A fiber laying head for laying a composite grid structure

Abstract

The application discloses a filament laying head for laying a composite material grid rib structure, comprising a frame, a female head of a gun changing disc being installed at one end of the frame, an actuating head being installed at the other end of the frame, an electrical control system being installed inside the frame, a yarn rack and a tension control system being installed outside the frame, the female head of the gun changing disc being connected with a male head of a gun changing disc installed at the end of a filament laying machine tool, and the filament laying head being hung on the filament laying machine; the yarn rack and the tension control system are used for storing a spiral-wound composite material prepreg cylinder and maintaining constant tension during laying; the actuating head receives the prepreg led out from the yarn rack and the tension control system, and cuts, clamps, pulls and compacts the prepreg, and finally lays the prepreg in a groove of a grid rib mold; the electrical control system communicates with a numerical control system of the filament laying machine, and controls the filament laying machine tool and laying actions. The filament laying head is a special filament laying head with the advantages of a pressure roller capable of being pressed into a groove, short-length filament laying, adaptability to high-viscosity and low-rigidity prepreg, and grid rib profile positioning function.

Description

Technical Field

[0001] This invention relates to the field of automated composite material placement, and more particularly to a wire placement head for laying composite material mesh reinforcement structures. Background Technology

[0002] Automatic composite material fiber placement machines are the industrial mother machines required for laying and molding large composite material structural components in aerospace. Mesh reinforcement ribs are a common reinforcement structure in composite material components, but this type of structure cannot be laid using the universal multi-filament fiber placement head equipped on the fiber placement machine. The main reasons are as follows: 1. The universal fiber placement head uses a flexible rubber pressure roller to press multiple composite prepreg tapes firmly onto a flat mold surface. However, the mesh reinforcement laying process requires pressing the composite prepreg tapes into grooves on the mold surface that are the same width and depth as the mesh ribs. The flexible rubber pressure roller on the universal fiber placement head cannot deform to fill these grooves, thus failing to compact the material into shape; 2. Due to the need to break yarns at the mesh intersections, the mesh reinforcement structure contains... A large number of composite prepreg tapes are less than 5cm in length. However, due to mechanical structural limitations, the shortest placement length of a general-purpose yarn placement head is generally around 10cm. This makes it impossible for general-purpose yarn placement heads to lay up mesh reinforcement structures. Secondly, the mesh reinforcement placement process takes much longer than the skin placement process, resulting in mesh reinforcement materials often differing from those used in automated yarn placement. To ensure the mesh reinforcement material remains viscous and layable for several working days, this material typically contains a high level of volatile solvents, making its stiffness much lower and its viscosity much higher than that of the prepreg used in automated yarn placement. In general-purpose automated yarn placement heads, the yarn feeding principle involves two rollers clamping the prepreg and pushing it towards a guide trough downstream of the rollers through the rollers' rotation, ultimately ejecting it from the yarn placement head. Clearly, the more viscous the prepreg, the easier it is to adhere and wind onto the feeding rollers; the softer the prepreg, the easier it is to buckle during ejection from the guide trough. Abnormal winding and buckling of the prepreg can lead to yarn feeding failure of the placement head. Therefore, as the stiffness of the prepreg decreases and the viscosity increases, the reliability of the placement head's operation will drop sharply. Thus, using a universal placement head principle for mesh reinforcement placement is prone to reliability degradation due to raw material compatibility issues. 4. The mold for the mesh reinforcement placement process differs from the universal placement mold. To facilitate demolding, the mesh reinforcement surface of the mold typically uses an assembly structure. After each placement / reassembly, the position of the mesh reinforcement forming groove will randomly shift due to assembly tolerances. The mesh reinforcement placement process requires the placement head pressure roller to be precisely pressed into the mesh reinforcement groove on the mold. Therefore, simply improving the absolute / repeatable positioning accuracy of the placement machine is insufficient to complete the mesh reinforcement placement; the position of the mesh reinforcement groove on the mold must be measured before each placement, and the processing program must be adjusted accordingly. Summary of the Invention

