Composite material stringer forming die and forming method

Abstract

The invention relates to the technical field of composite material stringer forming, and particularly discloses a composite material stringer forming mold and method.The composite material stringer forming mold comprises a mold pressing machine, a jacking cavity, a clamping cavity, a positioning mechanism, a mold pressing mechanism and a jacking mechanism, and the jacking cavity is formed in the bottom end of an inner cavity of the mold pressing machine; clamping cavities communicated with an inner cavity of the molding press are formed in the left side and the right side of the molding press, the positioning mechanisms are arranged in inner cavities of the clamping cavities, the molding mechanism is arranged at the top end of the inner cavity of the molding press, and the jacking mechanism is arranged in an inner cavity of the jacking cavity. The device can effectively overcome the defects of edge fiber distortion and interlayer slippage caused by resin flow and thermal expansion coefficient difference in the prior art, can ensure that the prepreg is kept at a design angle when being laid, can timely identify and adjust an abnormal stress state during demolding, greatly reduces the rejection rate, and improves the production efficiency. The mold system can realize accurate control of the hot press molding process and safety protection of the demolding process, and has remarkable economic benefits and application values.

Description

Technical Field

[0001] The present invention relates to the technical field of composite stringer forming, and specifically to a composite stringer forming die and a forming method. Background Art

[0002] As a high-performance structural component, composite stringers have been widely used in fields such as aerospace and rail transit due to their excellent specific strength and specific stiffness characteristics. Such components are usually formed by a molding process using reinforcing materials such as carbon fiber and glass fiber and thermosetting resin matrices such as epoxy resin and bismaleimide. During the molding process, the prepreg ply is placed between the upper and lower dies, and the resin is melted and flowed through heating and pressing and finally cured. However, there are still several key technical problems in the hot pressing and demolding processes of the existing composite stringer forming dies, which seriously affect the forming quality and production efficiency of the parts. In the hot pressing stage, the die needs to heat the composite material to promote resin curing. During this process, when the die temperature rises to the resin melting temperature range, the incompletely cured thermosetting resin will present a low-viscosity flowing state. Due to the significant difference in the coefficient of thermal expansion (CTE) between the resin and the reinforcing fiber (the resin CTE is usually 50 - 100 ppm / °C, while the axial CTE of carbon fiber is close to 0 ppm / °C), an obvious thermal mismatch effect will occur during the heating process. This effect will cause two problems: on the one hand, the lateral flow of the resin will generate shear stress between the fiber layers; on the other hand, the thermal expansion of the resin will be restricted by the fiber network, resulting in additional shear stress at the interlayer interface. Especially in the edge area of the component, due to the lack of sufficient restraint, this stress concentration effect is more significant, and it is extremely easy to cause defects such as edge fiber distortion and interlayer slip, seriously affecting the dimensional accuracy and mechanical properties of the parts. In the demolding stage, due to the inherent high brittleness of thermosetting composites, coupled with problems such as die adhesion and fiber jamming that may occur during the curing process, there are great risks in the demolding process. The existing die systems generally lack the real-time force monitoring function and cannot timely sense the abnormal force conditions during the demolding process. When local sticking or fiber jamming occurs, the jacking system will still continue to apply force, which is extremely easy to generate microcracks or cause fiber breakage inside the part. More seriously, due to the possible uneven force of the multi-jack system, this uncontrollable jacking process may also cause overall deformation or local damage of the part. These problems not only increase the scrap rate but also greatly increase the subsequent repair cost. Especially for high-value components in the aerospace field, the economic losses caused are more significant. Summary of the Invention

[0003] The object of the present invention is to provide a composite stringer forming die and a forming method, so as to solve at least the problems of inability to monitor the demolding jacking force in real time and easy occurrence of edge fiber distortion and interlayer slip proposed in the prior art.

[0004] To achieve the above object, the present invention provides the following technical solutions: A composite stringer forming die and a forming method, including: a molding press, a jacking cavity, a clamping cavity, a positioning mechanism, a molding mechanism, and a jacking mechanism. The bottom end of the inner cavity of the molding press is provided with a jacking cavity, and clamping cavities communicating with its inner cavity are respectively provided on the left and right sides of the molding press. The positioning mechanism is arranged in the inner cavity of the clamping cavity, the molding mechanism is arranged at the top end of the inner cavity of the molding press, and the jacking mechanism is arranged in the inner cavity of the jacking cavity; The molding mechanism includes: four third guide rods, a positioning plate, extrusion grooves, a clamping component, several fourth guide rods, an upper mold, a pre-pressing component, and a full-pressing component. The number of the third guide rods is four, and the upper and lower ends of the four third guide rods are respectively arranged at the four corners of the upper and lower sides of the inner cavity of the molding press. The four corners of the positioning plate are respectively slidably and fittingly sleeved on the outer walls of the tops of the four third guide rods. A plurality of extrusion grooves are respectively arranged on the left and right sides of the positioning plate. The clamping component is arranged in the inner cavity of the extrusion groove. The position of the positioning plate can be fixed by the cooperation of the clamping component and the positioning mechanism. The number of the fourth guide rods is several, and the outer wall tops of the several fourth guide rods are respectively slidably and fittingly inserted into the left and right sides of the positioning plate in equal amounts. The left and right sides of the top end of the upper mold are respectively arranged at the bottom ends of the several fourth guide rods. A plurality of storage holes are arranged at the top end of the upper mold. The pre-pressing component is slidably sleeved on the outer wall of the fourth guide rod, and the full-pressing component is slidably sleeved on the outer wall of the fourth guide rod.

[0005] Preferably, the clamping component includes: a first spring and a second clamping block. The first spring is embedded in the inner cavity of the extrusion groove. One end of the first spring is clamped to the inner wall of the extrusion groove. A part of the second clamping block is slidably embedded in the inner cavity of the extrusion groove, and the other part of the second clamping block extends out of the inner cavity of the extrusion groove in a slidable manner. The other end of the first spring is clamped to the outer wall of the second clamping block.

[0006] Preferably, the pre-pressing component includes: pressure sensors, pressing sheets, and second springs. The number of the pressure sensors is several, and the several pressure sensors are respectively arranged on the left and right sides of the bottom end of the positioning plate in equal amounts. The pressure sensors are slidably sleeved on the outer wall of the fourth guide rod. The pressing sheets are slidably sleeved on the outer wall of the fourth guide rod. The top end of the pressing sheet is in contact with the bottom end of the pressure sensor. The second springs are sleeved on the outer wall of the fourth guide rod. One end of the second spring is clamped to the outer wall of the fourth guide rod, and the other end of the second spring is clamped to the bottom end of the pressing sheet.

