A rivet and its processing technology

Abstract

This invention discloses a rivet and its processing technology, comprising a rivet and a collar. The rivet includes a rivet head, a locking groove section, and a short tail connected sequentially from front to back. One end of the collar is connected to a collar flange, and the collar is fitted onto the locking groove section. The yield strength of the collar's sidewall is unevenly distributed. This invention aims to improve the pull-out force of the collar after riveting, prevent rivet failure and pull-out, and improve the stability and reliability of the riveted connection.

Description

Technical Field

[0001] This invention relates to the field of rivet technology, specifically to a rivet and its processing technology. Background Technology

[0002] Currently, the collar (one of the main components) of grooved rivets is made of low-carbon steel and formed by processes such as cold heading. Because the collar material needs to have good toughness and flowability, the collar strength is relatively low, resulting in a smaller pull-out force between the collar and the rivet after riveting. This is somewhat inferior compared to bolts of the same diameter, specification, and grade, thus limiting the product's application range.

[0003] Because collars are manufactured using low-carbon steel and require a certain degree of fluidity in the metal during deformation under the pressure of a conical anvil, they need to possess a certain level of toughness and fluidity during riveting operations. The strength of the collar is always lower than that of the rivet, and the collar's strength has a crucial impact on the pull-out force. Currently used collars are made of low-carbon steel similar to 08A, with a final collar strength of approximately 280HB, while rivets have strength similar to bolts of the same grade, far exceeding the strength of collar components.

[0004] However, when the rivet is subjected to axial tension after riveting, due to the low strength of the collar, the protrusion structure formed by the collar and rivet being squeezed together slips after being subjected to strong shear force. The pull-out force of the riveting connection is insufficient, and the rivet is prone to failure and pull-out, thus affecting the riveting quality. Summary of the Invention

[0005] The purpose of this invention is to provide a rivet and its processing technology to improve the pull-out force of the collar after riveting, avoid rivet failure and pull-out, and improve the stability and reliability of the riveted connection.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following solution:

[0007] A rivet is composed of a rivet and a collar. The rivet includes a rivet head, a locking groove section, and a short tail connected sequentially from front to back. One end of the collar is connected to a collar flange, and the collar is fitted onto the locking groove section. The yield strength of the collar sidewall is unevenly distributed.

[0008] By adopting the above technical solution, the distribution of yield strength on the sidewall of the collar is changed based on the existing rivet, making its yield strength unevenly distributed. The uneven distribution of strength not only ensures the toughness and fluidity required by the collar during riveting and provides effective deformation space, but also improves the material strength at the joint between the collar and the rivet. In this way, when the collar and the rivet are riveted, a greater pull-out force can be provided under the existing assembly process, effectively avoiding rivet failure and pull-out, thus providing higher stability and reliability of the riveting and better connection strength.

[0009] Optionally, after the local reinforcement treatment of the collar, the yield strength of its sidewall is not uniformly distributed along the radial direction of the collar.

[0010] Optionally, the yield strength of the inner side of the collar sidewall is greater than the yield strength of the outer side.

[0011] Optionally, the inner side of the collar is 0.25-0.5 times the collar wall thickness.

[0012] Optionally, the yield strength at the rear end of the collar after local reinforcement treatment is greater than the yield strength before treatment.

[0013] Optionally, the length of the rear end of the collar is 0.1-0.2 times the length of the collar.

[0014] Optionally, the local strengthening treatment may be performed by heat quenching, carburizing, or nitriding.

[0015] A rivet manufacturing process includes the following steps:

[0016] S1: The collar is locally reinforced. After the local reinforcement treatment, the yield strength of the inner side of the collar sidewall is greater than the yield strength of the outer side, and the yield strength of the rear end of the collar is greater than the yield strength of the untreated rear end.

[0017] S10: The range of local reinforcement treatment on the inner side of the collar sidewall is 0.25-0.5 times the sidewall thickness;

[0018] S11: The range of local reinforcement treatment at the rear end of the collar is 0.1-0.2 times the length of the collar;

[0019] S12: Local strengthening treatment is carried out by electromagnetic induction heating quenching, carburizing or nitriding.

[0020] Optionally, local strengthening treatment can be performed by electromagnetic induction heating quenching, with local strengthening treatment being carried out simultaneously on the inner side and rear end of the collar by an inductor.

[0021] The beneficial effects of this invention are as follows:

[0022] 1. In this invention, the improved collar can provide greater pull-out force while maintaining the original assembly process, thus providing better connection strength. In practical applications, smaller rivets can achieve the connection strength previously required by more rivets, thereby reducing costs; it can also be applied to more space-constrained situations, where a smaller number of rivets can achieve the designed connection strength within a limited space; with the same number of rivets, it provides a more reliable connection for the product, improving product quality; this invention promotes the application of riveting technology in various industries from multiple directions.

