Rivets and apparatus for riveting multi-layer composites

Abstract

The utility model discloses rivet and device of riveting of multilayer composite material in the material connection technical field, including the flange of rod part and setting in the one end of rod part, the recess is set in the middle part of the other end of rod part, the puncture department of forming has in the recess outside on the rod part. The utility model discloses through setting rod part, recess, puncture department, upper die subassembly and lower die subassembly, make that composite material board need not prefabricated hole and adopt the connection method of self -puncturing riveting, utilize the rod part with recess and puncture department cooperation upper die subassembly and lower die subassembly, realize the effective blanking cutting of multilayer composite material board, and the rod part penetrates multilayer composite material board and realizes the rivet interlocking of rod part, not only cancel the trepanning process, solve the problem to the hole, and solve the defect such as the cracking delamination of composite material riveting section, make after riveting have higher static tensile property and fatigue property.

Description

Technical Field

[0001] This utility model relates to the field of material joining technology, and in particular to rivets and devices for riveting multilayer composite materials. Background Technology

[0002] Carbon fiber composites are a new type of composite material with advantages such as high strength and specific modulus, good fatigue resistance, low coefficient of thermal expansion and good corrosion resistance. Carbon fiber reinforced composites are often used in the aerospace and automotive fields by riveting.

[0003] However, existing technologies have some problems: due to the poor plasticity of carbon fiber composites, fiber breakage, matrix cracking, interface degumming and delamination are prone to occur during riveting, which reduces the joint performance and may even directly lead to joint failure. In practical applications, it is usually necessary to pre-drill holes in the composite material before riveting, but pre-drilling holes will increase the riveting process and the difficulty of aligning tooling with the hole. Therefore, we propose rivets and devices for riveting multi-layer composite materials. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides rivets and devices for riveting multi-layer composite materials. By using a rivet fitting device with a punching function, it not only solves the problem of hole matching but also solves defects such as cracking and delamination of the riveted cross section of the composite material.

[0005] The purpose of this utility model is achieved as follows: a rivet for riveting multi-layer composite materials includes a shank and a flange disposed at one end of the shank, the other end of the shank is provided with a groove, the groove is disposed in the middle of the end face of the shank, and a piercing portion is formed on the shank located outside the groove.

[0006] Optionally, the cross-section of the groove is circular arc-shaped.

[0007] A device for riveting multi-layer composite materials includes the aforementioned rivets for riveting multi-layer composite materials, and also includes an upper die assembly and a lower die assembly that cooperate with each other. The upper die assembly includes a pressure ring and a punching die for limiting and punching the composite material. The lower die assembly includes a cutting die and a support die, and the cutting die and the support die can be switched according to processing needs.

[0008] Optionally, the pressure ring has a through hole in the middle, and the punching die is movably inserted into the through hole, with the diameter of the punching die matching the inner diameter of the through hole.

[0009] Optionally, the top of the cutting die is arc-shaped, and a conical hole is provided in the middle of the cutting die, wherein the inner diameter of the top of the conical hole is larger than the diameter of the rod.

[0010] Optionally, a riveting die is movably sleeved inside the support mold, and the top of the riveting die is provided with a protrusion.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention, by setting up a rod, groove, piercing part, upper mold assembly, and lower mold assembly, enables composite material plates to be connected by self-piercing riveting without pre-drilling holes. The rod with groove and piercing part, in conjunction with the upper mold assembly and lower mold assembly, achieves effective punching and cutting of multi-layer composite material plates. The rod penetrates the multi-layer composite material plate and achieves interlocking riveting of the rod. This not only eliminates the hole-making process and solves the hole-matching problem, but also solves the defects such as cracking and delamination of the riveted section of composite materials. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0013] Figure 1 This is a structural schematic diagram provided by this utility model.

[0014] Figure 2 This is a schematic diagram of the rivet structure provided by this utility model.

[0015] Figure 3 This is a cross-sectional view of the material before punching provided by this utility model.

[0016] Figure 4 This is a cross-sectional view of the material after punching provided by this utility model.

[0017] Figure 5 This is a cross-sectional structural diagram of the riveting material provided by this utility model.

[0018] Figure 6 This is a cross-sectional structural diagram of the material after riveting provided by this utility model.

[0019] In the diagram: 1. Rod; 2. Flange; 3. Groove; 4. Punch section; 5. Pressure ring; 6. Punching die; 7. Through hole; 8. Cutting die; 9. Support die; 10. Tapered hole; 11. Riveting die; 12. Protrusion. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] like Figures 1 to 6 As shown, the rivet for riveting multi-layer composite materials provided in this embodiment of the present invention includes a shank 1 and a flange 2 disposed at one end of the shank 1. A groove 3 is provided at the other end of the shank 1. The groove 3 is disposed in the middle of the end face of the shank 1. A piercing portion 4 is formed on the shank 1 located outside the groove 3.

[0022] When the composite material is punched through the rod 1, the piercing part 4 contacts the composite material. Since the contact area between the piercing part 4 and the composite material is small, the punching pressure can be increased, making it easier to punch and pierce the material. The groove 3 facilitates the riveting of the composite material after punching.

