A kind of filament laying and compacting mechanism for complex steep curvature profile structure

Abstract

This invention discloses a wire-laying and compaction mechanism for complex, steeply curved surface structures. Addressing the forming requirements of different ply-lay curved surface structures, an adaptive wire-laying and compaction mechanism is designed to accommodate both curved and flat surfaces. By designing a bistable mechanism, the overall mechanism can switch between a compliant and a rigid state. When laying flat surfaces, the overall mechanism is in a rigid state, with no flexible links, allowing for rapid and stable laying and avoiding unnecessary micro-vibrations. When laying curved surfaces, the overall mechanism is in a flexible state; the adaptive design of the under-constrained mechanism ensures that the two compaction rollers adhere to the curved surface, thus enabling the laying of complex curved surfaces. Therefore, the steady-state position of the bistable mechanism can be adjusted based on different forming curvature variations to achieve the switching between the two states. During the laying process, this invention ensures a constant pressure output from the pressure rollers when laying steeply curved surface structures, avoiding forming defects caused by uneven pressure.

Description

Technical Field

[0001] This invention relates to the field of automated molding of continuous carbon fiber composite materials and fusion mechanics, and particularly to a fiber-laying and compaction mechanism for complex, steeply varied surface structures. This mechanism can compact continuous fiber composite materials and adjust the laying angle of the pressure rollers to improve the stability of the molded structural parts. Background Technology

[0002] With the rapid development of my country's national economy and the modernization of national defense and armed forces, continuous carbon fiber composite materials have become a key strategic material and an ideal structural material that China is currently focusing on developing due to their unparalleled advantages such as high specific strength, high specific modulus, good fatigue resistance and low coefficient of thermal expansion. Aerospace has also become a very important application field for carbon fiber composite materials worldwide.

[0003] Common automated molding processes include fiber winding, automated tape laying, and automated filament placement. Among these, automated filament placement technology, combining the advantages of both automated tape laying and fiber winding, significantly improves production efficiency and the reliability of molding quality, and has thus gained widespread commercial application. However, current automated filament placement technology and equipment still struggle to meet the high-precision, low-damage molding requirements of high-performance structural components with complex, abruptly changing surface features, such as aero-engine blades, S-shaped air intakes, and blended wing-body structures.

[0004] The design of existing carbon fiber automatic fiber placement heads in China largely relies on the accumulated design experience of engineers. These mechanisms typically use cylinders to connect one or more independent flexible compaction shoes to achieve curved surface placement. However, their motion modes are limited, and their adaptability to curved surfaces is poor. They are only suitable for compacting flat or low-curvature surface structures. When placing complex curvature surface structures, insufficient flexibility and low precision in process parameter control cause sudden changes in compaction force, leading to defects such as buckling and wrinkling of the layup material. Therefore, it is necessary to design the configuration and structure of the fiber placement and compaction mechanism to match the curvature variation characteristics of the structural surface, in order to meet the adaptive placement and forming requirements of complex, abruptly changing curvature surface structures and multiple material specifications. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes an adaptive fiber placement and compaction mechanism for steeply curved surface structures. Fixed to the body of the automatic carbon fiber placement head and serving as part of it, the mechanism can adaptively adjust the angle of the pressure rollers during the placement process based on changes in the curvature of the structural surface. This ensures that the pressure rollers output a constant pressure force when placing steeply curved surface structures, thus avoiding molding defects caused by uneven pressure.

[0006] The present invention relates to an adaptive wire laying and compaction mechanism for steeply curvature surface structures, comprising a support device and a pneumatic slide, a symmetrical bistable mechanism and an underactuated mechanism installed sequentially from top to bottom on the support device.

[0007] The symmetrical bistable mechanism includes a translation link, a first steady-state link, a second steady-state link, a third steady-state link, a fourth steady-state link, a steady-state spring, and a steady-state limit block.

[0008] The translation link is horizontally positioned and fixed to the cylinder of the pneumatic slide, controlling its vertical movement. The top ends of the first and third stable links are hinged to the ends of the translation link, forming a revolute joint. The top ends of the second and fourth stable links are hinged to the bottom ends of the first and third stable links, respectively, forming a revolute joint. The bottom ends of the second and fourth stable links are hinged to the slider, forming a revolute joint. The slider is slidably connected to the slider guide rail mounted on the support device, allowing it to move vertically.