[0003] To address the shortcomings of the existing technology, the present invention aims to provide a filament placement head for laying composite material mesh reinforcement structures. This head is a specialized filament placement head that allows the pressure roller to press into grooves, enables short-length filament placement, adapts to high-viscosity, low-stiffness prepregs, and has mesh reinforcement surface positioning capabilities. Simultaneously, it features a quick-change pneumatic / electrical / structural interface consistent with general-purpose filament placement heads, allowing it to be automatically mounted on a filament placement machine, enabling the machine to perform both skinning and mesh reinforcement placement functions. Furthermore, this filament placement head leverages its advantages of short minimum placement distance, compact shape, and high reliability, serving as a supplement to general-purpose filament placement heads. It can supplement concave surfaces and fill corner areas during complex curved surface skinning, thereby expanding the process adaptability of the filament placement machine.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] A filament placement head for laying composite mesh reinforcement structures includes a frame, with a female filament changer mounted at one end and an actuating head at the other end. An electrical control system is installed inside the frame, and a yarn frame and tension control system are mounted on the outside. The female filament changer connects to a male filament changer mounted at the end of the filament placement machine, thus mounting the filament placement head onto the machine. The yarn frame and tension control system store spirally wound composite prepreg cartridges and maintain constant tension during placement. The actuating head receives the prepreg from the yarn frame and tension control system and cuts, clamps, pulls, and compacts the material, ultimately placing the prepreg into the groove of the mesh reinforcement mold. The electrical control system communicates with the CNC system of the filament placement machine to control the machine tool and placement actions.

[0006] Furthermore, the yarn frame and tension control system includes a servo motor, a yarn feeding shaft, a film take-up shaft, a tension roller, a guide rail, a spring, and a displacement sensor. The servo motor is fixed to the frame, and its output end is connected to the yarn feeding shaft to provide a reverse torque. A carbon fiber prepreg cylinder is fitted onto the yarn feeding shaft. The film take-up shaft is connected to the frame and is a passive shaft. The prepreg pulled from the yarn feeding shaft passes around the film take-up shaft, and the backing plastic film of the prepreg is wound onto the film take-up shaft. The guide rail is fixedly connected to the frame, and the tension roller is slidably connected to the guide rail. One end of the tension roller and guide rail is fixedly connected to the frame, and the other end is connected to the tension roller. The elongation direction is parallel to the guide rail direction. The prepreg leaving the film take-up shaft passes around the tension roller again. Under the tension of the prepreg, the tension roller moves along the guide rail and is pulled by the spring until the spring pull reaches twice the tension, achieving force balance. The displacement sensor is used to feed back the measured spring elongation to the electrical control system. The electrical control system controls the reverse torque of the servo motor, thereby controlling the rotational speed of the yarn feeding shaft to maintain constant tension.

[0007] Furthermore, the yarn bundle direction of the yarn frame and tension control system is parallel to the axis of the yarn laying head. The prepreg output from the tension roller is twisted by 90° and then enters the actuating head through a passive guide wheel.

[0008] Furthermore, the actuating head includes an actuating head back plate, which is fixedly connected to the frame. In the order of the yarn path from upstream to downstream, a primary reciprocating cylinder, a secondary reciprocating cylinder assembly, a yarn-stopping cylinder assembly, a yarn-cutting cylinder assembly, and a pressure roller cylinder assembly are sequentially installed on the actuating head back plate. The primary and secondary reciprocating cylinder assemblies are used to pull the prepreg, the yarn-stopping cylinder assembly is used to clamp the prepreg, the yarn-cutting cylinder assembly is used to cut the prepreg, and the pressure roller cylinder assembly is used to lay the prepreg in the groove of the mesh mold.

[0009] Furthermore, the primary reciprocating cylinder is a guide cylinder directly mounted on the back plate of the actuating head, and the secondary reciprocating cylinder assembly is mounted on the piston rod end of the primary reciprocating cylinder. The primary reciprocating cylinder is parallel to the direction of yarn movement.

[0010] Furthermore, the secondary reciprocating cylinder assembly includes a secondary reciprocating cylinder mounting plate 25 and a secondary reciprocating cylinder 18 mounted on the return cylinder mounting plate 25. The secondary reciprocating cylinder 18 is parallel to the yarn path movement direction, and the yarn stop cylinder assembly is mounted on the piston rod end of the secondary reciprocating cylinder 18.

