A new hot plate based on fluidity experimental teaching equipment and a preparation method thereof

Abstract

The application discloses a novel heating plate based on fluidity experimental teaching equipment and a preparation method thereof, and belongs to the technical field of experimental instrument and equipment for investment casting teaching. The novel heating plate sequentially comprises an aluminum alloy mold bottom plate, a heat-conducting gel layer, an insulating heat-conducting film layer, a heating element, a glass fiber insulation heat insulation film layer, a silica gel foamed insulation cotton leveling layer, a polyurethane insulation layer and a mold protection bottom shell. The heating element is a flat double helix heating element formed by a metal wire being twisted into double strands from the center to the periphery. The glass fiber layer insulation heat insulation film layer comprises glass fiber tows and glass fiber cloth. The glass fiber tows are filled in the gaps of the flat double helix heating element, and the glass fiber cloth is arranged below the flat double helix heating element. The heating plate realizes one-way heat conduction, the bottom surface of the heating plate is flat, the structure layers are closely attached to each other and have small assembly gaps, the heating speed is high, heat loss is small, and the heating effect is high.

Description

Technical Field

[0001] This invention belongs to the technical field of teaching experimental instruments and equipment for investment casting, specifically relating to a novel heating plate based on fluidity-based experimental teaching equipment and its preparation method. Background Technology

[0002] Casting is one of the fundamental processes in modern basic machinery manufacturing. Fluidity experiments related to casting are a basic experimental course for mechanical engineering majors in ordinary colleges and universities. Fluidity is one of the casting properties of alloys, directly affecting the filling ability of liquid alloys. Alloys with better fluidity have stronger filling ability, enabling the casting of thin-walled and complex parts with clear contours. It also facilitates the floating and expulsion of inclusions and gases, as well as shrinkage during solidification. Conversely, alloys with poor fluidity struggle to fill the mold cavity, resulting in poor filling ability and defects such as incomplete filling, cold shuts, porosity, and slag inclusions. Through fluidity experiments, students learn about the concept, testing methods, and influencing factors of material fluidity, while gaining a comprehensive understanding of engineering materials and the basic knowledge of material forming.

[0003] With the development of casting industry technology, new requirements have been put forward for experimental and practical teaching in colleges and universities, necessitating teaching experiments on the flowability measurement of low-melting-point materials for investment casting. However, existing material flowability experimental teaching devices suffer from technical problems such as low heating efficiency. For example, patent CN113804584A discloses a material flowability experimental device based on a spiral flow channel. The mold system heating and insulation module uses a heating plate placed at the bottom of the mold for direct heating. The heating and insulation pad, heat insulation layer, and protective bottom shell are then placed on the bottom surface of the lower mold plate and locked with fastening screws. However, due to the protruding wires of the heating plate causing unevenness between the upper and lower surfaces, there are assembly gaps, resulting in heat loss and low heating efficiency during the experiment. The low space utilization of the heating circuit also leads to slow heating speed and long preheating time. Summary of the Invention

[0004] To address the technical problem of low heating efficiency in existing experimental teaching equipment for material flowability, this invention provides a novel heating plate based on flowability experimental teaching equipment; this invention also provides a method for preparing the novel heating plate based on flowability experimental teaching equipment.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a novel heating plate based on mobile experimental teaching equipment, comprising, from top to bottom, an aluminum alloy mold base plate, a thermally conductive gel layer, an insulating thermally conductive film layer, a heating element, a glass fiber insulation cotton insulating film layer, a silicone foam insulation cotton leveling layer, a polyurethane insulation layer, and a mold protective bottom shell; the heating element is a flat double-helix heating element formed by combining two strands of a metal wire and wrapping them around from the center to the periphery; the glass fiber insulation cotton insulating film layer includes glass fiber bundles and glass fiber cloth, the glass fiber bundles fill the gaps in the flat double-helix heating element, and the glass fiber cloth is disposed below the flat double-helix heating element.

[0006] Furthermore, the metal wire is made of nickel-chromium alloy, and the mold base plate has an opening on its side. Insulating glue is injected into both ends of the metal wire to serve as lead-out circuit terminals placed in the opening.

[0007] Furthermore, the aluminum alloy mold base plate and the mold protective shell are connected by bolts.

