Robot composite material laying machine with on-line cutting detection characteristic of fiber tows

Abstract

The invention discloses a robot composite material laying machine with a fiber tow online cutting detection characteristic. The robot composite material laying machine comprises a material receiving and discharging system, a re-conveying system, a tow cutting system, a heating and pressure applying system and a robot movement system. Firstly, the prepreg is fed into the guiding device, and after the prepreg passes through the receiving device, an interlayer film of the prepreg can be recycled; secondly, the prepreg enters a re-conveying system, a tension detection device detects the tension of the prepreg, and the re-conveying device compacts the prepreg and conveys the prepreg at the same time; then the prepreg enters a tow cutting system, a nitrogen cooling device cools the prepreg, and a detection control device detects the cut prepreg so as to prevent the prepreg from being completely cut off; and finally, the prepreg enters a heating and pressure applying system, heating treatment is conducted on the prepreg, and the prepreg is laid and compacted. The invention provides the structural design of the laying machine with comprehensive functions and low cost, and the prepreg can be effectively cut off and cannot be bonded through the tow cutting system.

Description

Technical Field

[0001] The invention relates to the field of composite material manufacturing, and in particular to a robot composite material placement machine with a fiber bundle online cutting detection feature. Background Art

[0002] In the field of aerospace, the automatic prepreg placement technology is used to manufacture key components such as aircraft parts and satellite brackets, achieving the requirements of lightweight, high strength and high durability. In the automotive field, this technology is used to manufacture key components such as automobile bodies, engine hoods, chassis, etc., improving the safety and comfort of automobiles. In the future, the automatic fiber placement process of composite materials is expected to develop further and promote the in-depth practice of intelligent manufacturing. However, the existing fiber placement equipment for fiber placement technology still has many shortcomings, such as complex structure and heavy weight resulting in high manufacturing costs; weak adaptability and inability to meet the needs of complex curved surface placement; poor process quality and the inability to completely cut the prepreg during work. These problems seriously affect the process and finished product quality of prepreg placement products, thereby increasing equipment maintenance costs.

[0003] The patent with publication number CN212499066U and title “A Pressing and Shearing Device, Laying Head and Automatic Fiber Laying Machine” aims at the technical problems that the pressing device and the shearing device of the laying head in the prior art are separately arranged, and the pressing device and the shearing device need to be operated successively to achieve the pressing and shearing of the fiber, and the structure and operation are complicated. A pressing and shearing device, a laying head and an automatic fiber laying machine are provided to achieve the driving and control of the pressing and shearing parts, with a simple structure and convenient operation, and the laying head can move in different dimensions, thereby improving the laying quality. The patent with publication number CN 211968496U and title “A Composite Material Automatic Laying Non-pause Cutting Device” aims at the problems that the movement speed of the prepreg tape laying process is uneven and the heating temperature has large fluctuations in the pause area. A new composite material automatic laying non-pause cutting device is provided to achieve the automatic laying of composite materials without pausing, so as to eliminate the influence of the cutting operation logic on the automatic laying movement speed, and improve the product stability and performance consistency. The patent with publication number CN115611053A and titled "A Textile Cutting Device Based on Internet of Things Big Data Technology" aims to solve the problem that existing textile cutting devices cannot perform fixed-point positioning according to the location of the holes and cut off textiles with holes. It provides a textile cutting device based on Internet of Things big data technology, which can minimize the error of subsequent cut textiles and improve the utilization rate of textiles.

[0004] Although the existing full-function prepreg placement heads are diverse and fully functional, there are still many problems in the actual prepreg placement process, especially the substandard design of the prepreg cutting device, which leads to connection problems during the placement of the prepreg, resulting in project suspension and a very poor user experience of the automatic prepreg placement machine. Secondly, in the process of the cutter cutting the prepreg, the energy generated instantly is too large, causing the resin at the break of the prepreg to melt and stick to the parts, which requires manual adjustment, which has a serious impact on the processing efficiency. Summary of the invention

[0005] Purpose of the invention: To overcome the shortcomings of the prior art, a robotic composite material placement machine with an online fiber tow cutting detection feature is provided to improve the prepreg shearing device, which can perfectly cut the prepreg and improve the working efficiency of the placement head.