[0023] 2. The collar adopts a local strengthening process to improve the strength of the front section of the riveting deformation (the rear end of the collar). By increasing the deformation stress at the riveting starting point, the preload of the front section of the riveting process is increased, thereby achieving the effect of providing a strong preload. This can effectively eliminate the gap between components, especially when used for connecting and fastening plate-shaped components and collar flange-type components in large components. During the riveting operation, it can effectively eliminate the connection gap, improve the connection strength of components, and improve product reliability. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention;

[0025] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure of the FF;

[0026] Figure 3 This is a schematic diagram of the structure of the reinforced part inside the collar;

[0027] Figure 4 This is a structural schematic diagram of the reinforced section at the rear end of the collar;

[0028] Reference numerals: 1-nail head, 2-locking groove section, 3-short tail, 4-flanged flange, 5-flanged flange, 6-component, 7-rear end, 8-outer side, 9-inner side. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0030] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "longitudinal," "lateral," "horizontal," "inner," "outer," "front," "rear," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0031] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "have," "install," "connect," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] Example 1

[0033] A rivet is composed of a rivet and a collar. The rivet includes a rivet head 1, a locking groove section 2, and a short tail 3 connected sequentially from front to back. One end of the collar 5 is connected to a collar flange 4. The collar is fitted onto the locking groove section 2. The yield strength of the sidewall of the collar 5 is unevenly distributed.

[0034] In this embodiment, as Figure 1 As shown, the lower end of the collar 5 is integrally connected to the collar flange 4. The rivet and the collar are riveted together by a rivet gun. The rivet gun is existing technology, and the structure of the rivet has not been changed. This solution is based on the existing rivet, but changes the distribution of the yield strength of the side wall of the collar 5 to make its yield strength unevenly distributed. The uneven distribution of strength not only ensures the toughness and fluidity required by the collar during riveting and provides effective deformation space, but also improves the material strength at the joint between the collar and the rivet. In this way, when the collar and the rivet are riveted, a greater pull-out force can be provided under the existing assembly process, effectively avoiding rivet failure and pull-out, thus providing higher stability and reliability of the riveting and better connection strength.

[0035] Furthermore, after the local reinforcement treatment of the collar 5, the yield strength of its sidewall is unevenly distributed along the radial direction of the collar 5.

[0036] Furthermore, the yield strength of the inner side 9 of the collar 5 is greater than the yield strength of the outer side 8.

[0037] Specifically, such as Figure 1-3As shown, after the sidewall of the collar 5 is locally reinforced, the yield strength of the sidewall of the collar 5 is unevenly distributed radially, resulting in a greater yield strength on the inner side 9 of the collar 5 than on the outer side 8. The inner side 9 of the collar 5 is the part directly connected to the locking groove section 2, which has a spiral groove. The riveting method of the rivet is to press the collar 5 onto the locking groove section 2 of the rivet using a rivet gun. After the local reinforcement treatment, the yield strength of the outer side 8 of the collar 5 remains unchanged, retaining its initial toughness and fluidity, while the yield strength of the inner side 9 of the collar 5 increases, and its toughness and fluidity are greater than the initial values. Therefore, after the rivet passes through the two components 6, the collar is placed on the rivet... After the locking groove section 2 of the rivet is engaged, when the rivet gun presses the collar 5, the clamping force required for the outer side 8 of the collar 5 to deform remains unchanged, but the clamping force required for the inner side 9 to deform increases. This causes the inner side 9 to be compressed into a protruding structure. Compared to before the inner side 9 was reinforced, the increased clamping force after treatment results in a stronger bond between the inner side 9 of the collar 5 and the rivet. This leads to a greater axial tensile force on the entire rivet after riveting, and the collar 5 and locking groove section 2 are less prone to slippage after shearing. The improved collar is less likely to fail or pull out after riveting. The improved collar can provide greater pull-out force while maintaining the original assembly process, thus providing better connection strength. In practical applications, smaller rivets can achieve the connection strength previously achieved with more rivets, thereby reducing costs. It can also be applied to more space-constrained situations, where a smaller number of rivets can achieve the designed connection strength within a limited space. With the same number of rivets, it provides a more reliable connection for the product, improving product quality. This invention promotes the application of riveting technology in various industries from multiple directions.