[0008] A method for preparing a novel heating plate using the above-mentioned fluid experimental teaching equipment includes the following steps: S1, preparing an aluminum alloy mold base plate; S2, inverting the mold base plate on the surface of a workbench, sequentially spraying a thermally conductive gel layer and applying an insulating thermally conductive film layer into the groove on the back of the mold base plate; S3, combining two strands of a metal wire and wrapping them around from the center to the periphery to form a flat double-helix heating element, and placing it at the center of the insulating thermally conductive film layer; S4, filling the internal gaps of the flat double-helix heating element with glass fiber bundles, and then using glass... A fiber cloth covers the top of the flat double-helix heating element. The glass fiber bundles and glass fiber cloth form a glass fiber insulation cotton insulating film layer; S5, silicone foaming agent is filled into the surface of the glass fiber insulation cotton insulating film layer to fill the groove cavity, and then pressure is applied by heating and static pressure to form a silicone foam insulation cotton leveling layer; S6, a polyurethane insulation layer is applied to the silicone foam insulation cotton leveling layer; S7, the mold bottom shell is installed on the polyurethane insulation layer and connected to the mold bottom plate by bolts to lock the newly formed heating plate.

[0009] Furthermore, the preparation method of the aluminum alloy mold base plate includes the following steps: S11, clamping the aluminum alloy plate to the machining center and milling the surface smooth with a face milling cutter to ensure levelness; S22, slotting the back of the aluminum alloy mold base plate according to the drawing; S33, machining M10 threaded holes, M8 threaded holes, and locating pins sequentially on the aluminum alloy mold base plate; S44, machining the spiral flow channel required for the mold using a vertical CNC machine tool.

[0010] Furthermore, the preparation method of the novel heating plate based on the mobile experimental teaching equipment also includes: injecting insulating glue into both ends of the metal wire to form lead-out circuit terminals, and embedding the two lead-out circuit terminals into a socket module for connecting external circuits through soldering conductive connection points.

[0011] Furthermore, in S4, the glass fiber bundles are sequentially filled along the direction of the metal wire wrapping, and the thickness of the glass fiber bundles is the same as the thickness of the metal wire.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] (1) This invention uses high-quality high-temperature refractory metal nickel-chromium alloy as the heating element to improve thermal conductivity and heater life; flat heating metal wires are used, and the metal wires are spirally laid out along the flow channel to improve space utilization and heating efficiency; glass fiber bundles are laid between the flat heating metal wires and the flat double spiral heating element is covered with glass fiber cloth. The glass fiber bundles can better fill the gaps between the metal wires that are wrapped together, making heat conduction faster and more uniform, and can also reduce heating time and improve production efficiency; silicone foam insulation cotton leveling layer is filled under the glass fiber insulation cotton insulation film layer, and pressure is applied by heating and static pressure to ensure that the bottom surface is flat.

[0014] (2) The heating plate achieves unidirectional heat conduction. The upper layer of the flat double-helix heating element is arranged with a heat-conducting gel layer and an insulating heat-conducting film layer, which is conducive to the upward conduction of heat and the formation of effective energy. The lower layer of the heating element is arranged with an insulating heat-insulating film layer and a polyurethane insulation layer, forming a double insulation layer, which is conducive to preventing heat from being conducted downward and reducing energy waste. Attached Figure Description

[0015] Figure 1 This is an exploded view of the assembly of the novel heating plate of the present invention;

[0016] Figure 2 This is a schematic diagram of the structure of a flat double-helix heating element;

[0017] Figure 3 This is a schematic diagram of the structure on the back of the mold base plate;

[0018] Among them, 1 is the alloy mold base plate, 11 is the groove, 12 is the M10 threaded hole, 13 is the M8 threaded hole, 14 is the positioning pin, 15 is the opening, 2 is the thermal conductive gel layer, 3 is the insulating thermal conductive film layer, 4 is the heating element, 5 is the glass fiber insulation cotton insulation film layer, 6 is the silicone foam insulation cotton leveling layer, 7 is the polyurethane insulation layer, 8 is the mold protective bottom shell, and 9 is the socket module. Detailed Implementation

[0019] The following explanation, in conjunction with the accompanying drawings, provides further details.

