Aluminum bolt for self-piercing riveting of aluminum sheet metal

Abstract

The utility model relates to the technical field of riveting, in particular to an aluminum bolt for self-piercing riveting of an aluminum sheet metal, which comprises an aluminum bolt body, a reinforcing mechanism is arranged at the lower end of the aluminum bolt body and comprises a step table, trapezoidal teeth and a groove, the step table is positioned on the circumferential surface of the aluminum bolt body, and the step table and the aluminum bolt body are fixedly mounted. Each trapezoidal tooth is located on the circumferential surface of the stepped table, each trapezoidal tooth and the stepped table are fixedly installed, a groove is formed between every two trapezoidal teeth, the trapezoidal teeth are arranged on the surface of the stepped table in a circular array mode, the stepped table is partially exposed below the trapezoidal teeth, a polished rod is arranged on the aluminum bolt body, and threads are arranged on the circumferential surface of the polished rod. A matching mechanism is arranged at the lower end of the aluminum bolt body and comprises a riveting die, a cutting boss is arranged at the upper end of the riveting die, a sheet metal part is arranged at the upper end of the cutting boss, and the strength of each trapezoidal tooth can be improved by arranging the trapezoidal teeth on the stepped table and adopting a cold heading machining mode.

Description

Technical Field

[0001] The utility model relates to the technical field of riveting, in particular to an aluminum bolt for self-piercing riveting of aluminum sheet metal. Background Art

[0002] Lightweighting is an important trend in the development of the automotive industry. Aluminum alloys are widely used in automobiles, and a large number of steel-aluminum dissimilar material connections and aluminum-aluminum connections appear on the car body. Traditional welding cannot be applied or the welding effect is poor. Riveting is usually used to achieve the above connection. Compression rivet bolts are a very important connection method used in sheet metal parts. At present, compression rivet bolts are basically made of carbon steel and are treated with electroplating protection to meet the above connection. However, even if the steel compression rivet bolts are treated with surface protection, potential corrosion cannot be avoided when connected with aluminum sheet metal; in addition, due to the different thermal expansion coefficients of steel and aluminum, the riveting points of aluminum plates connected with steel compression rivet bolts may be affected by temperature changes, which may cause connection failure and create safety hazards; at the same time, steel compression rivet bolts do not meet the design principles of lightweighting, and the aluminum compression rivet bolts seen on the market, due to their structure and materials are not enough to meet the self-piercing riveting, the sheet metal needs to be opened, which results in extremely stringent matching requirements between the sheet metal and the bolt riveting area, otherwise it is easy to cause insufficient riveting performance and insufficient practicality, which needs to be improved. Utility Model Content

[0003] 1. Technical issues to be solved

[0004] In view of the deficiencies in the prior art, the utility model provides an aluminum bolt for self-piercing riveting of aluminum sheet metal, which solves the technical problem of insufficient practicality of the prior art devices.

[0005] (II) Technical solution

[0006] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] An aluminum bolt for self-piercing riveting of aluminum sheet metal, comprising an aluminum bolt body;

[0008] A reinforcing mechanism is provided at the lower end of the aluminum bolt body;

[0009] The reinforcing mechanism includes a stepped platform, trapezoidal teeth and grooves. The stepped platform is located on the circumferential surface of the aluminum bolt body, and the stepped platform is fixedly installed on the aluminum bolt body. Each of the trapezoidal teeth is located on the circumferential surface of the stepped platform, and each of the trapezoidal teeth is fixedly installed on the stepped platform. A groove is formed between each of the trapezoidal teeth. The trapezoidal teeth are arranged in a circular array on the surface of the stepped platform, and the stepped platform is partially exposed under the trapezoidal teeth.

[0010] Preferably, a polished rod is provided on the aluminum bolt body, a thread is provided on the circumferential surface of the polished rod, a matching mechanism is provided at the lower end of the aluminum bolt body, the matching mechanism comprises a rivet die, and a cutting boss is provided at the upper end of the rivet die.

