A composite material differential pressure coating machine

Abstract

The present invention discloses a differential pressure coating machine for composite materials, belonging to the technical field of coating machines, which includes a frame, a sliding table installed on the frame, and a lower vacuum hood fixed to the sliding table. A mold assembly is installed at the inner bottom of the lower vacuum hood. The mold assembly is connected to a lifting device. An upper vacuum hood is installed above the lower vacuum hood. A heating system is installed in the upper vacuum hood. A forming cavity is formed by the cooperation between the upper vacuum hood and the lower vacuum hood. The forming cavity is connected to a differential pressure generating system. A workpiece positioning mechanism for fixing the workpiece to be coated is installed at the lower opening of the upper vacuum hood. The mold assembly includes a support plate. A support frame is formed in the middle of the support plate. A plurality of mold units are arrayed and installed in the support frame. The upper surfaces of the plurality of mold units cooperate to form a coating working surface for the workpiece. The bottom of the mold unit is connected to the support frame through a vibration cylinder. The device of the present invention can increase the coating strength of the material on the workpiece surface and improve the coating quality of the workpiece surface.

Description

Technical Field

[0001] The present invention belongs to the technical field of coating machines, and particularly relates to a differential pressure coating machine for composite materials. Background Art

[0002] A differential pressure coating machine is a special equipment for composite material forming. Its core principle is to use the air pressure difference to make the flexible coating film closely adhere to the mold surface, so as to achieve uniform compaction and forming of the composite material blank. This technology is widely used in fields such as aerospace, automobile manufacturing, and wind power blades, especially suitable for the manufacturing of components with complex curved surfaces or large-size structures. At present, the mainstream differential pressure coating machines mainly adopt the methods of vacuum negative pressure or positive pressure pressurization, and drive the deformation of the coating film through the pressure change in the sealed chamber, so that the prepreg or dry fiber blank can fully remove bubbles and be compacted before curing, in order to improve the mechanical properties and surface quality of the workpiece. However, in the prior art, due to the differences between equipment, there are often problems of insufficient bonding strength before the composite material is combined with the workpiece, which affects the coating quality of the workpiece surface. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a differential pressure coating machine for composite materials, which can solve the above technical problems.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] A differential pressure coating machine for composite materials disclosed by the present invention includes a frame, a slide table installed on the frame, a lower vacuum hood fixed to the slide table. A mold assembly is installed at the inner bottom of the lower vacuum hood. The mold assembly is connected with a lifting device. An upper vacuum hood is installed above the lower vacuum hood. A heating system is installed in the upper vacuum hood. A forming cavity is formed by the cooperation between the upper vacuum hood and the lower vacuum hood. The forming cavity is connected with a differential pressure generating system. A workpiece positioning mechanism for fixing the workpiece to be coated is installed at the lower opening of the upper vacuum hood. The mold assembly includes a support plate, a support frame is formed in the middle of the support plate, and a plurality of mold units are arrayed and installed in the support frame. The upper surfaces of the plurality of mold units cooperate to form a coating working surface for the workpiece. The bottom of the mold unit is connected to the support frame through a vibration cylinder, and adjacent two mold units are in vertical sliding fit.

[0006] Further, the mold unit includes a plurality of central units located at the center and a plurality of edge units annularly installed outside the central units. The plurality of edge units are connected in series in the circumferential direction to form a ring, and the plurality of central units and edge units are combined to form a mold.

[0007] Furthermore, a through hole is provided on the central unit. An irregular hole is formed at the lower part of the through hole. A plurality of vertical grooves are circumferentially formed on the inner side of the irregular hole. A scraping ring is slidably installed in the irregular hole. The scraping ring is connected with a limiting block through an elastic stretching device. When the elastic stretching device extends, the scraping ring can be in sliding fit with the inner wall of the through hole.

[0008] Furthermore, a central blind hole is formed in the center of the central unit. A piston is slidably installed in the central blind hole. The piston is connected to the output end of a vibration cylinder installed in the central blind hole. An air inlet hole is formed at the bottom of the central blind hole. An air outlet hole is formed on the side wall of the central blind hole. The other end of the air outlet hole communicates with the through hole.

[0009] Furthermore, a sleeve is installed in the air outlet hole. A tapered hole is provided in the sleeve. A ball is fitted in the tapered hole. The ball is connected with a filter plate through an elastic support device. The filter plate is fixed at the opening on the side of the sleeve away from the central blind hole.

[0010] Furthermore, a mounting hole is formed on the edge unit. An elastic tube is fixedly installed in the mounting hole. An expansion tube is coaxially installed in the elastic tube. A micro hole penetrating up and down is formed in the center of the expansion tube. When the expansion tube is heated, the diameter of the micro hole can expand.