[0007] Preferably, the full-pressure assembly includes: a first hydraulic cylinder, a pressing plate, a plugging rod, a sleeve, a first electromagnet, a connecting column, and a second electromagnet. The number of the first hydraulic cylinders is several, and several of the first hydraulic cylinders are respectively arranged equidistantly in the left-right direction at the top of the molding press. The bottom end of the first hydraulic cylinder extends into the inner cavity of the molding press. The positioning plate is slidably sleeved on the outer wall of the first hydraulic cylinder. The left and right sides of the pressing plate are respectively slidably sleeved on the outer walls of several fourth guide rods. The bottom end of the first hydraulic cylinder is arranged on the top of the pressing plate. The number of the plugging rods is several, and several of the plugging rods are all arranged at the bottom of the pressing plate. The positions of several of the plugging rods correspond to the positions of several receiving holes one by one, and the outer diameter of the plugging rod matches the inner diameter of the receiving hole. The number of the sleeves is two, and the two sleeves are respectively arranged on the left and right sides at the bottom of the positioning plate. The first electromagnet is arranged at the top end of the inner cavity of the sleeve. The number of the connecting columns is two, and the two connecting columns are respectively arranged on the left and right sides at the top of the pressing plate. The connecting column is slidably inserted into the inner cavity of the sleeve. The second electromagnet is arranged at the top end of the connecting column. The second electromagnet and the first electromagnet are magnetically attracted to each other. The second electromagnet and the first electromagnet are both electrically connected to the pressure sensor.

[0008] Preferably, the positioning mechanism includes: a first guide rod, a sliding plate, a first clamping block, a driving rod, a bracket, and a lifting assembly. The number of the first guide rods is eight, and the left and right ends of the eight first guide rods are respectively arranged at the four corners on the left and right sides of the inner cavities of two clamping cavities. The number of the sliding plates is two, and the four corners of the two sliding plates are respectively slidably sleeved on the inner sides of the outer walls of the eight first guide rods. Several driving grooves penetrating through from front to back are equidistantly arranged in the inclined direction from top to bottom on the front side of the sliding plate. The number of the first clamping blocks is several, and several of the first clamping blocks are respectively arranged equidistantly in the up-down direction on the inner sides of the two sliding plates. The first clamping block is slidably extended into the inner cavity of the molding press. The second clamping block matches the first clamping block. The middle part of the outer wall of the driving rod is slidably and adaptively inserted into the outer side of the inner cavity of the driving groove. The left and right ends of several of the driving rods are respectively arranged equidistantly in the up-down direction on the left and right sides of the inner cavity of the bracket. The lifting assembly is arranged at the bottom end of the inner cavity of the clamping cavity. By using the lifting assembly, the bracket can be driven to drive the driving rod to move up and down.

[0009] Preferably, the jacking mechanism includes: a positioning cylinder, a support rod, a jacking plate, a rotating rod, a gear, a second hydraulic cylinder, a lower mold, a jacking hole and a jacking positioning component. The number of the positioning cylinders is two, and the two positioning cylinders are respectively arranged on the left and right sides of the bottom end of the inner cavity of the jacking cavity. The support rod is slidably and adaptively inserted into the inner cavity of the positioning cylinder. The top end of the support rod extends out of the top end of the positioning cylinder in a slidable manner. The left and right sides of the bottom end of the jacking plate are respectively arranged at the top ends of the two support rods. The left and right sides of the outer wall of the rotating rod are respectively rotatably arranged at the bottom end of the inner cavity of the jacking cavity through bearings. The number of the gears is two, and the two gears are respectively sleeved on the left and right sides of the outer wall of the rotating rod and locked by set screws. The two gears are respectively meshed with the two support rods. The second hydraulic cylinder is arranged in the middle of the bottom end of the inner cavity of the jacking cavity. The top end of the second hydraulic cylinder is arranged in the middle of the bottom end of the jacking plate. The lower mold is arranged at the bottom end of the inner cavity of the molding press. The position of the lower mold corresponds to and matches the position of the upper mold. A plurality of jacking holes penetrating up and down are formed in the top end of the lower mold. The positions of the plurality of jacking holes correspond to the positions of the plurality of receiving holes one by one, and the inner diameters are the same. The jacking plate is slidably and adaptively inserted into the inner cavity of the lower mold. The jacking positioning component is arranged in the inner cavity of the jacking plate.

[0010] Preferably, the jacking and positioning assembly includes: positioning pins, third springs, induction blocks, support frames, first infrared sensors, second infrared sensors, first infrared receivers, and second infrared receivers. The number of the positioning pins is several, and the several positioning pins are equally divided into several groups. The several groups of positioning pins are respectively arranged at equal intervals in the inner cavity of the jacking plate in the left-right direction. In each group, the several positioning pins are respectively arranged at equal intervals in the inner cavity of the jacking plate in the front-back direction. The positions of the several positioning pins respectively correspond to the positions of the several jacking holes one by one. The top end of the positioning pin slidably extends out of the top end of the jacking plate. The top end of the positioning pin slidably penetrates the inner cavity of the jacking hole and extends out of the top end of the lower mold. The outer diameter of the positioning pin is the same as the outer diameter of the plugging rod. The third spring is sleeved on the outer wall of the positioning pin. The bottom end of the third spring is clamped on the outer wall of the positioning pin. The top end of the third spring is clamped on the top end of the inner cavity of the jacking plate. The induction block is arranged at the bottom end of the positioning pin. The support frame is arranged at the top end of the inner cavity of the jacking plate. The several positioning pins are all located in the inner cavity of the support frame. The number of the first infrared sensors is several. The several first infrared sensors are respectively arranged at equal intervals in the front side of the inner cavity of the support frame in the left-right direction. The positions of the several first infrared sensors respectively correspond to the positions of the several groups of positioning pins one by one. The position of the first infrared sensor is below the induction block. The number of the first infrared receivers is several. The several first infrared receivers are respectively arranged at equal intervals in the rear side of the inner cavity of the support frame in the left-right direction. The positions of the several first infrared receivers respectively correspond to the positions of the several first infrared sensors one by one and are matched with each other. The number of the second infrared sensors is several. The several second infrared sensors are respectively arranged at equal intervals in the right side of the inner cavity of the support frame in the front-back direction. The positions of the several second infrared sensors respectively correspond to the positions of the several positioning pins in each group one by one. The position of the second infrared sensor is below the induction block. The number of the second infrared receivers is several. The several second infrared receivers are respectively arranged at equal intervals in the left side of the inner cavity of the support frame in the front-back direction. The positions of the several second infrared receivers respectively correspond to the positions of the several second infrared sensors one by one and are matched with each other.

[0011] A composite material stringer forming die and forming method proposed by the present invention have the beneficial effects that: 1. In the present invention, the positioning pins can physically restrict the positions of the fibers in the multi-layer prepregs laid on the lower mold. The upper and lower layer fibers are aligned through the shared positioning pin holes to avoid interlayer misalignment, ensure that they maintain the designed angles, and the upper mold can pre-press the prepregs on the lower mold. The second spring can maintain the pressure on the upper mold to ensure that the pressure exerted by the upper mold on the prepregs is constant. During the low-pressure pre-pressing stage, the fiber layers are initially fixed, the resin slowly infiltrates the fibers, reducing the transverse flow shear force. The resin viscosity decreases with the temperature gradient, and the flow stress is gently released. At the same time, the positioning pins are used to position the fiber layers, thus preventing defects such as edge fiber distortion and interlayer slip.

[0012] 2. After the pre-pressing of the present invention is completed, the positioning pins are urged to retract into the inner cavity of the jacking holes, and the upper mold is pressurized by the first hydraulic cylinder and the pressing plate. Thus, the upper mold can perform full pressing on the multi-layer prepregs laid on the lower mold and heat them to cause the thermosetting resin of the multi-layer prepregs laid on the lower mold to solidify and be molded by pressing.

