A pre-forming device for a racket frame of a badminton racket and a forming process thereof

Abstract

This invention relates to the field of badminton racket manufacturing technology, specifically disclosing a badminton racket frame pre-forming equipment and its forming process. The equipment includes a pressing unit, a top support unit, and an inner mold unit. The pressing unit secures the upper and lower outer molds via a V-shaped frame. The outer mold forming surface has vacuum micropores and is connected to a vacuum generator via an air pipe penetrating the V-shaped frame. The inner mold unit includes an elastic bladder and a top cover. The top cover has symmetrically arranged contour-following support components, whose extension parts include motor-driven hollow rods. The inner cavity of the elastic bladder is divided into multiple independent pressurization zones. The top support unit has vertically movable partitions. The process involves contour-following support, hollow rod extension to form a temporary support surface, layering, retraction to retain the laminated layers, mold closing, vacuum adsorption, zoned pressurization, heating and curing, and demolding to complete the forming process. This invention effectively avoids layer adhesion, achieves differentiated pressurization, integrates support, heating, and maintenance functions, and significantly improves forming quality and equipment maintainability.

Description

Technical Field

[0001] This invention relates to the field of badminton racket manufacturing technology, specifically to a badminton racket frame preforming equipment and its forming process. Background Technology

[0002] As a high-performance sports equipment, badminton rackets are usually made of carbon fiber composite materials for their frames. The molding process directly affects the weight, strength and service life of the racket. At present, the molding process of carbon fiber badminton rackets mainly includes two stages: preforming and final hot pressing and curing. The preforming stage requires laying multiple layers of prepreg according to the design requirements and pre-shaping them so that they can be placed into the final mold for hot pressing and curing.

[0003] Currently, Chinese patent application number CN201310220948.3 discloses a method for wind-pressure-free molding of carbon fiber badminton rackets. This method involves preparing a foaming resin and coating it onto a non-woven fabric to create a foamed prepreg. The foamed prepreg is then wrapped around a carbon fiber fabric to form a preform. The preform is then placed in a mold and heated. The pressure generated by the expansion of the foamed prepreg during heating causes the carbon fiber fabric to solidify and form. This method uses the internal pressure generated by the foamed material to replace the external air pressure in the traditional wind-pressure molding process, eliminating the need for an air compressor, reducing energy consumption and exhaust pollution. At the same time, after the foamed material solidifies, it forms a sponge-like structure in the inner cavity of the racket frame, which has a certain shock absorption performance.

[0004] However, in the pre-forming process of badminton racket frames, the existing technology makes it difficult to precisely control the foaming process, resulting in poor pressure stability, uneven stress on the frame, and insufficient consistency in molding quality. Furthermore, it is inconvenient to effectively position and support the prepreg before foaming, which can easily lead to displacement and wrinkles, and the layup accuracy in areas with large curvature changes is difficult to guarantee. It is also difficult to perform differentiated pressure control for thickness differences in different parts of the frame, resulting in insufficient density in material accumulation areas such as T-joints. At the same time, equipment maintenance requires disassembling many parts, making operation inconvenient. Summary of the Invention

[0005] The purpose of this invention is to provide a badminton racket frame preforming device and its forming process to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a badminton racket frame preforming device for pre-pressing composite prepreg into a racket frame blank. The preforming device includes a pressing unit, a top support unit, an inner mold unit, a first V-shaped frame, a second V-shaped frame, an upper outer mold, a first air pipe, a lower outer mold, and a second air pipe. The pressing unit has a top support unit mounted on its top center side, and the top of the top support unit is connected to the inner mold unit. The left and right sides of the top of the pressing unit are respectively connected to the first V-shaped frame and the second V-shaped frame, used to drive the first V-shaped frame and the second V-shaped frame to perform opposite or opposite displacement movements; the first V-shaped frame… The upper outer mold is fastened to the side of the frame near the second V-frame, and the lower outer membrane is fastened to the side of the second V-frame near the first V-frame. After the upper outer mold and the lower outer membrane come into contact, their inner wall surfaces form a forming surface corresponding to the outline of the final frame blank. Vacuum micro-holes are provided circumferentially on the forming surface. The vacuum micro-holes located in the upper outer mold are connected to an external vacuum generator through a first air pipe, which is installed inside the first V-frame. The vacuum micro-holes located in the lower outer membrane are connected to an external vacuum generator through a second air pipe, which is installed inside the second V-frame.

[0008] The inner mold unit includes an inner mold base plate connected to the bottom of the top support unit. An elastic bladder is arranged around the outer surface of the inner mold base plate, and a top cover is tightly attached to the top side of the inner mold base plate. A first contouring support component is arranged on the top of the top cover near the upper outer mold, and a second contouring support component is arranged on the top of the top cover near the lower outer mold. The second contouring support component has the same structure and size as the first contouring support component and is arranged symmetrically. The inner cavity of the elastic bladder is divided into multiple independent pressurization zones. The pressure of the pressurization medium in each pressurization zone is independently controlled by an external pressurization system.

[0009] Preferably, the plurality of independent pressurization zones include a racket head zone corresponding to the racket frame, side arc zones on both sides of the racket frame, and a T-shaped joint zone near the racket shaft connection. The pressurization system is configured to provide a pressure value to the T-shaped joint zone that is higher than that to the racket head zone and the side arc zones.

