A vacuum heating structure for pressure differential coating machine

Abstract

The present invention discloses a vacuum heating structure for a pressure differential coating machine, which belongs to the technical field of coating machines and includes a lower vacuum hood, an upper vacuum hood installed on the upper side of the lower vacuum hood, and a vertical displacement drive device for driving the upper vacuum hood to cooperate with the lower vacuum hood. The upper side of the lower vacuum hood is provided with an upper opening, and the lower side of the upper vacuum hood is provided with a lower opening corresponding to the upper opening. Both the upper vacuum hood and the lower vacuum hood are square, and a coating film is installed at the lower opening. The size and shape of the upper opening and the lower opening are exactly the same and can overlap. A heating component is installed in the upper vacuum hood, and the heating system is used to heat the coating film to soften it, facilitate the coating of the material, and ensure the uniformity of the coating layer. The upper vacuum hood and the lower vacuum hood cooperate to form a molding cavity. The present invention can adjust the shape and position of the radiation area to meet the heating needs of diversified products, while taking into account structural reliability and energy consumption optimization.

Description

Technical Field

[0001] The invention belongs to the technical field of coating machines, and in particular relates to a vacuum heating structure for a pressure difference coating machine. Background Art

[0002] The differential pressure coating machine is a type of equipment widely used in the surface treatment industry, mainly used to apply decorative films or functional coatings to complex curved or special-shaped workpieces. Its core process principle is to establish a pressure difference in a closed cavity, so that the film is tightly adhered to the surface of the workpiece under the action of air pressure, and then cured by heating to form a durable adhesion. This technology is widely used in automotive interiors, electronic product housings, home decoration and other fields, and has the advantages of high efficiency, strong adaptability and high yield rate. Among the key structures of the differential pressure coating machine, the role of the heating system is crucial. In recent years, vacuum heating structures have gradually become the focus of industry research. The vacuum heating structure arranges radiant heating elements, such as infrared heating tubes and ceramic heating elements, in a closed cavity, and uses the vacuum environment to reduce heat convection loss, so that heat energy can be more efficiently transferred to the workpiece surface in the form of radiation. This heating method has the advantages of fast heating, high thermal efficiency and precise temperature control, and is particularly suitable for film materials with high temperature sensitivity.

[0003] However, existing vacuum heating structures still face significant technical bottlenecks in practical applications, particularly the issue of maintaining a stable heating radiation area. Due to the wide variation in the shape, size, and film properties of coated products, the required heating area often needs to be dynamically adjusted. For example, a small workpiece may only require localized, concentrated heating, while a large, curved workpiece requires uniform and extensive radiation coverage. However, the radiation range of traditional heating structures is typically determined by the physical layout of the heating elements, making it difficult to adjust once installed. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a vacuum heating structure for a pressure differential coating machine, which can adjust the shape and position of the radiation area to adapt to the heating needs of diversified products while taking into account structural reliability and energy consumption optimization.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention discloses a vacuum heating structure for a pressure differential coating machine, comprising a lower vacuum hood, an upper vacuum hood mounted on the upper side of the lower vacuum hood, and a vertical displacement drive device for driving the upper vacuum hood to cooperate with the lower vacuum hood. The upper side of the lower vacuum hood is provided with an upper opening, and the lower side of the upper vacuum hood is provided with a lower opening corresponding to the upper opening. Both the upper vacuum hood and the lower vacuum hood are square in shape, and a coating film is mounted at the lower opening. The upper and lower openings are completely consistent in size and shape and can overlap. A heating component is mounted in the upper vacuum hood. The heating system is used to heat the coating film to soften it, facilitate the coating of the material, and ensure the uniformity of the coating layer. The upper vacuum hood and the lower vacuum hood cooperate to form a molding cavity.

[0007] Specifically, the heating assembly includes a top plate and a plurality of heating tubes spaced laterally parallel to and mounted on the underside of the top plate. The top plate is a rectangular plate-like structure, and the heating tubes are straight tubes extending longitudinally along the top plate. The heating tubes are mounted to the top plate in a transversely sliding manner and secured to the top plate by locking members. The heating tubes are provided with a heating portion and a longitudinal displacement drive mechanism capable of driving the heating portion to move longitudinally along the heating tubes.