[0013] 3. After the composite stringer is molded by pressing in the present invention, the jacking plate drives the positioning pins to move upward. Thus, the positioning pins can be used to jack up and demold the molded composite stringer. When problems such as mold adhesion and fiber jamming exist in the molded composite stringer, the positioning pins at that place will be squeezed to move into the inner cavity of the jacking plate, thereby driving the corresponding induction blocks to move into the inner cavity of the jacking plate. The coordinates of the positioning pins are located by the cooperation between the first infrared sensor, the second infrared sensor, the first infrared receiver, and the second infrared receiver, and then manual intervention is carried out for demolding treatment.

[0014] 4. This device can effectively solve the defects of edge fiber distortion and interlayer slip caused by resin flow and differences in thermal expansion coefficients in the prior art, improve the dimensional accuracy and mechanical properties of the parts. And when laying the prepregs, the positioning pins can be urged to insert through the natural gaps of the fiber bundles or woven layers to physically restrict the positions of the fibers and ensure that they maintain the designed angles. At the same time, by real-time monitoring the demolding jacking force, abnormal stress states can be identified and adjusted in a timely manner to avoid microcracks and fractures caused by mold sticking or fiber jamming, significantly reducing the scrap rate. This mold system can achieve precise control of the hot pressing process and safety protection during the demolding process, and is especially suitable for the molding requirements of high-precision and high-performance composite stringers in fields such as aerospace, with significant economic benefits and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the present invention; Figure 2 is a front view of the present invention; Figure 3 is an exploded view of the present invention; Figure 4 Schematic structural diagram of the positioning mechanism; Figure 5 Exploded view of the positioning mechanism; Figure 6 Schematic structural diagram of the molding mechanism; Figure 7 Exploded view of the molding mechanism; Figure 8 Schematic structural diagram of the sleeve; Figure 9 Schematic structural diagram of the lifting mechanism; Figure 10 Exploded view of the lifting mechanism; Figure 11 For Figure 7 Enlarged view of part A of Figure 12 For Figure 8 Enlarged view of part B of Figure 13 For Figure 10 Enlarged view of part C of Figure 14 For Figure 10 Enlarged view of part D of Figure 15 For Figure 10 Enlarged view of part E of Figure 16 For Figure 10 Enlarged view of part F of

[0016] In the figure: 1. Molding press; 2. Lifting cavity; 3. Clamping cavity; 4. Positioning mechanism; 41. First guide rod; 42. Slide plate; 43. Driving groove; 44. First clamping block; 45. Second guide rod; 46. Bracket; 47. Electric telescopic rod; 48. Driving rod; 5. Molding mechanism; 51. Third guide rod; 52. Positioning plate; 53. Extrusion groove; 54. First spring; 55. Second clamping block; 56. First hydraulic cylinder; 57. Fourth guide rod; 58. Second spring; 59. Upper mold; 510. Storage hole; 511. Pressure sensor; 512. Pressing piece; 513. Sleeve; 514. First electromagnet; 515. Pressing plate; 516. Connecting column; 517. Second electromagnet; 518. Sealing rod; 6. Lifting mechanism; 61. Positioning cylinder; 62. Support rod; 63. Lifting plate; 64. Rotating rod; 65. Gear; 66. Second hydraulic cylinder; 67. Positioning pin; 68. Third spring; 69. Induction block; 610. Support frame; 611. First infrared sensor; 612. Second infrared sensor; 613. Lower mold; 614. Lifting hole; 615. First infrared receiver; 616. Second infrared receiver. Detailed implementation manners

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0018] Please refer to Figures 1 - 16 , the present invention provides a technical solution for a composite stringer forming die and a forming method, including: a molding press 1, a lifting cavity 2, a clamping cavity 3, a positioning mechanism 4, a molding mechanism 5, and a lifting mechanism 6. A lifting cavity 2 is opened at the bottom end of the inner cavity of the molding press 1. Clamping cavities 3 communicating with its inner cavity are opened on both the left and right sides of the molding press 1. The molding press 1 is a prior art and will not be elaborated here. The positioning mechanism 4 is arranged in the inner cavity of the clamping cavity 3. The molding mechanism 5 is arranged at the top end of the inner cavity of the molding press 1. The lifting mechanism 6 is arranged in the inner cavity of the lifting cavity 2.

[0019] As a preferred solution, further, the molding mechanism 5 includes: four third guide rods 51, a positioning plate 52, a clamping assembly, a plurality of fourth guide rods 57, an upper mold 59, a receiving hole 510, a pre-pressing assembly, and a full-pressing assembly. The number of the third guide rods 51 is four. The upper and lower ends of the four third guide rods 51 are respectively arranged at the four corners of the upper and lower sides of the inner cavity of the molding press 1. The third guide rods 51 are used to limit the positioning plate 52. The four corners of the positioning plate 52 are respectively slidably and adaptively sleeved on the outer walls of the tops of the four third guide rods 51. A plurality of extrusion grooves 53 are opened on both the left and right sides of the positioning plate 52. The positioning plate 52 is used to block the second spring 58, thereby stabilizing the pressure on the upper mold 59. The clamping assembly is arranged in the inner cavity of the extrusion groove 53. The position of the positioning plate 52 can be fixed by the cooperation of the clamping assembly and the positioning mechanism 4. The number of the fourth guide rods 57 is a plurality. The tops of the outer walls of the plurality of fourth guide rods 57 are respectively slidably and adaptively inserted into both the left and right sides of the positioning plate 52 in equal amounts. The fourth guide rods 57 are used to connect the positioning plate 52 and the upper mold 59. The left and right sides of the top end of the upper mold 59 are respectively arranged at the bottom ends of the plurality of fourth guide rods 57. A plurality of receiving holes 510 are opened at the top end of the upper mold 59. The upper mold 59 is a prior art and will not be elaborated here. The upper mold 59 is internally provided with a heating device. The pre-pressing assembly is slidably sleeved on the outer wall of the fourth guide rod 57. The full-pressing assembly is slidably sleeved on the outer wall of the fourth guide rod 57; The clamping component includes: a first spring 54 and a second clamping block 55. The first spring 54 is embedded in the inner cavity of the extrusion groove 53. One end of the first spring 54 is clamped to the inner wall of the extrusion groove 53. The first spring 54 is a torsion spring, which undergoes elastic deformation when subjected to external extrusion or stretching and returns to its initial state after the external force is removed. The first spring 54 is used here to push the second clamping block 55 out of the inner cavity of the extrusion groove 53. A part of the second clamping block 55 is slidably embedded in the inner cavity of the extrusion groove 53, and the other part of the second clamping block 55 extends out of the inner cavity of the extrusion groove 53 in a slidable manner. The other end of the first spring 54 is clamped to the outer wall of the second clamping block 55; The preloading component includes: a pressure sensor 511, a pressing piece 512, and a second spring 58. The number of pressure sensors 511 is several. Several pressure sensors 511 are respectively and equally arranged on the left and right sides of the bottom end of the positioning plate 52. The pressure sensor 511 is slidably sleeved on the outer wall of the fourth guide rod 57. The pressure sensor 511 is a prior art and will not be elaborated here. The pressure sensor 511 is used here to monitor the pressure exerted by the upper die 59 on the prepreg. The pressing piece 512 is slidably sleeved on the outer wall of the fourth guide rod 57. The top end of the pressing piece 512 is in contact with the bottom end of the pressure sensor 511. The pressing piece 512 is used to press the pressure sensor 511. The second spring 58 is sleeved on the outer wall of the fourth guide rod 57. One end of the second spring 58 is clamped to the outer wall of the fourth guide rod 57, and the other end of the second spring 58 is clamped to the bottom end of the pressing piece 512. The second spring 58 is a torsion spring, which undergoes elastic deformation when subjected to external extrusion or stretching and returns to its initial state after the external force is removed. The second spring 58 is used here to increase the pressure exerted by the upper die 59 on the prepreg; The full-pressure assembly includes: a first hydraulic cylinder 56, a pressing plate 515, a plugging rod 518, a sleeve 513, a first electromagnet 514, a connecting column 516, and a second electromagnet 517. The number of the first hydraulic cylinders 56 is several, and several first hydraulic cylinders 56 are respectively arranged at equal intervals in the left-right direction on the top of the molding press 1. The bottom end of the first hydraulic cylinder 56 extends into the inner cavity of the molding press 1. The positioning plate 52 is slidably sleeved on the outer wall of the first hydraulic cylinder 56. The first hydraulic cylinder 56 is a prior art and will not be elaborated here. The first hydraulic cylinder 56 is used to drive the pressing plate 515 to move. The left and right sides of the pressing plate 515 are respectively slidably sleeved on the outer walls of several fourth guide rods 57. The bottom end of the first hydraulic cylinder 56 is arranged on the top of the pressing plate 515. The number of the plugging rods 518 is several, and several plugging rods 518 are all arranged at the bottom of the pressing plate 515. The positions of several plugging rods 518 correspond to the positions of several receiving holes 510 one by one, and the outer diameter of the plugging rod 518 matches the inner diameter of the receiving hole 510. The plugging rod 518 is used to close the inner cavity of the receiving hole 510. The number of the sleeves 513 is two, and the two sleeves 513 are respectively arranged on the left and right sides at the bottom of the positioning plate 52. The first electromagnet 514 is arranged at the top end of the inner cavity of the sleeve 513. The number of the connecting columns 516 is two, and the two connecting columns 516 are respectively arranged on the left and right sides at the top of the pressing plate 515. The connecting column 516 is slidably inserted into the inner cavity of the sleeve 513. The second electromagnet 517 is arranged at the top end of the connecting column 516. The second electromagnet 517 and the first electromagnet 514 are magnetically attracted to each other. The second electromagnet 517 and the first electromagnet 514 are both electrically connected to the pressure sensor 511. The first electromagnet 514 and the second electromagnet 517 are both prior arts and will not be elaborated here. The cooperation between the first electromagnet 514 and the second electromagnet 517 here can make the tablet 512 and the positioning plate 52 connected together.