[0011] Furthermore, the yarn-stopping cylinder assembly includes a yarn-stopping assembly mounting plate, a yarn-stopping cylinder, a yarn-stopping driven wheel, and a yarn-stopping block. The yarn-stopping cylinder and the yarn-stopping driven wheel are mounted on the yarn-stopping assembly mounting plate, and the yarn-stopping block is mounted on the piston rod end of the yarn-stopping cylinder, opposite to the yarn-stopping driven wheel. The prepreg yarn path passes between the yarn-stopping driven wheel and the yarn-stopping block, and the yarn path is perpendicular to the movement direction of the yarn-stopping cylinder. The yarn-stopping driven wheel and the yarn-stopping block form a gripper, and the opening and closing of the gripper is controlled by the extension and retraction of the yarn-stopping cylinder. When the gripper is open, the prepreg is in a free state, and when the gripper is closed, the prepreg is clamped.

[0012] Furthermore, the yarn cutting cylinder assembly includes a yarn cutting assembly mounting frame, a yarn cutting cylinder, a linear guide rail, a cutter, and an anvil. The yarn cutting assembly mounting frame is fixedly mounted on the back plate of the actuating head. The yarn cutting cylinder, the linear guide rail, and the anvil are mounted on the yarn cutting assembly mounting frame. The cutter is mounted on the piston rod end of the yarn cutting cylinder and is slidably connected to the linear guide rail via a slider. The movement direction of the prepreg yarn path and the yarn cutting cylinder is perpendicular. The cutter and the anvil are perpendicular to each other. The prepreg passes between the cutter and the anvil. As the yarn cutting cylinder moves, the cutter cuts the prepreg on the anvil.

[0013] Furthermore, the pressure roller cylinder assembly includes a pressure roller cylinder and a pressure roller. The pressure roller cylinder is mounted on the yarn cutting assembly mounting frame, and the pressure roller is mounted on the piston rod end of the pressure roller cylinder. The pressure roller matches the groove of the mesh rib mold 8. The movement direction of the pressure roller cylinder is perpendicular to the yarn path direction. When the prepreg is pulled to the front of the pressure roller, the pressure roller cylinder is extended forward to push out the prepreg. Then, the pressure roller is inserted into the groove of the mesh rib mold 8 using the yarn laying machine to start laying.

[0014] Furthermore, the electrical control system includes electrical / compressed air cables, valves, a PLC, a touch screen, and terminal blocks.

[0015] The present invention has the following advantages over the prior art:

[0016] 1. Solve the problem that the universal filament placement head pressure roller cannot be pressed into the groove of the mesh reinforcement mold: The filament placement head adopts a single filament design, and the size of the pressure roller matches the groove on the mesh reinforcement mold, so it can sink into the mold to lay and form.

[0017] 2. Solve the problem of short-length prepreg laying: By arranging the yarn cutting cylinder assembly close to the pressure roller cylinder assembly, the shortest yarn laying length of the yarn laying head can be compressed to less than 50mm, which is only half that of the general yarn laying head, adapting to the need for frequent short yarn bundle laying in the grid structure.

[0018] 3. Solving the problem of excessive viscosity of prepreg affecting reliability during mesh reinforcement placement: All actions in the placement process that required twisting and pushing the yarn by a pair of rollers were replaced with traction actions. A series of traction actions relay each other, ultimately pressing the pulled-out end of the prepreg firmly onto the mold, and then releasing each traction mechanism. This avoids the problem of prepreg sticking to the surface of the yarn placement head mechanism without traction tension. At the same time, a two-stage reciprocating component was designed inside the yarn placement head for the yarn cutting action, solving the problem of the cutter sticking to the prepreg and greatly improving the reliability of the operation.

[0019] 4. Solve the problems of poor repetitive accuracy in mesh reinforcement mold assembly and inability to reuse laying programs: After the relative position of the mesh reinforcement wire laying head and the line laser profilometer installed on the wire laying machine is calibrated, the position of the groove of the repeatedly assembled mold can be measured by the line laser profilometer and offset and laid according to the actual position.

[0020] 5. Solve the problem of insufficient adaptability of general-purpose yarn placement heads to concave surfaces and extremely short trajectory lengths: The yarn placement head can be used for non-mesh yarn placement (skin placement) by replacing the yarn guide module, and can be interchanged with ordinary yarn placement heads using a universal gun changing plate interface, thereby giving full play to its advantages of small size envelope and short minimum yarn placement length, and can be used to supplement yarn placement in special areas such as concave surfaces, thereby improving the process adaptability of the yarn placement machine. Attached Figure Description

[0021] Figure 1 This is a diagram of the overall structure of the wire laying head.