[0006] Technical solution: The present invention proposes a robotic composite material placement machine with an online fiber tow cutting detection feature, comprising a robot motion system and a prepreg fiber placement head located at the execution end of the robot motion system;

[0007] The prepreg fiber placement head includes a material collection and unloading system, a re-feeding system located downstream of the material collection and unloading system, a tow cutting system connected to the re-feeding system, and a heating and pressure system connected to the tow cutting system; the material collection and unloading system is used to transfer the tow to the re-feeding system; the re-feeding system, the material collection device, the material discharge device and the guide device are all fixed on a fixed back plate; the re-feeding system includes a transmission pressure device, a pressure roller and a servo system connected to the pressure roller, and a transmission pressure device is installed above the pressure roller; the tow cutting system includes a nitrogen cooling device, a residual tension detection device and a shearing device, the nitrogen cooling device is installed on the side of the shearing device, the shearing device is used to shear the tow passing through the re-feeding system, and the residual tension detection device is used to detect the residual tension of the tow after being sheared by the shearing device; the heating and pressure system includes a heating device and an output pressure device, the output pressure device is installed at the lowest end of the left side of the fixed back plate, and the heating device is installed between the output pressure device and the tow cutting system.

[0008] Preferably, the robot motion system is a six-axis robot.

[0009] Preferably, the material collecting and unloading system is connected to the robot motion system via a joint flange.

[0010] Preferably, the tension detection system comprises a tension sensor, the rated range of the tension sensor is 20-300N, and the output sensitivity is 2.0±0.1%mV / V.

[0011] Preferably, the servo system includes a servo motor, and the servo motor is connected to the pressure roller through a synchronous belt and a connecting shaft.

[0012] Preferably, the transmission pressure device applies pressure and releases pressure according to the laying position of the robot composite material laying machine. When the laying work is carried out, the transmission pressure device works first to compress the fibers. When the laying work is completed, the transmission pressure device stops working to release pressure. The servo motor in the adjustable speed servo system performs real-time speed adjustment according to the movement speed of the laying machine.

[0013] Preferably, the nitrogen cooling device is connected to a nitrogen source, and when the shearing device receives a shearing command, the nitrogen cooling device releases nitrogen in advance to cool the prepreg.

[0014] Preferably, the tow cutting system further comprises a transition block, the cutting groove at the front end of the transition block is aligned with the shearing device, and the rear end of the transition block is fixed to the fixed back plate through a support rod.

[0015] Preferably, the heating and pressure system further comprises a conductive base plate, which is fixed to the fixed backing plate by support rods, receives the prepreg cut from the tow cutting system, and transports it to the heating device for heating.

[0016] Preferably, the residual tension detection device is connected to the transmission pressure device and the shearing device through signals. The residual tension detection device is used to measure whether there is residual tension in the prepreg after cutting. When tension is detected in the prepreg, it means that the fiber has not been completely cut off. The residual tension detection device releases a signal to stop the transmission pressure device from transmitting, and at the same time releases a signal to the shearing device to continue the shearing task until the residual tension detection device measures that the prepreg has no tension, indicating that the prepreg has been completely cut off; at this time, the shearing device stops shearing, and at the same time the transmission pressure device continues to transmit the prepreg to the preset position.

[0017] Beneficial effects: The present invention proposes a robotic composite material placement machine with an online fiber tow cutting detection feature, which provides a low-cost placement machine structure design with comprehensive functions. At the same time, the tow cutting system can effectively cut the prepreg without bonding, which improves the overall working efficiency of the fiber placement head. The placement machine can predict whether the prepreg is broken by detecting whether there is residual tension in the sheared prepreg. At the same time, the cooling of nitrogen also makes the prepreg more brittle and the cutting effect more obvious, which improves the shearing efficiency of the prepreg and improves the quality of prepreg placement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the robot composite material placement machine with the fiber tow online cutting detection feature of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the prepreg fiber placement head of the present invention;

[0020] Figure 3 It is a structural schematic diagram of the material collection and discharge system in the present invention;

[0021] Figure 4 It is a structural schematic diagram of the re-delivery system in the present invention;

[0022] Figure 5 It is a structural schematic diagram of the tow cutting system in the present invention;

[0023] Figure 6 It is a schematic diagram of the structure of the heating and pressurizing system in the present invention. DETAILED DESCRIPTION

[0024] like Figure 1 As shown, the present invention provides a robotic composite material placement machine with an online fiber bundle cutting detection feature. The placement machine is connected to a robotic arm through a joint flange designed at the top. The placement head moves with the movement of the robotic arm. The prepreg needs to pass through a discharge device 11, a guide device 7, a receiving device 8, a tension detection system 6, an adjustable speed servo system 14, a nitrogen cooling device 17, a shearing device 15, a residual tension detection system 16, a heating device 20 and an output pressure device 21 in sequence.

[0025] like Figure 2 The system shown includes a material collection and release system 2, a re-feeding system 3, a tow cutting system 4, and a heating and pressurizing system 5:

[0026] like Figure 3 As shown, the material receiving and unloading system 2 includes a material receiving device 8, a guiding device 7, a material unloading device 11 and a tension detection system 6. The material receiving device 8 and the guiding device 7 are fixed on the fixed back plate 9 through support rods in a corresponding order.