[0020] As a preferred solution, further, the positioning mechanism 4 includes: a first guide rod 41, a slide plate 42, a drive groove 43, a first clamping block 44, a bracket 46, a drive rod 48, and a lifting assembly. The number of the first guide rods 41 is eight, and the left and right ends of the eight first guide rods 41 are respectively arranged at the four corners on the left and right sides of the inner cavity of the two clamping cavities 3. The number of the slide plates 42 is two, and the four corners of the two slide plates 42 are respectively slidably sleeved on the inner sides of the outer walls of the eight first guide rods 41. A plurality of drive grooves 43 penetrating through from front to back are arranged at equal intervals in the inclined direction from top to bottom on the front side of the slide plate 42. The number of the first clamping blocks 44 is several, and the several first clamping blocks 44 are respectively arranged at equal intervals in the vertical direction on the inner sides of the two slide plates 42. The first clamping blocks 44 can slidably extend into the inner cavity of the die press 1. The second clamping block 55 is matched with the first clamping block 44, and the position of the positioning plate 52 can be fixed by the cooperation between the second clamping block 55 and the first clamping block 44. The middle part of the outer wall of the drive rod 48 is slidably and adaptively inserted into the outer side of the inner cavity of the drive groove 43. The left and right ends of the several drive rods 48 are respectively arranged at equal intervals in the vertical direction on the left and right sides of the inner cavity of the bracket 46. The lifting assembly is arranged at the bottom end of the inner cavity of the clamping cavity 3, and the lifting assembly can drive the bracket 46 to drive the drive rod 48 to move up and down; The lifting assembly includes: a second guide rod 45 and an electric telescopic rod 47. The number of the second guide rods 45 is four, and the four second guide rods 45 are respectively arranged at the bottom ends of the front and back sides of the inner cavity of the two clamping cavities 3. The bracket 46 is slidably sleeved on the outer wall of the second guide rod 45. The number of the electric telescopic rods 47 is two, and the two electric telescopic rods 47 are respectively arranged at the middle parts of the bottom ends of the inner cavities of the two clamping cavities 3. The top ends of the two electric telescopic rods 47 are respectively arranged at the middle parts of the bottom ends of the two brackets 46. The electric telescopic rod 47 is a prior art and will not be elaborated here too much. The electric telescopic rod 47 is used here to push the bracket 46 to move up and down.