[0011] Preferably, a sheet metal part is arranged at the upper end of the cutting boss, the sheet metal part is located between the aluminum bolt body and the rivet die, and the stepped platform, trapezoidal teeth and grooves are all matched with the sheet metal part.

[0012] (III) Beneficial effects

[0013] First, by optimizing the structural design of the aluminum bolt body and using cold heading for processing, the high efficiency and high material utilization rate of the aluminum bolt body can be guaranteed, thereby greatly improving the processing efficiency and material utilization rate, thereby improving practicality, and by optimizing the high-strength aluminum alloy material used in the aluminum bolt body and the reinforcement mechanism, the cold heading of the riveted bolt can be realized, and after aging treatment, ultra-high strength and hardness can be achieved, which provides a guarantee for the self-piercing riveting of common aluminum sheet metal (6000 series). By setting trapezoidal teeth on the stepped platform and using cold heading processing, the strength of each trapezoidal tooth can be improved, which provides a guarantee for the self-piercing riveting and riveting performance;

[0014] 2. By optimizing the strength of the aluminum bolt body and the reinforcement mechanism, a significant difference in strength compared to conventional aluminum sheet metal can be achieved. In combination with the product riveting structure and riveting die, there is no need to open a hole on the lower end face of the sheet metal. The reinforcement mechanism on the aluminum bolt body can directly self-pierce and rivet to achieve connection with the sheet metal, solving the problem of poor matching accuracy between the riveting area in the reinforcement mechanism on the aluminum bolt body and the aperture of the opening, thereby improving practicality. By setting a cutting boss, the cutting boss can be made and the sheet metal can be placed on the cutting boss for riveting. The boss height of the cutting boss and the diameter design that matches the riveting requirements can greatly ensure that the sheet metal is effectively sheared without burrs, while prompting the material to fill the riveting groove in the reinforcement mechanism to ensure the riveting performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the utility model in conjunction with the accompanying drawings.

[0016] Figure 1 It is a planar structural diagram of the utility model;

[0017] Figure 2 This is a plane cross-sectional view of the aluminum bolt body of the utility model;

[0018] Figure 3 This is a planar structural diagram of a polished rod of the utility model;

[0019] Figure 4 This is a riveting diagram of the reinforcing mechanism and the sheet metal part of the utility model.

[0020] Legend: 11. Aluminum bolt body; 12. Polished rod; 13. Thread; 14. Stepped platform; 15. Trapezoidal teeth; 16. Groove; 17. Riveting die; 18. Cutting boss; 19. Sheet metal part. DETAILED DESCRIPTION

[0021] The embodiment of the present application effectively solves the technical problem of insufficient practicality of the existing device by providing an aluminum bolt for self-piercing riveting of aluminum sheet metal. By optimizing the structural design of the aluminum bolt body and adopting cold heading processing, the high efficiency and high material utilization rate of the aluminum bolt body can be guaranteed, thereby greatly improving the processing efficiency and material utilization rate, thereby improving practicality. By optimizing the high-strength aluminum alloy material used in the aluminum bolt body and the reinforcement mechanism, cold heading forming of the riveted bolt can be achieved, and after aging treatment, ultra-high strength and hardness can be achieved, which provides a guarantee for the self-piercing riveting of common aluminum sheet metal (6000 series). By arranging trapezoidal teeth on the stepped platform and adopting cold heading processing, the strength of each trapezoidal tooth can be improved, which can realize self-piercing riveting. The piercing riveting and riveting performance are guaranteed, and by optimizing the strength of the aluminum bolt body and the reinforcement mechanism, a large difference in strength compared to conventional aluminum sheet metal can be achieved. In combination with the product riveting structure and riveting die, there is no need to open a hole on the lower end face of the sheet metal, and the reinforcement mechanism on the aluminum bolt body can directly self-pierce and rivet to achieve connection with the sheet metal, solving the problem of poor matching accuracy between the riveting area in the reinforcement mechanism on the aluminum bolt body and the aperture of the opening, thereby improving practicality. By setting a cutting boss, the cutting boss can be made, and the sheet metal is placed on the cutting boss for riveting, and the boss height of the cutting boss and the diameter design that matches the riveting requirements can greatly ensure that the sheet metal is effectively sheared without burrs, while prompting the material to fill the riveting groove in the reinforcement mechanism to ensure riveting performance.