[0022] Figure 2 This is an example diagram of a wire placement head mounted on a wire placement machine tool system.

[0023] Figure 3 An example diagram showing the pressure roller pressing the filament layup head into the surface of the die.

[0024] Figure 4 This is a structural diagram of the tension system for the filament laying head.

[0025] Figure 5 A structural diagram of the moving head for the wire laying head. Detailed Implementation

[0026] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0027] The present invention will now be described in detail with reference to the accompanying drawings.

[0028] Combination Figures 1-5 This embodiment provides a yarn-laying head for laying composite mesh reinforcement structures. This yarn-laying head only carries one prepreg stream and consists of components such as a changer head 1, a frame 2, a yarn rack and tension control system 3, an electrical control system 4, and an actuator 5. The changer head 1 serves as the mechanical, electrical, and compressed air interface between the mesh reinforcement yarn-laying head and the yarn-laying machine 6. In use, the changer head 1 connects to the changer head 7 installed at the end of the yarn-laying machine 6, thus mounting the yarn-laying head onto the machine 6. The frame 2 is the main support structure of the yarn-laying head, primarily ensuring the strength / rigidity of the mesh reinforcement yarn-laying head and coordinating the dimensional layout of each subsystem. One end of the frame 2 is connected to the changer head 1, and the other end is connected to the actuator 5. The yarn rack and tension control system 3 are installed on the outside of the frame 2, while the electrical control system 4 is installed inside the frame 2. The yarn rack and tension control system 3 stores the composite prepreg cartridge and maintains constant tension during the laying process. The actuating head 5 receives the prepreg from the tension control system 3 and performs a series of operations such as cutting, clamping, pulling, and compacting the material through a series of cylinders installed on the actuating head 5 and cutters / clamps / pressure rollers installed on the cylinders, finally laying it into the groove on the surface of the mold 8. The electrical control system 4 includes all electrical / compressed air cables, valves, PLC, touch screen, terminal blocks, etc. installed on the yarn laying head, and plays the role of communicating with the overall yarn laying machine system and controlling the laying action. During use, the yarn laying head is installed at the end of the yarn laying machine 6 through the gun changing plate female head 1. At this time, the yarn laying head does not contact the mold 8; then the PLC in the yarn laying head electrical control system 4 controls its actuating head 5 to pull the composite prepreg loaded in the yarn laying head and tension control system 3 to below the pressure roller 9 at the end of the actuating head 5; after confirming that the prepreg is in place, the yarn laying machine 6 moves the yarn laying head, pressing the pressure roller 9 at the end of the actuating head 5 into the mesh rib groove on the mold 8 and moving along the groove, thereby laying the prepreg in the groove. When yarn breakage is required, the actuator 5 clamps and cuts the prepreg loaded in the mesh rib yarn laying head, and the yarn laying machine 6 removes the yarn laying head and prepares for the next work cycle.

[0029] The filament placement head can be interchanged with ordinary filament placement heads using a universal gun-changing disc interface, thereby leveraging its advantages of small size envelope and shortest minimum filament placement length to perform supplementary filament placement in special areas such as concave curved surfaces and corner filling areas, thus improving the process adaptability of the filament placement machine.

[0030] The principle of the yarn frame and tension control system 3 is as follows: The yarn feeder inserts a standard carbon fiber prepreg canister onto a shaft provided with reverse torque by a servo motor 10. This shaft is called the yarn feeder 11. The prepreg drawn from the yarn feeder 11 passes around a passive rotating shaft, and the backing plastic film of the prepreg is wound around this passive shaft, which is called the film take-up shaft 12. The prepreg leaving the film take-up shaft 12 passes around a movable rotating shaft connected to a spring 13. This shaft activates a pulley, and the tension of the spring 13 is balanced by twice the tension of the prepreg. At the same time, a displacement sensor 14 is connected to this shaft to measure the elongation of the tension spring 13, thereby measuring the tension of the raw material. This shaft is called the tension roller 15. The parallel connection of the spring 13, displacement sensor 14, and tension roller 15 means that the tension roller 15 is arranged on a linear guide rail 32. One end of the spring 13 and the displacement sensor 14 are connected to the frame 2, and the other end is connected to the tension roller 15, with the elongation direction parallel to the direction of the guide rail 32. When tension roller 15 moves along guide rail 32 under the tension of prepreg, it is pulled by spring 13 until the tension of spring 13 reaches twice the tension, achieving force balance among yarn feeding shaft 11, take-up shaft 12, and tension roller 15 (pulley principle). The elongation of spring 13 can be measured by the stroke of displacement sensor 14. The PLC in the yarn laying head electrical control system 4 reads this tension value and feeds back the reverse torque of servo motor 10, thereby controlling the speed of yarn feeding shaft 11 to maintain constant tension. Yarn feeding shaft 11, take-up shaft 12, and tension roller 15 are all connected to frame 2. The yarn bundle direction of yarn frame and tension control system 3 is parallel to the axis of yarn laying head. The prepreg output from tension roller 15 is twisted 90° and passes through a passive guide wheel 16 (passive guide wheel 16 is connected to actuation head back plate 27) before entering actuation head 5.