[0027] like Figure 4 As shown, the re-conveyance system 3 includes a transmission pressure device 12, a pressure roller 13 and an adjustable speed servo system 14. The adjustable speed servo system 14 includes a servo motor, which is connected to the pressure roller 13 through a synchronous belt and a connecting shaft. The transmission pressure device 12 is installed above the pressure roller 13. The entire re-conveyance system 3 is installed at the end of the material collection and release system 2.

[0028] like Figure 5 As shown, the tow cutting system 4 includes a nitrogen cooling device 17 , a residual tension detection device 16 and a shearing device 15 , and the nitrogen cooling device 17 is installed on the side of the shearing device 15 .

[0029] like Figure 6As shown, the heating and pressurizing system 5 includes a heating device 20 and an output pressurizing device 21 . The output pressurizing device 21 is installed at the lowest end of the fixed back plate 9 , and the heating device 20 is installed between the output pressurizing device 21 and the tow cutting system 4 .

[0030] like Figure 3 As shown, the material collection and unloading system 2 includes a material collection device 8, a guide device 7, a material unloading device 11 and a tension detection system 6. The material collection device 8 and the guide device 7 are fixed to the fixed back plate 9 through support rods in a corresponding order. The whole machine structure is connected to the robot motion system 1 through a joint flange. The unloading device is installed and fixed at the upper right end of the back plate 9, and has the function of assembling the material tray and controlling the tension. The material collection device 11 can effectively collect the diaphragm between the fiber layers through friction, and the fiber belt enters the next system through the guide structure.

[0031] The Dayang three-pulley tension sensor in the tension detection system 6 can detect the fiber tension in real time and transmit the detected fiber tension to the TC950 tension meter. The tension meter can adjust the AHB-3M magnetic powder tension brake according to the pre-modulated tension range to control the fiber tension to achieve the predetermined tension.

[0032] like Figure 4 As shown, the re-feeding system 3 includes a transmission pressure device 12, a pressure roller 13 and an adjustable speed servo system 14. The adjustable speed servo system includes a servo motor, which is connected to the pressure roller 13 through a synchronous belt and a connecting shaft to transmit kinetic energy. A transmission pressure device 12 is installed above the pressure roller 13 to compress the fiber on the pressure roller 13 to provide friction during operation. The entire re-feeding system 3 is installed at the end of the material collection and release system 2.

[0033] The transmission pressure device 12 can apply pressure and release pressure according to the laying position of the robot composite material placement machine. When the laying work is carried out, the transmission pressure device 12 works first to compress the fibers. When the laying work is completed, the transmission pressure device 12 stops working to release pressure. The servo motor in the adjustable speed servo system 14 can perform real-time speed adjustment according to the movement speed of the placement machine.

[0034] like Figure 5As shown, the tow cutting system 4 includes a nitrogen cooling device 17, a residual tension detection device 16 and a shearing device 15. The nitrogen cooling device 17 is installed on the side of the shearing device 15, and the nitrogen outlet is aligned with the prepreg cutting position, which is used to cool the sheared prepreg; the residual tension detection device 16 is installed between the heating and pressure system 5 and the tow cutting system 4, which is used to detect whether the prepreg still has tension; the shearing device 15 is installed between the nitrogen cooling device 17 and the residual tension detection device 16, which is used to shear the prepreg. The cutting groove at the front end of the transition block 18 is aligned with the shearing device 15, and the rear end is fixed to the fixed back plate 9 through a support rod, which is used to cool and cut the prepreg through the nitrogen cooling device 17 and the tow cutting system 4.

[0035] The nitrogen cooling device 17 is connected to the nitrogen source. When the shearing device 15 receives the shearing command, the nitrogen cooling device 17 will release nitrogen in advance to cool the prepreg, so that the cutter can cut the prepreg more easily. The residual tension detection device 16 is connected to the transmission pressure device 12 and the shearing device 15 through a signal. The residual tension detection device 16 can measure whether the prepreg after cutting has residual tension. When it is detected that the prepreg has tension, it means that the fiber has not been completely cut off. The residual tension detection device 16 releases a signal to stop the transmission pressure device 12 from transmitting, and at the same time releases a signal to the shearing device 15 to continue the shearing task, until the residual tension detection device 16 measures that the prepreg has no tension, indicating that the prepreg has been completely cut off. At this time, the residual tension detection device 16 transmits a signal to the shearing device 15 to stop the shearing work, and at the same time transmits a signal to the transmission pressure device 12 to continue to transmit the prepreg to the preset position.

