Vacuum coating device for sofa fabric

Abstract

The invention discloses a sofa fabric vacuum coating device, and belongs to the technical field of upholstered furniture manufacturing, the device comprises a base, a central rotary workbench, a supporting disc and a central control system, the central rotary workbench is connected with the supporting disc above through a supporting rod, and can perform indexing rotation; a sponge profiling preheating station, a quantitative glue spraying station, a fabric negative-pressure pre-stretching station and a vacuum coating main station are sequentially arranged around the workbench, and a static-dynamic separation layout is formed. Through multi-station linkage, accurate hot-pressing shaping of sponge, variable-flow glue spraying under visual guidance and negative-pressure two-way pre-stretching of fabric are sequentially and automatically completed; the device is high in integration level, realizes full-automatic and continuous production from raw materials to finished products, effectively solves the problems of insufficient pretreatment, non-uniform gluing, fabric wrinkling, low efficiency and poor quality consistency in the traditional process, and remarkably improves the coating quality, the production efficiency and the automation level.

Description

Technical Field

[0001] This invention relates to the field of upholstered furniture manufacturing technology, and in particular to a vacuum wrapping device for sofa fabric. Background Technology

[0002] In sofa manufacturing, covering a foam or wood substrate with leather, fabric, or other materials is a crucial step. Traditional production methods mainly rely on skilled workers operating by hand, which is inefficient, produces inconsistent quality, and cannot efficiently handle complex three-dimensional curved surfaces.

[0003] To improve efficiency, automated and semi-automated vacuum coating technologies have been applied. A typical existing vacuum coating apparatus usually includes: a worktable or mold with suction holes, a pressure frame that presses the edges of the fabric to form a sealed cavity, a heating system, and a vacuum generation system. The basic process is as follows: the substrate is placed on the worktable, the fabric is covered, and the edges are sealed with the pressure frame. Then, the air inside the sealed cavity is heated and extracted, using atmospheric pressure to make the fabric conform to the shape of the substrate.

[0004] However, such existing technologies still have shortcomings in the process of moving towards high-quality, fully automated production, which restricts their further development. Steps such as sponge placement, fabric laying, preforming, gluing, vacuum wrapping, and cooling and unloading are often completed intermittently on different equipment or workstations, relying on manual transfer, resulting in low production efficiency and easy product damage or positioning errors during the transfer process, making it difficult to form an efficient and stable continuous production line. Summary of the Invention

[0005] The purpose of this invention is to provide a vacuum wrapping device for sofa fabric, which solves the problems of slow adjustment using tools and loose casters in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a sofa fabric vacuum wrapping device, comprising:

[0007] Base;

[0008] A central rotary worktable, the bottom of which is rotatably connected to the base;

[0009] Multiple mold support seats are set on the central rotating worktable for supporting and positioning sofa component molds;

[0010] A support plate is mounted above the central rotary worktable via a support rod, and the support rod is slidably connected to the support plate.

[0011] A drive motor is installed above the support plate. The output end of the drive motor is connected to the support rod or the central rotary table through a connecting rod to drive it to rotate 90° in increments.

[0012] At least four workstations are arranged sequentially around the circumference of the central rotating worktable: a sponge molding preheating workstation, a quantitative adhesive spraying workstation, a fabric negative pressure pre-stretching workstation, and a vacuum wrapping main workstation.

[0013] And the central control system;

[0014] The main actuators of each workstation are mounted on the support plate, and the central rotary table rotates intermittently under the control of the central control system, sending the mold carrier to each workstation in sequence.

[0015] Preferably, the sponge molding preheating station includes:

[0016] A pressure box is vertically mounted above the workstation, and a first hydraulic cylinder for driving its lifting and lowering is connected above the pressure box;

[0017] A hot air circulation system is installed inside the pressure chamber, the hot air circulation system including a heating platform installed above the pressure chamber, the heating platform being connected to the pressure chamber via a circulation pipe.