[0031] The structure of the yarn placement head actuator 5 is as follows: This yarn placement head actuator 5 includes the following cylinders arranged in the order of yarn path from upstream to downstream: a primary reciprocating cylinder 17, a secondary reciprocating cylinder assembly, a yarn-stopping cylinder assembly, a yarn-cutting cylinder assembly, and a pressure roller cylinder assembly. By utilizing multiple cylinders installed within the actuator head, the action of pushing yarn by the rotation of the motor wheel in a conventional yarn placement head is changed to a series of cylinder clamping and traction actions. Ultimately, the pulled-out prepreg end is pressed firmly onto the mold, and then the clamping mechanisms are released, avoiding the problem of the prepreg sticking to the surface of the mechanisms in the yarn placement head without traction tension.

[0032] The yarn-stopping cylinder assembly mainly consists of a yarn-stopping assembly mounting plate 22, a yarn-stopping cylinder 19 mounted on the yarn-stopping assembly mounting plate 22, a yarn-stopping driven wheel 23 mounted on the yarn-stopping assembly mounting plate 22, and a yarn-stopping block 24 mounted on the piston rod end of the yarn-stopping cylinder 19 opposite to the yarn-stopping driven wheel 23. The prepreg yarn path passes between the driven wheel 23 and the yarn-stopping block 24, and the yarn path is perpendicular to the movement direction of the yarn-stopping cylinder 19. In this way, the driven wheel 23 and the yarn-stopping block 24 form a gripper. The opening and closing of the gripper can be controlled by the extension and retraction of the yarn-stopping cylinder 19. When the gripper is open, the raw material is in a free state; when the gripper is closed, the raw material is clamped. The yarn-stopping cylinder 19 is a guide cylinder.

[0033] The secondary reciprocating cylinder assembly consists of a secondary reciprocating cylinder mounting plate 25 and a secondary reciprocating cylinder 18 mounted on the plate. The movement direction of the secondary reciprocating cylinder 18 is parallel to the yarn path direction. The yarn-stopping cylinder assembly is mounted on the piston rod end of the secondary reciprocating cylinder 18. The secondary reciprocating cylinder 18 has a short stroke. Its function is as follows: when the cutter 26 cuts the prepreg, the prepreg may stick to the cutter 26, affecting the reliability of subsequent actions. Therefore, after completing the yarn cutting action, the secondary reciprocating cylinder 18 reciprocates once, driving the yarn-stopping cylinder assembly to move, thereby pulling the prepreg away from the cutter 26 without significantly changing the yarn bundle state, thus avoiding malfunction. The secondary reciprocating cylinder 18 is a guide cylinder. A secondary reciprocating assembly is designed inside the yarn-laying head for the yarn cutting action, solving the problem of the cutter sticking to the prepreg and improving the reliability of the action.