[0021] As a preferred solution, further, the lifting mechanism 6 includes: a positioning cylinder 61, a support rod 62, a lifting plate 63, a rotating rod 64, a gear 65, a second hydraulic cylinder 66, a lower mold 613, a lifting hole 614, and a lifting positioning assembly. The number of positioning cylinders 61 is two, and the two positioning cylinders 61 are respectively arranged on the left and right sides of the bottom end of the inner cavity of the lifting cavity 2. The support rod 62 is slidably and adaptively inserted into the inner cavity of the positioning cylinder 61, and the top end of the support rod 62 extends out of the top end of the positioning cylinder 61 slidably. The left and right sides of the bottom end of the lifting plate 63 are respectively arranged at the top ends of the two support rods 62. The left and right sides of the outer wall of the rotating rod 64 are respectively rotatably arranged at the bottom end of the inner cavity of the lifting cavity 2 through bearings. The number of gears 65 is two, and the two gears 65 are respectively sleeved on the left and right sides of the outer wall of the rotating rod 64 and locked by set screws. The two gears 65 are respectively meshed with the two support rods 62. The cooperation between the gear 65 and the support rod 62 can promote the synchronous lifting of the left and right sides of the lifting plate 63. The second hydraulic cylinder 66 is arranged in the middle of the bottom end of the inner cavity of the lifting cavity 2, and the top end of the second hydraulic cylinder 66 is arranged in the middle of the bottom end of the lifting plate 63. The second hydraulic cylinder 66 is a prior art and will not be elaborated here. The second hydraulic cylinder 66 is used to push the lifting plate 63 to move up and down. The lower mold 613 is arranged at the bottom end of the inner cavity of the molding press 1. The position of the lower mold 613 corresponds to and matches the position of the upper mold 59. A plurality of vertically penetrating lifting holes 614 are opened at the top end of the lower mold 613. The positions of the plurality of lifting holes 614 correspond to the positions of the plurality of receiving holes 510 one by one and have the same inner diameter. The lifting plate 63 is slidably and adaptively inserted into the inner cavity of the lower mold 613. The lower mold 613 is a prior art and will not be elaborated here. The lower mold 613 is internally provided with a heating device. The lifting positioning assembly is arranged in the inner cavity of the lifting plate 63; The jacking and positioning assembly includes: positioning pins 67, third springs 68, induction blocks 69, support frames 610, first infrared sensors 611, second infrared sensors 612, first infrared receivers 615, and second infrared receivers 616. The number of positioning pins 67 is several. The several positioning pins 67 are equally divided into several groups. The several groups of positioning pins 67 are respectively arranged at equal intervals in the inner cavity of the jacking plate 63 in the left-right direction. The several positioning pins 67 in each group are respectively arranged at equal intervals in the inner cavity of the jacking plate 63 in the front-back direction. The positions of the several positioning pins 67 respectively correspond to the positions of the several jacking holes 614 one by one. The top end of the positioning pin 67 slidably extends out of the top end of the jacking plate 63. The top end of the positioning pin 67 slidably penetrates through the inner cavity of the jacking hole 614 and extends out of the top end of the lower mold 613. The outer diameter of the positioning pin 67 is the same as the outer diameter of the plugging rod 518. The positioning pin 67 is used to position the fiber layer of the composite material and demold the formed composite material. The third spring 68 is sleeved on the outer wall of the positioning pin 67. The bottom end of the third spring 68 is clamped to the outer wall of the positioning pin 67. The top end of the third spring 68 is clamped to the top end of the inner cavity of the jacking plate 63. The third spring 68 is a torsion spring. It undergoes elastic deformation when subjected to external force extrusion or stretching and returns to its initial state after the external force is removed. The third spring 68 is used here to support the positioning pin 67. The induction block 69 is arranged at the bottom end of the positioning pin 67. The support frame 610 is arranged at the top end of the inner cavity of the jacking plate 63. The several positioning pins 67 are all located in the inner cavity of the support frame 610. The number of first infrared sensors 611 is several. The several first infrared sensors 611 are respectively arranged at equal intervals in the front side of the inner cavity of the support frame 610 in the left-right direction. The positions of the several first infrared sensors 611 respectively correspond to the positions of the several groups of positioning pins 67 one by one. The position of the first infrared sensor 611 is below the induction block 69. The first infrared sensor 611 is a prior art and will not be elaborated here. The number of first infrared receivers 615 is several. The several first infrared receivers 615 are respectively arranged at equal intervals in the rear side of the inner cavity of the support frame 610 in the left-right direction. The positions of the several first infrared receivers 615 respectively correspond to the positions of the several first infrared sensors 611 one by one and are matched. The first infrared receiver 615 is a prior art and will not be elaborated here. The number of second infrared sensors 612 is several. The several second infrared sensors 612 are respectively arranged at equal intervals in the right side of the inner cavity of the support frame 610 in the front-back direction. The positions of the several second infrared sensors 612 respectively correspond to the positions of the several positioning pins 67 in each group one by one. The position of the second infrared sensor 612 is below the induction block 69. The second infrared sensor 612 is a prior art and will not be elaborated here. The number of second infrared receivers 616 is several. The several second infrared receivers 616 are respectively arranged at equal intervals in the left side of the inner cavity of the support frame 610 in the front-back direction. The positions of the several second infrared receivers 616 respectively correspond to the positions of the several second infrared sensors 612 one by one and are matched.The second infrared receiver 616 is a prior art and will not be elaborated here. The cooperation among the second infrared receiver 616, the first infrared receiver 615, the second infrared sensor 612, and the first infrared sensor 611 can locate the coordinates of problems such as mold adhesion and fiber jamming in the composite material.

[0022] The working principle includes the following steps: Step 1: First, lay multiple layers of prepregs, such as carbon fiber / epoxy resin, on the top of the lower mold 613, and prompt the positioning pins 67 to insert into the natural gaps of the fiber bundles or woven layers, thereby physically restricting the positions of the fibers. The upper and lower layer fibers are aligned through the holes of the common positioning pins 67 to avoid interlayer misalignment and ensure that they maintain the designed angles. After the prepreg laying is completed, start the first hydraulic cylinder 56, and use the first hydraulic cylinder 56 to push the pressing plate 515 downward. The downward movement of the pressing plate 515 uses the cooperation between the first electromagnet 514 and the second electromagnet 517 to prompt the connecting column 516 to drive the positioning plate 52 downward through the sleeve 513. The downward movement of the positioning plate 52 uses the self-gravity of the upper mold 59 to move downward. At the same time, when the positioning plate 52 moves downward, the first block 44 is used to squeeze the second block 55 to move into the inner cavity of the extrusion groove 53 and squeeze the first spring 54 to generate elastic deformation until the second block 55 and the first block 44 are separated, which can prompt the positioning plate 52 to move downward. After the bottom end of the upper mold 59 contacts the prepreg on the top of the lower mold 613, at this time, the positioning pins 67 are inserted into the inner cavity of the receiving hole 510, and the first hydraulic cylinder 56 continues to push the pressing plate 515 downward, thereby driving the positioning plate 52 downward. Since the prepreg on the top of the lower mold 613 is used to block the upper mold 59 at this time, the downward movement of the positioning plate 52 can squeeze the second spring 58 to generate elastic deformation. The elastic deformation of the second spring 58 can use the elastic force of the second spring 58 to increase the pressure applied by the upper mold 59 to the prepreg. At the same time, the elastic force of the second spring 58 is used to push the pressing piece 512 upward and squeeze the pressure sensor 511. By reading the value displayed by the pressure sensor 511, the pressure applied by the upper mold 59 to the prepreg can be reflected. Until the upper mold 59 applies an appropriate pressure value to the prepreg, turn off the first hydraulic cylinder 56 for pre-pressing the prepreg. At this time, under the elastic force of the first spring 54, the second block 55 can be pushed out of the inner cavity of the extrusion groove 53 and cooperate with the first block 44 to fix the position of the positioning plate 52. At this time, start the heating devices of the lower mold 613 and the upper mold 59 to preheat the prepreg; Step 2: During the low-pressure pre-pressing stage, initially fix the fiber layer, slowly infiltrate the resin into the fiber, reduce the transverse flow shear force, the resin viscosity decreases with the temperature gradient, and the flow stress is gently released. At the same time, use the positioning pins 67 to position the fiber layer, so as to prevent defects such as edge fiber distortion and interlayer slip. After pre-pressing and pre-heating for a period of time, start the second hydraulic cylinder 66 to drive the lifting plate 63 to move downward. When the lifting plate 63 moves downward, it can drive the positioning pins 67 to move downward until the positioning pins 67 completely move into the inner cavity of the lifting holes 614. At this time, turn off the first electromagnet 514 and the second electromagnet 517, and the magnetism of the first electromagnet 514 and the second electromagnet 517 disappears. Start the first hydraulic cylinder 56 to continue pushing the pressing plate 515 downward. Since the magnetism of the first electromagnet 514 and the second electromagnet 517 disappears at this time, when the pressing plate 515 moves downward, it will not drive the positioning plate 52 to move downward. At the same time, since the position of the positioning plate 52 is fixed, under the elastic force of the second spring 58, it can ensure that the pressure applied by the upper mold 59 to the prepreg is constant until the pressing plate 515 contacts the upper mold 59. At this time, the plugging rod 518 is inserted into the inner cavity of the storage hole 510 to block the inner cavity of the storage hole 510, and use the first hydraulic cylinder 56 to apply pressure to the pressing plate 515. Thus, the pressure of the pressing plate 515 is transmitted to the prepreg through the upper mold 59, and then heat and full pressure are applied to the prepreg; Step 3: After the thermosetting resin on the prepreg solidifies, start the lifting assembly to drive the bracket 46 to move upward. When the bracket 46 moves upward, it drives the driving rod 48 to move upward. The upward movement of the driving rod 48 cooperates with the driving groove 43 to cause the sliding plate 42 to drive the first latch 44 to move outward until the first latch 44 and the second latch 55 are separated, thereby releasing the positioning of the positioning plate 52. Under the elastic force of the second spring 58, it can push the positioning plate 52 to move upward until the second spring 58 returns to its initial state. Start the first hydraulic cylinder 56 to drive the pressing plate 515 to move upward until the connecting column 516 is inserted into the inner cavity of the sleeve 513. Start the first electromagnet 514 and the second electromagnet 517, and the first electromagnet 514 and the second electromagnet 517 attract each other magnetically. Thus, when the pressing plate 515 continues to move upward, it can drive the positioning plate 52 to move upward through the cooperation between the connecting column 516 and the sleeve 513. When the positioning plate 52 moves upward, it can drive the upper mold 59 to move upward through the fourth guide rod 57 until it returns to the initial position; Step 4. At this time, the molded composite stringer is stored at the top of the lower mold 613. Since the natural gaps between the fiber bundles and the braided layers of the composite stringer are filled with the solidified thermosetting resin, the second hydraulic cylinder 66 is then activated to push the lifting plate 63 upward. In this way, the positioning pins 67 can be driven by the lifting plate 63 to move upward out of the inner cavity of the lifting holes 614. At the same time, the cooperation between the support rod 62 and the gear 65 is used to ensure that the lifting plate 63 rises synchronously left and right, so as to ensure the synchronous movement of several positioning pins 67, preventing the size deviation caused by the inclination of the composite stringer due to asynchronous lifting, or even tearing the ply. Thus, the upward-moving positioning pins 67 are used to lift and demold the formed composite stringer stored at the top of the lower mold 613. When there are problems such as mold adhesion and fiber jamming in the composite stringer, the resistance applied by the positioning pins 67 at the corresponding points will increase. As the lifting plate 63 moves upward, it will cause the positioning pins 67 at the corresponding points not to move upward with the lifting plate 63. Therefore, compared with the lifting plate 63, the positioning pins 67 at the corresponding points move downward, stretching the third spring 68 to produce elastic deformation. The downward movement of the positioning pins 67 at the corresponding points compared with the lifting plate 63 can drive the corresponding induction blocks 69 downward. When the induction blocks 69 move to the positions of the first infrared sensor 611 and the second infrared sensor 612, the induction blocks 69 will block the light of one first infrared sensor 611 and the light of one second infrared sensor 612 respectively, resulting in the first infrared receiver 615 and the second infrared receiver 616 corresponding to them being unable to receive the infrared signal. At this time, according to the coordinates of the induction blocks 69, the positions of mold adhesion and fiber jamming in the composite stringer can be judged, and then manual intervention can be carried out for treatment.