[0018] Preferably, the metered adhesive spraying station includes:

[0019] Multi-axis motion robotic arm;

[0020] A high-precision dispensing valve installed at the end of the multi-axis motion robotic arm;

[0021] The melting and supply system is connected to the high-precision dispensing valve;

[0022] A visual positioning system is used to identify the outline and position of the sponge on the mold support;

[0023] The central control system controls the multi-axis motion robotic arm to drive the high-precision dispensing valve to move along the sponge surface in a three-dimensional trajectory based on the feedback information from the vision positioning system, and simultaneously controls the amount of glue dispensed.

[0024] Preferably, the fabric negative pressure pre-stretching station includes:

[0025] A negative pressure box is vertically mounted above the workstation, and a second hydraulic cylinder for driving its lifting and lowering is connected above the negative pressure box.

[0026] The bottom of the negative pressure box is provided with an opening and a porous adsorption plate;

[0027] A negative pressure generator connected to the interior of the negative pressure box;

[0028] A fabric clamping mechanism is provided on the side of the mold support;

[0029] The central control system is configured to: control the clamping fabric to be laid flat above the mold, control the negative pressure box to descend, and generate negative pressure inside the negative pressure box through the negative pressure generator, thereby adsorbing the middle part of the fabric through the porous adsorption plate and lifting it up, so as to achieve bidirectional pre-stretching of the fabric.

[0030] Preferably, the vacuum-coating main station includes:

[0031] The liftable integral sealing pressure frame can close with the mold support to form a sealed cavity when it is lowered;

[0032] The bottom of the mold support is provided with a perforated mold plate;

[0033] The rapid vacuum valve assembly is connected to the lower cavity of the porous mold plate via a vacuum pipeline. Under the control of the central control system, the rapid vacuum valve assembly can open, close, and regulate pressure within tens of milliseconds.

[0034] Preferably, a third hydraulic cylinder is connected above the integral sealing pressure frame, and the third hydraulic cylinder is mounted on the support plate.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] The sponge is precisely shaped in three dimensions through a preheating station, providing a standardized and uniformly dense core for wrapping, fundamentally solving the problems of finished product contour deformation, local bulging, or collapse. Combined with visually guided precision spraying at the quantitative adhesive spraying station and uniform bidirectional tensioning at the fabric negative pressure pre-stretching station, this ensures a perfect, bubble-free, and wrinkle-free fit between the fabric and sponge at the main vacuum wrapping station, resulting in a smooth surface and sharp, clear lines on the finished product.

[0037] The equipment adopts a rotary production line design, with four workstations operating in parallel around a central rotating worktable. This enables continuous production from sponge loading to finished product unloading, resulting in short cycle times and significantly increased capacity. The entire process is automatically coordinated by a central control system, including automatic fabric gripping, laying, stretching, as well as sponge shaping, adhesive spraying, and coating. This minimizes reliance on manual operation and significantly reduces labor intensity and labor costs.

[0038] Each actuator is fixedly mounted on a support plate, forming a static-dynamic separation structure with the rotating worktable, ensuring high repeatability and system rigidity. The rapid vacuum valve assembly achieves millisecond-level vacuum build-up and release control, allowing for precise programming of the pressure curve during the covering process. It not only responds quickly but also effectively prevents the fabric from rebounding and wrinkling during pressure release, exhibiting strong process adaptability and stability.

[0039] The unique top negative pressure pre-stretching design completely frees up the space directly below the mold, facilitating the integration of automated loading and unloading equipment. By replacing the dedicated mold on the mold carrier and adjusting the control system parameters, this device can quickly adapt to the production of sofa parts of different styles and sizes, achieving efficient switching between flexible small-batch, multi-variety production and large-scale standardized production. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the overall structure of the product of the present invention;

[0041] Figure 2 This is a schematic diagram of the preheating station structure for sponge molding of the product of the present invention;

[0042] Figure 3 This is a schematic diagram of the quantitative adhesive spraying station structure for the product of this invention;

[0043] Figure 4 This is a schematic diagram of the front structure of the fabric negative pressure pre-stretching station for the product of this invention.

