A three-dimensional braiding type blunt ball-head truncated cone core mold

Abstract

This utility model relates to a segmented blunt-spherical truncated cone core mold for three-dimensional weaving, comprising a detachably connected base plate, a mold cylinder, and blunt-spherical truncated cone molds. The mold cylinder includes a plurality of truncated cone truncated cone molds arranged sequentially along the circumference, with radially extending truncated cone mold holes on the inner wall of each mold. It also includes a fixedly mounted support frame, on which a camshaft is rotatably connected. A plurality of cams, each radially opposite to a truncated cone mold hole, are fixedly mounted on the camshaft. A guide cylinder, fixed to the support frame, is provided between the radially opposite cams and the truncated cone mold holes. A push rod is slidably connected to the inner hole of the guide cylinder, and the push rod is connected to the guide cylinder by a spring. One end of the push rod engages with the wheel surface of the cam. At least one truncated cone truncated cone mold is a follower mold, and the follower mold is fixedly connected to its corresponding push rod. In this utility model, by disassembling the integral core mold into several thin-walled truncated cone molds, the core mold can be quickly and conveniently installed, reducing damage to the preform during demolding.

Description

Technical Field

[0001] This utility model relates to the field of textile composite materials technology, and in particular to a three-dimensional weaving mold, specifically a three-dimensional weaving segmented blunt ball-head truncated cone core mold. Background Technology

[0002] Three-dimensional braided composite materials have superior integrity and uniform fiber distribution. In the preparation process of different three-dimensional braided preforms, different shaped mandrels are required. The shape of the outer surface of the mandrel is used to meet the shape of the three-dimensional braided preform.

[0003] However, for large-volume, thick, and low-draft-angle three-dimensional braided preforms, using a traditional integral mandrel presents two major challenges: firstly, the mandrel is heavy and difficult to install; secondly, demolding the three-dimensional braided preform is difficult, and forced demolding can damage the inner and outer surfaces of the preform, even causing fabric deformation and disrupting the fiber distribution direction, thus affecting the performance of the composite material. This is especially true for truncated cone preforms with low draft angles and long draft distances, where the damage to the fabric is even more severe during demolding using a traditional integral mandrel. Utility Model Content

[0004] This invention addresses the shortcomings of existing technologies by providing a segmented blunt-headed truncated cone core mold for three-dimensional braiding. This solves the problems encountered during demolding of large truncated cone three-dimensional braided preforms, and also addresses the issue of excessive weight of the overall core mold, making it difficult to install. It also avoids the problem of fiber damage caused by the preform during demolding, which could affect the performance of the composite material.

[0005] This utility model is achieved through the following technical solution: a three-dimensional braiding type blunt ball head truncated cone core mold is provided, including a base plate, a mold cylinder and a blunt ball head mold that are detachably connected in sequence along the axial direction. The mold cylinder includes a plurality of truncated cone molds arranged in sequence along the circumferential direction. The inner wall of the truncated cone mold has a mold hole extending in the radial direction.

[0006] It also includes a fixed support frame, on which a camshaft is rotatably connected. Several cams are fixed on the camshaft, each radially opposite to a petal mold hole. A guide cylinder fixed to the support frame is provided between the radially opposite cams and the petal mold holes. A radially extending push rod is slidably connected to the inner hole of the guide cylinder. The push rod is connected to the guide cylinder by a spring. One end of the push rod mates with the wheel surface of the cam, and the other end of the push rod extends toward the petal mold hole. At least one section of the conical petal mold is a follower petal mold. The follower petal mold is fixedly connected to its corresponding push rod. The distance between the two edges of the inner arc surface of the follower petal mold is greater than or equal to the distance between the two edges of the outer arc surface.

