the second temperature control zone 220. This adjustable thermal resistance boundary unit 300 includes a boundary air cavity 310 extending along the zone boundary 230, embedded inside the molding working section 110 and close to the molding surface where the cavity 130 is located. The boundary air cavity 310 can be continuously arranged or segmented according to the boundary length, heat exchange requirements, and manufacturing process. The boundary air cavity 310 communicates with multiple jet micro-holes 320, which are opened towards the boundary heat exchange region 350 near the zone boundary 230. A gas supply unit 430 communicates with the boundary air cavity 310 and is used to supply a gas medium with controlled pressure and flow rate to the boundary air cavity 310. An exhaust regulating structure 330 communicates with the boundary heat exchange region 350 and is used to regulate the resistance of gas discharged from the boundary region.

[0025] See Figure 3 and Figure 4 , Figure 4 for Figure 3 A magnified schematic diagram of the boundary structure of the partition at point A. When the gas supply unit 430 supplies gas to the boundary gas chamber 310, the gas enters the boundary heat exchange region 350 through the jet micro-holes 320 and spreads to form an air film layer 340 near the partition boundary 230. This air film layer 340 is located between adjacent temperature control partitions, requiring the heat flow that would normally be directly conducted through the mold substrate to cross the air film layer 340 for transfer, thus forming a thermal resistance boundary at the partition boundary 230.

[0026] In this embodiment, the thermal resistance of the gas film layer 340 is not fixed, but can be controlled by adjusting the gas supply and exhaust in a coordinated manner. Specifically, when the gas supply pressure is increased, the gas supply flow rate is increased, or the exhaust throttling degree is increased, the thickness, continuity, and coverage of the gas film layer 340 are enhanced, the equivalent thermal resistance at the partition boundary 230 increases, and the thermal coupling between adjacent temperature control partitions is weakened. When the gas supply pressure is reduced, the gas supply flow rate is decreased, or the exhaust throttling degree is weakened, the gas film layer 340 is thinned, intermittent, or locally shrinks, the equivalent thermal resistance at the partition boundary 230 decreases, and the thermal coupling between adjacent temperature control partitions is enhanced.

[0027] The jet micro-orifices 320 can be formed by micro-drilling, electrical discharge machining, laser drilling, or other methods suitable for forming micro-channels. Preferably, the diameter of the jet micro-orifices 320 is 0.02 mm to 1.00 mm, and the spacing between adjacent jet micro-orifices 320 is 0.10 mm to 5.00 mm. The depth of the boundary air cavity 310 from the forming surface is preferably 0.5 mm to 20 mm, the equivalent width is preferably 0.2 mm to 10 mm, and the equivalent height is preferably 0.2 mm to 8 mm. By matching the above parameters, a continuous air film layer 340 or a pulsed air film layer 340 can be formed near the partition boundary 230.

[0028] The gas medium can be air, nitrogen, argon, or a mixture thereof. The gas supply pressure output by the gas supply unit 430 is preferably 0.01 MPa to 0.80 MPa, and the gas supply flow rate is preferably 0.1 L / min to 50 L / min, to adapt to different mold structures, different partition boundary lengths, and different thermal resistance adjustment requirements.

[0029] See Figure 5The system also includes a control unit 400, a heating unit 410, a cooling unit 420, and a temperature acquisition unit 500. The heating unit 410 and cooling unit 420 are respectively located at corresponding positions in the first temperature control zone 210 and the second temperature control zone 220, forming independent thermal control loops. The temperature acquisition unit 500 includes a zone temperature sensor 510 located within each temperature control zone and a boundary temperature sensor 520 located near the zone boundary 230. The control unit 400 is connected to the air supply unit 430, the exhaust regulating structure 330, the heating unit 410, the cooling unit 420, and the temperature acquisition unit 500, respectively, to collect temperature information from each zone and the boundary area, and accordingly adjust the air supply, exhaust, and zone thermal control parameters in a coordinated manner. In one application, when a decrease in temperature gradient and increased thermal crosstalk are detected between the first temperature control zone 210 and the second temperature control zone 220, the control unit 400 can increase the supply pressure or flow rate of the air supply unit 430 and increase the throttling degree of the exhaust regulating structure 330 to form a more stable air film layer 340 at the zone boundary 230, thereby increasing the boundary thermal resistance and suppressing heat conduction across zones. When it is necessary to enhance the heat exchange consistency near the boundary or weaken the boundary insulation effect, the supply parameters or exhaust resistance can be reduced accordingly to reduce thermal resistance.

[0030] See Figure 6 In (a) when no air film thermal resistance boundary is formed, the heat flow between the first temperature control zone 210 and the second temperature control zone 220 is directly transferred through the mold substrate, resulting in significant thermal crosstalk; see reference Figure 6 In (b), after the formation of the air film thermal resistance boundary, the heat flow conduction path in the boundary region is weakened, the heat flow exchange between adjacent zones is reduced, the thermal boundary is clearer, and the temperature control independence of each zone is significantly improved.