[0038] Furthermore, the inner side 9 of the collar 5 has a range of 0.25-0.5 times the wall thickness of the collar 5. Specifically, the inner side 9 of the collar 5 is the width range of the localized reinforcement treatment, which is 0.25-0.5 times the wall thickness of the collar 5, and the length range is the length of the collar 5. That is, the maximum width range of the localized treatment on the inner side 9 is half the wall thickness of the collar 5, and the remaining half is the outer side 8 of the collar 5.

[0039] Example 2

[0040] Furthermore, the yield strength of the rear end 7 of the collar 5 after local reinforcement treatment is greater than the yield strength before treatment.

[0041] In this embodiment, as Figure 2 and 4As shown, while the inner side 9 of the collar 5 is locally reinforced, the rear end 7 of the collar 5 is also locally reinforced. The rear end 7 refers to the end of the collar 5 away from the collar flange 4. When the rivet is used to rivet the components 6, the rivet passes through the two components 6, and then the collar is installed in the locking groove section 2. The rivet gun will first clamp the short tail 3 of the rivet firmly, pull the rivet gun and squeeze the collar 5 axially, so that the gap between the two components 6 is reduced. Before the rear end 7 of the collar 5 is locally reinforced, when the rivet gun squeezes the starting end of the collar, that is, the rear end 7 of the collar 5, due to the small amount of compression, it can begin to deform under the push of a small axial force, and the relative position of the collar and the rivet ring groove (existing technology) is fixed. When the rivet is used to rivet the components 6 with warped deformation and there is a gap between the components 6, the axial force of the initial deformation of the collar is small and insufficient to eliminate the gap between the components 6, resulting in a gap in the riveted components 6, which affects the final connection quality. If the overall strength of the collar is increased, the riveting force during construction will increase, the extrusion force on the conical anvil inside the rivet gun will increase significantly, and the wear on the conical anvil will also be aggravated, resulting in a significant increase in construction costs.

[0042] In this embodiment, the rear end 7 of the collar 5 is locally reinforced, which increases the yield strength of the rear end 7. Therefore, when the rivet gun presses the rear end 7 of the collar 5, the axial force required for the initial deformation of the rear end 7 of the collar 5 is greater. This increases the preload in the early stage of the riveting process by increasing the deformation stress at the riveting starting point, thereby providing a strong preload. This can effectively eliminate the gap between components 6, resulting in better riveting quality and connection strength. In particular, it is applicable to the connection and fastening of plate-shaped components 6 and the connection and fastening of collar flanges 4 types of components 6 in large components 6. It can effectively eliminate connection gaps, improve the connection strength of components 6, and improve product reliability during riveting operations.

[0043] Furthermore, the length of the rear end 7 of the collar 5 is 0.1-0.2 times the length of the collar 5. The length of the rear end 7 of the collar 5 that undergoes local reinforcement treatment is 0.1-0.2 times the length of the collar 5, which can be adaptively adjusted according to the size of the rivet and the collar.

[0044] Furthermore, the local strengthening treatment employs methods such as heat quenching, carburizing, or nitriding. Local strengthening treatment can take many forms; in this embodiment, electromagnetic induction heating quenching is used, a common heat treatment process. In this embodiment, local strengthening is simultaneously performed on the inner side 9 and rear end 7 of the collar 5 using an inductor. The inductor (existing technology) is a circular ring made of copper square tubing with a height of 10mm. The gap between the inductor and the collar 5 is 1.45-1.55mm. An ultrasonic frequency of 300kHz is selected as the induction frequency, the heating time is 2-3 seconds, the heating temperature is above 800℃, and the required power density is 1.8-2.0KW / cm². The collar 5 rotates at a speed of 5r / s during the heat quenching process. Power density refers to the power value obtained per unit area of ​​the heated surface; this density ensures that the heating speed meets the requirements while reducing heat conduction.

[0045] Example 3

[0046] A rivet manufacturing process includes the following steps:

[0047] S1: The collar 5 undergoes local strengthening treatment. After the local strengthening treatment, the yield strength of the inner side 9 of the collar 5 sidewall is greater than the yield strength of the outer side 8, and the yield strength of the rear end 7 of the collar 5 is greater than the yield strength of the rear end 7 before and after the treatment.

[0048] S10: The range of local reinforcement treatment on the inner side 9 of the sidewall of the collar 5 is 0.25-0.5 times the thickness of the sidewall;

[0049] S11: The range of local reinforcement treatment of the rear end 7 of the collar 5 is 0.1-0.2 times the length of the collar 5;

[0050] S12: Local strengthening treatment is carried out by electromagnetic induction heating quenching, carburizing or nitriding.