[0009] There are two steady-state limit blocks between the second and fourth steady-state links to restrict their rotation. Pins are installed in the middle of the second and fourth steady-state links, and the two ends of the steady-state spring are respectively hinged to the middle of the second and fourth steady-state links via pins to form a rotating pair.

[0010] The underactuated mechanism is adaptive and includes a central connecting rod, a main compaction roller, an auxiliary compaction roller, a main pressure roller connecting rod, an auxiliary pressure roller connecting rod, and a transmission support mechanism.

[0011] The central connecting rod is hinged to the slider to form a rotating pair; the main pressure roller connecting rod and the auxiliary pressure roller connecting rod are arranged crosswise, with their top ends hinged to the central connecting rod to form a rotating pair. The main compaction roller and the auxiliary compaction roller are installed at the bottom ends of the main pressure roller connecting rod and the auxiliary pressure roller connecting rod.

[0012] A transmission support mechanism is slidably sleeved on the aforementioned active roller connecting rod and auxiliary pressure roller connecting rod; the transmission support mechanism includes a support block and a cantilever pin. The support block has a through hole, which, in conjunction with a linear bearing, connects the active roller connecting rod and the auxiliary pressure roller connecting rod; and it is connected to the mounting platform via the cantilever pin, enabling the transmission support mechanism to rotate relative to the mounting platform.

[0013] The aforementioned symmetrical bistable mechanism and underactuated mechanism are connected and force-transmitted via a first transmission link, a second transmission link, a third transmission link, and a fourth transmission link. Specifically, the first transmission link is connected to the hinge axis between the first and second stable links, forming a revolute joint. The third transmission link is connected to the hinge axis between the third and fourth stable links, forming a revolute joint. The bottom ends of the first and third transmission links are respectively connected to the top ends of the second and fourth transmission links, forming revolute joints. The bottom ends of the second and fourth transmission links are respectively connected to the two ends of the central link of the underactuated mechanism, forming revolute joints.

[0014] The second and fourth transmission links are also equipped with conversion limit blocks near their top ends, which are used to limit the relative rotation angle between the first and second transmission links and between the third and fourth transmission links, respectively.

[0015] The adaptive wire-laying and compaction mechanism of this invention, which is designed for steeply curvature surface structures, provides a method for adaptive wire-laying and compaction on curved / flat surfaces:

[0016] S1: The carbon fiber automatic fiber placement head moves to the initial fiber placement position; at this time, the main compaction roller and the auxiliary compaction roller are in contact with the mold surface.

[0017] S2: Controls the pneumatic slide to apply a force less than the steady-state spring preload; pushes the slider down along the slider guide rail, and the central connecting rod further drives the main compaction roller and auxiliary compaction roller to contact the mold surface, and the contact force compacts the fiber strip onto the mold surface.

[0018] S3: When encountering a curved surface, the central connecting rod of the underactuated mechanism passively rotates relative to the slider around the center point. At the same time, the slider drives the entire underactuated mechanism to slide along the direction of movement of the pneumatic slide. The passive rotation and relative sliding of the central connecting rod enable the driving force of the pneumatic slide to be evenly distributed between the main compaction roller and the auxiliary compaction roller.

[0019] S4: The pneumatic slide adjusts its motion stroke in real time based on the force feedback from the sensor.

[0020] The present invention relates to an adaptive wire-laying and compaction mechanism for steeply curvature surface structures, and a method for wire-laying and compaction on a flat plane is as follows:

[0021] S21: The carbon fiber automatic fiber placement head moves to the initial placement position; at this time, the main compaction roller and the auxiliary compaction roller are in contact with the mold surface;

[0022] S22: Control the pneumatic slide to apply driving force, push the slider to move down along the slider guide rail, and the central connecting rod further drives the main compaction roller and the auxiliary compaction roller to contact the mold surface, and the contact force compacts the fiber strip onto the mold surface; when the driving force applied by the pneumatic slide is greater than the preload of the steady spring, the second steady-state connecting rod and the fourth steady-state connecting rod rotate in opposite directions until the conversion limit block cooperates with the first transmission connecting rod and the third transmission connecting rod to limit the movement;

[0023] S23: The conversion limit block restricts the relative rotation between the first and second transmission links, the third transmission link and the fourth transmission link, forming a closed chain with zero degrees of freedom between the entire symmetrical bistable mechanism and the four transmission links; the positions of the main compaction roller and the auxiliary compaction roller relative to the slider are fixed, with only one degree of freedom along the slider guide rail direction.