[0044] Figure 5 This is a schematic diagram of the back structure of the fabric negative pressure pre-stretching station of the product of the present invention.

[0045] Figure 6 This is a schematic diagram of the main vacuum coating station structure of the product of the present invention.

[0046] In the diagram: 1. Central rotary worktable; 2. Sponge molding preheating station; 3. Quantitative glue spraying station; 4. Fabric negative pressure pre-stretching station; 5. Vacuum wrapping main station; 11. Mold support seat; 12. Support plate; 13. Support rod; 14. Drive motor; 15. Connecting rod; 21. Pressure box; 22. First hydraulic cylinder; 23. Heating table; 24. Circulation pipeline; 31. Multi-axis motion robotic arm; 32. High-precision glue dispensing valve ; 41. Negative pressure box; 42. Second hydraulic cylinder; 43. Porous adsorption plate; 44. Fabric clamping mechanism; 441. Cylinder; 442. Positioning plate; 443. First moving plate; 444. First meshing rod; 445. Meshing gear; 446. Second meshing rod; 447. Second moving plate; 448. Adjusting plate; 449. Cylinder clamping plate; 51. Integral sealing pressure frame; 52. Third hydraulic cylinder; 100. Base. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] This invention relates to a vacuum wrapping device for sofa fabric, such as... Figure 1-5 As shown, the overall frame of the device is based on the design concept of static and dynamic separation. The base 100 serves as the rigid foundation of the entire device and is fixedly installed on the ground. The central rotating worktable 1 is rotatably connected to the center of the base 100 via a large slewing bearing (not shown in the figure), forming the dynamic circulation core of the device. Four mold support seats 11 are evenly distributed along the circumference on the upper surface of the worktable 1, used for the precise placement and positioning of different styles of sofa component molds and sponge blanks.

[0049] Furthermore, a support plate 12 is installed directly above the central rotary table 1. This support plate 12 is fixedly connected to the base 100 or the factory structure below via four vertical support rods 13. Crucially, the connection between the top of the support rods 13 and the support plate 12 is a sliding connection, for example, achieved through linear bearings or sliding sleeves. This allows the support plate 12 to exhibit slight floating when heated or subjected to uneven loads, effectively eliminating stress and ensuring long-term operational stability and the alignment accuracy of the actuators at each workstation.

[0050] Furthermore, the drive system of the device is located at the top: a drive motor 14;

[0051] Preferably, a servo motor with braking function is fixedly installed at the center of the upper surface of the support plate 12;

[0052] The output shaft of the drive motor 14 is connected to the connecting rod 15;

[0053] It can be a drive shaft that runs through the support plate, with its bottom end connected to the central drive shaft of the central rotary table 1 via a bevel gear or worm gear mechanism;

[0054] A central control system, such as a PLC or industrial computer, controls the drive motor 14 to rotate precisely in 90° increments, thereby intermittently and sequentially conveying each mold carrier 11 to the four fixed workstations arranged around it.

[0055] Furthermore, the four core workstations are the sponge molding and preheating station 2, the quantitative adhesive spraying station 3, the fabric negative pressure pre-stretching station 4, and the vacuum coating main station 5. All major actuators are fixedly mounted on the stationary support plate 12. This layout ensures high stability of the actuators, while only the workpiece sponge and fabric assembly moves on the worktable, achieving efficient and precise automated linkage.

[0056] Furthermore, the sponge molding preheating station 2 is responsible for pre-processing the soft, irregularly shaped sponge blank into a three-dimensional core that is completely consistent with the final product.