[0023] In summary, the present device can effectively solve the defects of edge fiber distortion and interlayer slip caused by resin flow and different thermal expansion coefficients in the prior art, improve the dimensional accuracy and mechanical properties of the parts. And when laying the prepreg, the positioning pins are promoted to insert into the natural gaps between the fiber bundles or the braided layers, physically restricting the positions of the fibers to ensure that they maintain the designed angles. At the same time, by real-time monitoring of the demolding lifting force, abnormal stress states can be identified and adjusted in time, avoiding microcracks and fracture problems caused by mold sticking or fiber jamming, and greatly reducing the scrap rate. This mold system can achieve precise control of the hot pressing forming process and safety protection of the demolding process, especially suitable for the forming requirements of high-precision and high-performance composite stringers in the fields of aerospace and the like, with significant economic benefits and application values.

[0024] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirits of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A forming die for a composite stringer, characterized in that, Including: A molding press (1), a jacking cavity (2) is provided at the bottom end of the inner cavity of the molding press (1), and clamping cavities (3) communicating with the inner cavity are provided on both the left and right sides of the molding press (1); A positioning mechanism (4), which is arranged in the inner cavity of the clamping cavity (3); A molding mechanism (5), which is arranged at the top end of the inner cavity of the molding press (1); A jacking mechanism (6), which is arranged in the inner cavity of the jacking cavity (2); The molding mechanism (5) includes: Four third guide rods (51), the upper and lower ends of the four third guide rods (51) are respectively arranged at the four corners of the upper and lower sides of the inner cavity of the molding press (1); A positioning plate (52), the four corners of the positioning plate (52) are respectively slidably and adaptively sleeved on the outer walls of the tops of the four third guide rods (51), and a plurality of extrusion grooves (53) are provided on both the left and right sides of the positioning plate (52); A clamping assembly, which is arranged in the inner cavity of the extrusion groove (53), and the position of the positioning plate (52) can be fixed by the cooperation of the clamping assembly and the positioning mechanism (4); A plurality of fourth guide rods (57), the outer wall tops of the plurality of fourth guide rods (57) are respectively slidably and adaptively inserted into both the left and right sides of the positioning plate (52) in equal amounts; An upper mold (59), the left and right sides of the top end of the upper mold (59) are respectively arranged at the bottom ends of the plurality of fourth guide rods (57), and a plurality of storage holes (510) are provided at the top end of the upper mold (59); A pre-pressing assembly, which is slidably sleeved on the outer wall of the fourth guide rod (57); A full-pressing assembly, which is slidably sleeved on the outer wall of the fourth guide rod (57).

2. The composite stringer forming die according to claim 1, wherein, The clamping assembly includes: A first spring (54), which is embedded in the inner cavity of the extrusion groove (53), and one end of the first spring (54) is clamped to the inner wall of the extrusion groove (53); A second clamping block (55), a part of the second clamping block (55) is slidably embedded in the inner cavity of the extrusion groove (53), and the other part of the second clamping block (55) extends out of the inner cavity of the extrusion groove (53) slidably, and the other end of the first spring (54) is clamped to the outer wall of the second clamping block (55).

3. The composite stringer forming die according to claim 2, wherein, The pre-pressing assembly includes: A plurality of pressure sensors (511), the plurality of pressure sensors (511) are respectively arranged on the left and right sides of the bottom end of the positioning plate (52) in equal amounts, and the pressure sensors (511) are slidably sleeved on the outer wall of the fourth guide rod (57); A pressing piece (512), which is slidably sleeved on the outer wall of the fourth guide rod (57), and the top end of the pressing piece (512) is in contact with the bottom end of the pressure sensor (511); Second spring (58), the second spring (58) is sleeved on the outer wall of the fourth guide rod (57), one end of the second spring (58) is clamped on the outer wall of the fourth guide rod (57), and the other end of the second spring (58) is clamped on the bottom end of the pressing piece (512).