[0034] The primary reciprocating cylinder 17 is a guide cylinder directly mounted on the actuating head back plate 27 (the actuating head back plate 27 is fixedly connected to the frame 2). The secondary reciprocating cylinder assembly and the yarn-stopping cylinder assembly are both connected in series on the piston rod end of the primary reciprocating cylinder 17. The guiding direction of the primary reciprocating cylinder 17 is parallel to the yarn path direction. The function of the primary reciprocating cylinder 17 is as follows: before the yarn cutting operation, the primary reciprocating cylinder 17 retracts to its minimum stroke, and the yarn-stopping cylinder assembly clamps the prepreg to be cut, preventing the raw material from being pulled back by tension after cutting. After the yarn cutting is completed, the secondary reciprocating cylinder 18 drives the yarn-stopping cylinder assembly and the secondary reciprocating cylinder assembly to pull the prepreg away from the cutter 26. Then, the primary reciprocating cylinder 17 pulls the clamped prepreg downstream of the yarn path. When the primary reciprocating cylinder 17 is fully extended, the end of the prepreg will return to below the pressure roller 9, ready for the next laying.

[0035] The yarn-cutting cylinder assembly mainly consists of a yarn-cutting assembly mounting frame 28, a yarn-cutting cylinder 20 mounted on the mounting frame 28, two linear guide rails 29 arranged on the mounting frame 28 parallel to the yarn-cutting cylinder 20, a cutter 26 mounted on the slider of the linear guide rails 29 and pushed by the yarn-cutting cylinder, and an anvil plate 30 mounted on the mounting frame 28. This assembly is fixedly mounted on the actuating head back plate 27, located downstream of the primary reciprocating cylinder 17. The movement direction of the prepreg yarn path and the yarn-cutting cylinder 20 is perpendicular, and the cutter 26 and the anvil plate 30 are perpendicular to each other. The prepreg passes between the cutter 26 and the anvil plate 30. As the yarn-cutting cylinder 20 moves, the cutter 26 can cut the prepreg on the anvil plate 30. The yarn-cutting cylinder 20 is a guide cylinder.

[0036] The pressure roller cylinder assembly mainly consists of a pressure roller cylinder assembly mounting frame (shared with the yarn cutting assembly mounting frame 28), a pressure roller cylinder 21 mounted on the mounting frame 28, and a pressure roller 9 mounted on the piston rod end of the pressure roller cylinder 21. The width and diameter of the pressure roller 9 are set to allow insertion into the groove of the mesh mold 8. The movement direction of the pressure roller cylinder 21 is perpendicular to the yarn path direction. When the pressure roller cylinder 21 retracts, the prepreg passage is cleared, and the raw material can be pulled down to the front of the pressure roller 9 using the primary reciprocating cylinder 17. After the prepreg is pulled to the front of the pressure roller 9, the pressure roller cylinder 21 can be extended forward to push out the prepreg, and then the yarn laying machine 6 can be used to insert the pressure roller 9 into the groove of the mesh mold 8 to begin laying. The pressure roller cylinder 21 is a guide cylinder.

[0037] The workflow of the mesh reinforcement yarn laying head from yarn feeding is as follows: Step 1: The initial states of the cylinders in the actuator head 5 are as follows: the primary reciprocating cylinder 17 retracts, the secondary reciprocating cylinder 18 extends forward, the yarn-stopping cylinder 19 extends forward and clamps the raw material, the yarn-cutting cylinder 20 retracts, the pressure roller cylinder 21 retracts, and the entire yarn laying machine 6 rotates the yarn laying head to make its yarn path vertical. Step 2: The primary reciprocating cylinder 17 extends forward, moving the prepreg end to the front of the pressure roller 9. Step 3: The pressure roller cylinder 21 extends forward, pushing the prepreg end out of the yarn laying head. Step 4: The entire yarn laying machine 6 rotates the yarn laying head and moves it to the mesh reinforcement mold 8 area, pressing the pressure roller 9 into the mesh reinforcement groove. Step 5: The yarn-stopping cylinder 19 retracts. Step 6: The primary reciprocating cylinder 17 retracts. Step 7: The entire yarn laying machine 6 moves along the direction of the mesh reinforcement groove to lay the mesh reinforcement. Step 8: When the end of this trajectory is reached, the entire movement of the yarn laying machine 6 stops. Step 9: The yarn-stopping cylinder 19 extends forward to clamp the prepreg again. Step 10: The yarn-cutting cylinder 20 extends forward to cut the prepreg. Step 11: The yarn-laying machine 6 continues to move forward as a whole, completing the placement of this section of prepreg. Step 12: The yarn-laying machine 6 lifts the yarn-laying head and rotates it as a whole, causing the pressure roller 9 to leave the mesh rib groove and ensuring the yarn path inside the yarn-laying head actuator 5 is vertically downward. Step 13: The yarn-cutting cylinder 20 retracts. Step 14: The pressure roller cylinder 21 retracts. Step 15: The secondary reciprocating cylinder 18 performs one retraction-extension cycle, pulling the prepreg away from the anvil 30 to prevent yarn sticking. Step 16: Return to the initial state.