[0010] Preferably, the pressing unit includes a base plate, with a carrier plate fixedly connected to the top four sides of the base plate. A first motor is locked and fixed to the bottom rear side of the carrier plate. A worm gear is connected to the right output end of the first motor. A worm wheel is meshed and driven on the side of the worm gear. The top middle side of the worm wheel is rotatably connected to the carrier plate, and a rocker arm is coaxially rotatably connected to the bottom middle side of the worm wheel. A push rod is rotatably connected to both ends of the rocker arm. A slider is rotatably connected to the ends of the two push rods that are far apart from each other. The two sliders slide through the left and right sides of the carrier plate, respectively. A column is fixedly connected to the top of each slider. The two columns are locked and fixed to the first V-shaped frame and the second V-shaped frame, respectively.

[0011] Preferably, the top support unit includes a housing that is fastened to the pressing unit at its bottom. A cylindrical frame is fixed inside the upper part of the housing. A second motor is locked and fixed to the middle rear part of the cylindrical frame. A drive gear is connected to the front output end of the second motor. A driven gear meshes with the left side of the drive gear. A gear plate is coaxially fixed at the central shaft of the front part of the driven gear. The left side of the gear plate meshes with a groove column. A support rod is integrally fixed to the top of the groove column. A partition is fixedly connected to the top of the support rod. A hollow cylinder slides through both the left and right sides inside the partition. The bottom of the hollow cylinder is fixed to the housing, and the top of the hollow cylinder is fastened to the inner mold unit. A connecting pipe is installed through the hollow cylinder. The top of the connecting pipe is connected to the inner mold unit, and the bottom of the connecting pipe is installed through the rear side wall of the housing and connected to an external air pressure device. The groove column slides through the cylindrical frame, and the bottom of the groove column slides inside the limiting cylinder. The limiting cylinder is locked and fixed to the lower part of the housing.

[0012] Preferably, the first contour support assembly includes a mounting bracket whose bottom is fastened to the top cover. A third motor is locked and fixed above the mounting bracket on the side near the middle of the top cover. An arc-shaped slide rail is wrapped around the side of the mounting bracket away from the third motor. A rotating rod is connected to the output end of the third motor near the arc-shaped slide rail. Both ends of the rotating rod are ball-shaped, and each ball-shaped part at both ends is wrapped with a rotating hemisphere rod. A sliding sleeve is wrapped around the end of each hemisphere rod away from the rotating rod. The two sliding sleeves are respectively wrapped around and slide on both sides of the arc of the arc-shaped slide rail. A support component is provided on the side of each sliding sleeve away from the third motor.

[0013] Preferably, the supporting component includes a positioning seat fixed to the sliding sleeve on one side, a fourth motor locked and fixed to the top center of the positioning seat, a protective cover covering the outside of the fourth motor, an inner cylinder fixedly connected to the bottom inner side of the positioning seat, a screw rod passing through the middle of the inner cylinder, and the top end of the screw rod being connected to the bottom output end of the fourth motor, an internal threaded sleeve threaded to the outer surface of the screw rod, the internal threaded sleeve being embedded and fixed to the top side of the hollow rod, and the hollow rod being inserted into the inner cylinder and slidably connected to it longitudinally.

[0014] Secondly, the present invention also provides a badminton racket frame forming process, applied to the aforementioned badminton racket frame preforming equipment, comprising the following steps:

[0015] S1. Start the third motor of the first contouring support assembly and the second contouring support assembly, drive the sliding sleeve to slide along the bow-shaped slide rail, and move the stretching component to the predetermined contouring position corresponding to the part of the frame to be formed.

[0016] S2. Start the fourth motor to drive the screw to rotate, so that the inner thread sleeve drives the hollow rod to extend longitudinally along the inner cylinder to the predetermined height, so that the ends of the four hollow rods together form a temporary support surface that matches the inner contour of the frame.

[0017] S3. Lay the cut composite prepreg layer by layer on the temporary support surface formed by the ends of the four hollow rods to form an annular prepreg stack. At this time, a gap is maintained between the prepreg stack and the outer surface of the elastic capsule.

[0018] S4. Start the fourth motor to drive the hollow rod to retract longitudinally, so that the prepreg stack is left on the outer surface of the elastic capsule.

[0019] S5. Start the third motor to drive the sliding sleeve to slide in the opposite direction along the bow-shaped slide rail, so that the extension component exits the working area and returns to the standby position;

[0020] S6. Start the pressing unit, drive the first V-frame and the second V-frame to move closer to each other, so that the upper outer mold and the lower outer film are closed, and wrap the prepreg layer between the molding surface formed by the inner wall of the outer mold and the elastic capsule.

[0021] S7. The vacuum generator is connected through the first and second air pipes to extract air from the vacuum micropores on the molding surface, so that the prepreg stack is tightly adsorbed and attached to the inner wall of the upper outer mold and the lower outer film.

[0022] S8. Connect to an external pressurization system through a pipe, and fill multiple independent pressurization zones inside the elastic bladder with pressurizing medium to make the elastic bladder expand radially, apply radial pressure to the prepreg stack, and press it against the molding surface.

[0023] S9. Under pressure, the upper outer mold, lower outer film and elastic bladder in the mold-closed state are heated by the heating system to heat the prepreg stack to the molding temperature and keep it warm, so as to solidify and form a frame blank.

[0024] S10. Stop heating, release the pressure inside the elastic capsule, turn off the vacuum generator, start the pressing unit to drive the first V-frame and the second V-frame away from each other, open the upper outer mold and the lower outer membrane, and take out the formed racket frame blank.