[0011] Furthermore, a column is fixed on the sliding table. The columns are distributed at the four corners of the lower vacuum cover. The upper end of the column is fixed with an upper plate. The middle part of the column is slidably installed with a middle plate. The upper vacuum cover is installed on the lower side of the middle plate. A displacement driving device for driving the displacement of the middle plate is installed on the upper plate.

[0012] Furthermore, an ejecting assembly is installed on the side of the upper vacuum cover. The ejecting assembly includes a cylinder, a support plate, a guide rod, and a guide sleeve. The cylinder is installed on the middle plate. The output end of the cylinder is connected with a guide rod through a support plate. The guide rod is slidably arranged in the guide sleeve. The guide sleeve is installed on the support on the side wall of the upper vacuum cover.

[0013] The beneficial effects of the present invention are as follows:

[0014] Disclosed by the present invention, the die units are independently controlled by vibration cylinders, and local micro-vibrations can be applied to the surface of the workpiece during the coating process, promoting the close fit between the coating material (such as a film or prepreg) and the surface of the workpiece, eliminating bubbles or wrinkles, and improving the coating uniformity. At the same time, the array-type die unit design of the present invention is adapted to workpieces of different shapes, and a customized coating working surface is formed by adjusting the unit height, expanding the applicability of equipment such as concave-convex curved surfaces and special-shaped structures.

[0015] After the positioning mechanism of the present invention fixes the position of the workpiece, the mold unit adjusts the local contact pressure through vibration, which is particularly suitable for the composite material lamination scenario, ensuring the interfacial bonding strength between the fiber-reinforced material and the matrix. The frequency amplitude of the vibration cylinder is adjustable to adapt to the differential coating processes of thermosetting prepregs or thermoplastic films, avoiding fiber damage or uneven resin distribution. Through the synergistic effect of pressure difference and vibration, the qualification rate of the traditional coating process is improved in this device.

[0016] Other advantages, objectives, and features of the present invention will be described in the subsequent specification, and to some extent, they are obvious to those skilled in the art, 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 achieved and obtained through the following specification. Brief Description of the Drawings

[0017] In order to make the objectives, technical solutions, and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0018] Figure 1 It is a schematic structural diagram of the differential pressure coating machine of the present invention;

[0019] Figure 2 It is a cross-sectional view of the mold assembly of the present invention;

[0020] Figure 3 It is a schematic structural diagram of the central unit;

[0021] Figure 4 It is Figure 3 The enlarged view of part A in

[0022] Figure 5 It is a schematic structural diagram of the edge unit;

[0023] Figure 6 It is a schematic structural diagram of the mold assembly;

[0024] Figure 7 It is a schematic structural diagram of the special-shaped hole.

[0025] The reference numerals in the drawings are as follows: frame 1, sliding table 2, lower vacuum hood 3, mold assembly 4, lifting device 5, upper vacuum hood 6, support plate 7, support frame 8, vibration cylinder 9, central unit 10, edge unit 11, through hole 12, special-shaped hole 13, vertical groove 14, scraping ring 15, elastic stretching device 16, limit block 17, central blind hole 18, piston 19, air inlet hole 20, air outlet hole 21, sleeve 22, tapered hole 23, ball 24, elastic support device 25, filter plate 26, mounting hole 27, elastic tube 28, expansion tube 29, micropore 30, column 31, upper plate 32, middle plate 33, displacement driving device 34, cylinder 35, support plate 36, guide rod 37, guide sleeve 38. Detailed Description of the Invention

[0026] As Figures 1 - 7 shown, a differential pressure coating machine for composite materials disclosed by the present invention includes a frame 1, a slide table 2 installed on the frame 1, and a lower vacuum hood 3 fixed to the slide table 2. The lower vacuum hood 3 has an upper opening. A mold assembly 4 is installed at the inner bottom of the lower vacuum hood 3. The mold assembly 4 is connected to a lifting device 5. By setting the slide table 2, the slide table 2 can drive the lower vacuum hood 3 to move horizontally. Combining with the lifting device 5 of the mold assembly 4, it realizes the automation of rapid positioning of the workpiece and cavity closing, reduces manual intervention, and lowers the operation difficulty.

[0027] Among them, an upper vacuum hood 6 is installed on the upper side of the lower vacuum hood 3 disclosed by the present invention. The structure of the upper vacuum hood 6 is basically the same as that of the lower vacuum hood 3. The upper vacuum hood 6 has a lower opening. The size and shape of the upper opening and the lower opening are exactly the same and can be overlapped. A heating system is installed in the upper vacuum hood 6. The heating system is used to heat the coating film to soften it, which is convenient for the coating of materials and ensures the uniformity of the coating layer. In the embodiment of the present invention, the heating system adopts infrared heating tubes, which belongs to the prior art and can be understood by those skilled in the art.