[0057] Pressure Box 21: A contoured box with an internal cavity, the lower surface of which is machined with a complex curved surface that perfectly matches the target sofa components such as cushions and backrests;

[0058] First hydraulic cylinder 22: vertically fixed on support plate 12, its piston rod is rigidly connected downward to the top of pressure box 21, providing stable and powerful lifting power;

[0059] Hot air circulation system: includes a heating platform 23 mounted on the support plate 12, which integrates electric heating elements and a circulating fan, as well as a flexible circulation pipe 24 connecting the air outlet of the heating platform 23 to the air inlet of the pressure box 21. The pressure box 21 is provided with a return air inlet, forming a closed-loop hot air circuit with the heating platform 23;

[0060] Once the mold support 11 carrying the sponge blank rotates to the designated position and locks in place, the central control system first activates the hot air circulation system. High-temperature airflow circulates within the pressure chamber 21, uniformly and rapidly heating the sponge, softening it and making it malleable. Subsequently, the first hydraulic cylinder 22 pushes the pressure chamber 21 downwards steadily along the guide column, pressing the softened sponge tightly onto the shaping mold below with a preset pressure. During the pressure holding period, hot air continues to circulate, ensuring uniform heating of all parts of the sponge and reshaping its internal structure. After the pressure holding time ends, the pressure chamber 21 is raised, and a precisely shaped, uniformly dense sponge core is completed, laying a perfect foundation for subsequent processes.

[0061] Furthermore, at the quantitative adhesive spraying station 3, the task is to spray a uniform and appropriate amount of hot melt adhesive onto the surface of the shaped sponge.

[0062] Multi-axis motion robotic arm 31: For example, a six-axis industrial robot, fixedly installed on the base 100 or independent foundation in this workstation area;

[0063] High-precision dispensing valve 32: Installed at the end of the robotic arm 31, it can achieve milliliter-level precise control of the amount of adhesive;

[0064] Melting and supply system: Located outside the equipment, it continuously supplies molten hot melt adhesive to dispensing valve 32 through a constant temperature pipeline;

[0065] Visual positioning system: including an industrial camera and light source mounted above this workstation, used for non-contact scanning and identification of the three-dimensional contour and spatial coordinates of the molded sponge on the mold support 11;

[0066] After the mold support 11 is inserted, the vision positioning system immediately activates, acquiring images of the sponge and generating high-precision 3D point cloud data, which is then sent to the central control system. The system software compares the point cloud data with the preset CAD model and automatically plans the optimal spraying path, typically a parallel zigzag trajectory or a contour line trajectory. Subsequently, the central control system synchronously drives the multi-axis motion robotic arm 31 and the dispensing valve 32, ensuring that the dispensing head moves along the 3D curved surface of the sponge at a constant height and speed, and dynamically adjusts the amount of adhesive dispensed in real time according to changes in curvature. This process ensures that the entire sponge surface receives a uniform and complete adhesive layer, fundamentally avoiding defects such as air bubbles or weak adhesion caused by uneven adhesive application.

[0067] Furthermore, the fabric negative pressure pre-stretching station 4 is used to pre-tension the cut sofa fabric and flatly cover it on the sprayed sponge.

[0068] Second hydraulic cylinder 42: vertically fixed on support plate 12;

[0069] Negative pressure box 41: Connected to the lower end of the piston rod of the second hydraulic cylinder 42, it is a box with a sealed top and an open bottom. A porous adsorption plate 43, such as a sintered metal plate with dense micropores or a high-strength engineering plastic plate, is installed at its bottom.

[0070] Negative pressure generator: a high-flow vortex fan or vacuum pump, connected to the top of the negative pressure box 41 via a flexible pipe;

[0071] Fabric clamping mechanism 44: Located at this workstation, it is used to grip and convey the fabric, and to laterally tension it in the initial stage, including:

[0072] Positioning plate 442, the top of which is fixed below the support plate 12, serves as the base mounting plate for the entire mechanism;

[0073] Cylinder 441, the cylinder body of which is fixed to the side wall of positioning plate 442;

[0074] The first movable plate 443 and the second movable plate 447 are arranged in parallel and opposite to each other.

[0075] The output end of cylinder 441 is connected to the back of the first moving plate 443, which can drive it to move linearly along the guide mechanism;

[0076] The first engagement rod 444 is vertically fixed to the side of the first moving plate 443 facing the second moving plate 447, and its bottom end is provided with serrations.

[0077] The meshing gear 445 is rotatably connected to the positioning plate 442 via a rotating shaft and is located between the first moving plate 443 and the second moving plate 447. Its teeth mesh with the saw teeth at the bottom of the first meshing rod 444 and the second meshing rod 446, respectively.