[0022] Example

[0023] like Figure 1-Figure 4 As shown, the technical solution in the embodiment of the present application effectively solves the technical problem of insufficient practicality of the existing device, and the overall idea is as follows:

[0024] In view of the problems existing in the prior art, the utility model provides an aluminum bolt for self-piercing riveting of aluminum sheet metal, comprising an aluminum bolt body 11;

[0025] A reinforcement mechanism is provided at the lower end of the aluminum bolt body 11;

[0026] The strengthening mechanism includes a stepped platform 14, trapezoidal teeth 15 and a groove 16. The stepped platform 14 is located on the circumferential surface of the aluminum bolt body 11, and the stepped platform 14 is fixedly installed with the aluminum bolt body 11. Each trapezoidal tooth 15 is located on the circumferential surface of the stepped platform 14, and each trapezoidal tooth 15 is fixedly installed with the stepped platform 14. A groove 16 is formed between each trapezoidal tooth 15. The trapezoidal teeth 15 are arranged in a circular array on the surface of the stepped platform 14, and the stepped platform 14 is partially exposed under the trapezoidal teeth 15. By arranging the trapezoidal teeth 15 on the stepped platform 14 and adopting a cold heading process, the strength of each trapezoidal tooth 15 can be improved.

[0027] A polished rod 12 is provided on the aluminum bolt body 11, and a thread 13 is provided on the circumferential surface of the polished rod 12. A matching mechanism is provided at the lower end of the aluminum bolt body 11, and the matching mechanism includes a rivet die 17. A cutting boss 18 is provided on the upper end of the rivet die 17, and a sheet metal part 19 is provided on the upper end of the cutting boss 18. The strengthening mechanism cooperates with the rivet die 17 to directly realize the connection with the sheet metal by self-piercing riveting, which can avoid the situation where the bolt riveting area on the step platform 14 and the aperture matching accuracy of the sheet metal part 19 are poor, thereby improving the processing efficiency. By setting the cutting boss 18, the cutting boss 18 can be made, and the sheet metal part 19 can be placed on the cutting boss 18 for riveting, and the boss height of the cutting boss 18 and the diameter design matching the riveting requirements can greatly ensure that the sheet metal part 19 is effectively sheared without burrs, and at the same time, the material is prompted to fill the bolt riveting groove to ensure the riveting performance.

[0028] The sheet metal part 19 is located between the aluminum bolt body 11 and the rivet die 17. The stepped platform 14, the trapezoidal teeth 15 and the grooves 16 are all adapted to the sheet metal part 19. The sheet metal part 19 is an aluminum alloy sheet metal, usually a T6 state 6000 series extruded aluminum material, corresponding to a yield strength of about 300MPa and a hardness of about 100HV. It is necessary to ensure that the trapezoidal teeth 15 and the grooves 16 on the riveting area of ​​the aluminum bolt body 11 do not deform during riveting, and the sheet metal part 19 needs to be effectively self-piercing and cut. Therefore, the aluminum bolt body 11 and the reinforcement mechanism are made of high-strength aluminum alloy material, (the mass percentage of each component of the alloy wire is: 2-6wt.% Zn, 0.2-6wt.% Mg, 0.2-3wt.% Mn, 0.2-3wt.% Cu, 0.1-2wt.% Sc, 0.1-2wt.% Yb , 0.1~1wt.% Tb, 0.2~2wt.% Zr, and the balance is Al) and the alloy is subjected to a double-stage homogenization treatment, first at 350~460℃ for 4~36h, and then at 470~510℃ for 1h~20h. The aluminum material after homogenization meets the requirement of cold forging 1 / 4 without cracking, ensuring cold heading forming, and then the alloy wire is cold headed, and a multi-station cold heading machine is used to cold head the aluminum bolt body 11 and the reinforcement mechanism. Subsequently, the cold heading blank will be degreased and cleaned, and then a double-stage aging treatment is performed, first at 70~120℃ for 4~36h, and then at 130~210℃ for 1h~36h, to meet the bolt yield strength of more than 450MPa, so the hardness of the sheet metal part 19 can reach more than 170HV.