[0051] Furthermore, the local strengthening treatment adopts electromagnetic induction heating and quenching. The local strengthening treatment is carried out simultaneously on the inner side 9 and the rear end 7 of the collar 5 through the inductor. The inductor is made of copper square tube into a ring with a height of 10mm. The gap between the inductor and the collar 5 is 1.45-1.55mm. The ultrasonic frequency of 300KHz is selected as the induction frequency, the heating time is 2-3 seconds, the heating temperature is above 800℃, and the power density required for heating is 1.8-2.0KW / cm2. The collar 5 rotates at a speed of 5r / s during the heating and quenching process.

[0052] In this embodiment, the inner side 9 and the rear end 7 of the collar 5 are simultaneously heated and quenched using an electromagnetic induction device, changing the yield strength of the rear end 7 and the inner side 9 of the collar 5. This results in the yield strength of the inner side 9 of the collar 5 being greater than that of the outer side 8, and the yield strength of the rear end 7 of the collar 5 being greater than its initial yield strength. Thus, when riveting the component 6, the axial force required for the rear end 7 of the collar 5 to undergo initial deformation when the rivet gun presses against it is greater. This increases the preload in the early stage of the riveting process by increasing the deformation stress at the riveting starting point, thereby providing a strong preload. This effectively eliminates gaps in the component 6, achieving better riveting quality and connection strength. It is particularly suitable for connecting and fastening plate-shaped components 6 and collar flanges 4 types of components 6 in large components 6. During riveting operations, it can effectively eliminate connection gaps, improve the connection strength of the component 6, and enhance product reliability. When the rivet gun presses against the sidewall of the collar 5, the clamping force required to deform the outer side 8 of the collar 5 remains unchanged, but the clamping force required to deform the inner side 9 increases. This causes the inner side 9 to be compressed into a protruding structure. Compared to before the inner side 9 was reinforced, the increased clamping force after the treatment results in a stronger bond between the inner side 9 of the collar 5 and the rivet. This means the rivet can withstand greater axial tensile force after riveting, and the collar 5 and locking groove 2 are less prone to slippage under shear force, making it less likely to fail or pull out after riveting. The improved collar can provide greater pull-out force while maintaining the original assembly process, thus providing better connection strength. In practical applications, smaller rivets can achieve the connection strength previously required with more rivets, reducing costs. It can also be applied in more space-constrained situations, where a smaller number of rivets can achieve the designed connection strength within a limited space. With the same number of rivets, it provides a more reliable connection for the product, improving product quality.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Based on the technical essence of the present invention, any simple modifications, equivalent substitutions, and improvements made to the above embodiments within the spirit and principles of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A rivet, comprising a rivet and a collar, the rivet including a rivet head (1), a locking groove section (2), and a short tail (3) connected sequentially from front to back, the collar (5) having a collar flange (4) connected to one end, the collar (5) being fitted onto the locking groove section (2), characterized in that, The yield strength of the sidewall of the collar (5) is not uniformly distributed, and the yield strength of the inner side (9) of the sidewall of the collar (5) is greater than that of the outer side (8).

2. The rivet according to claim 1, characterized in that, After the local reinforcement treatment of the collar (5), the yield strength of its sidewall is unevenly distributed along the radial direction of the collar (5).

3. A rivet according to claim 1, characterized in that, The inner side (9) of the collar (5) is 0.25-0.5 times the wall thickness of the collar (5).

4. A rivet according to claim 1, characterized in that, After the local reinforcement treatment of the collar (5), the yield strength of its rear end (7) is greater than the yield strength before the treatment.

5. A rivet according to claim 4, characterized in that, The length of the rear end (7) of the collar (5) is 0.1-0.2 times the length of the collar (5).

6. A rivet according to any one of claims 2 or 4, characterized in that, The local strengthening treatment is carried out by heating and quenching, carburizing, or nitriding.

7. A processing method for a rivet as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: The collar (5) is locally reinforced. After the local reinforcement treatment, the yield strength of the inner side (9) of the collar (5) sidewall is greater than the yield strength of the outer side (8), and the yield strength of the rear end (7) of the collar (5) is greater than the yield strength of the rear end (7) before the treatment. S10: The range of local reinforcement treatment on the inner side (9) of the collar (5) sidewall is 0.25-0.5 times the sidewall thickness; S11: The range of local reinforcement treatment of the rear end (7) of the collar (5) is 0.1-0.2 times the length of the collar (5); S12: Local strengthening treatment is carried out by electromagnetic induction heating quenching, carburizing or nitriding.

8. The processing technology of the rivet according to claim 7, characterized in that, The local strengthening treatment adopts electromagnetic induction heating quenching, and the local strengthening treatment is carried out simultaneously on the inner side (9) and the rear end (7) of the collar (5) by the inductor.

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