[0024] S24: The pneumatic slide adjusts its motion stroke in real time based on the force feedback from the sensor.

[0025] The advantages of this invention are:

[0026] This invention relates to a wire-laying and compaction mechanism for complex, steeply curvature surface structures. It is an adaptive wire-laying and compaction mechanism that can meet the forming requirements of curved and flat surfaces, addressing the forming needs of different ply-lay curved surface structures. By designing a bistable mechanism, the steady-state position of the bistable mechanism can be adjusted based on different forming curvature variations, enabling the wire-laying and compaction mechanism to switch between rigid and flexible states. When laying flat surfaces, the wire-laying and compaction mechanism is in a rigid state, with no flexible links, allowing for rapid and stable completion of the laying task and avoiding unnecessary minor vibrations. When laying curved surfaces, the wire-laying and compaction mechanism is in a flexible state. The adaptive design of the under-constrained mechanism ensures that the two pressure rollers fit snugly against the curved surface, thereby enabling the laying of complex curved surfaces. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the wire laying and compaction mechanism for complex, steeply curvature surface structures according to the present invention;

[0028] Figure 2 This is a schematic diagram of the transmission support mechanism in the wire laying and compaction mechanism for complex steeply curvature surface structures of the present invention;

[0029] Figure 3 This is a schematic diagram of the conversion limiting block structure in the wire laying and compaction mechanism for complex steeply curvature surface structures of the present invention;

[0030] Figure 4 A flowchart of a method for adaptive wire placement and compaction of curved / flat surfaces using the wire placement and compaction mechanism of the present invention for complex steeply curvature surface structures;

[0031] Figure 5This is an illustration of an example of the adaptive wire laying and compaction mechanism for complex, steeply curvature surface structures according to the present invention, demonstrating its application on curved surfaces.

[0032] Figure 6 A flowchart illustrating a method for efficient and high-quality wire placement and compaction of a flat plane using the wire placement and compaction mechanism of the present invention for complex steeply curvature surface structures.

[0033] Figure 7 This is an illustrated example of the wire-laying and compaction mechanism of the present invention, which is designed for complex and steeply curvature surface structures, and its efficient and high-quality wire-laying and compaction on a flat plane.

[0034] In the picture:

[0035] 100-Fiber Placement and Compaction Mechanism 200-Cylinder Connector 101-Support Device 102-Pneumatic slide table 103-Symmetric Bistable Mechanism 120-support frame 121-Installation Platform 130-Underactd Mechanism 110-Conversion Limit Block 106-First Transmission Link 107-Third Passing Link 108-Second Transmission Link 109-Fourth Passing Link 131-Center Link 132-Transmission Support Mechanism 133-Main pressure roller connecting rod 134-Auxiliary pressure roller connecting rod 135-Main Compaction Roller 136-Auxiliary Compaction Roller 301-Support Block 302-Linear Bearing 303-Elastic retaining ring 304-Cantilever Pin 401-Limit Block 402-Limit Adjustment Rod Detailed Implementation

[0036] The present invention will now be described in further detail with reference to the accompanying drawings.

[0037] This invention relates to a wire-laying and compaction mechanism for complex, abruptly curvature surface structures, such as... Figure 1 As shown, the overall filament laying and compaction mechanism 100 includes a support device 101, a pneumatic slide table 102, a symmetrical bistable mechanism 103, and an underactuated mechanism 130.

[0038] The support device 101 has an inverted T-shaped support frame 120 to meet the installation requirements of other components; at the same time, a flat plate with the same shape and size as the front side of the support frame 120 is designed and fixedly installed on the front side of the support frame 120 as the installation platform 121 for other components; thereby ensuring the flatness of the installation plane of each component, so that each component is located on the same plane; and facilitating the processing of installation holes.

[0039] The pneumatic slide 102, the symmetrical bistable mechanism 103, and the underactuated mechanism 130 are arranged from top to bottom. The pneumatic slide 102 is fixedly connected to the mounting platform 121, and its cylinder moves in the vertical direction to provide driving force for the adaptive wire laying and compaction mechanism.