[0023] Furthermore, the cross-section of groove 3 is arc-shaped.

[0024] The device for riveting multi-layer composite materials includes the aforementioned rivets for riveting multi-layer composite materials, and also includes an upper die assembly and a lower die assembly that cooperate with each other. The upper die assembly includes a pressure ring 5 and a punching die 6, which are used to limit and punch the composite material. The lower die assembly includes a cutting die 8 and a support die 9, which can be switched according to processing needs.

[0025] During punching, the composite material is pressed down onto the cutting die 8 by the pressure ring 5, and then the rod 1 is pressed down by the punching die 6 and the external force application tool, so that the rod 1 punches the composite material; during riveting, the upper die assembly and the rod 1 remain unchanged, and the lower die assembly switches to the support die 9 to maintain the clamping force of the pressure ring 5 and the support die 9 on the composite material, so that the riveting work can be carried out.

[0026] Furthermore, a through hole 7 is provided in the middle of the pressure ring 5, and the punching die 6 is movably inserted into the through hole 7, with the diameter of the punching die 6 matching the inner diameter of the through hole 7.

[0027] The rod 1 is placed inside the through hole 7, so that the piercing part 4 fits against the composite material. Then, the punching die 6 is inserted into the through hole 7 and abuts against the flange 2. The rod 1 can be punched by pressing the punching die 6 with an external force tool.

[0028] Furthermore, the top of the cutting die 8 is arc-shaped, and a conical hole 10 is provided in the middle of the cutting die 8. The inner diameter of the top of the conical hole 10 is larger than the diameter of the rod part 1.

[0029] The arc-shaped top of the cutting die 8 allows the composite material to be clamped in a certain arc, thereby transforming the concentrated impact force of the rod 1 on the composite material into a smoother and more uniform stress distribution area during punching, effectively avoiding stress concentration and greatly reducing the risk of composite material delamination and internal microcracks; the tapered hole 10 facilitates the removal and discharge of the punched material.

[0030] Furthermore, a riveting mold 11 is movably sleeved inside the support mold 9, and the top of the riveting mold 11 is provided with a protrusion 12.

[0031] By driving the riveting die 11 upward, the protrusion 12 at its top presses against the puncture part 4 and the groove 3 area, causing the puncture part 4 to deform outward, such as... Figure 6 As shown, this enables the riveting of composite materials.

[0032] Working principle and usage process of this utility model: First, the worker performs punching and piercing: The rod 1 is inserted into the through hole 7, placing the multi-layer composite material sheet between the pressure ring 5 and the cutting die 8, clamping the multi-layer composite material sheet. Then, the punching die 6 is inserted into the through hole 7 and driven downwards. Through the flange 2, the rod 1 impacts and penetrates the composite material sheet, causing the bottom of the rod 1 to enter the conical hole 10, and the punched material falls out from the conical hole 10. Next, the worker performs riveting: Keeping the upper die assembly unchanged, the cutting die 8 is replaced with the support die 9, maintaining the clamping state of the sheet material. The riveting die 11 is driven upwards, and its top protrusion 12 presses against the piercing part 4 and the groove 3 area, causing the piercing part 4 to deform outwards. Figure 6 As shown, this method enables the riveting of composite materials, eliminating the need for drilling and solving the problem of hole alignment. It also addresses defects such as cracking and delamination in the riveted cross-section of composite materials, resulting in high static tensile and fatigue properties after riveting.

[0033] The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A rivet for riveting multiple layers of composite materials, characterized in that: It includes a rod (1) and a flange (2) disposed at one end of the rod (1). A groove (3) is provided at the other end of the rod (1). The groove (3) is disposed in the middle of the end face of the rod (1). A puncture part (4) is formed on the rod (1) located outside the groove (3).

2. The rivet for riveting multi-layer composite materials according to claim 1, characterized in that: The cross-section of the groove (3) is circular arc.

3. A device for riveting multi-layer composite materials, comprising the rivets for riveting multi-layer composite materials as described in any one of claims 1-2, characterized in that: It also includes an upper die assembly and a lower die assembly that cooperate with each other. The upper die assembly includes a pressure ring (5) and a punching die (6) for limiting and punching composite materials. The lower die assembly includes a cutting die (8) and a support die (9). The cutting die (8) and the support die (9) can be switched according to processing needs.

4. The riveting device for multi-layer composite materials according to claim 3, characterized in that: The pressure ring (5) has a through hole (7) in the middle, and the punching die (6) is movably inserted into the through hole (7) and the diameter of the punching die (6) is adapted to the inner diameter of the through hole (7).

5. The riveting device for multi-layer composite materials according to claim 3, characterized in that: The top of the cutting die (8) is arc-shaped, and a conical hole (10) is provided in the middle of the cutting die (8). The inner diameter of the top of the conical hole (10) is larger than the diameter of the rod (1).

6. The riveting device for multi-layer composite materials according to claim 3, characterized in that: The support mold (9) is movably fitted with a riveting mold (11), and the top of the riveting mold (11) is provided with a protrusion (12).

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