[0025] Preferably, in step S8, the pressurization system provides different pressure values ​​to multiple independent pressurization zones of the elastic bladder based on the material properties of the prepreg laminate and the cross-sectional thickness of different parts of the frame, wherein:

[0026] A first pressure value P1 is applied to the pressure area corresponding to the T-joint area of ​​the racket frame, a second pressure value P2 is applied to the pressure area corresponding to the side arc area of ​​the racket frame, and a third pressure value P3 is applied to the pressure area corresponding to the racket head area of ​​the racket frame.

[0027] The first pressure value P1 is greater than the second pressure value P2 and the third pressure value P3, and the value range of P1 is 0.6-0.8MPa, while the value ranges of P2 and P3 are 0.3-0.5MPa.

[0028] Preferably, in step S1, the sliding sleeve driving process of the first contouring support assembly and the second contouring support assembly specifically includes:

[0029] The third motor is started, driving the rotating rod to rotate. Through the cooperation of the ball head at the end of the rotating rod and the hemispherical rod, the two sliding sleeves slide along the arc trajectory of the bow-shaped slide rail, thereby moving the two supporting components precisely to the predetermined position that matches the curvature of the part of the racket frame to be formed.

[0030] Preferably, in step S2, the predetermined height of the hollow rod extension is set such that the temporary support surface is flush with or substantially coplanar with the outer surface of the elastic capsule.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] This invention, by setting up a first and a second contour support component, allows the hollow rod to extend during the layup stage, forming a temporary support surface that matches the inner contour of the frame. Prepreg layers are laid on the ends of the hollow rod, maintaining a gap with the elastic capsule, effectively preventing the uncured prepreg from sticking to the inner mold due to its adhesiveness, thus avoiding layup displacement or wrinkling. The temporary support surface formed at the ends of the hollow rod is flush with the outer surface of the elastic capsule, ensuring stable layer placement when the hollow rod retracts. Simultaneously, the cooperation between the arc-shaped slide rail and the ball joint mechanism allows the support component to move precisely along an arc trajectory to a position matching the frame curvature, achieving precise contour support for different curvature areas. After mold closing, the elastic capsule uses zoned pressurization to achieve differentiated pressure control for different parts of the frame. Combined with the vacuum adsorption function on the molding surface, the prepreg layers adhere tightly to the molding surface, significantly improving the consistency of molding quality across all parts of the frame.

[0033] This invention integrates the first and second air pipes, respectively, into the interiors of the first and second V-shaped frames, thus embedding the vacuum piping within the V-shaped frame structure. This avoids the problem of exposed pipes entanglement and interference during mold opening and closing, as seen in traditional equipment. The inner cavity of the elastic bladder is divided into multiple independent pressurization zones corresponding to the racket head area, side arc area, and T-joint area. Each pressurization zone independently controls the pressure, allowing for differentiated pressure application based on the molding requirements of different parts of the racket frame: higher pressure is applied to the T-joint area to ensure compactness, while appropriate pressure is applied to the side arc area and racket head area to avoid fiber damage. This effectively solves the problem of uneven pressure distribution during mold closing in traditional rigid molds, significantly improving the overall molding quality of the racket frame.

[0034] This invention features a vertically movable partition in the top support unit, driven by a second motor and gear transmission mechanism, ensuring smooth and precise lifting. During layup and molding, the partition rises to the working position, providing auxiliary support for the prepreg layer from below, ensuring layup geometric accuracy. Simultaneously, an auxiliary heating device can be installed on the partition to compensate for the temperature of the frame preform from the bottom, solving the problem of low temperature at the bottom of the frame and ensuring uniform curing. After demolding, the partition descends to the maintenance position, providing ample space for operators to easily clean residual resin from the elastic capsule and support components. This achieves an organic combination of support, heating, and maintenance functions, significantly improving the automation level and maintainability of the equipment. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the preforming equipment of the present invention;

[0036] Figure 2 This is a schematic diagram of the pressing unit of the present invention;

[0037] Figure 3 This is a bottom view of the carrier plate of the present invention;

[0038] Figure 4 This is a schematic diagram of the structure of the top support unit of the present invention;

[0039] Figure 5 This is a schematic diagram of the internal mold unit of the present invention;

[0040] Figure 6 This is a schematic diagram of the structure of the first contour support component of the present invention;

[0041] Figure 7 This is a schematic diagram of the structure of the support component of the present invention.

[0042] In the diagram: Pressing unit-1, Top support unit-2, Inner mold unit-3, First V-frame-4, Second V-frame-5, Upper outer mold-6, First air pipe-7, Lower outer membrane-8, Second air pipe-9, Base plate-11, Carrier plate-12, First motor-13, Worm gear-14, Worm wheel-15, Rocker arm-16, Push rod-17, Slider-18, Column-19, Compartment cover-21, Cylindrical frame-22, Second motor-23, Drive gear-24, Driven gear-25, Gear block-26, Groove column-27, Support rod-28, Partition plate-29, Hollow cylinder -210, Connector -211, Limiting Cylinder -212, Inner Mold Base Plate -31, Elastic Cap -32, Top Cover -33, First Contouring Support Assembly -34, Second Contouring Support Assembly -35, Mounting Bracket -341, Third Motor -342, Bow-shaped Slide Rail -343, Rotating Rod -344, Hemispherical Head Rod -345, Sliding Sleeve -346, Expansion Part -347, Positioning Seat -3471, Fourth Motor -3472, Protective Cover -3473, Inner Cylinder -3474, Screw -3475, Internal Threaded Sleeve -3476, Hollow Rod -3477. Detailed Implementation

[0043] To further explain the technical solution of the present invention, a detailed description is provided below through specific embodiments.