[0038] Throughout the entire laying process, the cylinders on the mesh reinforcement wire laying head do not move simultaneously with the overall wire laying machine 6; the movement of each cylinder is controlled by a PLC installed inside the wire laying head, and the PLC communicates with the wire laying machine control system through a network cable installed on the gun changing plate 1 to ensure that the actions of the wire laying machine 6 and the wire laying head are executed in the above sequence.

[0039] The end position of the pressure roller 9 of this filament placement head is designed to coincide with the end position of the pressure roller of the universal filament placement head. That is, from the perspective of machine tool kinematics model, the mesh filament placement head and the universal filament placement head have the same kinematic matrix. Therefore, the mesh filament placement trajectory planning can be completed using the universal trajectory planning software of the filament placement machine.

[0040] The yarn placement head is equipped with a line laser profilometer 31 at the end of the yarn placement machine 6 for measuring the mold size. The position relationship between the profilometer 31 and the end point of the universal yarn placement head pressure roller has been strictly calibrated. Since the end point of the yarn placement head pressure roller 9 coincides with the end point of the universal yarn placement head pressure roller, the actual position of the mesh rib groove can be measured by the line laser profilometer 31 using the position relationship, ensuring that the pressure roller is aligned with the mold and is offset and placed according to the actual position. The guide wheel 16, anvil 30 and pressure roller 9 of this yarn placement head are modularly designed to match the yarn width, and the mesh ribs / prepregs of different widths can be adapted by replacing the above components.

[0041] The yarn placement head has a compact overall envelope. By switching the yarn width as described above, the yarn width of this yarn placement head can be switched to be consistent with that of a universal yarn placement head. This allows for the supplementary placement of yarn in concave curved areas that a universal yarn placement head cannot access, as well as areas requiring shorter track lengths, during the skin laying process. The yarn placement head actuator 5 adopts a modular design. If subsequent process expansion is required, the entire actuator 5 can be replaced to adapt to potential new processes.

[0042] The above embodiments are merely illustrative examples of the present invention and do not limit its scope of protection. Those skilled in the art can make partial changes to them, as long as they do not exceed the spirit and essence of the present invention, they are all within the scope of protection of the present invention.

Claims

1. A wire-laying head for laying composite mesh reinforcement structures, characterized in that, The system includes a frame, with a female gun-changing disc at one end and an actuating head at the other. An electrical control system is installed inside the frame, while a yarn frame and tension control system are installed on the outside. The female gun-changing disc connects to a male gun-changing disc at the end of the yarn-laying machine, allowing the yarn-laying head to be mounted on the machine. The yarn frame and tension control system store the spirally wound composite prepreg cartridges and maintain constant tension during the laying process. The actuating head receives the prepreg from the yarn frame and tension control system, and cuts, clamps, pulls, and compacts the prepreg, ultimately laying it in the groove of the mesh reinforcement mold. The electrical control system communicates with the CNC system of the yarn-laying machine to control the machine tool and the laying actions. The actuator head includes an actuator head back plate, which is fixedly connected to the frame. In the order of the yarn path from upstream to downstream, a primary reciprocating cylinder, a secondary reciprocating cylinder assembly, a yarn-stopping cylinder assembly, a yarn-cutting cylinder assembly, and a pressure roller cylinder assembly are sequentially installed on the actuator head back plate. The primary and secondary reciprocating cylinder assemblies are used to pull the prepreg, the yarn-stopping cylinder assembly is used to clamp the prepreg, the yarn-cutting cylinder assembly is used to cut the prepreg, and the pressure roller cylinder assembly is used to lay the prepreg in the groove of the mesh mold. The yarn-stopping cylinder assembly includes a yarn-stopping assembly mounting plate, a yarn-stopping cylinder, a yarn-stopping driven wheel, and a yarn-stopping block. The yarn-stopping cylinder and the yarn-stopping driven wheel are mounted on the yarn-stopping assembly mounting plate. The yarn-stopping block is mounted on the piston rod end of the yarn-stopping cylinder, opposite to the yarn-stopping driven wheel. The prepreg yarn path passes between the yarn-stopping driven wheel and the yarn-stopping block. The yarn path is perpendicular to the movement direction of the yarn-stopping cylinder. The yarn-stopping driven wheel and the yarn-stopping block form a gripper. The opening and closing of the gripper is controlled by the extension and retraction of the yarn-stopping cylinder. When the gripper is open, the prepreg is in a free state. When the gripper is closed, the prepreg is clamped. The yarn cutting cylinder assembly includes a yarn cutting assembly mounting frame, a yarn cutting cylinder, a linear guide rail, a cutter, and an anvil. The yarn cutting assembly mounting frame is fixedly mounted on the back plate of the actuating head. The yarn cutting cylinder, linear guide rail, and anvil are mounted on the yarn cutting assembly mounting frame. The cutter is mounted on the piston rod end of the yarn cutting cylinder and is slidably connected to the linear guide rail via a slider. The movement direction of the prepreg yarn path and the yarn cutting cylinder is perpendicular. The cutter and the anvil are perpendicular to each other. The prepreg passes between the cutter and the anvil. As the yarn cutting cylinder moves, the cutter cuts the prepreg on the anvil.