[0036] like Figure 6 As shown, the heating and pressurizing system 5 includes a heating device 20 and an output pressurizing device 21. The output pressurizing device 21 is installed at the lowest end of the fixed back plate 9 to compress the prepreg on the surface of the core mold by stretching up and down. The heating device 20 is installed between the output pressurizing device 21 and the tow cutting system 4 to preheat the transported prepreg. The conductive bottom plate 19 is fixed to the fixed back plate 9 by a support rod, receives the prepreg cut from the tow cutting system 4, and transports it to the heating device 20 for heating.

Claims

1. A robotic composite material placement machine with an in-line fiber tow cutting detection feature, characterized in that: It comprises a robot motion system (1) and a prepreg fiber placement head located at the execution end of the robot motion system (1); The prepreg fiber placement head comprises a material collection and discharge system (2), a re-feeding system (3) located downstream of the material collection and discharge system (2), a tow cutting system (4) connected to the re-feeding system (3), and a heating and pressure system (5) connected to the tow cutting system (4); the material collection and discharge system (2) is used to transfer the tow to the re-feeding system (3); the re-feeding system (3), the material collection device (8), the material discharge device (11) and the guide device (7) are all fixed on a fixed back plate (9); the re-feeding system (3) comprises a transmission pressure device (12), a pressure roller (13) and a servo system (14) connected to the pressure roller (13); a transmission pressure device is installed above the pressure roller (13). The yarn cutting system (4) comprises a nitrogen cooling device (17), a residual tension detection device (16) and a shearing device (15), wherein the nitrogen cooling device (17) is installed on the side of the shearing device (15), the shearing device (15) is used to shear the yarns passing through the re-feeding system (3), and the residual tension detection device (16) is used to detect the residual tension of the yarns after being sheared by the shearing device (15); the heating and pressurizing system (5) comprises a heating device (20) and an output pressurizing device (21), wherein the output pressurizing device (21) is installed at the lowest end on the left side of the fixed back plate (9), and the heating device (20) is installed between the output pressurizing device (21) and the yarn cutting system (4).

2. The robotic composite placement machine with fiber tow online cutting detection feature according to claim 1, characterized in that: The robot motion system (1) is a six-axis robot.

3. The robotic composite material placement machine with fiber tow online cutting detection feature according to claim 1, characterized in that: The material collection and release system (2) is connected to the robot motion system (1) via a joint flange (10).

4. The robotic composite material placement machine with fiber tow online cutting detection feature according to claim 1, characterized in that: The tension detection system (6) comprises a tension sensor, wherein the rated range of the tension sensor is 20-300N and the output sensitivity is 2.0±0.1% mV / V.

5. The robotic composite placement machine with fiber tow online cutting detection feature according to claim 1, characterized in that: The servo system (14) includes a servo motor, and the servo motor is connected to the pressure roller (13) via a synchronous belt and a connecting shaft.

6. The robotic composite material placement machine with fiber tow online cutting detection feature according to claim 5, characterized in that: The transmission pressure device (12) applies pressure and releases pressure according to the placement position of the robot composite material placement machine. When the placement work is carried out, the transmission pressure device (12) works first to compact the fibers. When the placement work is completed, the transmission pressure device (12) stops working to release pressure. The servo motor in the adjustable speed servo system (14) performs real-time speed adjustment according to the movement speed of the placement machine.

7. The robotic composite placement machine with fiber tow online cutting detection feature according to claim 1, characterized in that: The nitrogen cooling device (17) is connected to a nitrogen source, and when the shearing device (15) receives a shearing command, the nitrogen cooling device (17) releases nitrogen in advance to cool the prepreg.

8. The robotic composite placement machine with fiber tow online cutting detection feature according to claim 1, characterized in that: The tow cutting system (4) further comprises a transition block (18), the cutting groove at the front end of the transition block (18) being aligned with the shearing device (15), and the rear end of the transition block (18) being fixed to the fixed back plate (9) via a support rod.

9. The robotic composite placement machine with fiber tow online cutting detection feature according to claim 1, characterized in that: The heating and pressure system (5) also includes a conductive base plate (19) which is fixed to the fixed backing plate (9) via support rods, receives the prepreg cut from the tow cutting system (4), and transports it to the heating device (20) for heating.

10. The robotic composite placement machine with fiber tow online cutting detection feature according to claim 1, characterized in that: The residual tension detection device (16) is connected to the transmission pressure device (12) and the shearing device (15) via signals. The residual tension detection device (16) is used to measure whether there is residual tension in the prepreg after cutting. When it is detected that there is tension in the prepreg, it means that the fibers have not been completely sheared. The residual tension detection device (16) releases a signal to stop the transmission pressure device (12) from transmitting, and at the same time releases a signal to the shearing device (15) to continue the shearing task, until the residual tension detection device (16) measures that the prepreg has no tension, indicating that the prepreg has been completely sheared; at this time, the shearing device (15) stops shearing, and at the same time the transmission pressure device (12) continues to transmit the prepreg to a preset position.

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