Flow drill screw convenient to install

Abstract

The utility model relates to a flow drill screw convenient to install, which comprises a screw body, and a nut part, a thread part, a positioning part, a pyramid part and a centering part are sequentially distributed on the screw body from top to bottom along the central axis of the screw body. The spiral tooth starts from the second arc, farthest from the central axis, of the positioning part and stops at the lowest position of the thread in the thread part, when the spiral tooth rotates and moves downwards relative to a workpiece, the cutting amount of the spiral tooth is slowly increased, the function of guiding tapping is achieved, and the self-tapping installation efficiency of the screw is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of fasteners, and particularly relates to a flow drill screw convenient for installation. Background Art

[0002] The flow drill screw is a fast-installing self-tapping screw made of steel and passivated by surface galvanizing, and is mostly used for connecting thin metal plates. When connecting, first make a bottom hole in the workpiece to be connected, and then screw the self-tapping screw into the threaded bottom hole of the workpiece to be connected. The threaded part of the self-tapping screw functions as a tap to cut the thread connected to itself.

[0003] Among them, the application number CN2024204545711 discloses a new type of flow drill screw, which includes a screw body. The screw body is sequentially distributed with a nut part, a threaded part, a positioning part and a taper part from top to bottom. Among them, the positioning part plays a positioning role, and the threaded part is used for tapping. When the screw body is installed, a transition structure is required between the positioning part and the threaded part to improve the tapping efficiency. Content of the Utility Model

[0004] In order to overcome the deficiencies of the background art, the technical solution adopted by the utility model is: a flow drill screw convenient for installation, including a screw body. The screw body is sequentially distributed with a nut part, a threaded part, a positioning part, a pyramid part and a centering part along its central axis from top to bottom. The cross-section of the positioning part is approximately arc-shaped triangle, and the cross-section of the pyramid part and the cross-section of the positioning part are similar figures. The positioning part is provided with a first arc distributed in a circumferential manner, and a second arc connecting adjacent first arcs. The distance from the first arc to the central axis is less than the distance from the second arc to the central axis. A spiral tooth is provided between the threaded part and the positioning part. One end of the spiral tooth is connected to the second arc, and the other end is smoothly connected to the threaded part.

[0005] By adopting the above technical solution, during the installation process of the screw body, the centering is carried out by the centering part in sequence, the pyramid part enlarges the hole of the workpiece, the positioning part is clamped into the enlarged hole and positioned, and the threaded part taps and locks the workpiece. Since the cross-sectional shapes of the positioning part and the pyramid part are non-circular, it has the effect of balancing air pressure and heat dissipation during hole enlargement and positioning. A turn of spiral teeth is provided between the threaded part and the positioning part. The spiral teeth start from the second arc farthest from the central axis of the positioning part and end at the lowest position of the thread in the threaded part. When the spiral teeth rotate and move downward relative to the workpiece, the cutting amount slowly increases, which has the function of guiding tapping and improves the self-tapping installation efficiency of the screw.

[0006] The utility model is further provided that the positioning part is provided with a chip removal groove corresponding to the threaded part.

[0007] Furthermore, the spiral tooth is provided with an outer contour line. One end of the outer contour line is connected to the position near the midpoint c of the second arc, and the other end is tangent to the top surface of the threaded part.

[0008] Further, the pitch of the thread portion is the same as that of the spiral teeth, and the outer contour line is a spiral line with a gradually increasing radius centered on the central axis.

[0009] Further, a fillet surface is provided between the spiral teeth located between the outer contour line and the positioning portion.

[0010] Adopting the above technical solution, taking an M5 model screw as an example, the vertical distance from the starting point a of the spiral teeth to the central axis is 2.06 mm, the vertical distance from the ending point b of the spiral teeth to the central axis is 2.55 mm, the pitch of both the spiral teeth and the thread portion is 0.8 mm, and the radius of the fillet surface is 0.6 mm; the vertical distance from the midpoint c of the second arc to the central axis is 2.07 mm. The midpoint c is the point farthest from the central axis in the positioning portion and is the support point between the positioning portion and the mounting hole. The starting point a serves as the cutting point and is located on the side of the support point closer to the tapping direction, enabling the screw to first support and position and then cut and tap during tapping, and the overall structural design is reasonable.