[0044] Example 1:

[0045] Please see Figures 1-7 This embodiment provides a badminton racket frame preforming device for pre-pressing composite prepreg into a racket frame blank. The device includes a pressing unit 1, a top support unit 2, an inner mold unit 3, a first V-shaped frame 4, a second V-shaped frame 5, an upper outer mold 6, a first air pipe 7, a lower outer membrane 8, and a second air pipe 9. The top support unit 2 is installed on the top middle side of the pressing unit 1, and the top of the top support unit 2 is connected to the inner mold unit 3. The first V-shaped frame 4 and the second V-shaped frame 5 are respectively connected to the left and right sides of the top of the pressing unit 1, which are used to drive the first V-shaped frame 4 and the second V-shaped frame 5 to move towards or away from each other.

[0046] The first V-frame 4 is secured with an upper outer mold 6 on the side near the second V-frame 5, and the second V-frame 5 is secured with a lower outer mold 8 on the side near the first V-frame 4. After the upper outer mold 6 and the lower outer mold 8 come into contact, their inner wall surfaces form a forming surface corresponding to the outline of the final frame blank. Vacuum micro-holes are provided circumferentially on the forming surface. The vacuum micro-holes located in the upper outer mold 6 are connected to an external vacuum generator through a first air pipe 7, which is installed inside the first V-frame 4. The vacuum micro-holes located in the lower outer mold 8 are connected to an external vacuum generator through a second air pipe 9, which is installed inside the second V-frame 5. By incorporating the first air pipe 7 and the second air pipe 9 internally, the problems of entanglement and interference of exposed pipes during the mold opening and closing process are effectively avoided.

[0047] Please see Figures 1-3 The pressing unit 1 includes a base plate 11, with a carrier plate 12 fixedly connected to the top four sides of the base plate 11. A first motor 13 is locked and fixed to the bottom rear side of the carrier plate 12. A worm gear 14 is connected to the right output end of the first motor 13. A worm wheel 15 is meshed and driven on the side of the worm gear 14. The top middle side of the worm wheel 15 is rotatably connected to the carrier plate 12, and a rocker arm 16 is coaxially rotatably connected to the bottom middle side of the worm wheel 15. A push rod 17 is rotatably connected to both ends of the rocker arm 16. A slider 18 is rotatably connected to the ends of the two push rods 17 that are far apart from each other. The two sliders 18 slide through the left and right sides of the carrier plate 12, and a column 19 is fixedly connected to the top of the two sliders 18. The two columns 19 are locked and fixed to the first V-shaped frame 4 and the second V-shaped frame 5, respectively, so that after the first motor 13 is started, the first V-shaped frame 4 and the second V-shaped frame 5 can be driven to move closer or further away through the two columns 19.

[0048] Please see Figure 1 and Figure 4 The top support unit 2 includes a hopper cover 21 whose bottom is fastened to the pressing unit 1. A cylinder frame 22 is fixed inside the upper middle side of the hopper cover 21. A second motor 23 is locked and fixed to the middle rear part of the cylinder frame 22. The output end of the second motor 23 is connected to a drive gear 24. A driven gear 25 is meshed and driven on the left side of the drive gear 24. A gear plate block 26 is coaxially fixed at the central shaft of the front part of the driven gear 25. The left side of the gear plate block 26 meshes with a groove column 27. A support rod 28 is integrally fixed to the top of the groove column 27. A partition plate 29 is fixedly connected to the top of the support rod 28. A hollow cylinder 210 slides through both the left and right sides inside the partition plate 29. The bottom of the hollow cylinder 210 is fixed to the hopper cover 21, and the top of the hollow cylinder 210 is fastened to the inner mold unit 3. That is, the inner mold unit 3 is fixed above the hopper cover 21 through the hollow cylinder 210, and its position remains fixed and does not move with the movement of the top support unit 2.

[0049] A pipe 211 is provided through the hollow cylinder 210. The top of the pipe 211 is connected to the inner mold unit 3, and the bottom of the pipe 211 is provided through the rear side wall of the hood 21 and connected to the external air pressure equipment. The slot column 27 slides through the cylinder frame 22, and the bottom of the slot column 27 is inserted into the inner side of the limiting cylinder 212. The limiting cylinder 212 is locked and fixed inside the lower middle side of the hood 21.

[0050] When the second motor 23 starts, it drives the gear plate 26 to rotate through the driving gear 24 and driven gear 25. The meshing of the gear plate 26 with the groove column 27 causes the groove column 27 to rise and fall, which in turn drives the partition plate 29 to move up and down through the support rod 28. During the movement of the partition plate 29, it is guided by the hollow cylinder 210 that slides through it to ensure smooth lifting and lowering. When it is necessary to maintain, clean or replace parts of the inner mold unit 3, the second motor 23 drives the partition plate 29 to descend to a maintenance position away from the inner mold unit 3, providing sufficient operating space for the operator to clean the resin residue on the surface of the elastic capsule 32. During the layup and molding process, the second motor 23 can drive the partition plate 29 to rise to a predetermined working position close to the inner mold unit 3. In this position, the partition plate 29 performs the following functions:

[0051] Bottom support: The partition plate 29 provides auxiliary support from below for the prepreg stack laid at the end of the hollow rod 3477, preventing the stack from sagging and deforming due to its own weight, ensuring the geometric accuracy of the stack, and assisting the prepreg stack to be stably placed outside the inner mold unit 3.

[0052] Auxiliary heating: An auxiliary heating device (such as an infrared heating plate, hot air nozzle or resistance heating element) can be installed on the partition 29. When the partition rises to the working position, the auxiliary heating device preheats or compensates the temperature of the prepreg stack from the bottom, improves the heating uniformity, and can effectively compensate for the temperature loss at the bottom of the frame, ensuring that the entire frame cross section is cured uniformly.