[0008] Furthermore, the longitudinal displacement driving device includes a first piston and a second piston that are slidingly sealed and installed in the heating tube. The first piston and the second piston divide the heating tube into a first pressure chamber, a receiving chamber and a second pressure chamber in sequence. The receiving chamber is formed between the first piston and the second piston, and the heating part is the molten liquid filled in the receiving chamber.

[0009] Furthermore, the longitudinal displacement driving device includes a first pump, a first pressure detection device, a first air inlet pipe, a first air outlet pipe, a second pump, a second pressure detection device, a second air inlet pipe, and a second air outlet pipe. The first air inlet pipe and the first air outlet pipe are connected to the first pressure chamber at the same time, and the first air inlet pipe is equipped with the first pump and the first pressure detection device at the same time. The second air inlet pipe and the second air outlet pipe are connected to the second pressure chamber at the same time, and the second air inlet pipe is equipped with the second pump and the second pressure detection device at the same time.

[0010] Furthermore, a first heating wire is installed on the inner side of the first piston. The first heating wire is spiral and can be stretched or compressed along the axial direction of the heating tube. One end of the first heating wire passes through the end of the first pressure chamber and is connected to the power supply, and the other end of the first heating wire passes through the first piston and extends into the accommodating chamber.

[0011] Furthermore, a liquid control tube is installed on the inner side of the second piston. One end of the liquid control tube passes through the end of the second pressure chamber and is connected to the molten liquid storage tank. The molten liquid storage tank is connected to a pressure controller. The other end of the liquid control tube passes through the second piston and is connected to the accommodating chamber.

[0012] Furthermore, a second heating wire is wrapped around the outside of the liquid control tube. The first heating wire is spiral and can be stretched or compressed along the axial direction of the heating tube. One end of the second heating wire passes through the end of the second pressure chamber and is connected to the power supply. The other end of the first heating wire is connected to the second piston.

[0013] Furthermore, both the first air intake pipe and the second air intake pipe are made of hoses, one end of the first air intake pipe is extended into the first pressure chamber and connected to the first piston, a through hole is provided on the outer wall of the first air intake pipe near the first piston, one end of the second air intake pipe is extended into the second pressure chamber and connected to the second piston, and a through hole is provided on the outer wall of the second air intake pipe near the second piston.

[0014] Furthermore, a T-shaped slider is fixed to one end of the heating tube, a T-shaped slide groove corresponding to the T-shaped slider is provided on the top plate, a U-shaped groove is provided at the other end of the heating tube, a slide groove is provided horizontally on the upper edge of the top plate, and the locking part is a bolt, which passes through the U-shaped groove and the slide groove at the same time to fix the heating tube and the top plate.

[0015] Furthermore, a fixed tube is installed on the outside of the heating tube, and a first open groove is provided on the outside of the fixed tube, and the first open groove extends along the axial direction of the heating tube. The outside of the fixed tube is rotatably connected to a rotating tube, and a second open groove is provided on the outside of the rotating tube, and the second open groove extends along the axial direction of the heating tube. The length of the second open groove corresponds to that of the first open groove. By rotating the rotating tube, the degree of overlap between the first open groove and the second open groove can be changed.

[0016] The beneficial effects of the present invention are:

[0017] The present invention discloses a vacuum heating structure for a pressure differential coating machine. The heating parts of multiple heating tubes are combined to form a heating radiation plane. For a single heating tube, a longitudinal displacement drive device can drive the heating part to move along the longitudinal direction of the heating tube, thereby adjusting the longitudinal position of the heating part. By moving each heating tube laterally, the arrangement and combination of the heating parts can be adjusted, thereby adjusting the shape and position of the radiation area to meet the heating needs of diverse products while taking into account structural reliability and energy consumption optimization. The adjustment method of the present invention is stable, the produced products are of high quality, and are more suitable for high-temperature environments.