[0020] This invention discloses a novel heating plate based on mobile experimental teaching equipment, such as... Figure 1 As shown, from top to bottom, the structure includes an aluminum alloy mold base plate 1, a thermally conductive gel layer 2, an insulating thermally conductive film layer 3, a heating element 4, a glass fiber insulation cotton insulating film layer 5, a silicone foam insulation cotton leveling layer 6, a polyurethane insulation layer 7, and a mold protective bottom shell 8. The heating element is a flat double-helix heating element formed by two strands of a single metal wire wrapping around the center. The glass fiber insulation cotton insulating film layer includes glass fiber bundles and glass fiber cloth. The glass fiber bundles fill the gaps in the flat double-helix heating element, and the glass fiber cloth is positioned below the flat double-helix heating element. Figure 2 The image shows a flat double-helix heating element. The metal wire is made of high-temperature refractory nickel-chromium alloy, which improves thermal conductivity and heater life. The metal wire is arranged in a flat structure and spirally spread along the flow channel direction on the aluminum alloy mold, which improves space utilization and heating efficiency. The double-helix length of the metal wire is equal to or exceeds the length of the spiral flow channel on the mold, further ensuring the temperature uniformity of the flow channel area on the upper surface of the aluminum alloy mold base plate.

[0021] The metal wire is made of nickel-chromium alloy. The mold base plate has an opening on its side, and the two ends of the metal wire are filled with insulating glue and placed in the opening as lead-out circuit terminals. Figure 3 As shown, an opening 15 is provided on the side of the aluminum alloy mold base plate to place the metal wire lead-out circuit terminal.

[0022] The aluminum alloy mold base plate and the mold protective shell are connected by bolts.

[0023] The preparation method of the novel heating plate based on the above-mentioned fluid experimental teaching equipment includes the following steps: S1, preparing an aluminum alloy mold base plate; S2, inverting the mold base plate on the workbench surface, and sequentially spraying a thermally conductive gel layer and applying an insulating thermally conductive film layer into the groove on the back of the mold base plate; S3, combining two strands of a metal wire and wrapping them around from the center to the periphery to form a flat double-helix heating element, and placing it at the center of the insulating thermally conductive film layer; S4, filling the internal gaps of the flat double-helix heating element with glass fiber bundles, and then using glass... A glass fiber cloth is placed over the flat double-helix heating element. The glass fiber bundles and glass fiber cloth form a glass fiber insulation cotton insulating film layer. S5. Silicone foaming agent is filled into the surface of the glass fiber insulation cotton insulating film layer, and then pressure is applied by heating and static pressing to form a silicone foam insulation cotton leveling layer. S6. A polyurethane insulation layer is applied on top of the silicone foam insulation cotton leveling layer. S7. The mold bottom shell is installed on the polyurethane insulation layer and connected to the mold bottom plate by bolts to lock the newly formed heating plate.

[0024] This invention utilizes the loose, slender fibers of glass fiber bundles to fill the gaps in the metal wire coils, enabling the metal wires to heat up and conduct heat more quickly and evenly, reducing heating time and improving heating efficiency. Preferably, in step S4, the glass fiber bundles are sequentially filled along the spiral direction of the metal wires, with the thickness of the glass fiber bundles being the same as the thickness of the metal wires, facilitating flatness. Below the glass fiber bundles filling the metal wires, a glass fiber cloth is placed. The glass fiber cloth has good wrapping properties; covering the metal wires with the glass fiber cloth further fills the gaps, ensuring a tight fit and reducing assembly gaps. The polyurethane insulation layer of this invention can be cut and processed according to size requirements, covering the silicone foam insulation cotton leveling layer to further prevent heat from being transferred downwards and wasted.

[0025] This invention enables the glass fiber insulation cotton insulation film layer to be flat and shaped. In this invention, the glass fiber insulation cotton is bonded and fixed by silicone foaming agent in S5. The foaming process fills the entire groove cavity of the aluminum alloy mold base plate. The material in the groove cavity of the aluminum alloy mold base plate is flattened by heating and static pressing to ensure that the bottom surface is flat.

[0026] The method for preparing the aluminum alloy mold base plate of the present invention includes the following steps: S11, clamping the 6160 aluminum alloy plate to the machining center and milling the surface smooth with a face milling cutter to ensure levelness; S22, cutting grooves on the back of the aluminum alloy mold base plate according to the drawing to form a groove 11; S33, machining M10 threaded holes 12, M8 threaded holes 13, and locating pins 14 on the aluminum alloy mold base plate according to the dimensions; S44, machining the spiral flow channel required for the mold using a vertical CNC machine tool. Figure 3 This is a schematic diagram of the back structure of the aluminum alloy mold base plate, as shown below. Figure 3 As shown, four M10 threaded holes 12 and four M8 threaded holes 13 are machined into the aluminum alloy mold base plate according to the dimensions, as follows. Figure 2 As shown, two [items] are machined on the front side of the aluminum alloy mold base plate. Positioning pin 14.