[0053] Please see Figure 1 , Figures 5-7 The inner mold unit 3 includes an inner mold base plate 31 connected to the top support unit 2 at the bottom. An elastic bladder 32 is arranged around the outer surface of the inner mold base plate 31, and a top cover 33 is tightly attached to the top side of the inner mold base plate 31. A first contouring support component 34 is provided on the top side of the top cover 33 near the upper outer mold 6, and a second contouring support component 35 is provided on the top side of the top cover 33 near the lower outer mold 8. The second contouring support component 35 has the same structure and size as the first contouring support component 34 and is arranged symmetrically.

[0054] The inner cavity of the elastic bladder 32 is divided into multiple independent pressurization zones, each of which independently controls the pressure of the pressurizing medium through an external pressurization system. Specifically, the multiple independent pressurization zones include the racket head zone corresponding to the frame, the side arc zones on both sides of the frame, and the T-shaped joint zone near the racket shaft. The pressurization system is configured to provide the T-shaped joint zone with a higher pressure value than the racket head zone and the side arc zone.

[0055] The first contour support component 34 includes a mounting bracket 341 that is fastened to the top cover 33 at the bottom. A third motor 342 is locked and fixed on the upper side of the mounting bracket 341 near the middle of the top cover 33. An arc-shaped slide rail 343 is wrapped around the side of the mounting bracket 341 away from the third motor 342. A rotating rod 344 is connected to the output end of the third motor 342 near the arc-shaped slide rail 343. Both ends of the rotating rod 344 are ball-shaped, and a semi-spherical rod 345 is wrapped around the ball-shaped part at both ends. A sliding sleeve 346 is wrapped around the end of the two semi-spherical rods 345 away from the rotating rod 344. The two sliding sleeves 346 are respectively wrapped around and slide on both sides of the arc of the arc-shaped slide rail 343. A support component 347 is provided on the side of the two sliding sleeves 346 away from the third motor 342.

[0056] The ball joint linkage transmission mechanism used above enables the two sliding sleeves 346 to slide precisely along the arc-shaped track of the bow-shaped slide rail 343 through the transmission of the hemispherical rod 345 when the third motor 342 drives the rotating rod 344 to rotate. This allows the two supporting components 347 to move to a predetermined position that matches the curvature of the part of the racket frame to be formed. The curvature of the bow-shaped slide rail 343 is designed according to the contour of the racket frame to ensure that the movement trajectory of the supporting components 347 completely matches the curvature change of the racket frame.

[0057] The supporting component 347 includes a positioning seat 3471 fixed to a sliding sleeve 346 on one side. A fourth motor 3472 is locked and fixed to the top center of the positioning seat 3471. A protective cover 3473 is provided on the outside of the fourth motor 3472. An inner cylinder 3474 is fixedly connected to the bottom inner side of the positioning seat 3471. A screw 3475 is provided through the middle side of the inner cylinder 3474. The top of the screw 3475 is connected to the bottom output end of the fourth motor 3472. An internal threaded sleeve 3476 is threaded to the outer surface of the screw 3475. The internal threaded sleeve 3476 is embedded and fixed to the top side of the hollow rod 3477. The hollow rod 3477 is inserted into the inner cylinder 3474 and is slidably connected to it longitudinally.

[0058] When the fourth motor 3472 starts, it drives the screw 3475 to rotate. Through the threaded transmission, the inner threaded sleeve 3476 drives the hollow rod 3477 to slide longitudinally along the inner cylinder 3474, so that the hollow rod 3477 can extend or retract. This allows the hollow rod 3477 to extend to a predetermined height when needed to form a temporary support surface. After the layup is completed, it retracts, leaving the prepreg laminate on the outside of the elastic bladder 32.

[0059] Example 2:

[0060] This embodiment provides a badminton racket frame forming process, applied to the badminton racket frame preforming equipment of embodiment 1. The process includes the following steps:

[0061] S1. Start the third motor 342 of the first contour support component 34 and the second contour support component 35, drive the sliding sleeve 346 to slide along the bow-shaped slide rail 343, and drive the stretching component 347 to move to the predetermined contour position corresponding to the part of the frame to be formed.

[0062] Specifically, the third motor 342 is started to drive the rotating rod 344 to rotate. Through the cooperation of the ball head at the end of the rotating rod 344 and the hemispherical rod 345, the two sliding sleeves 346 are driven to slide along the arc trajectory of the bow-shaped slide rail 343, thereby making the two supporting components 347 move precisely to the predetermined position that matches the curvature of the part of the racket frame to be formed, providing precise contour support for subsequent layering.

[0063] S2. Start the fourth motor 3472 to drive the screw 3475 to rotate, so that the inner threaded sleeve 3476 drives the hollow rod 3477 to extend longitudinally along the inner cylinder 3474 to a predetermined height, so that the ends of the four hollow rods 3477 together form a temporary support surface that matches the inner contour of the frame.

[0064] In this embodiment, the predetermined height of the hollow rod 3477 is set so that the temporary support surface is flush with or substantially coplanar with the outer surface of the elastic capsule 32. This ensures that during subsequent lay-up, although the prepreg stack is supported by the end of the hollow rod 3477, it is already at the same height as the surface of the elastic capsule 32, creating conditions for smooth subsequent transfer.

[0065] S3. The cut composite prepreg is laid layer by layer on the temporary support surface formed by the ends of the four hollow rods 3477 to form an annular prepreg stack. At this time, a gap is maintained between the prepreg stack and the outer surface of the elastic capsule 32.