[0040] The symmetrical bistable mechanism 103 is used to realize the switching between rigid and flexible states of the wire laying and compaction mechanism of the present invention. It includes a translation link, a first stable link, a second stable link, a third stable link, a fourth stable link, a stable spring, and a stable limit block.

[0041] The translation link is perpendicular to the movement direction of the pneumatic slide 102. Its middle section is connected and fixed to the cylinder of the pneumatic slide 102 via a cylinder connector 200, allowing it to slide up and down with the pneumatic slide. The first and third stable links are symmetrically arranged, with their top ends hinged to the ends of the translation link to form a revolute joint. The second and fourth stable links are also symmetrically arranged, with their top ends hinged to the bottom ends of the first and third stable links to form a revolute joint. The bottom ends of the second and fourth stable links are hinged to the outer upper part of the slider 104 to form a revolute joint. The inner side of the slider 104 is slidably connected to the slider guide rail fixed in the middle of the mounting platform 121, allowing it to slide vertically. Simultaneously, two stable limit blocks are designed on the upper part of the slider 104 between the second and fourth stable links, contacting the second and fourth stable links respectively to restrict their inward relative rotation.

[0042] The second and fourth steady-state connecting rods are fitted with pins at their midpoints, and the two ends of the steady-state springs are respectively hinged to the midpoints of the second and fourth steady-state connecting rods via pins. The preload provided by the steady-state springs causes the second and fourth steady-state connecting rods to contact the two steady-state limit blocks respectively.

[0043] The underactuated mechanism 130 is adaptive, ensuring the pressure roller fits snugly against the curved surface when the filament laying and compaction mechanism is in both rigid and flexible states. The underactuated mechanism 130 includes a central connecting rod 131, a large-diameter main compaction roller 135, a small-diameter auxiliary compaction roller 136, a main pressure roller connecting rod 133, an auxiliary pressure roller connecting rod 134, and a transmission and support mechanism 132, as shown below. Figure 2 As shown.

[0044] The geometric center of the central connecting rod 131 is hinged to the lower outer side of the slider 104, forming a revolute joint. The hinge point is located on the perpendicular bisector of the line connecting the hinge points of the second and fourth steady-state connecting rods and the slider 104. The main pressure roller connecting rod 133 and the auxiliary pressure roller connecting rod 134 are arranged intersectingly, with their top ends located on the inner and outer sides of the central connecting rod 131, respectively. They are hinged to the central connecting rod 131 to form a revolute joint, with the hinge points located at 1 / 4 of the rod length on the left and right sides of the central connecting rod 131. The bottom ends of the main pressure roller connecting rod 133 and the auxiliary pressure roller connecting rod 134 are connected to U-shaped roller frames. Large-diameter main pressure rollers 135 and small-diameter auxiliary pressure rollers 136 are respectively installed within the two U-shaped roller frames. The ends of the roller shafts of the two compaction rollers 135 are fixedly connected to the sides of the roller frames.

[0045] The aforementioned active roller connecting rod 133 and auxiliary pressure roller connecting rod 134 are slidably sleeved with a transmission support mechanism 132. For example... Figure 2As shown, the transmission support mechanism 132 includes a support block 301, a linear bearing 302, an elastic retaining ring 303, and a cantilever pin 304. The linear bearing 302 is installed in the central hole of the support block 301, and its two ends are positioned by the elastic retaining rings 303. It is connected to the active roller connecting rod 133 and the auxiliary pressure roller connecting rod 134 via the linear bearing. The axis of the cantilever pin 304 is perpendicular to the axis of the central hole. The pin end of the cantilever pin 304 is connected to the outer wall of the support block 301 to form a rotating pair, and the circumferential movement is restricted by the elastic retaining rings. The threaded end of the cantilever pin 304 is threadedly engaged with threaded holes on opposite sides of the lower part of the mounting platform 121, enabling the transmission support mechanism 132 to rotate relative to the mounting platform 121. Therefore, when the central connecting rod 131 rotates around the hinge axis, the active roller connecting rod 133 and the auxiliary pressure roller connecting rod 134 can slide relative to the transmission support mechanism 132.