[0018] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the purpose, technical solutions and beneficial effects of the present invention more clear, the present invention provides the following drawings for illustration:

[0020] Figure 1 The structure diagram of the vacuum heating structure of the present invention is as follows Figure 1 ;

[0021] Figure 2 The structure diagram of the vacuum heating structure of the present invention is as follows Figure 2 ;

[0022] Figure 3 It is a structural schematic diagram of the heating component;

[0023] Figure 4 Schematic diagram of the distribution of heating pipes;

[0024] Figure 5 for Figure 4 Enlarged view of point C in the middle;

[0025] Figure 6 is a cross-sectional view of the heating tube;

[0026] Figure 7 Schematic diagram of the structure of the first pressure chamber;

[0027] Figure 8 for Figure 7 Enlarged view of point A in the middle;

[0028] Figure 9 Schematic diagram of the structure of the second pressure chamber;

[0029] Figure 10 for Figure 9 Enlarged view of point B in the middle;

[0030] Figure 11 A schematic diagram of the arrangement of one type of heating unit;

[0031] Figure 12 Schematic diagram of the structure of the fixed tube and the rotating tube.

[0032] The markings in the accompanying drawings are as follows: lower vacuum cover 1, upper vacuum cover 2, vertical displacement drive device 3, upper opening 4, lower opening 5, heating assembly 6, top plate 7, heating tube 8, locking piece 9, heating part 10, first piston 11, second piston 12, first pressure chamber 13, accommodating chamber 14, second pressure chamber 15, first air inlet pipe 16, first air outlet pipe 17, second air inlet pipe 18, second air outlet pipe 19, first heating wire 20, liquid control pipe 21, molten liquid storage tank 22, second heating wire 23, through hole 24, T-shaped slider 25, T-shaped slide groove 26, U-shaped groove 27, slide groove 28, fixed tube 29, first opening groove 30, rotating tube 31, second opening groove 32. DETAILED DESCRIPTION

[0033] like Figures 1 to 11 As shown, the present invention discloses a vacuum heating structure for a pressure differential coating machine, comprising a lower vacuum cover 1, an upper vacuum cover 2 installed on the upper side of the lower vacuum cover 1, and a vertical displacement drive device 3 for driving the upper vacuum cover 2 to cooperate with the lower vacuum cover 1. The vertical displacement drive device 3 adopts a hydraulic cylinder, and the output end of the hydraulic cylinder is connected to the upper vacuum cover 2, which can drive the upper vacuum cover 2 to move up and down.

[0034] An upper opening 4 is provided on the upper side of the lower vacuum cover 1, and a lower opening 5 corresponding to the upper opening 4 is provided on the lower side of the upper vacuum cover 2. A covering film is installed at the lower opening 5. The upper vacuum cover 2 and the lower vacuum cover 1 cooperate to form a molding cavity. A heating assembly 6 is installed on the inner side of the upper vacuum cover 2; the heating assembly 6 includes a top plate 7 and a plurality of heating tubes 8 installed on the lower side of the top plate 7 at parallel intervals in the horizontal direction. The heating tubes 8 are installed on the top plate 7 in a horizontal sliding manner. The heating tubes 8 and the top plate 7 are fixed by locking members 9. A heating portion 10 and a longitudinal displacement drive device are provided in the heating tube 8. The longitudinal displacement drive device can drive the heating portion 10 to move longitudinally along the heating tube 8.

[0035] The vacuum heating structure proposed in the present invention adjusts the position and spacing of the heating tubes 8 by lateral sliding and adjusts the position of the heating part 10 by longitudinal displacement, thereby realizing multi-dimensional dynamic adjustment of the heating radiation area. Specifically, the heating tubes 8 are installed along the top plate 7 for horizontal sliding, and the position of the heating tubes 8 and the spacing between the heating tubes 8 can be flexibly adjusted according to the size of the workpiece. For example, when targeting narrow workpieces, the spacing can be reduced to concentrate heat radiation, thereby improving the heating efficiency. When targeting wide workpieces, the spacing can be expanded to achieve uniform coverage and ensure uniform heating. At the same time, each heating tube 8 is integrated with a longitudinal displacement drive device, which can independently control the longitudinal movement of the heating part 10 in the heating tube 8, thereby further adjusting the axial distribution range of the radiated heat. This lateral and longitudinal dual-degree-of-freedom adjustment mechanism breaks through the rigidity limitations of traditional fixed heating elements and significantly improves the matching accuracy between the heating area and the shape of the workpiece.