[0011] The present utility model is further configured such that the pyramid portion is provided with a first conical surface and a second conical surface corresponding to the first arc and the second arc respectively. In the same cross-section of the pyramid portion, the maximum distance from the first conical surface to the central axis is less than the maximum distance from the second conical surface to the central axis.

[0012] Adopting the above technical solution, the first arc and the second arc are respectively connected to the centering portion through the first conical surface and the second conical surface for transition. During the reaming of the pyramid portion, the second conical surface always abuts against the mounting hole of the workpiece, and there is a gap between the first conical surface and the mounting hole for balancing air pressure and dissipating heat to improve the reaming efficiency.

[0013] The present utility model is further configured such that a support ring is provided at the bottom of the nut portion, and a receiving groove is formed between the thread portion and the support ring.

[0014] Adopting the above technical solution, during the installation process of the screw body, the surface of the bottom hole of the workpiece will deform and form a convex block. The receiving groove of the nut portion is used to receive the convex block, enabling the support ring to abut against the surface of the workpiece, and having a strong locking effect.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0016] There is one turn of spiral teeth between the thread portion and the positioning portion. The spiral teeth start from the second arc of the positioning portion farthest from the central axis and end at the lowest position of the thread in the thread portion. When the spiral teeth rotate and move downward relative to the workpiece, the cutting amount thereof slowly increases, having the function of guiding tapping and improving the self-tapping installation efficiency of the screw.

[0017] The following further illustrates the embodiments of the present utility model with reference to the accompanying drawings. Brief Description of the Drawings

[0018] Figure 1 is a perspective view of the first embodiment of the present utility model;

[0019] Figure 2 is a bottom view of the first embodiment of the present utility model;

[0020] Figure 3 is a cross-sectional view of the positioning portion of the first embodiment of the present utility model;

[0021] Figure 4 of the present utility model Figure 1 is a partially enlarged view of the view in the direction A;

[0022] Figure 5 of the present utility model Figure 2 is a partially enlarged view of the view in the direction B;

[0023] Figure 6 is a perspective view of the second embodiment of the present utility model;

[0024] Wherein: 1 - screw body, 2 - nut portion, 3 - thread portion, 4 - positioning portion, 5 - pyramid portion, 6 - centering portion, 7 - spiral tooth, 10 - axis, 11 - outer contour line, 12 - rounded surface, 21 - support ring, 22 - receiving groove, 31 - top surface, 40 - chip removal groove, 41 - first arc, 42 - second arc, 51 - first conical surface, 2 - second conical surface 52; Detailed Description of the Preferred Embodiments

[0025] As Figures 1-3 shown, the present embodiment provides a first embodiment of a flow drill screw that is convenient for installation, including a screw body 1. The screw body 1 is sequentially provided with a nut portion 2, a thread portion 3, a positioning portion 4, a pyramid portion 5, and a centering portion 6 along its axis 10 from top to bottom. The cross-section of the positioning portion 4 is approximately arc-shaped triangular, and the cross-section of the pyramid portion 5 and the cross-section of the positioning portion 4 are similar figures. The positioning portion 4 is provided with first arcs 41 distributed in a circumferential manner, and second arcs 42 connecting adjacent first arcs 41. The distance from the first arc 41 to the axis 10 is less than the distance from the second arc 42 to the axis 10. A spiral tooth 7 is provided between the thread portion 3 and the positioning portion 4. One end of the spiral tooth 7 is connected to the second arc 42, and the other end is smoothly connected to the thread portion 3 in a transitional manner.

[0026] Combined with Figure 4 , 5As shown in the figure, in this embodiment, the spiral tooth 7 is provided with an outer contour line 11. One end of the outer contour line 11 is connected to a position near the midpoint c of the second arc 42, and the other end is tangent to the top surface 31 of the thread portion 3. The thread portion 3 has the same pitch as the spiral tooth 7. The outer contour line 11 is a spiral line with a gradually increasing radius centered on the central axis 10. There is a fillet surface 12 between the spiral tooth 7 located between the outer contour line 11 and the positioning portion 4.

[0027] In this embodiment, the pyramid portion 5 is provided with a first conical surface 51 and a second conical surface 52 corresponding to the first arc 41 and the second arc 42 respectively. In the same cross-section of the pyramid portion 5, the maximum distance from the first conical surface 51 to the central axis 10 is less than the maximum distance from the second conical surface 52 to the central axis 10. The first arc 41 and the second arc 42 are respectively connected to the centering portion 6 through the transition of the first conical surface 51 and the second conical surface 52. When the pyramid portion 5 reams the hole, the second conical surface 52 always abuts against the mounting hole of the workpiece, and there is a gap between the first conical surface 51 and the mounting hole for balancing air pressure and heat dissipation to improve the reaming efficiency.