[0029] The mass percentage of each component of the alloy wire selected for the reinforcement mechanism and the aluminum bolt body 11 can also be: 6wt.% Zn, 2.2wt.% Mg, 1.5wt.% Mn, 2.8wt.% Cu, 0.1wt.% Sc, 0.1wt.% Yb, 0.2wt.% Tb, 0.6wt.% Zr, and the remainder is Al. The alloy is subjected to a double-stage homogenization treatment, first at 380°C for 25h, and then at 450°C for 10h. The aluminum material after the homogenization treatment meets the cold forging 1 / 4 without cracking, and then the alloy wire is cold-forged into M8 specification bolts, and a multi-station cold-forging machine is used to cold-forge the reinforcement mechanism and the aluminum bolt body 11. The reinforcement mechanism and the aluminum bolt body 11 are all cold-forged, and then the cold-forged blank is degreased and cleaned, and then subjected to a double-stage aging treatment, first at 135°C for 24h, and then at 1 After aging treatment at 70℃ for 30h, the yield strength of the reinforcing mechanism and the aluminum bolt body 11 is 515MPa and the hardness is 180HV. The processed reinforcing mechanism and the aluminum bolt body 11 can self-pierce and rivet 6061-T6 aluminum sheet metal with a thickness of T=2.0mm. After riveting, the appearance is intact and free of burrs. The flange surface of the aluminum bolt body 11 fits tightly with the sheet metal part 19, and the lower end surface is flush with the sheet metal part 19. The anti-rotation torque reaches 65Nm, which is much larger than the destructive torque of the aluminum bolt body 11, and the push-out force reaches 4.5kN.

[0030] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present invention, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present invention.

Claims

1. An aluminum bolt for self-piercing riveting of aluminum sheet metal, comprising an aluminum bolt body (11), It is characterized by: The lower end of the aluminum bolt body (11) is provided with a reinforcement mechanism; The reinforcing mechanism comprises a stepped platform (14), a trapezoidal tooth (15) and a groove (16); the stepped platform (14) is located on the circumferential surface of the aluminum bolt body (11); the stepped platform (14) is fixedly mounted to the aluminum bolt body (11); each of the trapezoidal teeth (15) is located on the circumferential surface of the stepped platform (14); each of the trapezoidal teeth (15) is fixedly mounted to the stepped platform (14); and a groove (16) is formed between each of the trapezoidal teeth (15).

2. The aluminum bolt for self-piercing riveting of aluminum sheet metal according to claim 1, characterized in that: The trapezoidal teeth (15) are arranged in a circular array on the surface of the stepped platform (14), and the stepped platform (14) is partially exposed below the trapezoidal teeth (15).

3. The aluminum bolt for self-piercing riveting of aluminum sheet metal as claimed in claim 2, characterized in that: The aluminum bolt body (11) is provided with a polished rod (12); Wherein, the circumferential surface of the polished rod (12) is provided with a thread (13).

4. The aluminum bolt for self-piercing riveting of aluminum sheet metal as claimed in claim 3, characterized in that: The lower end of the aluminum bolt body (11) is provided with a matching mechanism; Wherein, the matching mechanism comprises a riveting die (17), and a cutting boss (18) is provided at the upper end of the riveting die (17).

5. The aluminum bolt for self-piercing riveting of aluminum sheet metal as claimed in claim 4, characterized in that: A sheet metal part (19) is provided at the upper end of the cutting boss (18); Wherein, the sheet metal part (19) is located between the aluminum bolt body (11) and the riveting die (17).

6. The aluminum bolt for self-piercing riveting of aluminum sheet metal as claimed in claim 5, characterized in that: The stepped platform (14), the trapezoidal teeth (15) and the grooves (16) are all adapted to the sheet metal part (19).

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