Flow drill screw structure capable of effectively preventing looseness

Abstract

The utility model relates to the technical field of flow drill screws, in particular to a flow drill screw structure capable of effectively preventing looseness, which comprises a screw body, one end of the screw body is fixedly connected with a screw cap, the lower end face of the screw cap is provided with a screw cap flange integrated with the screw cap, and the inner side of the periphery of the lower end face of the screw cap flange is provided with a first step surface. A second step surface is arranged on the outer side of the periphery of the lower end surface of the nail cap flange, and the radius of the lower end surface of the nail cap flange is 2.7 mm, so that under the condition that the sizes of the nail caps are consistent, the contact area is increased, the friction force is effectively improved, the widths of the first step surface and the second step surface are 0.07 MM and 0.1 MM respectively, the angle is about 8 degrees formed by outward opening of the nail feet, and the service life of the nail caps is prolonged. The structure is beneficial to adapting to the working condition that the material is soft or hard, when the plate slightly deforms, such as warping or bending, the two steps form the annular protrusion and the annular recess, friction force can be effectively increased, and therefore the purpose of reducing torque attenuation is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of flow drill screws, in particular to a flow drill screw structure which can effectively prevent loosening. Background Art

[0002] With the increasing popularity of new energy vehicles, new body joining technologies have also been developed, especially with the increasing use of aluminum in body-in-white (BIW). In addition to traditional hot joining technologies such as resistance spot welding and arc welding, cold joining technologies such as FDS and SPR have also emerged.

[0003] FDS (Flow Drilling and Screwing) is a cold forming process that uses a central tightening shaft to transmit high-speed rotation from a motor to the sheet metal to be connected. This friction-generated heat causes plastic deformation, which then leads to self-tapping and screwing. The process consists of six stages: rotation (heating) → penetration → through-hole → tapping → threading → tightening.

[0004] The FDS (Flow Drill Screwing) process involves rotating and pressing a screw downward to penetrate the base material and tap the bottom hole, ultimately fully driving the screw into the threaded hole for self-locking securement. Several widely used flow drill screwing equipment brands, such as DEPRAG and GUJ I, feature proprietary controllers. The software in these controllers monitors parameters such as pressure, torque, speed, and position in real time at each process stage. Of particular concern to process and quality control personnel is the torque value during the tightening phase, as it reflects the reliability and stability of the screwing process. This value can be tested offline using a torque wrench to determine if the torque has decayed. Field engineering experience shows that residual torque is typically lower than the set value and can be further reduced by subsequent vibration. This is primarily due to the FDS screwing process, which essentially involves thread tightening. After tightening, the torque decays due to environmental factors. Utility Model Content

[0005] The utility model aims to provide a flow drill screw structure which can effectively prevent loosening and has the characteristics of increasing the friction between the nail cap flange and the wood, thereby achieving the purpose of reducing torque attenuation.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a flow drill screw structure that effectively prevents loosening, comprising a screw body, one end of the screw body is fixedly connected to a nail cap, the other end of the screw body is provided with a striking portion, the lower end face of the nail cap is provided with a nail cap flange that is integral with the nail cap, a first step surface is provided on the inner side of the periphery of the lower end face of the nail cap flange, a second step surface is provided on the outer side of the periphery of the lower end face of the nail cap flange, and the lower end face of the nail cap flange is provided with an inner groove located on the inner side of the first step surface.

[0007] In order to match with the mainstream flow drill screw equipment, as a preferred flow drill screw structure of the present invention that effectively prevents loosening, the maximum diameter of the nail cap flange is 13 mm.

[0008] In order to increase the contact area between the nail cap flange and the wood, as a preferred flow drill screw structure of the present invention that effectively prevents loosening, the radius of the lower end surface of the nail cap flange is 2.7 mm.

[0009] In order to increase the friction force at the bottom of the nail cap flange, as a preferred flow drill screw structure of the present invention that effectively prevents loosening, the widths of the first step surface and the second step surface are 0.07MM and 0.1MM respectively.

[0010] In order to increase the friction force at the bottom of the nail cap flange, as a preferred flow drill screw structure of the present invention that effectively prevents loosening, the first step surface and the second step surface are opened outward by 8-10° from the nail foot.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] The maximum diameter of the nail cap flange is 13mm, and the structure of the top of the nail cap remains unchanged. In this way, mainstream flow drill screw equipment can continue to be compatible with this screw structure. The radius of the lower end face of the nail cap flange is 2.7mm. In this way, when the nail cap size is consistent, the contact area is increased and the friction is effectively improved. The widths of the first step surface and the second step surface are 0.07MM and 0.1MM respectively, and the angle is about 8° from the nail foot to the outside. This structure is conducive to adapting to soft or hard working conditions. When the plate undergoes slight deformation, such as warping or bending, the two steps form annular protrusions and depressions, which can effectively increase friction, thereby achieving the purpose of reducing torque attenuation. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the overall three-dimensional structure diagram of the utility model;

[0014] Figure 2 This is the overall cross-sectional structural diagram of the utility model;

[0015] Figure 3 This is a top view of the overall structure of the utility model;

[0016] Figure 4 For this utility model Figure 2 Enlarged structural diagram of part a in the middle.