[0036] Of course, targeted adjustments can also be made according to the shape of the workpiece. Thicker areas can be combined with denser heating parts 10. Conversely, thinner areas can reduce heat transfer by increasing the spacing, making the workpiece heated more evenly and ensuring product quality.

[0037] During the curved surface coating process, adjusting the position of the heating element 10 can avoid uneven film curing at the edges due to insufficient heat radiation. Furthermore, the heating tube 8 is secured to the top plate 7 via a locking member 9, ensuring both adjustable flexibility and structural stability in a vacuum environment. The overall design balances flexible production requirements with equipment reliability, enabling rapid switching between high-volume, low-volume orders while reducing energy waste caused by redundant heating.

[0038] In this embodiment, the longitudinal displacement drive device includes a first piston 11 and a second piston 12, which are slidingly and hermetically mounted within the heating tube 8. The first and second pistons 11 and 12 sequentially divide the heating tube 8 into a first pressure chamber 13, a receiving chamber 14, and a second pressure chamber 15. The receiving chamber 14 is formed between the first and second pistons 11 and 12, and the heating portion 10 is filled with molten liquid within the receiving chamber 14. When the longitudinal displacement drive device propels the pistons via a pressure differential, the volume and position of the molten liquid can be precisely controlled, thereby dynamically adjusting the radiation range.

[0039] Specifically, when controlling the melt to move toward the second piston 12, the pressure in the first pressure chamber 13 is increased. Since the pressure in the first pressure chamber 13 is greater than that in the second pressure chamber 15, the first piston 11 can force the melt in the accommodating chamber 14 to move toward the second piston 12. Once the melt is positioned properly, the pressure in the first pressure chamber 13 is adjusted to be consistent with the pressure in the second pressure chamber 15. Conversely, when controlling the melt to move toward the first piston 11, the pressure in the second pressure chamber 15 is increased. Those skilled in the art will understand this.

[0040] In this embodiment, the longitudinal displacement drive device includes a first pump, a first pressure detection device, a first air inlet pipe 16, a first air outlet pipe 17, a second pump, a second pressure detection device, a second air inlet pipe 18, and a second air outlet pipe 19. The first pump and the second pump are used to provide power. The first air inlet pipe 16 and the first air outlet pipe 17 are simultaneously connected to the first pressure chamber 13. The first air inlet pipe 16 and the first air outlet pipe 17 can be used to control the entry and exit of gas or liquid, respectively. The first pump and the first pressure detection device are simultaneously installed on the first air inlet pipe 16. The second air inlet pipe 18 and the second air outlet pipe 19 are simultaneously connected to the second pressure chamber 15. The second pump and the second pressure detection device are simultaneously installed on the second air inlet pipe 18. The first pressure detection device and the second pressure detection device are respectively used to accurately detect the pressure in the first pressure chamber 13 and the second pressure chamber 15, making the pressure control more precise. The installation method of the pump and the pressure detection device belongs to the prior art and can be understood by those skilled in the art.

[0041] In this embodiment, a first heating wire 20 is installed on the inner side of the first piston 11. The first heating wire 20 is spiral and can be stretched or compressed along the axial direction of the heating tube 8. One end of the first heating wire 20 passes through the end of the first pressure chamber 13 and is connected to the power supply, and the other end of the first heating wire 20 passes through the first piston 11 and extends into the accommodating chamber 14. By providing the first heating wire 20, it can be used to heat the molten liquid, and the molten liquid can be liquid mercury. In some other embodiments, the molten liquid can be iron, which is solid at room temperature. When the workpiece needs to be heated, the iron block is heated by the first heating wire 20 to liquefy it, which is convenient for controlling its position. The heating block is made of ceramic material to avoid the influence of high temperature. The air inlet and outlet pipes are made of ceramic fiber composite materials, which can withstand higher temperatures while ensuring elasticity.