[0078] The second engagement rod 446 is vertically fixed to the side of the second moving plate 447;

[0079] There are two adjusting plates 448, which are respectively adjustablely mounted on the opposite sides of the first movable plate 443 and the second movable plate 447 by bolts.

[0080] The cylinder clamping plate 449 is L-shaped, and its vertical edges are fixed to the lower ends of the two adjusting plates 448 respectively, for directly clamping the two sides of the fabric.

[0081] The mold support 11, carrying a sponge coated with adhesive, is transferred to this station. First, the fabric clamping mechanism 44 grabs the fabric from the pre-positioned station, moves it directly above the mold, and releases it flat, allowing the fabric to naturally cover the sponge surface. Next, the second hydraulic cylinder 42 drives the negative pressure box 41 to descend until the porous suction plate 43 gently contacts the central area of ​​the fabric. At this moment, the negative pressure generator instantly activates, generating a strong negative pressure within the negative pressure box 41, which firmly holds the fabric in place through the porous suction plate 43. Subsequently, the second hydraulic cylinder 42 moves in the opposite direction, lifting the negative pressure box 41, along with the center of the adsorbed fabric, upwards to a set height. This lifting action causes the center point of the fabric to be vertically pulled, while its surrounding edges contract towards the center, thereby generating a uniform bidirectional tensile force in the horizontal plane. This effectively eliminates the original wrinkles and internal stress of the fabric, achieving an ideal state of flatness and tension. After a brief holding period, the negative pressure is turned off, and the fabric, under its own weight, gently and flatly falls onto the adhesive-coated sponge, forming a combined assembly to be covered.

[0082] Furthermore, the vacuum wrapping main station 5 is the core of the final molding process, which uses the huge pressure difference generated by the high vacuum to achieve permanent bonding between the fabric and the sponge.

[0083] Third hydraulic cylinder 52: vertically fixed on support plate 12;

[0084] Integral sealing frame 51: A rectangular or irregular frame made of robust profile, the top of which is connected to the piston rod of the third hydraulic cylinder 52, and the lower edge is inlaid with a high-performance silicone rubber sealing strip;

[0085] Multi-hole mold plate: As the bottom support plate of the mold support seat 11, it is made of aluminum alloy and has densely distributed through-hole ventilation micropores.

[0086] Rapid vacuum valve assembly: Integrated inside the base 100, it is directly connected to the sealed cavity below the porous mold plate via a large-diameter vacuum pipeline. This valve assembly typically consists of a large-diameter high-speed solenoid valve in parallel for rapid vacuuming and a precision proportional regulating valve for pressure holding and slow release.

[0087] After the sponge, adhesive, and fabric assembly, processed through the previous three steps, rotates to this workstation, the third hydraulic cylinder 52 drives the integral sealing pressure frame 51 to descend rapidly and powerfully. The sealing strip at its lower edge tightly presses the edges of the fabric against the peripheral platform of the mold support 11, thus forming a completely sealed chamber above the fabric. Almost simultaneously with the closing of the pressure frame, the central control system commands the large-diameter, high-speed solenoid valve of the rapid vacuum valve group to fully open, rapidly drawing air out of the sealed chamber within tens of milliseconds through the porous mold plate. The pressure inside the chamber drops sharply, creating a significant pressure difference between the upper and lower surfaces of the fabric, approaching one atmosphere, equivalent to approximately 10 tons of uniform pressure per square meter of fabric. This force presses the fabric at high speed and evenly against every curved surface, groove, and corner of the sponge, forcing the fibers on the back of the fabric to fully impregnate and adhere to the hot melt adhesive on the sponge surface. Once the set vacuum level is reached, the system automatically switches to a precision proportional regulating valve for closed-loop environmental pressure, maintaining a constant vacuum environment and allowing the hot melt adhesive sufficient time to cool and solidify. After curing, the proportional control valve slowly opens, allowing outside air to flow smoothly into the chamber, gradually releasing the vacuum and preventing sudden pressure changes that could cause displacement or minor wrinkles in the bonded fabric. Finally, the third hydraulic cylinder 52 lifts the sealing frame, completing a sofa component with a clear outline, a smooth surface, and strong adhesion.