[0066] During the layup process, the second motor 23 of the top support unit 2 is started, driving the partition 29 to rise to the predetermined working position close to the inner mold unit 3. The partition 29 provides auxiliary support from below for the prepreg laminate laid at the end of the hollow rod 3477, preventing the laminate from sagging and deforming due to its own weight during the layup process, and ensuring the geometric accuracy of the laminate.

[0067] S4. Start the fourth motor 3472 to drive the hollow rod 3477 to retract longitudinally, so that the prepreg stack is left on the outer surface of the elastic capsule 32.

[0068] Since the temporary support surface is flush with the outer surface of the elastic bladder 32 and the partition 29 remains in an upward support state, when the hollow rod 3477 retracts, the prepreg stack remains smoothly on the surface of the elastic bladder 32 and the partition 29, ensuring the smoothness and positional accuracy of the stack transfer process.

[0069] S5. Start the third motor 342 to drive the sliding sleeve 346 to slide in the opposite direction along the bow-shaped slide rail 343, so that the extension component 347 exits the working area and returns to the standby position.

[0070] This ensures that during subsequent mold closing, vacuum adsorption, and capsule expansion processes, the contour support components 34 and 35 completely exit the working area and do not interfere with the elastic capsule 32 or the outer mold, thus guaranteeing the smooth progress of the molding process.

[0071] S6. Start the pressing unit 1, drive the first V-frame 4 and the second V-frame 5 to move closer to each other, so that the upper outer mold 6 and the lower outer film 8 are closed, and wrap the prepreg layer between the molding surface formed by the inner wall of the outer mold and the elastic capsule 32.

[0072] The working process of the pressing unit 1 is as follows: the first motor 13 is started, and the worm gear 14 drives the worm wheel 15 to rotate. The worm wheel 15 drives the rocker arm 16 to swing. The rocker arm 16 drives the two sliders 18 to slide towards each other along the carrier plate 12 through the push rod 17. Then, the first V-shaped frame 4 and the second V-shaped frame 5 are driven to move closer to each other through the column 19, so as to realize the closure of the upper outer mold 6 and the lower outer film 8.

[0073] S7. The vacuum generator is connected through the first air pipe 7 and the second air pipe 9 to evacuate the vacuum micropores on the molding surface, so that the prepreg stack is tightly adsorbed and attached to the inner wall of the upper outer mold 6 and the lower outer film 8; this ensures that the prepreg stack is precisely attached to the inner wall of the outer mold, and avoids displacement of the stack during subsequent pressurization. At the same time, the vacuuming process also helps to remove the gas between the prepreg layers and improve the density of the preform.

[0074] S8. Connect to an external pressurization system through pipe 211, and fill multiple independent pressurization zones inside the elastic bladder 32 with pressurizing medium, causing the elastic bladder 32 to expand radially, applying radial pressure to the prepreg stack and pressing it against the molding surface.

[0075] The pressurization system applies different pressure values ​​to multiple independent pressurization zones of the elastic bladder 32 based on the material properties of the prepreg laminate and the cross-sectional thickness of different parts of the frame. Specifically, a first pressure value P1 is applied to the pressurization zone corresponding to the T-joint area of ​​the frame, a second pressure value P2 is applied to the pressurization zone corresponding to the side arc area of ​​the frame, and a third pressure value P3 is applied to the pressurization zone corresponding to the head area of ​​the frame. The first pressure value P1 is greater than the second pressure value P2 and the third pressure value P3, and the value range of P1 is 0.6-0.8 MPa, while the values ​​of P2 and P3 are 0.3-0.5 MPa.

[0076] By applying differentiated pressure, higher pressure is applied to the T-shaped joint area where the material is thicker, ensuring that the area is fully compacted; lower pressure is applied to the side arc area and the head area to avoid over-compaction that could damage the fibers, thereby significantly improving the molding quality and consistency of all parts of the frame.

[0077] S9. Under pressure, the upper outer mold 6, lower outer film 8 and elastic capsule 32 in the mold-closed state are heated by the heating system to heat the prepreg stack to the molding temperature and keep it warm, so as to solidify and form a frame blank.

[0078] Meanwhile, the partition 29 remains raised to the working position, and the auxiliary heating device (such as an infrared heating plate, hot air nozzle or resistance heating element) installed on it provides auxiliary heating to the frame blank from the bottom, effectively solving the problem of low bottom temperature during the heating and curing process of the frame, ensuring uniform temperature across the entire frame cross section, and avoiding uneven curing caused by temperature differences.

[0079] The heating temperature and time are determined according to the material properties of the prepreg, usually 120-150℃, and the holding time is 30-60 minutes. During the heating process, the resin matrix melts and flows, filling the gaps between the fibers, and then a cross-linking reaction occurs, causing the prepreg to be laminated and cured into a frame preform with a certain strength and shape.

[0080] S10. Stop heating, release the pressure inside the elastic bladder 32, turn off the vacuum generator, start the pressing unit 1 to drive the first V-frame 4 and the second V-frame 5 to move away from each other, open the upper outer mold 6 and the lower outer membrane 8, and take out the formed racket frame blank.

[0081] After demolding, the top support unit 2 is activated to drive the partition plate 29 to descend to a maintenance position away from the inner mold unit 3, providing ample operating space for the operator. At this time, the operator can easily perform maintenance work on the inner mold unit 3, including cleaning the surface of the elastic bladder 32 and the end of the hollow rod 3477 to remove residual resin.