4. The composite stringer forming die according to claim 3, characterized in that, The full-pressure assembly includes: First hydraulic cylinders (56), the number of the first hydraulic cylinders (56) is several, and several of the first hydraulic cylinders (56) are respectively arranged at equal intervals in the left-right direction on the top end of the molding press (1), the bottom end of the first hydraulic cylinder (56) extends into the inner cavity of the molding press (1), and the positioning plate (52) is slidably sleeved on the outer wall of the first hydraulic cylinder (56); Pressing plate (515), the left and right sides of the pressing plate (515) are respectively slidably sleeved on the outer walls of several fourth guide rods (57), and the bottom end of the first hydraulic cylinder (56) is arranged on the top end of the pressing plate (515); Blocking rods (518), the number of the blocking rods (518) is several, and several of the blocking rods (518) are all arranged at the bottom end of the pressing plate (515), the positions of several of the blocking rods (518) correspond to the positions of several receiving holes (510) one by one, and the outer diameter of the blocking rod (518) matches the inner diameter of the receiving hole (510); Sleeves (513), the number of the sleeves (513) is two, and two of the sleeves (513) are respectively arranged on the left and right sides at the bottom end of the positioning plate (52); First electromagnet (514), the first electromagnet (514) is arranged at the top end inside the sleeve (513); Connecting columns (516), the number of the connecting columns (516) is two, and two of the connecting columns (516) are respectively arranged on the left and right sides at the top end of the pressing plate (515), and the connecting columns (516) are slidably inserted into the inner cavity of the sleeve (513); Second electromagnet (517), the second electromagnet (517) is arranged at the top end of the connecting column (516), the second electromagnet (517) and the first electromagnet (514) are magnetically attracted to each other, and the second electromagnet (517) and the first electromagnet (514) are both electrically connected to the pressure sensor (511).

5. The composite stringer forming die according to claim 4, characterized in that, The positioning mechanism (4) includes: First guide rods (41), the number of the first guide rods (41) is eight, and the left and right ends of the eight first guide rods (41) are respectively arranged at the four corners on the left and right sides inside the inner cavities of the two clamping cavities (3); Sliding plates (42), the number of the sliding plates (42) is two, the four corners of the two sliding plates (42) are respectively slidably sleeved on the inner sides of the outer walls of the eight first guide rods (41), and several driving grooves (43) running through from front to back are arranged at equal intervals in the inclined direction from top to bottom on the front side of the sliding plate (42); First clamping blocks (44), the number of the first clamping blocks (44) is several, and several of the first clamping blocks (44) are respectively arranged at equal intervals in the up-down direction on the inner sides of the two sliding plates (42), the first clamping blocks (44) are slidably extended into the inner cavity of the molding press (1), and the second clamping block (55) matches the first clamping block (44); The driving rod (48), the middle part of the outer wall of the driving rod (48) is slidably and adaptively inserted into the outer side of the inner cavity of the driving groove (43); The bracket (46), the left and right ends of several driving rods (48) are respectively arranged on the left and right sides of the inner cavity of the bracket (46) at equal intervals in the up and down direction; The lifting assembly, the lifting assembly is arranged at the bottom end of the inner cavity of the clamping cavity (3), and the lifting assembly can be used to drive the bracket (46) to drive the driving rod (48) to move up and down.

6. The composite stringer forming die according to claim 5, wherein, The jacking mechanism (6) includes: The positioning cylinders (61), the number of the positioning cylinders (61) is two, and the two positioning cylinders (61) are respectively arranged on the left and right sides of the bottom end of the inner cavity of the jacking cavity (2); The support rods (62), the support rods (62) are slidably and adaptively inserted into the inner cavity of the positioning cylinders (61), and the top ends of the support rods (62) slidably extend out of the top ends of the positioning cylinders (61); The jacking plate (63), the left and right sides of the bottom end of the jacking plate (63) are respectively arranged at the top ends of the two support rods (62); The rotating rods (64), the left and right sides of the outer walls of the rotating rods (64) are respectively rotatably arranged at the bottom end of the inner cavity of the jacking cavity (2) through bearings; The gears (65), the number of the gears (65) is two, and the two gears (65) are respectively sleeved on the left and right sides of the outer wall of the rotating rod (64) and locked by set screws, and the two gears (65) are respectively meshed with the two support rods (62); The second hydraulic cylinder (66), the second hydraulic cylinder (66) is arranged in the middle of the bottom end of the inner cavity of the jacking cavity (2), and the top end of the second hydraulic cylinder (66) is arranged in the middle of the bottom end of the jacking plate (63); The lower die (613), the lower die (613) is arranged at the bottom end of the inner cavity of the molding press (1), the position of the lower die (613) corresponds to and matches the position of the upper die (59), and a plurality of jacking holes (614) penetrating up and down are formed in the top end of the lower die (613), the positions of the plurality of jacking holes (614) correspond to the positions of the plurality of receiving holes (510) one by one and have the same inner diameter, and the jacking plate (63) is slidably and adaptively inserted into the inner cavity of the lower die (613); The jacking and positioning assembly, the jacking and positioning assembly is arranged in the inner cavity of the jacking plate (63).

7. A composite stringer forming die according to claim 6, characterized in that, The jacking and positioning assembly includes: Positioning pins (67), the number of the positioning pins (67) is several, the several positioning pins (67) are equally divided into several groups, the several groups of positioning pins (67) are respectively arranged equidistantly in the inner cavity of the lifting plate (63) along the left-right direction, and several positioning pins (67) in each group are respectively arranged equidistantly in the inner cavity of the lifting plate (63) along the front-back direction. The positions of the several positioning pins (67) respectively correspond to the positions of several lifting holes (614) one by one. The top end of the positioning pin (67) slidably extends out of the top end of the lifting plate (63). The top end of the positioning pin (67) slidably penetrates through the inner cavity of the lifting hole (614) and extends out of the top end of the lower die (613). The outer diameter of the positioning pin (67) is the same as the outer diameter of the plugging rod (518); The third spring (68), the third spring (68) is sleeved on the outer wall of the positioning pin (67), the bottom end of the third spring (68) is clamped on the outer wall of the positioning pin (67), and the top end of the third spring (68) is clamped on the top end of the inner cavity of the lifting plate (63); The induction block (69), the induction block (69) is arranged at the bottom end of the positioning pin (67); The support frame (610), the support frame (610) is arranged at the top end of the inner cavity of the lifting plate (63), and several positioning pins (67) are all located in the inner cavity of the support frame (610); The first infrared sensors (611), the number of the first infrared sensors (611) is several, the several first infrared sensors (611) are respectively arranged equidistantly in the front side of the inner cavity of the support frame (610) along the left-right direction. The positions of the several first infrared sensors (611) respectively correspond to the positions of several groups of positioning pins (67) one by one. The position of the first infrared sensor (611) is located below the induction block (69); The first infrared receivers (615), the number of the first infrared receivers (615) is several, the several first infrared receivers (615) are respectively arranged equidistantly in the rear side of the inner cavity of the support frame (610) along the left-right direction. The positions of the several first infrared receivers (615) respectively correspond to the positions of several first infrared sensors (611) one by one and are matched; The second infrared sensors (612), the number of the second infrared sensors (612) is several, the several second infrared sensors (612) are respectively arranged equidistantly in the right side of the inner cavity of the support frame (610) along the front-back direction. The positions of the several second infrared sensors (612) respectively correspond to the positions of several positioning pins (67) in each group one by one. The position of the second infrared sensor (612) is located below the induction block (69); The second infrared receivers (616), the number of the second infrared receivers (616) is several, the several second infrared receivers (616) are respectively arranged equidistantly in the left side of the inner cavity of the support frame (610) along the front-back direction. The positions of the several second infrared receivers (616) respectively correspond to the positions of several second infrared sensors (612) one by one and are matched.