[0031] This invention is not limited to a structure with two temperature control zones. For molds with three or more temperature control zones, corresponding gas film adjustable thermal resistance boundary units 300 can be set between multiple adjacent zones. Each boundary unit can be independently supplied with gas, independently discharged, and independently adjusted to adapt to the temperature field control requirements of different areas of complex parts.

[0032] Any equivalent substitutions or modifications made by those skilled in the art to the shape of the boundary air chamber, the arrangement of the jet micro-holes, the form of the exhaust adjustment structure, the air supply method, the number of temperature control zones, the control strategy, and the applicable mold type without departing from the concept of the present invention shall fall within the protection scope of the present invention.

Claims

1. A mold zoned temperature control system based on an adjustable thermal resistance boundary of an air film, characterized in that, include: The mold body (100) includes a molding working part (110) and a mold support part (120); at least two temperature control zones (200), which are respectively arranged in different areas of the molding working part (110), and each temperature control zone (200) is provided with an independent heating unit (410) and / or cooling unit (420); an adjustable thermal resistance boundary unit (300) is arranged between adjacent temperature control zones (200), and the adjustable thermal resistance boundary unit (300) includes: a boundary air cavity (310) arranged along the boundary (230) and embedded in the interior of the molding working part (110); and a plurality of boundary air cavities (310) communicating with the boundary air cavities (310). The system includes: jet micro-holes (320) opening towards the area near the partition boundary (230); an exhaust regulating structure (330) communicating with the partition boundary (230); and an air supply unit (430) communicating with the boundary air chamber (310). The jet micro-holes (320) cooperate with the exhaust regulating structure (330) to form an air film layer (340) in the partition boundary (230) area. The air film layer (340) constitutes an air film thermal resistance boundary between adjacent temperature control partitions (200). By adjusting the air supply pressure, air supply flow rate, and exhaust resistance, the thickness, continuity, stability, and coverage of the air film layer (340) are changed to adjust the thermal coupling strength between adjacent temperature control partitions (200).

2. The mold zoned temperature control system based on adjustable thermal resistance boundary of air film according to claim 1, characterized in that: The boundary air cavity (310) is continuously or intermittently arranged along the partition boundary (230) to form a continuous air film thermal resistance boundary or a segmented air film thermal resistance boundary.

3. The mold zoned temperature control system based on adjustable thermal resistance boundary of air film according to claim 1, characterized in that: The jet micro-orifices (320) are an array of micro-orifices arranged along the partition boundary (230). The diameter of the jet micro-orifices (320) is 0.02 mm to 1.00 mm, and the spacing between adjacent jet micro-orifices (320) is 0.10 mm to 5.00 mm. The boundary air cavity (310) is arranged at a depth of 0.5 mm to 20 mm from the forming working surface. The equivalent width of the boundary air cavity (310) is 0.2 mm to 10 mm, and the equivalent height is 0.2 mm to 8 mm. The air supply unit (430) outputs an air supply pressure of 0.01 MPa to 0.80 MPa and an air supply flow rate of 0.1 L / min to 50 L / min to form a thickness of 0.01 mm to 1.00 mm in the partition boundary (230) region. A continuous air film layer (340) or a pulsed air film layer (340) of mm; the exhaust regulating structure (330) is a throttle orifice, a throttle valve, a variable cross-section exhaust channel or a combination thereof.

4. The mold zoned temperature control system based on adjustable thermal resistance boundary of air film according to claim 1, characterized in that: The gas medium is air, nitrogen, argon or a mixture thereof; the heating unit (410) and / or cooling unit (420) of each temperature control zone (200) constitute an independent thermal control loop; it also includes a control unit (400) and a temperature acquisition unit (500), the temperature acquisition unit (500) includes a zone temperature sensor (510) disposed inside each temperature control zone (200) and a boundary temperature sensor (520) disposed near the zone boundary (230) area, the control unit (400) is connected to the gas supply unit (430), the exhaust regulating structure (330), the heating unit (410), the cooling unit (420) and the temperature acquisition unit (500) respectively.

5. The mold zoned temperature control system based on adjustable thermal resistance boundary of air film according to claim 4, characterized in that: The control unit (400) is used to adjust the gas supply pressure, gas supply flow rate, gas supply on / off status and exhaust resistance according to the temperature difference information between adjacent temperature control zones (200) and the temperature information of the zone boundary (230) area, and to adjust the heating intensity and / or cooling intensity of the corresponding temperature control zone (200) in conjunction with the adjustment.

6. The mold zoned temperature control system based on adjustable thermal resistance boundary of air film according to claim 1, characterized in that: The division of the temperature control zone (200) is determined based on the wall thickness distribution of the part, the gate position, the insert position, the surface quality sensitive area or the defect sensitive area; the mold is an injection mold, a die casting mold, a hot pressing mold or a composite material molding mold.

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