[0007] In use, this solution utilizes the cooperation of cams and push rods. When the camshaft rotates in the forward direction, each push rod pushes into the petal mold hole, supporting each truncated cone petal mold and thus forming a core mold. When demolding is required after weaving, the base plate is removed, and by reversing the camshaft, the petal mold and each push rod retract under the elastic action of the spring return, making it easy to disassemble the remaining truncated cone petal molds and avoiding damage to the fibers during demolding.

[0008] As an optimization, the support frame includes a housing sleeved on and rotatably connected to the camshaft, and a support rod fixedly connected to the housing. One end of the support rod, away from the housing, extends through a blunt ball-head mold. The guide cylinder is fixedly connected to the housing. This optimized support frame structure is simple, provides support for the camshaft and guide cylinder, utilizes the blunt ball-head mold to support the support rod, and is easy to assemble and disassemble.

[0009] As an optimization, the hole on the blunt spherical head mold through which the support rod passes is a polygonal hole, and the support rod has a cross-section adapted to the polygonal hole. This optimization design avoids relative rotation between the support rod and the blunt spherical head mold.

[0010] As an optimization, the end of the support rod that protrudes from the blunt ball head mold is threadedly connected to a first limiting nut; the camshaft protrudes from the base plate, and the end of the camshaft that protrudes from the base plate is threadedly connected to a second limiting nut. The end of the housing away from the support rod, and the end of the truncated cone mold away from the blunt ball head mold, both press against the base plate. This optimized solution, by setting the first and second limiting nuts, presses and fixes the housing and each truncated cone mold between the base plate and the blunt ball head mold. The fixing method is simple and reliable, and also convenient for assembly and disassembly.

[0011] As an optimization, an anti-rotation section is fixed to the camshaft and located in the base plate. The anti-rotation section has a polygonal cross-section, and the base plate has a through hole that matches the anti-rotation section. This optimization scheme, by setting the anti-rotation section, prevents relative rotation between the base plate and the camshaft after assembly.

[0012] As an optimization, a boss extending towards the side where the truncated cone-shaped mold is located is fixed on the base plate, and the end face of the truncated cone-shaped mold has a groove that matches the boss. This optimization solution prevents the truncated cone-shaped mold from shifting radially by locking the boss and groove in the groove, thus ensuring the reliability of the core mold.

[0013] As an optimization, the blunt spherical head valve mold includes a hemispherical shell, the outer diameter of which matches the diameter of the circle containing the outer arc surface of each truncated cone valve mold. This optimized blunt spherical head valve mold uses a hemispherical shell structure, reducing weight while ensuring sufficient strength and better fitting the truncated cone valve mold.

[0014] As an optimization, the valve cylinder includes four truncated cone valve molds, with the included angle between two adjacent push rods along the circumference being 90 degrees. One of the truncated cone valve molds is a follower valve mold, with its two sides along the circumference being parallel to each other and parallel to the push rod fixed to it. This optimized scheme uses a structure of one follower valve mold and three non-follower valve molds. After the follower valve mold is retracted, the remaining truncated cone valve molds can be disassembled one by one, resulting in a simple structure and easier assembly and disassembly.

[0015] The beneficial effects of this utility model are as follows:

[0016] 1. The three-dimensional braided core mold has been changed from an integral structure to a segmented structure. The internal structure of the segment mold cylinder and the blunt ball head segment mold is hollow, which reduces the weight of the core mold and increases the convenience of core mold installation.

[0017] 2. The core mold, which is difficult to demold, can be decomposed into several parts through the cam mechanism, thereby reducing the damage to the preform caused by demolding.