[0028] As Figure 2 shown, in this embodiment, a support ring 21 is provided at the bottom of the nut portion 2. A receiving groove 22 is formed between the thread portion 3 and the support ring 21. During the installation of the screw body 1, the bottom hole surface of the workpiece will deform and form a convex block. The receiving groove 22 of the nut portion 2 is used to receive the convex block, so that the support ring 21 can abut against the workpiece surface, having a strong locking effect.

[0029] A second embodiment of a flow drill screw that is easy to install is provided in this embodiment. The different technical feature from the first embodiment is that the positioning portion 4 is provided with a chip removal groove 40 corresponding to the thread portion 3; when machining the thread portion 3, the thread length is increased, thereby naturally forming the chip removal groove 40, reducing the torque during installation, and being applicable to the structure of a longer flow drill screw.

[0030] The working principle of the present invention is that during the installation of the screw body 1, the centering is sequentially performed by the centering portion 6, the pyramid portion 5 reams the hole of the workpiece, the positioning portion 4 is inserted into the reamed hole for positioning, and the thread portion 3 taps and locks the workpiece. Since the cross-sectional shapes of the positioning portion 4 and the pyramid portion 5 are non-circular, they have the effect of balancing air pressure and heat dissipation during reaming and positioning. There is one turn of spiral teeth 7 between the thread portion 3 and the positioning portion 4. The spiral teeth 7 start from the second arc 42 of the positioning portion 4 that is farthest from the central axis 10 and end at the lowest position of the thread in the thread portion 3. When the spiral teeth 7 rotate and move downward relative to the workpiece, the cutting amount slowly increases, having the function of guiding tapping and improving the self-tapping installation efficiency of the screw.

[0031] The above are all preferred embodiments of the present application, and do not limit the protection scope of the present application. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A flow drill screw that is easy to install, comprising a screw body (1), characterized in that: The screw body (1) is provided with a nut portion (2), a threaded portion (3), a positioning portion (4), a pyramid portion (5) and a centering portion (6) in order from top to bottom along its central axis (10); the cross section of the positioning portion (4) is approximately in the shape of an arc triangle, and the cross section of the pyramid portion (5) is similar to the cross section of the positioning portion (4); the positioning portion (4) is provided with first arcs (41) distributed in a circumferential manner, and second arcs (42) connected between adjacent first arcs (41); the distance between the first arc (41) and the central axis (10) is smaller than the distance between the second arc (42) and the central axis (10); a spiral tooth (7) is provided between the threaded portion (3) and the positioning portion (4); one end of the spiral tooth (7) is connected to the second arc (42), and the other end is smoothly transitioned and connected to the threaded portion (3).

2. The flow drill screw that is easy to install according to claim 1, characterized in that: The positioning portion (4) is provided with a chip removal groove (40) corresponding to the threaded portion (3).

3. A flow drill screw that is easy to install according to claim 1 or 2, characterized in that: The spiral tooth (7) is provided with an outer contour line (11), one end of the outer contour line (11) is connected to the midpoint c of the second arc (42), and the other end is tangent to the top surface (31) of the threaded portion (3).

4. The flow drill screw that is easy to install according to claim 3 is characterized by: The threaded portion (3) has the same pitch as the spiral teeth (7), and the outer contour line (11) is a spiral line with a gradually increasing radius with the central axis (10) as the center.

5. The flow drill screw that is easy to install according to claim 4, characterized in that: The spiral tooth (7) is provided with a rounded surface (12) between the outer contour line (11) and the positioning portion (4).

6. A flow drill screw that is easy to install according to claim 1 or 2, characterized in that: The pyramidal portion (5) is provided with a first conical surface (51) and a second conical surface (52) respectively corresponding to the first circular arc (41) and the second circular arc (42); in the same cross section of the pyramidal portion (5), the maximum distance from the first conical surface (51) to the central axis (10) is smaller than the maximum distance from the second conical surface (52) to the central axis (10).

7. A flow drill screw that is easy to install according to claim 1 or 2, characterized in that: A supporting ring (21) is provided at the bottom of the nut portion (2), and a receiving groove (22) is formed between the threaded portion (3) and the supporting ring (21).

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