[0046] The aforementioned symmetrical bistable mechanism 103 and underactuated mechanism 130 are connected and force-transmitted via a first transmission link 106, a second transmission link 108, a third transmission link 107, and a fourth transmission link 109. Specifically, the first transmission link 106 is connected to the hinge axis between the first and second stable links to form a revolute joint; the third transmission link 107 is connected to the hinge axis between the third and fourth stable links to form a revolute joint. The bottom ends of the first and third transmission links 106 and 107 are respectively connected to the top ends of the second and fourth transmission links 109 to form revolute joints; the bottom ends of the second and fourth transmission links 108 and 109 are respectively connected to the two ends of the central link 131 of the underactuated mechanism 130 to form revolute joints.

[0047] The second transmission link 108 and the fourth transmission link 109 are also equipped with conversion limit blocks 110 near their top positions, which are used to limit the relative rotation angle between the first transmission link 106 and the second transmission link 108 and between the third transmission link 107 and the fourth transmission link 109, respectively.

[0048] The conversion limiting block 110 includes a limiting block 401 and a limiting adjustment rod 402, such as Figure 3As shown. The limiting block 401 has a groove on its opposite sidewall that passes through it. The width of the groove matches the width of the transmission link. This groove enables the insertion and positioning of the limiting block 110 and the transmission link, and the limiting block 401 is fixed to the transmission link with screws. One end of the limiting adjustment rod 402 is an adjustment end, which is threadedly connected to a threaded hole on the sidewall of the limiting block 401. The other end of the limit adjustment rod 402 is a limit end. The limit blocks 401 on the second transmission link 108 and the fourth transmission link 109 are respectively oriented towards the first transmission link 106 and the third transmission link 107, and cooperate with the first transmission link 106 and the third transmission link 107 to achieve the limit. Moreover, the rotation range between the first transmission link 106 and the second transmission link 108 and between the third transmission link 107 and the fourth transmission link 109 can be changed by adjusting the length of the limit adjustment rod 402, thereby adjusting the motion range of the symmetrical bistable mechanism 103 and the tension of the steady spring.

[0049] This invention relates to an adaptive fiber placement and compaction mechanism for steeply curvature surface structures. Fixed to the body of an automatic carbon fiber placement head, it serves as part of the automatic carbon fiber placement head. During fiber placement, the movement of the second and fourth steady-state connecting rods is limited by the steady-state spring preload and the steady-state limit stop. When the driving force of the pneumatic slide 102 does not exceed a specific threshold, the symmetrical bistable mechanism 103 is in the first steady state, at which point the adaptive fiber placement and compaction mechanism 100 is in a compliant state. When the driving force of the pneumatic slide exceeds the specific threshold, the symmetrical bistable mechanism 103 transitions from the first steady state to the second steady state, and simultaneously, the fiber placement and compaction mechanism 100 transitions from a compliant state to a rigid state.

[0050] Therefore, this invention enables an adaptive wire-laying and compaction method for curved / flat surfaces, such as... Figure 4 As shown, the specific process is as follows:

[0051] S1: Control the fiber placement and compaction mechanism of the present invention to move to the initial position of the fiber placement with the automatic fiber placement head; at this time, the main compaction roller 135 and the auxiliary compaction roller 136 of the adaptive fiber placement and compaction mechanism are in contact with the surface of the mold.

[0052] S2: The pneumatic slide 102 is controlled to apply a force less than the preload of the steady-state spring; the slider 104 is pushed to move down along the slider guide rail, and the central connecting rod 131 further drives the main compaction roller 135 and the auxiliary compaction roller 136 to contact the mold surface, pressing the fiber strip onto the mold surface with a certain contact force. At this time, due to the tensile preload of the steady-state spring and the limiting position of the steady-state limit block 107, the symmetrical bistable mechanism 103 is in the first steady state.

[0053] S3: When encountering a curved surface during the wire laying process, the contact force of one of the compaction rollers changes. At this time, the central connecting rod 131 of the under-driven mechanism 130 passively rotates relative to the slider 104 around its center point. Simultaneously, the slider 104 drives the entire under-driven mechanism 130 to slide along the direction of movement of the pneumatic slide table 102. The passive rotation and relative sliding of the central connecting rod 131 allow the driving force of the pneumatic slide table 102 to be evenly distributed between the main compaction roller 135 and the auxiliary compaction roller 136. Figure 5 As shown

[0054] S4: The pneumatic slide 102 adjusts its motion stroke in real time based on the force feedback from the sensor.