[0018] 3. The camshaft does not require electric or pneumatic start-up; it can be manually rotated between the highest and lowest points of the cam, simplifying the requirements for the operating environment. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is a left view of the present invention after the base plate has been removed;

[0021] Figure 3 This is a cross-sectional view of the present invention based on the vertical centerline section of the left view;

[0022] Figure 4 This is a cross-sectional view of the present invention based on the horizontal center line section of the left view;

[0023] Figure 5 This is a schematic diagram of the base plate structure of this utility model;

[0024] As shown in the figure:

[0025] 1. Follow-up valve mold, 2. Frustoconical valve mold II, 3. Frustoconical valve mold III, 4. Frustoconical valve mold IV, 5. Push rod I, 6. Push rod II, 7. Push rod III, 8. Push rod IV, 9. Cam I, 10. Cam II, 11. Cam III, 12. Cam IV, 13. Valve mold hole I, 14. Valve mold hole II, 15. Valve mold hole III, 16. Valve mold hole IV, 17. Blunt ball head valve mold, 18. Washer, 19. First limit nut, 20. Front threaded section, 21. Support rod, 22. Spring, 23. Housing, 24. Camshaft, 25. Second limit nut, 26. Rear threaded section, 27. Base plate, 28. Boss, 29. Through hole, 30. Polygonal hole, 31. Guide cylinder, 32. Limiting pad, 33. Groove, 34. Anti-rotation section. Detailed Implementation

[0026] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0027] like Figure 1 The three-dimensional braiding lobed blunt ball head truncated cone core mold includes a base plate 27, a lobed mold cylinder and a blunt ball head lobed mold 17 that are detachably connected in sequence along the axial direction. The lobed mold cylinder is clamped between the base plate and the blunt ball head lobed mold, and the base plate 27, the lobed mold cylinder and the blunt ball head lobed mold 17 are coaxially arranged.

[0028] The valve cylinder includes several truncated cone valves arranged sequentially along the circumference. Each truncated cone valve has an arc-shaped thin-walled structure, and each valve forms a circumferentially closed cylindrical valve cylinder. The inner wall of each truncated cone valve has radially extending valve holes. At least one truncated cone valve is a follower valve 1, which is fixedly connected to its corresponding push rod. The distance between the two edges of the inner arc surface of the follower valve is greater than or equal to the distance between the two edges of the outer arc surface. The follower valve moves with the push rod, while the remaining truncated cone valves do not move with the push rod.

[0029] The blunt spherical head valve mold includes a hemispherical shell with the opening facing the side where the valve mold cylinder is located. The outer diameter of the hemispherical shell is matched with the diameter of the circle containing the outer arc surface of each truncated cone valve mold, and the wall thickness of the hemispherical shell is consistent with the wall thickness of the truncated cone valve mold.

[0030] The three-dimensional braiding segmented blunt ball-head truncated cone mandrel of this embodiment also includes a fixedly mounted support frame. A camshaft 24 is rotatably connected to the support frame, which does not rotate with the camshaft. A plurality of cams are fixedly mounted on the camshaft 24, each radially opposite to a segment of the mandrel hole. A guide cylinder 31, fixedly connected to the support frame, is provided between the radially opposite cams and the segment holes. The inner hole of the guide cylinder and the segment holes are coaxial radially. A radially extending push rod is slidably connected to the inner hole of the guide cylinder 31. The push rod and the guide cylinder are connected by a spring 22. Specifically, a limiting pad 32 located inside the guide cylinder is fixedly mounted on the push rod. The spring is sleeved on the push rod, with one end of the spring pressing against the limiting pad and the other end pressing against the top plate of the guide cylinder away from the camshaft. The proximal end of the ejector rod mates with the wheel surface of the cam, while the distal end of the ejector rod extends towards the mold hole. When the camshaft rotates in the forward direction, the cam moves the ejector rod to its highest point, using the wheel surface of the cam to push the ejector rod into the mold hole, compressing the spring 22. When the camshaft rotates in the reverse direction, the spring force causes the ejector rod to move back to its lowest point, ensuring that the proximal end of the ejector rod remains in contact with the wheel surface of the cam. A guide rod is fixedly connected to the distal end of the ejector rod, and the diameter of the guide rod is matched to the diameter of the mold hole.