[0027] Insulating glue is injected into both ends of the metal wire to form lead-out circuit terminals. The two lead-out circuit terminals are then embedded into the socket module for connecting to the external circuit via soldered conductive connection points. The injection of insulating glue ensures that the two lead-out circuit terminals are mutually insulated. The socket module is a two-core or three-core triangular socket module, which allows for quick connection to the external circuit.

Claims

1. A novel heating plate based on mobile experimental teaching equipment, characterized in that, From top to bottom, it includes an aluminum alloy mold base plate, a thermally conductive gel layer, an insulating thermally conductive film layer, a heating element, a glass fiber insulation cotton insulating film layer, a silicone foam insulation cotton leveling layer, a polyurethane insulation layer, and a mold protective bottom shell. The heating element is a flat double-helix heating element formed by combining two strands of a metal wire and wrapping them around from the center to the periphery. The glass fiber insulation cotton insulating film layer includes glass fiber bundles and glass fiber cloth. The glass fiber bundles fill the gaps in the flat double-helix heating element, and the glass fiber cloth is placed below the flat double-helix heating element. The glass fiber insulation cotton insulating film layer is bonded and fixed by silicone foaming agent. The silicone foaming agent is filled into the surface of the glass fiber insulation cotton insulating film layer to form a silicone foam insulation cotton leveling layer. The foaming process fills the entire groove cavity of the aluminum alloy mold base plate. The material in the groove cavity of the aluminum alloy mold base plate is flattened by heating and static pressing. The material in the groove cavity includes a thermally conductive gel layer, an insulating thermally conductive film layer, a heating element, a glass fiber insulation cotton insulating film layer, and a silicone foam insulation cotton leveling layer.

2. The novel heating plate based on mobile experimental teaching equipment according to claim 1, characterized in that, The metal wire is made of nickel-chromium alloy. The mold base plate has an opening on its side. Insulating glue is poured into both ends of the metal wire to serve as lead-out circuit terminals placed in the opening.

3. The novel heating plate based on mobile experimental teaching equipment according to claim 1, characterized in that, The aluminum alloy mold base plate and the mold protective shell are connected by bolts.

4. A method for preparing a novel heating plate based on a mobile experimental teaching equipment as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Prepare the aluminum alloy mold base plate; S2. Invert the mold base plate onto the workbench surface, and spray the thermal conductive gel layer and apply the insulating thermal conductive film layer into the groove on the back of the mold base plate in sequence. S3. A flat double-helix heating element is formed by combining two strands of a metal wire and wrapping them around from the center to the surrounding area, and then placed at the center of the insulating heat-conducting film layer. S4. Fill the internal gap of the flat double helix heating element with glass fiber bundles, and then cover the top of the flat double helix heating element with glass fiber cloth. The glass fiber bundles and glass fiber cloth form a glass fiber insulation and heat insulation film layer. S5. Fill the surface of the glass fiber insulation cotton insulation film layer with silicone foaming agent to fill the groove cavity, and then pressurize it by heating and static pressure to form a silicone foam insulation cotton leveling layer. S6. Apply the polyurethane insulation layer onto the silicone foam insulation cotton leveling layer. S7. Install the mold base shell onto the polyurethane insulation layer and connect it to the mold base plate with bolts to form the new type of heating... Lock the plate.

5. The preparation method according to claim 4, characterized in that, The method for preparing the aluminum alloy mold base plate includes: The steps are as follows: S11. Clamp the aluminum alloy plate onto the machining center and use a face milling cutter to smooth the surface and ensure levelness. S22. Groove the back of the aluminum alloy mold base plate according to the drawing; S33. Sequentially machine M10 threaded holes, M8 threaded holes, and locating pins on the aluminum alloy mold base plate. S44. Use a vertical CNC machine tool to machine the spiral flow channel required for the mold.

6. The preparation method according to claim 4, characterized in that, Also includes: Insulating glue is injected into both ends of the metal wire to form lead-out circuit terminals. The two lead-out circuit terminals are embedded into the socket module that connects to the external circuit through solder conductive connection points.

7. The preparation method according to claim 4, characterized in that, In S4, glass fiber bundles are sequentially filled along the direction of the metal wire wrapping, and the thickness of the glass fiber bundles is the same as the thickness of the metal wire.

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