[0088] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0089] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A vacuum wrapping device for sofa fabric, characterized in that, include: Base (100); A central rotating worktable (1) is rotatably connected to the base (100) at its bottom; Multiple mold support seats (11) are set on the central rotating worktable (1) for supporting and positioning sofa component molds; The support plate (12) is mounted above the central rotating worktable (1) via a support rod (13), and the support rod (13) is slidably connected to the support plate (12); A drive motor (14) is installed above the support plate (12). The output end of the drive motor (14) is connected to the support rod (13) or the central rotary table (1) via a connecting rod (15) to drive it to rotate 90°. At least four workstations are arranged in sequence around the circumference of the central rotating worktable (1): sponge molding preheating workstation (2), quantitative glue spraying workstation (3), fabric negative pressure pre-stretching workstation (4) and vacuum wrapping main workstation (5). And the central control system; The main actuators of each workstation are installed on the support plate (12), and the central rotary worktable (1) rotates intermittently under the control of the central control system, sending the mold carrier (11) to each workstation in sequence.

2. The sofa fabric vacuum wrapping device according to claim 1, characterized in that, The sponge molding preheating station (2) includes: A pressure box (21) is vertically mounted above the workstation, and a first hydraulic cylinder (22) for driving its lifting is connected above the pressure box (21). A hot air circulation system is installed inside the pressure chamber (21). The hot air circulation system includes a heating platform (23) installed above the pressure chamber (21). The heating platform (23) is connected to the pressure chamber (21) through a circulation pipe (24).

3. The sofa fabric vacuum wrapping device according to claim 1, characterized in that, The quantitative adhesive spraying station (3) includes: Multi-axis motion robotic arm (31); A high-precision dispensing valve (32) is installed at the end of the multi-axis motion robotic arm (31). A melting and supply system connected to the high-precision dispensing valve (32); A visual positioning system is used to identify the outline and position of the sponge on the mold support (11); The central control system controls the multi-axis motion robotic arm (31) to drive the high-precision dispensing valve (32) to move along the sponge surface in a three-dimensional trajectory based on the feedback information from the vision positioning system, and simultaneously controls the amount of glue dispensed.

4. The sofa fabric vacuum wrapping device according to claim 1, characterized in that, The fabric negative pressure pre-stretching station (4) includes: A negative pressure box (41) is vertically mounted above the workstation, and a second hydraulic cylinder (42) for driving its lifting and lowering is connected above the negative pressure box (41). The bottom of the negative pressure box (41) is provided with an opening and a porous adsorption plate (43). A negative pressure generator connected to the inside of the negative pressure box (41); Fabric clamping mechanism (44) is provided on the side of the mold support (11). The central control system is configured to: control the clamping fabric to be laid flat above the mold, control the negative pressure box (41) to descend, and generate negative pressure inside the negative pressure box (41) through the negative pressure generator, thereby adsorbing the middle part of the fabric through the porous adsorption plate (43) and lifting it up, so as to achieve bidirectional pre-stretching of the fabric.

5. The sofa fabric vacuum wrapping device according to claim 1, characterized in that, The vacuum-coating main station (5) includes: The liftable integral sealing pressure frame (51) can close with the mold support seat (11) to form a sealed cavity when it is lowered; The bottom of the mold support (11) is provided with a perforated mold plate; The rapid vacuum valve assembly is connected to the lower cavity of the porous mold plate via a vacuum pipeline. Under the control of the central control system, the rapid vacuum valve assembly can open, close, and regulate pressure within tens of milliseconds.

6. The sofa fabric vacuum wrapping device according to claim 5, characterized in that: A third hydraulic cylinder (52) is connected above the integral sealing pressure frame (51), and the third hydraulic cylinder (52) is mounted on the support plate (12).

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