[0042] In this embodiment, a liquid control tube 21 is installed on the inner side of the second piston 12. One end of the liquid control tube 21 passes through the end of the second pressure chamber 15 and is connected to a melt storage tank 22. The melt storage tank 22 is connected to a pressure controller. The other end of the liquid control tube 21 passes through the second piston 12 and is connected to the accommodating chamber 14. By providing the melt storage tank 22, under the control of the pressure controller, the melt in the accommodating chamber 14 can be absorbed or replenished through the liquid control tube 21 to adjust the length of the heating section 10. Specifically, when it is necessary to replenish liquid into the accommodating chamber 14, the pressure in the melt storage tank 22 can be increased, forcing the melt from the melt storage tank 22 into the accommodating chamber 14. Conversely, when it is necessary to absorb liquid into the accommodating chamber 14, the pressure in the melt storage tank 22 can be reduced, allowing the melt to flow back into the melt storage tank 22.

[0043] In this embodiment, a second heating wire 23 is wound around the outside of the liquid control tube 21. The first heating wire 20 is helical and can be stretched or compressed along the axial direction of the heating tube 8. One end of the second heating wire 23 extends through the end of the second pressure chamber 15 and is connected to a power source. The other end of the first heating wire 20 is connected to the second piston 12. The provision of the second heating wire 23 heats the liquid control tube 21, preventing the molten liquid from solidifying due to a temperature drop during transportation, thereby ensuring real-time flow regulation.

[0044] In this embodiment, both the first air intake pipe 16 and the second air intake pipe 18 are hoses. One end of the first air intake pipe 16 is extended into the first pressure chamber 13 and connected to the first piston 11. A through hole 24 is provided on the outer wall of the first air intake pipe 16 near the first piston 11. One end of the second air intake pipe 18 is extended into the second pressure chamber 15 and connected to the second piston 12. A through hole 24 is provided on the outer wall of the second air intake pipe 18 near the second piston 12, which can facilitate pressure control.

[0045] In this embodiment, a T-shaped slider 25 is fixed to one end of the heating tube 8. A T-shaped slot 26 corresponding to the T-shaped slider 25 is provided on the top plate 7. A U-shaped slot 27 is provided on the other end of the heating tube 8. A slot 28 is provided transversely on the top plate 7. The locking member 9 is a bolt that passes through both the U-shaped slot 27 and the slot 28 to secure the heating tube 8 to the top plate 7. The combined locking structure of the T-shaped slider 25 and the U-shaped slot 27 achieves efficient and stable position adjustment of the heating tube 8.

[0046] As a further improvement of the embodiment of the present invention, Figure 12 As shown, a fixed tube 29 is mounted on the outside of the heating tube 8. A first slot 30 is defined on the outside of the fixed tube 29, extending along the axial direction of the heating tube 8. A rotating tube 31 is rotatably connected to the outside of the fixed tube 29. A second slot 32 is defined on the outside of the rotating tube 31, extending along the axial direction of the heating tube 8. The length of the second slot 32 corresponds to that of the first slot 30. Rotating the rotating tube 31 can change the degree of overlap between the first slot 30 and the second slot 32. The overlap between the first slot 30 of the fixed tube 29 and the second slot 32 of the rotating tube 31 can be controlled by rotating the rotating tube 31, thereby varying the effective transmission area of ​​the thermal radiation. For areas requiring weak local heating, the slot overlap can be adjusted to 10% to limit the radiation flux. For areas requiring strong heating, the overlap can be adjusted to 90% to maximize heat output.

[0047] In the embodiment of the present invention, the fixed tube 29 and the rotating tube 31 are both made of high-temperature resistant materials, and there is a certain friction between the two. After relative rotation, the position of the rotating tube 31 can be limited to a certain extent, thereby ensuring the stability of the process.