2. The wire placement head for laying composite mesh reinforcement structures according to claim 1, characterized in that, The yarn frame and tension control system includes a servo motor, a yarn feeding shaft, a film take-up shaft, a tension roller, a guide rail, a spring, and a displacement sensor. The servo motor is fixed to the frame, and its output is connected to the yarn feeding shaft to provide a reverse torque. A carbon fiber prepreg cylinder is fitted onto the yarn feeding shaft. The film take-up shaft is connected to the frame and is a passive shaft. The prepreg pulled from the yarn feeding shaft passes around the film take-up shaft, and the backing plastic film of the prepreg is wound onto the film take-up shaft. The guide rail is fixedly connected to the frame, and the tension roller is slidably connected to the guide rail. The prepreg leaving the film take-up shaft passes around the tension roller again. The tension roller moves along the guide rail under the tension of the prepreg and is pulled by the spring until the spring tension reaches twice the tension, achieving force balance. The displacement sensor is used to feed back the measured spring elongation to the electrical control system. The electrical control system controls the reverse torque of the servo motor, thereby controlling the rotational speed of the yarn feeding shaft to maintain constant tension.

3. The wire-laying head for laying composite material mesh reinforcement structures according to claim 2, characterized in that, The yarn bundle direction of the yarn frame and tension control system is parallel to the axis of the yarn laying head. The prepreg output from the tension roller is twisted 90° and then enters the actuating head through a passive guide wheel.

4. The wire placement head for laying composite mesh reinforcement structures according to claim 1, characterized in that, The primary reciprocating cylinder is a guide cylinder directly mounted on the back plate of the actuating head. The secondary reciprocating cylinder assembly is mounted on the piston rod end of the primary reciprocating cylinder. The primary reciprocating cylinder is parallel to the direction of yarn movement.

5. The wire-laying head for laying composite material mesh reinforcement structures according to claim 1, characterized in that, The secondary reciprocating cylinder assembly includes a secondary reciprocating cylinder mounting plate and a secondary reciprocating cylinder mounted on the mounting plate. The secondary reciprocating cylinder is parallel to the yarn path movement direction, and the yarn-stopping cylinder assembly is mounted on the piston rod end of the secondary reciprocating cylinder.

6. The wire-laying head for laying composite material mesh reinforcement structures according to claim 1, characterized in that, The pressure roller cylinder assembly includes a pressure roller cylinder and a pressure roller. The pressure roller cylinder is mounted on the yarn cutting assembly mounting frame, and the pressure roller is mounted on the piston rod end of the pressure roller cylinder. The pressure roller matches the groove of the mesh reinforcement mold. The movement direction of the pressure roller cylinder is perpendicular to the yarn path direction. When the prepreg is pulled to the front of the pressure roller, the pressure roller cylinder is extended forward to push out the prepreg. Then, the pressure roller is inserted into the groove of the mesh reinforcement mold using a yarn laying machine to start laying.

7. The wire placement head for laying composite mesh reinforcement structures according to claim 1, characterized in that, The electrical control system includes compressed air cables, valves, a PLC, a touch screen, and terminal blocks.

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