[0017] In the figure: 1. Screw body; 2. Nail cap; 3. Screw insertion portion; 4. Nail cap flange; 5. First step surface; 6. Second step surface; 7. Inner groove. DETAILED DESCRIPTION

[0018] See also Figures 1 to 4 A flow drill screw structure that effectively prevents loosening includes a screw body 1, one end of the screw body 1 is fixedly connected to a nail cap 2, the other end of the screw body 1 is provided with a striking portion 3, the lower end surface of the nail cap 2 is provided with a nail cap flange 4 that is integrated with the nail cap 2, a first step surface 5 is provided on the inner side of the periphery of the lower end surface of the nail cap flange 4, a second step surface 6 is provided on the outer side of the periphery of the lower end surface of the nail cap flange 4, and the lower end surface of the nail cap flange 4 is provided with an inner groove 7 located inside the first step surface 5.

[0019] In this embodiment: the maximum diameter of the nail cap flange 4 is 13mm, and the structure of the top of the nail cap 2 is guaranteed to remain unchanged, so that the mainstream flow drilling screw equipment can continue to be compatible with this screw structure. The radius of the lower end surface of the nail cap flange 4 is 2.7mm. In this way, when the size of the nail cap 2 is consistent, the contact area is increased and the friction force is effectively improved. The widths of the first step surface 5 and the second step surface 6 are 0.07MM and 0.1MM respectively, and the angle is about 8° from the nail foot to the outside. This structure is conducive to adapting to soft or hard material conditions. When the plate undergoes slight deformation, such as warping or bending, the two steps form annular protrusions and depressions, which can effectively increase friction, thereby achieving the purpose of reducing torque attenuation.

[0020] As a technical optimization solution of the present invention, the maximum diameter of the nail cap flange 4 is 13 mm.

[0021] In this embodiment, the maximum diameter of the nail cap flange 4 is 13 mm, and the structure of the top of the nail cap 2 is ensured to remain unchanged, so that mainstream flow drilling screw equipment can continue to be compatible with this screw structure.

[0022] As a technical optimization solution of the present invention, the radius of the lower end surface of the nail cap flange 4 is 2.7 mm.

[0023] In this embodiment, the radius of the lower end surface of the nail cap flange 4 is 2.7 mm. In this way, when the size of the nail cap 2 is consistent, the contact area is increased and the friction force is effectively improved.

[0024] As a technical optimization solution of the present invention, the widths of the first step surface 5 and the second step surface 6 are 0.07MM and 0.1MM respectively.

[0025] In this embodiment: the widths of the first step surface 5 and the second step surface 6 are 0.07MM and 0.1MM respectively, and the angle is about 8° outward from the nail foot. This structure is conducive to adapting to working conditions where the material is soft or hard. When the plate undergoes slight deformation, such as warping or bending, the two steps form annular protrusions and depressions, which can effectively increase friction.

[0026] As a technical optimization solution of the present invention, the first step surface 5 and the second step surface 6 are opened outward by 8-10 degrees from the nail foot.

[0027] In this embodiment, the first step surface 5 and the second step surface 6 are opened outward by 8-10 degrees from the nail foot to form an annular protrusion and depression, which can effectively increase the friction force.

[0028] Working principle: The maximum diameter of the nail cap flange 4 is 13mm, and the structure of the top of the nail cap 2 is guaranteed to remain unchanged, so that the mainstream flow drilling screw equipment can continue to be compatible with this screw structure. The radius of the lower end face of the nail cap flange 4 is 2.7mm. In this way, when the size of the nail cap 2 is consistent, the contact area is increased and the friction is effectively improved. The widths of the first step surface 5 and the second step surface 6 are 0.07MM and 0.1MM respectively, and the angle is about 8° from the nail foot to the outside. This structure is conducive to adapting to soft or hard working conditions. When the plate undergoes slight deformation, such as warping or bending, the two steps form annular protrusions and depressions, which can effectively increase friction, thereby achieving the purpose of reducing torque attenuation.

[0029] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A flow drill screw structure that effectively prevents loosening, comprising a screw body (1), characterized in that: One end of the screw body (1) is fixedly connected to a nail cap (2), and the other end of the screw body (1) is provided with a striking portion (3). The lower end surface of the nail cap (2) is provided with a nail cap flange (4) which is integral with the nail cap (2). A first step surface (5) is provided on the inner side of the periphery of the lower end surface of the nail cap flange (4), and a second step surface (6) is provided on the outer side of the periphery of the lower end surface of the nail cap flange (4). The lower end surface of the nail cap flange (4) is provided with an inner groove (7) located on the inner side of the first step surface (5).

2. A flow drill screw structure that effectively prevents loosening according to claim 1, characterized in that: The maximum diameter of the nail cap flange (4) is 13 mm.

3. The flow drill screw structure that effectively prevents loosening according to claim 1, characterized in that: The radius of the lower end surface of the nail cap flange (4) is 2.7 mm.

4. The flow drill screw structure that effectively prevents loosening according to claim 1, characterized in that: The widths of the first step surface (5) and the second step surface (6) are 0.07 mm and 0.1 mm respectively.

5. The flow drill screw structure that effectively prevents loosening according to claim 1, characterized in that: The first step surface (5) and the second step surface (6) are opened outwards by 8-10 degrees from the nail foot.

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