[0048] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A vacuum heating structure for a pressure differential coating machine, characterized in that: The invention comprises a lower vacuum cover, an upper vacuum cover installed on the upper side of the lower vacuum cover, and a vertical displacement driving device for driving the upper vacuum cover to cooperate with the lower vacuum cover. The upper side of the lower vacuum cover is provided with an upper opening, and the lower side of the upper vacuum cover is provided with a lower opening corresponding to the upper opening. A covering film is installed at the lower opening. The upper vacuum cover and the lower vacuum cover cooperate to form a molding cavity. A heating assembly is installed on the inner side of the upper vacuum cover; the heating assembly comprises a top plate, and a plurality of heating tubes installed on the lower side of the top plate at parallel intervals in the transverse direction. The heating tubes are installed on the top plate in a transverse sliding manner. The heating tubes are fixed to the top plate by a locking member. A heating part and a longitudinal displacement driving device are provided in the heating tube. The longitudinal displacement driving device can drive the heating part to move longitudinally along the heating tube; the longitudinal displacement driving device comprises a sliding sealing device The first piston and the second piston in the heating tube divide the heating tube into a first pressure chamber, a receiving chamber and a second pressure chamber in sequence. The receiving chamber is formed between the first piston and the second piston, and the heating part is the molten liquid filled in the receiving chamber; a first heating wire is installed on the inner side of the first piston, and the first heating wire is spiral and can be stretched or compressed along the axial direction of the heating tube. One end of the first heating wire is connected to the power supply after passing through the end of the first pressure chamber, and the other end of the first heating wire is extended into the receiving chamber after passing through the first piston; a liquid control tube is installed on the inner side of the second piston, and one end of the liquid control tube is connected to the molten liquid storage tank after passing through the end of the second pressure chamber, and the molten liquid storage tank is connected to a pressure controller, and the other end of the liquid control tube is connected to the receiving chamber after passing through the second piston.

2. The vacuum heating structure for a pressure differential coating machine according to claim 1, characterized in that: The longitudinal displacement driving device includes a first pump, a first pressure detection device, a first air inlet pipe, a first air outlet pipe, a second pump, a second pressure detection device, a second air inlet pipe, and a second air outlet pipe. The first air inlet pipe and the first air outlet pipe are connected to the first pressure chamber at the same time. The first air inlet pipe is equipped with the first pump and the first pressure detection device at the same time. The second air inlet pipe and the second air outlet pipe are connected to the second pressure chamber at the same time. The second air inlet pipe is equipped with the second pump and the second pressure detection device at the same time.

3. The vacuum heating structure for a pressure differential coating machine according to claim 2, characterized in that: A second heating wire is wrapped around the outside of the liquid control tube. The second heating wire is spiral and can be stretched or compressed along the axial direction of the heating tube. One end of the second heating wire passes through the end of the second pressure chamber and is connected to the power supply, and the other end of the second heating wire is connected to the second piston.

4. The vacuum heating structure for a pressure differential coating machine according to claim 2, characterized in that: The first air intake pipe and the second air intake pipe are both made of hoses. One end of the first air intake pipe is extended into the first pressure chamber and connected to the first piston. A through hole is provided on the outer wall of the first air intake pipe near the first piston. One end of the second air intake pipe is extended into the second pressure chamber and connected to the second piston. A through hole is provided on the outer wall of the second air intake pipe near the second piston.

5. The vacuum heating structure for a pressure differential coating machine according to claim 1, characterized in that: A T-shaped slider is fixed to one end of the heating tube, and a T-shaped slide groove corresponding to the T-shaped slider is opened on the top plate. A U-shaped groove is provided at the other end of the heating tube, and a slide groove is opened horizontally on the upper edge of the top plate. The locking part is a bolt, and the bolt passes through the U-shaped groove and the slide groove at the same time to fix the heating tube and the top plate.

6. The vacuum heating structure for a pressure differential coating machine according to claim 1, characterized in that: A fixed tube is installed on the outside of the heating tube, and a first open groove is provided on the outside of the fixed tube, and the first open groove extends along the axial direction of the heating tube. A rotating tube is rotatably connected to the outside of the fixed tube, and a second open groove is provided on the outside of the rotating tube, and the second open groove extends along the axial direction of the heating tube. The length of the second open groove corresponds to that of the first open groove. By rotating the rotating tube, the degree of overlap between the first open groove and the second open groove can be changed.

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