[0031] The support frame includes a housing 23 sleeved on and rotatably connected to the camshaft, and a support rod 21 fixedly connected to the housing 23. One end of the support rod 21, away from the housing, extends through a blunt ball-head mold 17. The housing is square, and the guide cylinder is fixedly connected to the housing. Figure 2 As shown, in this embodiment, a guide cylinder is fixed to each of the four side walls of the box, and the guide cylinder is located on the center line of the side wall of the box.

[0032] The hole 30 on the blunt ball head mold 17 for the support rod to pass through is a polygonal hole. The support rod has a cross section that matches the polygonal hole. After assembly, the polygonal cross section of the support rod is located in the polygonal hole, preventing relative rotation between the blunt ball head mold and the support rod.

[0033] One end of the support rod that protrudes from the blunt ball head mold is connected to a first limiting nut 19 by a thread. A front threaded section 20 that is adapted to the first limiting nut is coaxially fixed on the support rod. The first limiting nut 19 is installed on the front threaded section 20. A washer 18 is also provided between the first limiting nut 19 and the blunt ball head mold and is sleeved on the support rod.

[0034] The support rod is coaxial with the camshaft. The end of the camshaft 24 away from the support rod extends through the base plate 27, and the end of the camshaft extending through the base plate is threadedly connected to a second limiting nut 25. The end of the housing away from the support rod and the end of the truncated cone-shaped mold away from the blunt ball-shaped mold both axially push against the base plate 27. Specifically, the camshaft is provided with a rear threaded section 26 adapted to the second limiting nut, and the second limiting nut 25 is located on the rear threaded section.

[0035] An anti-rotation section 34 is fixedly mounted on the camshaft and located in the base plate. The cross-section of the anti-rotation section 34 is polygonal, and a through hole 29 adapted to the anti-rotation section is provided on the base plate. In this embodiment, both the through hole 29 on the base plate and the polygonal hole on the blunt ball head mold 17 for the support rod to pass through are square holes, making processing simpler and more convenient.

[0036] A boss 28 extending toward the side where the truncated cone-shaped mold is located is fixed on the base plate, and a groove 33 adapted to the boss 28 is provided on the end face of the truncated cone-shaped mold. In order to reduce the assembly difficulty, both the boss and the groove in this embodiment are wedge-shaped, and the inclined surface of the wedge is used for guidance, which makes it easier to install the base plate.

[0037] After tightening the first and second limit nuts, the base plate and the blunt ball head petal mold clamp and fix the truncated cone petal mold. The support rod restricts the rotation of the blunt ball head petal mold, the anti-rotation section of the camshaft restricts the rotation of the base plate, and the engagement of the boss 28 and the groove restricts the radial movement of the truncated cone petal mold, thereby forming an integral structure of the core mold.

[0038] The valve cylinder of this embodiment includes four truncated cone valve molds, with the included angle between two adjacent top rods along the circumferential direction being 90 degrees. One of the truncated cone valve molds is a follower valve mold 1, such as... Figure 2 As shown, the two sides of the follower valve mold 1 are parallel to each other along the circumferential direction and are both parallel to the push rods fixed to the follower valve mold. The other three truncated cone valve molds are truncated cone valve mold II2, truncated cone valve mold III3, and truncated cone valve mold IV4. The push rod corresponding to the follower valve mold 1 is push rod I5, the push rod corresponding to the truncated cone valve mold II2 is push rod II6, the push rod corresponding to the truncated cone valve mold III3 is push rod III7, and the push rod corresponding to the truncated cone valve mold IV4 is push rod IV8. The cam that cooperates with push rod I5 is cam I9, the cam that cooperates with push rod II6 is cam II10, the cam that cooperates with push rod III7 is cam III11, and the cam that cooperates with push rod IV8 is cam IV12. The valve hole on the follower valve 1 is valve hole I13, the valve hole on the truncated cone valve 2 is valve hole II14, the valve hole on the truncated cone valve 3 is valve hole III15, and the valve hole on the truncated cone valve 4 is valve hole IV16.