[0082] After demolding, the racket frame blank can proceed to subsequent finishing, drilling, assembly and other processes to finally produce a complete badminton racket.

[0083] The badminton racket frame preforming equipment and its forming process provided by this invention can be widely applied to the industrial production of carbon fiber composite badminton rackets. Through the equipment and process of this invention, the quality stability and production efficiency of racket frame preforming can be significantly improved, the scrap rate can be reduced, and production costs can be saved. At the same time, the equipment of this invention has a compact structure, a high degree of automation, is easy to operate, and is easy to promote and use.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A badminton racket frame pre-forming apparatus for pre-pressing a composite material prepreg into a frame blank, characterized in that, The system includes a pressing unit (1), a top support unit (2) installed on the top center of the pressing unit (1), an inner mold unit (3) connected to the top of the top support unit (2), and a first V-shaped frame (4) and a second V-shaped frame (5) respectively connected to the left and right sides of the top of the pressing unit (1) to drive the first V-shaped frame (4) and the second V-shaped frame (5) to move towards or away from each other; the first V-shaped frame (4) has an upper outer mold (6) fastened to the side of the second V-shaped frame (5) close to the second V-shaped frame (5), and the second V-shaped frame (5) has a lower outer mold fastened to the side of the second V-shaped frame (4) close to the first V-shaped frame (4). The outer membrane (8) forms a molding surface on its inner wall surface that corresponds to the outline of the final frame blank after the upper outer mold (6) and the lower outer membrane (8) come into contact. Vacuum micro-holes are provided on the molding surface along the circumferential direction. The vacuum micro-holes located in the upper outer mold (6) are connected to an external vacuum generator through a first air pipe (7). The first air pipe (7) is installed inside the first V-shaped frame (4). The vacuum micro-holes located in the lower outer membrane (8) are connected to an external vacuum generator through a second air pipe (9). The second air pipe (9) is installed inside the second V-shaped frame (5). The inner mold unit (3) includes an inner mold base plate (31) connected to the top support unit (2) at the bottom. An elastic bladder (32) is arranged around the outer surface of the inner mold base plate (31), and a top cover (33) is tightly attached to the top side of the inner mold base plate (31). A first contouring support component (34) is arranged on the side of the top cover (33) near the upper outer mold (6), and a second contouring support component (35) is arranged on the side of the top cover (33) near the lower outer membrane (8). The second contouring support component (35) has the same structure and size as the first contouring support component (34) and is arranged symmetrically. The inner cavity of the elastic bladder (32) is divided into multiple independent pressurization zones. The pressure of the pressurization medium in each pressurization zone is independently controlled by an external pressurization system.

2. The badminton racket frame preforming equipment according to claim 1, characterized in that, The plurality of independent pressurization zones include a racket head zone corresponding to the racket frame, side arc zones on both sides of the racket frame, and a T-shaped joint zone near the racket shaft. The pressurization system is configured to provide a pressure value to the T-shaped joint zone that is higher than that to the racket head zone and the side arc zones.

3. The badminton racket frame preforming equipment according to claim 1, characterized in that, The pressing unit (1) includes a base plate (11), a carrier plate (12) is fixedly connected to the top four sides of the base plate (11), a first motor (13) is locked and fixed to the bottom rear side of the carrier plate (12), a worm gear (14) is connected to the right output end of the first motor (13), a worm wheel (15) is meshed and driven on the side of the worm gear (14), the top middle side of the worm wheel (15) is rotatably connected to the carrier plate (12), and a rocker arm (16) is coaxially rotated on the bottom middle side of the worm wheel (15). A push rod (17) is rotatably connected to both ends of the rocker arm (16), and a slider (18) is rotatably connected to the ends of the two push rods (17) that are far apart from each other. The two sliders (18) slide through the left and right sides of the carrier plate (12) respectively, and a column (19) is fixedly connected to the top of the two sliders (18). The two columns (19) are locked and fixed to the first V-shaped frame (4) and the second V-shaped frame (5) respectively.

4. The badminton racket frame preforming equipment according to claim 1, characterized in that, The top support unit (2) includes a hopper cover (21) that is fastened to the bottom of the pressing unit (1). A cylinder frame (22) is fixed inside the upper middle side of the hopper cover (21). A second motor (23) is locked and fixed to the middle rear part of the cylinder frame (22). A drive gear (24) is connected to the front output end of the second motor (23). A driven gear (25) meshes with the left side of the drive gear (24). A gear plate block (26) is coaxially fixed at the front central shaft of the driven gear (25). The left side of the gear plate block (26) meshes with a slotted column (27). A support rod (28) is integrally fixed to the top of the slotted column (27). A partition plate (29) is fixedly connected to the top of the support rod (28). A hollow cylinder (210) slides through both the left and right sides inside the partition (29). The bottom of the hollow cylinder (210) is fixed to the hood (21), and the top of the hollow cylinder (210) is fastened to the inner mold unit (3). A pipe (211) is installed through the hollow cylinder (210). The top of the pipe (211) is connected to the inner mold unit (3), and the bottom of the pipe (211) is installed through the rear side wall of the hood (21) and connected to the external air pressure equipment. The groove column (27) slides through the cylinder frame (22), and the bottom of the groove column (27) is inserted into the inner side of the limiting cylinder (212). The limiting cylinder (212) is locked and fixed inside the lower middle side of the hood (21).