[0055] Furthermore, this invention can also achieve a method for efficient and high-quality fiber laying and compaction on a flat plane, such as... Figure 6 As shown, the specific process is as follows:

[0056] S21: Control the fiber placement and compaction mechanism of the present invention to move to the initial position of fiber placement along with the automatic fiber placement head; at this time, the main compaction roller 135 and the auxiliary compaction roller 136 of the adaptive fiber placement and compaction mechanism are in contact with the mold surface.

[0057] S22: The pneumatic slide 102 is controlled to apply driving force, pushing the slider 104 downward along the slider guide rail. The central connecting rod 131 further drives the main compaction roller 135 and the auxiliary compaction roller 136 to contact the mold surface, compacting the fiber strip onto the mold surface with a certain contact force. When the driving force applied by the pneumatic slide 102 is greater than the preload of the steady-state spring, the second steady-state connecting rod and the fourth steady-state connecting rod rotate in opposite directions until the conversion limit block 110 cooperates with the first transmission connecting rod 106 and the third transmission connecting rod 107 to limit the movement, and the symmetrical bistable mechanism 103 is in the second steady state.

[0058] S23: The conversion steady-state limit block 110 restricts the relative rotation between the first transmission link 106, the second transmission link 108, the third transmission link 107, and the fourth transmission link 109. The entire symmetrical bistable mechanism 103 and the four transmission links form a closed chain with zero degrees of freedom. The positions of the main compaction roller 135 and the auxiliary compaction roller 136 relative to the slider 104 are fixed, with only one degree of freedom along the slider guide rail 105.

[0059] S24: The pneumatic slide 102 adjusts its stroke in real time based on the force feedback from the sensor. The entire adaptive wire laying and compaction mechanism maintains rigidity under the driving force of the pneumatic slide 102, reducing energy loss caused by minor undulations on the mold surface (plane) and fluctuations in the contact force between the main and auxiliary compaction rollers, thereby improving the efficiency and quality of wire laying and compaction.

Claims

1. A wire-laying and compaction mechanism for complex, steeply curvature surface structures, characterized in that: It includes a support device and a pneumatic slide, a symmetrical bistable mechanism and an underactuated mechanism installed on the support device from top to bottom; The symmetrical bistable mechanism includes a translation link, a first steady-state link, a second steady-state link, a third steady-state link, a fourth steady-state link, a steady-state spring, and a steady-state limiting block; The system comprises: a horizontally positioned translation link connected and fixed to the cylinder of a pneumatic slide, which controls its vertical movement; the top ends of the first and third stable links are hinged to the ends of the translation link to form a revolute joint; the top ends of the second and fourth stable links are hinged to the bottom ends of the first and third stable links to form a revolute joint; the bottom ends of the second and fourth stable links are hinged to the slider to form a revolute joint; the slider is slidably connected to the slider guide rail mounted on the support device, allowing it to move vertically; two stable limit blocks are provided between the second and fourth stable links to restrict their rotation; pins are installed in the middle of the second and fourth stable links, and the two ends of a stable spring are hinged to the middle of the second and fourth stable links via pins to form a revolute joint; The underactuated mechanism is adaptive and includes a central connecting rod, a main compaction roller, an auxiliary compaction roller, a main pressure roller connecting rod, an auxiliary pressure roller connecting rod, and a transmission support mechanism; The central connecting rod is hinged to the slider to form a rotating pair; the main pressure roller connecting rod and the auxiliary pressure roller connecting rod are arranged crosswise, and their top ends are hinged to the central connecting rod to form a rotating pair; the main compaction roller and the auxiliary compaction roller are installed at the bottom ends of the main pressure roller connecting rod and the auxiliary pressure roller connecting rod. The main pressure roller connecting rod and the auxiliary pressure roller connecting rod are slidably sleeved with a transmission support mechanism; the transmission support mechanism includes a support block and a cantilever pin; wherein, the support block has a through hole, which is matched with a linear bearing and connected to the main pressure roller connecting rod and the auxiliary pressure roller connecting rod; and is connected to the mounting platform through the cantilever pin to realize the rotational movement of the transmission support mechanism relative to the mounting platform; The aforementioned symmetrical bistable mechanism and underactuated mechanism are connected and force transmitted through a first transmission link, a second transmission link, a third transmission link, and a fourth transmission link. Specifically, the first transmission link is connected to the hinge axis between the first and second stable links to form a revolute joint; the third transmission link is connected to the hinge axis between the third and fourth stable links to form a revolute joint; the bottom ends of the first and third transmission links are respectively connected to the top ends of the second and fourth transmission links to form a revolute joint; the bottom ends of the second and fourth transmission links are respectively connected to the two ends of the central link of the underactuated mechanism to form a revolute joint. The second and fourth transmission links are also equipped with conversion limit blocks near their top ends, which are used to limit the relative rotation angle between the first and second transmission links and between the third and fourth transmission links, respectively.