[0028] Furthermore, a forming cavity is formed by the cooperation between the upper vacuum hood 6 and the lower vacuum hood 3 of the present invention. In the middle of the forming cavity, that is, between the upper vacuum hood 6 and the lower vacuum hood 3, it is separated by a coating film at the opening part. The forming cavity is connected to a differential pressure generation system. The differential pressure in the forming cavity makes the composite material closely fit the workpiece, reducing bubbles and wrinkles. The differential pressure generation system also adopts the prior art and can provide a positive pressure for the upper vacuum hood 6 and a negative pressure for the lower vacuum hood 3 to optimize the forming quality.

[0029] A workpiece positioning mechanism for fixing the workpiece to be coated is installed at the lower opening of the upper vacuum hood 6. The mold assembly 4 includes a support plate 7. A support frame 8 is formed in the middle of the support plate 7. A plurality of mold units are arrayed and installed in the support frame 8. The upper surfaces of the plurality of mold units cooperate to form a coating working surface for the workpiece. The bottom of the mold unit is connected to the support frame 8 through a vibration cylinder 9. Adjacent two mold units are in vertical sliding fit. By the mold units that can vibrate independently, the mold units are independently controlled by the vibration cylinder 9, and local micro-vibrations can be applied to the surface of the workpiece during the coating process, promoting the close fit between the coating material such as a film or prepreg and the surface of the workpiece, eliminating bubbles or wrinkles, and improving the coating uniformity.

[0030] In this embodiment, the die unit includes a plurality of central units 10 located at the center and a plurality of edge units 11 annularly installed outside the central units 10. The plurality of edge units 11 are connected in series circumferentially to form a ring, and the plurality of central units 10 and edge units 11 are combined to form a die. By adopting a sub-region control method, the independent vibration of the central units 10 and the edge units 11 can specifically eliminate the material stress concentration and reduce the edge warping. At the same time, the edge units 11 can be provided with finer micropores 30, so that a laminar flow can be formed at the outer edge of the workpiece, which is convenient for the material to be coated. The central units 10 adopt coarser through holes 12, which also saves costs.

[0031] In this embodiment, through holes 12 are provided on the central units 10. An irregular hole 13 is formed at the lower part of the through hole 12. A plurality of vertical grooves 14 are circumferentially formed on the inner side of the irregular hole 13. A scraping ring 15 is slidably installed in the irregular hole 13. The scraping ring 15 is connected with a limiting block 17 through an elastic stretching device 16. When the elastic stretching device 16 elongates, the scraping ring 15 can be slidably matched with the inner wall of the through hole 12. During backwashing, positive pressure gas can be introduced into the side of the irregular hole 13 facing the through hole 12. When the scraping ring 15 breaks through the restraint of the elastic stretching device 16, the scraping ring 15 can scrape the residual material in the through hole 12, reducing the frequency of shutdown cleaning. By providing the irregular hole 13, it can be avoided that the scraping ring 15 blocks the irregular hole 13, and negative pressure gas can pass through.

[0032] In this embodiment, a central blind hole 18 is formed at the center of the central unit 10. A piston 19 is slidably installed in the central blind hole 18. The piston 19 is connected to the output end of a vibration cylinder 9 installed in the central blind hole 18. An air inlet hole 20 is formed at the bottom of the central blind hole 18, and an air outlet hole 21 is formed on the side wall of the central blind hole 18. The other end of the air outlet hole 21 is communicated with the through hole 12. By providing the piston 19, when the vibration cylinder 9 acts, gas can be continuously introduced into the air inlet hole 20, forcing the impurities in the through hole 12 to be discharged, reducing the blockage of the through hole 12 and benefiting the smooth flow of air.

[0033] In this embodiment, a sleeve 22 is installed in the air outlet hole 21. A tapered hole 23 is provided in the sleeve. A ball 24 is fitted in the tapered hole 23. The ball 24 is connected with a filter plate 26 through an elastic support device 25. The filter plate 26 is fixed at the opening of the sleeve 22 on the side away from the central blind hole 18. The cooperation of the tapered hole 23 and the ball 24 automatically closes when the air flow reverses, preventing the material from flowing back and blocking.

[0034] In this embodiment, an installation hole 27 is formed in the edge unit 11. An elastic tube 28 is fixedly installed in the installation hole 27. An expansion tube 29 is coaxially installed in the elastic tube 28. The expansion tube 29 can be made of shape memory alloy and is convenient to return to its original position after the temperature recovers. A micro hole 30 penetrating up and down is formed in the center of the expansion tube 29. When the expansion tube 29 is heated, the diameter of the micro hole 30 can expand. During heating, it is convenient to discharge the material in the micro hole 30 for cleaning. By providing the elastic tube 28, it can adapt to the expansion change of the expansion tube 29, facilitate the discharge of residual materials, and also facilitate the replacement of the expansion tube 29 later.