[0039] This embodiment disassembles the integral core mold into several thin-walled petal molds, enabling quick and convenient core mold installation and reducing damage to the preform during demolding. A cam and camshaft drive a push rod in reciprocating motion, which allows for the assembly and disassembly of the truncated cone petal molds and the restriction or elimination of their degrees of freedom. When the cam drives the push rod to its highest point and the fasteners are installed, the truncated cone petal mold and the blunt ball-head petal mold are installed. When the cam drives the push rod to its lowest point, one of the truncated cone petal molds moves to the lowest point with the push rod, and the degree of freedom constraints of the other three truncated cone petal molds are eliminated, thus enabling demolding. This invention significantly reduces the demolding difficulties caused by core molds with large dimensions and small draft angles, thereby reducing damage to the three-dimensional braided preform and improving the mechanical properties of the three-dimensional braided composite material.

[0040] The core mold usage method in this embodiment includes:

[0041] 1. Core Mold Installation: Before core mold installation, the housing assembly, camshaft, and cam mechanism have been installed. First, install the blunt ball head mold 17 on the support rod 21. The washer 18 is installed on the support rod 21 with the blunt ball head mold tightly against the outside. Install the first limiting nut 19 on the front threaded section 20. At this time, the first limiting nut 19 is not tightened, and the circumferential and radial movement of the blunt ball head mold 17 is restricted. Then, fix the follower mold 1 and the push rod I5 through the mold hole I13, and at the same time rotate the anti-rotation section 34 of the camshaft to lower each push rod to the lowest point. Next, align each truncated cone-shaped petal mold with its corresponding petal mold hole position and with each ejector rod. Then, align the outer circle of each truncated cone-shaped petal mold with the outer circle of the blunt ball-head petal mold 17. Simultaneously, rotate the camshaft 180 degrees clockwise, using the cam to raise each ejector rod to its highest point. At this point, ejector rod I5 and follower petal mold 1 are raised to their highest points, and the outer circle of follower petal mold 1 is aligned with the outer circle of blunt ball-head petal mold 17. Ejector rods II6, III7, and IV8 are inserted into petal mold holes II14, III15, and IV16, respectively, restricting the radial movement of the follower petal mold and each truncated cone-shaped petal mold. Finally, engage the boss 28 on the base plate 27 into the wedge-shaped groove 33 of each petal mold, and mate the through hole 29 of the base plate with the anti-rotation section 34, restricting the circumferential movement of each petal mold. Install the second limiting nut 25 onto the rear threaded section 26. Then, tighten the second limiting nut 25 and the first limiting nut 19 together. The axial movement of the entire mandrel is restricted, and the mandrel installation is complete. Install the front threaded section 20 onto the robotic arm, and three-dimensional fabric preform weaving can be performed.

[0042] 2. Core Mold Demolding: Before demolding, the core mold contains a pre-woven three-dimensional fabric, with the head of the pre-woven fabric not sealed. First, remove the second limiting nut 25 and take out the base plate 27. Then, rotate the camshaft counterclockwise 180 degrees. At this time, each push rod descends to its lowest point, and simultaneously, the follower petal mold 1 descends to its lowest point along with the push rod I5, separating from each truncated cone petal mold. Remove the truncated cone petal molds. At this point, all truncated cone petal molds have been removed. Finally, remove the front threaded section 20 from the robotic arm, demold the three-dimensional fabric pre-woven fabric from the remaining blunt ball head petal mold 17, and remove the first limiting nut 19, washer 18, and blunt ball head petal mold 17. The core mold demolding is now complete.

[0043] In this embodiment, the core mold is changed from a single, integral type to a thin-walled, segmented type, reducing the weight of the core mold and increasing the ease of core mold mounting. During demolding, the core mold can be disassembled into several parts, reducing damage to the preform during demolding. The core mold has broad material compatibility. If the preform has high dimensional requirements, a metal core mold can be used; if the preform is thick, has many weaving layers, and requires sewing after preparation, a foam core mold can be used.