2. The wire-laying and compaction mechanism for complex, steeply curvature surface structures as described in claim 1, characterized in that: The conversion limiting block includes a limiting block and a limiting adjustment rod. The limiting block has a groove on its opposite sidewall, the width of which matches the width of the transmission link. This groove facilitates the insertion and positioning of the limiting block and the transmission link, and the limiting block is fixed to the transmission link with screws. One end of the limiting adjustment rod is an adjustment end, threadedly connected to a threaded hole in the wall of the limiting block; the other end is a limiting end. The limiting ends of the limiting blocks on the second and fourth transmission links face the first and third transmission links respectively, cooperating with them to achieve limiting. By adjusting the length of the limiting adjustment rod, the rotation range between the first and second transmission links, and between the third and fourth transmission links, is changed, thereby adjusting the motion range of the symmetrical bistable mechanism and the tension of the steady-state spring.

3. The wire-laying and compaction mechanism for complex, steeply curvature surface structures as described in claim 1, characterized in that: The middle part of the translation link is connected and fixed to the cylinder of the pneumatic slide table through the cylinder connector; the first and third stable links are symmetrically arranged left and right; the second and fourth stable links are symmetrically arranged left and right; the central link is hinged to the slider at the geometric center, and the hinge position is located on the perpendicular bisector of the line connecting the hinge positions of the second and fourth stable links and the slider; the tops of the main pressure roller link and the auxiliary pressure roller link are hinged to the central link at the left and right 1 / 4 of the link length of the central link.

4. The wire-laying and compaction mechanism for complex, steeply curvature surface structures as described in claim 1, characterized in that: The adaptive wire-laying compaction method for curved / flat surfaces is as follows: S1: The carbon fiber automatic fiber placement head moves to the initial placement position; at this time, the main compaction roller and the auxiliary compaction roller are in contact with the mold surface; S2: Control the pneumatic slide to apply a force less than the steady-state spring preload; push the slider to move down along the slider guide rail, and the central connecting rod further drives the main compaction roller and the auxiliary compaction roller to contact the mold surface, and the contact force compacts the fiber belt onto the mold surface; S3: When encountering a curved surface, the central connecting rod of the underactuated mechanism passively rotates relative to the slider around the center point. At the same time, the slider drives the entire underactuated mechanism to slide along the direction of movement of the pneumatic slide. The passive rotation and relative sliding of the central connecting rod enable the driving force of the pneumatic slide to be evenly distributed between the main compaction roller and the auxiliary compaction roller. S4: The pneumatic slide adjusts its motion stroke in real time based on the force feedback from the sensor.

5. The wire-laying and compaction mechanism for complex, steeply curvature surface structures as described in claim 1, characterized in that... The method for compacting wire in a flat plane is as follows: S21: The carbon fiber automatic fiber placement head moves to the initial placement position; at this time, the main compaction roller and the auxiliary compaction roller are in contact with the mold surface; S22: Control the pneumatic slide to apply driving force, push the slider to move down along the slider guide rail, and the central connecting rod further drives the main compaction roller and the auxiliary compaction roller to contact the mold surface, and the contact force compacts the fiber strip onto the mold surface; when the driving force applied by the pneumatic slide is greater than the preload of the steady spring, the second steady-state connecting rod and the fourth steady-state connecting rod rotate in opposite directions until the conversion limit block cooperates with the first transmission connecting rod and the third transmission connecting rod to limit the movement; S23: The conversion limit block restricts the relative rotation between the first and second transmission links, the third transmission link and the fourth transmission link, forming a closed chain with zero degrees of freedom between the entire symmetrical bistable mechanism and the four transmission links; the positions of the main compaction roller and the auxiliary compaction roller relative to the slider are fixed, with only one degree of freedom along the slider guide rail direction; S24: The pneumatic slide adjusts its motion stroke in real time based on the force feedback from the sensor.

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