5. The badminton racket frame preforming equipment according to claim 1, characterized in that, The first contour support assembly (34) includes a mounting bracket (341) that is fastened to the bottom of the top cover (33). A third motor (342) is locked and fixed above the side of the mounting bracket (341) near the middle of the top cover (33). An arc-shaped slide rail (343) is wrapped around the side of the mounting bracket (341) away from the third motor (342). A rotating rod (344) is connected to the output end of the third motor (342) near the arc-shaped slide rail (343). Both ends of the rotating rod (344) are ball-shaped, and a semi-spherical rod (345) is wrapped around the ball-shaped part at both ends. A sliding sleeve (346) is wrapped around the end of the two semi-spherical rods (345) away from the rotating rod (344). The two sliding sleeves (346) are respectively wrapped around and slide on both sides of the arc of the arc-shaped slide rail (343). A support component (347) is provided on the side of the two sliding sleeves (346) away from the third motor (342).

6. The badminton racket frame preforming equipment according to claim 5, characterized in that, The supporting component (347) includes a positioning seat (3471) fixed to a sliding sleeve (346) on one side. A fourth motor (3472) is locked and fixed to the top center of the positioning seat (3471). A protective cover (3473) is provided on the outside of the fourth motor (3472). An inner cylinder (3474) is fixedly connected to the bottom inner side of the positioning seat (3471). A screw (3475) is provided through the middle side of the inner cylinder (3474). The top of the screw (3475) is connected to the bottom output end of the fourth motor (3472). An internal threaded sleeve (3476) is threaded to the outer surface of the screw (3475). The internal threaded sleeve (3476) is embedded and fixed to the top side of the hollow rod (3477). The hollow rod (3477) is inserted into the inner cylinder (3474) and is longitudinally slidably connected to it.

7. A badminton racket frame forming process, applied to the badminton racket frame pre-forming equipment as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Start the third motor (342) of the first contour support component (34) and the second contour support component (35), drive the sliding sleeve (346) to slide along the bow-shaped slide rail (343), and drive the stretching component (347) to move to the predetermined contour position corresponding to the part of the frame to be formed; S2. Start the fourth motor (3472) to drive the screw (3475) to rotate, so that the inner thread sleeve (3476) drives the hollow rod (3477) to extend longitudinally along the inner cylinder (3474) to a predetermined height, so that the ends of the four hollow rods (3477) together form a temporary support surface that matches the inner contour of the frame. S3. The cut composite prepreg is laid layer by layer on the temporary support surface formed by the ends of the four hollow rods (3477) to form an annular prepreg stack. At this time, a gap is maintained between the prepreg stack and the outer surface of the elastic capsule (32). S4. Start the fourth motor (3472) to drive the hollow rod (3477) to retract longitudinally, so that the prepreg stack is left on the outer surface of the elastic capsule (32); S5. Start the third motor (342) to drive the sliding sleeve (346) to slide in the opposite direction along the bow-shaped slide rail (343), so that the extension component (347) exits the working area and returns to the standby position; S6. Start the pressing unit (1) to drive the first V-frame (4) and the second V-frame (5) to approach each other, so that the upper outer mold (6) and the lower outer film (8) are closed, and the prepreg is wrapped between the molding surface formed by the inner wall of the outer mold and the elastic capsule (32). S7. The vacuum generator is connected through the first air pipe (7) and the second air pipe (9) to extract air from the vacuum micropores on the molding surface, so that the prepreg stack is tightly adsorbed and attached to the inner wall of the upper outer mold (6) and the lower outer film (8). S8. Connect to an external pressurization system through the pipe (211) and fill the multiple independent pressurization zones inside the elastic bladder (32) with pressurizing medium, so that the elastic bladder (32) expands radially and applies radial pressure to the prepreg stack, pressing it against the molding surface. S9. Under pressure, the upper outer mold (6), lower outer film (8) and elastic capsule (32) in the mold-closed state are heated by the heating system to heat the prepreg stack to the molding temperature and keep it warm, so as to solidify and form a frame blank. S10. Stop heating, release the pressure inside the elastic bladder (32), turn off the vacuum generator, start the pressing unit (1) to drive the first V-frame (4) and the second V-frame (5) to move away from each other, open the upper outer mold (6) and the lower outer membrane (8), and take out the formed racket frame blank.

8. The badminton racket frame forming process according to claim 7, characterized in that, In step S8, the pressurization system provides different pressure values ​​to multiple independent pressurization zones of the elastic bladder (32) based on the material properties of the prepreg laminate and the cross-sectional thickness of different parts of the frame, wherein: A first pressure value P1 is applied to the pressure area corresponding to the T-joint area of ​​the racket frame, a second pressure value P2 is applied to the pressure area corresponding to the side arc area of ​​the racket frame, and a third pressure value P3 is applied to the pressure area corresponding to the racket head area of ​​the racket frame. The first pressure value P1 is greater than the second pressure value P2 and the third pressure value P3, and the value range of P1 is 0.6-0.8MPa, while the value ranges of P2 and P3 are 0.3-0.5MPa.

9. The badminton racket frame forming process according to claim 7, characterized in that, In step S1, the driving process of the sliding sleeve (346) of the first contouring support assembly (34) and the second contouring support assembly (35) specifically includes: The third motor (342) is started, driving the rotating rod (344) to rotate. Through the cooperation of the ball head at the end of the rotating rod (344) and the hemispherical rod (345), the two sliding sleeves (346) are driven to slide along the arc trajectory of the bow-shaped slide rail (343), thereby making the two supporting components (347) move precisely to the predetermined position that matches the curvature of the part of the racket frame to be formed.

10. The badminton racket frame forming process according to claim 7, characterized in that, In step S2, the predetermined height of the hollow rod (3477) is set so that the temporary support surface is flush with the outer surface of the elastic capsule (32).

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