8. A forming method for a composite stringer, which is applied to a composite stringer forming die as described in claim 7, characterized in that, Including the following steps: Step 1: First, lay multiple layers of prepreg on the top of the lower mold (613), and insert the positioning pins (67) into the natural gaps of the fiber bundles or woven layers, thereby physically restricting the positions of the fibers. The upper and lower layers of fibers are aligned through the holes of the common positioning pins (67). After the prepreg laying is completed, start the first hydraulic cylinder (56), and use the first hydraulic cylinder (56) to push the pressing plate (515) downward. The downward movement of the pressing plate (515) uses the cooperation between the first electromagnet (514) and the second electromagnet (517) to cause the connecting column (516) to drive the positioning plate (52) downward through the sleeve (513). The downward movement of the positioning plate (52) is caused by the self-gravity of the upper mold (59) moving downward. At the same time, when the positioning plate (52) moves downward, the first block (44) is used to squeeze the second block (55) to move into the inner cavity of the extrusion groove (53) and squeeze the first spring (54) to undergo elastic deformation until the second block (55) is separated from the first block (44), which can cause the positioning plate (52) to move downward. After the bottom end of the upper mold (59) contacts the prepreg on the top of the lower mold (613), at this time, the positioning pin (67) is inserted into the inner cavity of the receiving hole (510). The first hydraulic cylinder (56) continues to push the pressing plate (515) downward, thereby driving the positioning plate (52) downward. Since the prepreg on the top of the lower mold (613) is used to block the upper mold (59) at this time, the downward movement of the positioning plate (52) can squeeze the second spring (58) to undergo elastic deformation. The elastic deformation of the second spring (58) can use the elastic force of the second spring (58) to increase the pressure exerted by the upper mold (59) on the prepreg. At the same time, the elastic force of the second spring (58) is used to push the pressing piece (512) upward and squeeze the pressure sensor (511). By reading the value displayed by the pressure sensor (511), the pressure exerted by the upper mold (59) on the prepreg can be reflected. Until the upper mold (59) exerts an appropriate pressure value on the prepreg, close the first hydraulic cylinder (56) for pre-pressing the prepreg. At this time, under the elastic force of the first spring (54), the second block (55) can be pushed out of the inner cavity of the extrusion groove (53) and cooperate with the first block (44) to fix the position of the positioning plate (52). At this time, start the heating devices of the lower mold (613) and the upper mold (59) to preheat the prepreg; Step 2: During the low-pressure preloading stage, the fiber layer is initially fixed, the resin slowly infiltrates the fiber, reducing the transverse flow shear force. The resin viscosity decreases with the temperature gradient, and the flow stress is gently released. Meanwhile, the positioning needle (67) is used to position the fiber layer. After preloading and preheating for a period of time, the second hydraulic cylinder (66) is started to drive the lifting plate (63) to move downward. When the lifting plate (63) moves downward, it can drive the positioning needle (67) to move downward until the positioning needle (67) completely moves into the inner cavity of the lifting hole (614). At this time, the first electromagnet (514) and the second electromagnet (517) are turned off, and the magnetism of the first electromagnet (514) and the second electromagnet (517) disappears. The first hydraulic cylinder (56) is started to continue pushing the pressing plate (515) downward. Since the magnetism of the first electromagnet (514) and the second electromagnet (517) disappears at this time, the downward movement of the pressing plate (515) will not drive the positioning plate (52) to move downward. At the same time, since the position of the positioning plate (52) is fixed, the pressure applied by the upper mold (59) to the prepreg can be ensured to be constant under the elastic force of the second spring (58) until the pressing plate (515) contacts the upper mold (59). At this time, the plugging rod (518) is inserted into the inner cavity of the receiving hole (510) to block the inner cavity of the receiving hole (510), and the first hydraulic cylinder (56) is used to apply pressure to the pressing plate (515). Thus, the pressure of the pressing plate (515) is transmitted to the prepreg through the upper mold (59), and then the prepreg is heated and fully pressed; Step 3: After the thermosetting resin on the prepreg solidifies, the lifting assembly is started to drive the bracket (46) to move upward. When the bracket (46) moves upward, it drives the driving rod (48) to move upward. The upward movement of the driving rod (48) cooperates with the driving groove (43) to cause the sliding plate (42) to drive the first block (44) to move outward until the first block (44) separates from the second block (55), thereby releasing the positioning of the positioning plate (52). Under the elastic force of the second spring (58), the positioning plate (52) can be pushed upward until the second spring (58) returns to its initial state. The first hydraulic cylinder (56) is started to drive the pressing plate (515) to move upward until the connecting column (516) is inserted into the inner cavity of the sleeve (513). The first electromagnet (514) and the second electromagnet (517) are started, and the magnetism of the first electromagnet (514) and the second electromagnet (517) attracts each other. Thus, when the pressing plate (515) continues to move upward, it can drive the positioning plate (52) to move upward through the cooperation between the connecting column (516) and the sleeve (513). When the positioning plate (52) moves upward, it can drive the upper mold (59) to move upward through the fourth guide rod (57) until it returns to the initial position; Step 4. At this time, the molded composite stringer is stored at the top of the lower mold (613). Since the natural gaps between the fiber bundles and the woven layers of the composite stringer are filled with solidified thermosetting resin at this time, the second hydraulic cylinder (66) is then activated to push the lifting plate (63) upward. The lifting plate (63) can be used to drive the positioning pin (67) to move upward out of the inner cavity of the lifting hole (614). At the same time, the cooperation between the support rod (62) and the gear (65) is used to ensure that the lifting plate (63) rises synchronously left and right, so as to ensure the synchronous movement of several positioning pins (67). Thus, the molded composite stringer stored at the top of the lower mold (613) is lifted and demolded by the upward-moving positioning pins (67). When there are problems of mold adhesion and fiber jamming in the composite stringer, the resistance applied by the positioning pins (67) at the corresponding points will increase. As the lifting plate (63) moves upward, it will cause the positioning pins (67) at the corresponding points not to move upward with the lifting plate (63). Thus, compared with the lifting plate (63), the positioning pins (67) at the corresponding points move downward and stretch the third spring (68) to undergo elastic deformation. The downward movement of the positioning pins (67) at the corresponding points relative to the lifting plate (63) can drive the corresponding induction blocks (69) downward. When the induction blocks (69) move to the first infrared sensor (611) and the second infrared sensor (612), the induction blocks (69) will block the light of one first infrared sensor (611) and the light of one second infrared sensor (612) respectively, resulting in the first infrared receiver (615) and the second infrared receiver (616) corresponding to them being unable to receive infrared signals. At this time, according to the coordinates of the induction blocks (69), the positions of mold adhesion and fiber jamming in the composite stringer can be judged, and then manual intervention can be carried out for treatment.

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