[0044] Of course, the above description is not limited to the examples above. Technical features of this utility model not described can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solution of this utility model and are not intended to limit this utility model. This utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this utility model do not depart from the spirit of this utility model and should also fall within the protection scope of the claims of this utility model.

Claims

1. A three-dimensional braiding mandrel with a segmented blunt spherical head and a truncated cone shape, characterized in that: It includes a base plate (27), a valve mold cylinder and a blunt ball head valve mold (17) that are detachably connected in sequence along the axial direction. The valve mold cylinder includes a plurality of truncated cone valve molds arranged in sequence along the circumferential direction. The inner wall of the truncated cone valve mold is provided with a valve mold hole that extends radially. It also includes a fixed support frame, on which a camshaft (24) is rotatably connected. Several cams are fixed on the camshaft (24) and are radially opposite to each of the petal mold holes. A guide cylinder (31) fixed to the support frame is provided between the radially opposite cams and the petal mold holes. A radially extending push rod is slidably connected to the inner hole of the guide cylinder. The push rod is connected to the guide cylinder by a spring (22). One end of the push rod is engaged with the wheel surface of the cam, and the other end of the push rod extends toward the petal mold hole. At least one conical petal mold is a follower petal mold (1), and the follower petal mold (1) is fixedly connected to its corresponding top rod. The distance between the two edges of the inner arc surface of the follower petal mold is greater than or equal to the distance between the two edges of the outer arc surface.

2. The three-dimensional braiding segmented blunt spherical truncated cone core mold according to claim 1, characterized in that: The support frame includes a housing (23) sleeved on and rotatably connected to the camshaft, and a support rod (21) fixedly connected to the housing (23). The end of the support rod (21) away from the housing extends out of the blunt ball head mold (17), and the guide cylinder is fixedly connected to the housing.

3. The three-dimensional braiding segmented blunt spherical truncated cone core mold according to claim 2, characterized in that: The hole on the blunt ball head mold (17) through which the support rod passes is a polygonal hole, and the support rod has a cross section that matches the polygonal hole.

4. A three-dimensional braiding segmented blunt spherical truncated cone core mold according to claim 2, characterized in that: The end of the support rod that protrudes from the blunt ball head mold is connected to a first limiting nut (19) via a thread; The camshaft (24) extends out of the base plate (27), and the end of the camshaft extending out of the base plate is connected to the second limiting nut (25) by a thread. The end of the housing away from the support rod and the end of the truncated cone mold away from the blunt ball head mold both abut against the base plate (27).

5. A three-dimensional braiding segmented blunt spherical truncated cone core mold according to claim 4, characterized in that: An anti-rotation section is fixed on the camshaft and located in the base plate. The cross-section of the anti-rotation section is polygonal, and a through hole (29) adapted to the anti-rotation section is provided on the base plate.

6. A three-dimensional braiding segmented blunt spherical truncated cone core mold according to claim 1, characterized in that: A boss (28) extending toward the side where the truncated cone-shaped mold is located is fixed on the base plate, and a groove adapted to the boss (28) is provided on the end face of the truncated cone-shaped mold.

7. A three-dimensional braiding segmented blunt spherical truncated cone core mold according to claim 1, characterized in that: The blunt spherical head valve includes a hemispherical shell, the outer diameter of which is adapted to the diameter of the circle containing the outer arc surface of each truncated cone valve.

8. A three-dimensional braiding segmented blunt spherical truncated cone core mold according to claim 1, characterized in that: The valve cylinder includes four truncated cone valves. The angle between two adjacent push rods along the circumference is 90 degrees. One of the truncated cone valves is a follower valve. The two sides of the follower valve are parallel to each other along the circumference and are both parallel to the push rod fixed to the follower valve.

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