[0035] In this embodiment, a column 31 is fixed on the sliding table 2. The columns 31 are distributed at the four corners of the lower vacuum chamber 3. The upper end of the column 31 is fixed with an upper plate 32. A middle plate 33 is slidably installed in the middle of the column 31. An upper vacuum chamber 6 is installed on the lower side of the middle plate 33. A displacement driving device 34 for driving the displacement of the middle plate 33 is installed on the upper plate 32. The displacement driving device 34 uses a cylinder 35, which can facilitate the cooperation between the upper vacuum chamber 6 and the lower vacuum chamber 3 after the upper vacuum chamber 6 is moved.

[0036] In this embodiment, an ejection assembly is installed on the side of the upper vacuum chamber 6. The ejection assembly includes a cylinder 35, a support plate 36, a guide rod 37, and a guide sleeve 38. The cylinder 35 is installed on the middle plate 33. The output end of the cylinder 35 is connected with a guide rod 37 through the support plate 36. The guide rod 37 is slidably arranged in the guide sleeve 38. The guide sleeve 38 is installed on the support of the side wall of the upper vacuum chamber 6. By providing the ejection assembly, the workpiece can be ejected in time after being coated, making the device operation more automated.

[0037] 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 restrictive. 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 composite material differential pressure coating machine, characterized in that: The machine comprises a frame, a slide mounted on the frame, and a lower vacuum cover fixed to the slide, wherein a mold assembly is installed at the inner bottom of the lower vacuum cover, the mold assembly is connected to a lifting device, an upper vacuum cover is installed on the upper side of the lower vacuum cover, a heating system is installed in the upper vacuum cover, the upper vacuum cover cooperates with the lower vacuum cover to form a molding cavity, the molding cavity is connected to a pressure difference generating system, and a workpiece positioning mechanism for fixing the workpiece to be coated is installed at the lower opening of the upper vacuum cover; the mold assembly comprises a support plate, a support frame is formed in the middle of the support plate, a plurality of mold units are arrayed in the support frame, the upper surfaces of the plurality of mold units cooperate to form a coating working surface for the workpiece, the bottom of the mold unit is connected to the support frame by a vibration cylinder, and two adjacent mold units are vertically slidably matched; the mold unit comprises a plurality of center units located in the center and a plurality of edge units annularly installed on the outside of the center unit, and the plurality of edge units are circumferentially The mold is formed by combining a plurality of center units and edge units in a ring-shaped series; a through hole is provided on the center unit, a special-shaped hole is formed at the lower part of the through hole, a plurality of vertical grooves are provided on the inner side of the special-shaped hole along the circumferential direction, a scraper ring is slidably installed in the special-shaped hole, the scraper ring is connected to the limit block through an elastic stretching device, and when the elastic stretching device is extended, the scraper ring can slide with the inner wall of the through hole; a center blind hole is provided at the center of the center unit, a piston is slidably installed in the center blind hole, the piston is connected to the output end of the vibration cylinder installed in the center blind hole, an air inlet is provided at the bottom of the center blind hole, an air outlet is provided on the side wall of the center blind hole, and the other end of the air outlet is connected to the through hole; a mounting hole is provided on the edge unit, an elastic tube is fixedly installed in the mounting hole, an expansion tube is coaxially installed in the elastic tube, a microhole penetrating from top to bottom is formed in the center of the expansion tube, and the diameter of the microhole can expand when the expansion tube is heated.

2. A composite material differential pressure coating machine according to claim 1, characterized in that: A sleeve is installed in the air outlet, a conical hole is arranged in the sleeve, a ball is matched in the conical hole, the ball is connected to a filter plate through an elastic support device, and the filter plate is fixed at the opening of the sleeve away from the central blind hole.

3. A composite material differential pressure coating machine according to any one of claims 1-2, characterized in that: The slide is fixed with columns, which are distributed at the four corners of the lower vacuum cover. An upper plate is fixed to the upper end of the column, a middle plate is slidably installed in the middle of the column, an upper vacuum cover is installed on the lower side of the middle plate, and a displacement driving device for driving the displacement of the middle plate is installed on the upper plate.

4. A composite material differential pressure coating machine according to claim 3, characterized in that: An ejection assembly is installed on the side of the upper vacuum cover, and the ejection assembly includes a cylinder, a support plate, a guide rod, and a guide sleeve. The cylinder is installed on the middle plate, and the output end of the cylinder is connected to the guide rod through the support plate. The guide rod is slidably arranged in the guide sleeve, and the guide sleeve is installed on the support of the side wall of the upper vacuum cover.

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