TW202130926A - A self-tapping screw - Google Patents

Abstract

A self-tapping screw is provided to overcome the problem of the conventional self-tapping screw forming a bulge or crack on the object surface after being screwed into the object. The self-tapping screw includes a rod having a predetermined length and at least one screw teeth part helically formed on and extended along the rod from the first end to the second end of the rod. The self-tapping screw further includes a tapping part located at the first end of the rod. The self-tapping screw further includes a cap located at the second end of the rod and having a surface and a connection surface. A thickness is between the surface and a connection surface. The maximum outer diameter of the connection surface and the periphery of the cap has a diameter difference, so that a lip forms between the periphery of the cap and the outside of the connection surface. Several cutting edges are located around the connection surface. Each of the several cutting edges has a top. Each of two sides of the top has a cutting arc and an inclined plane.

Description

Self-tapping screws

The invention relates to a self-tapping screw, especially a head design of a self-tapping screw.

Please refer to Figure 1, which is a conventional self-tapping screw 9. The conventional self-tapping screw 9 has a nut 91, a screw 92, and a drill bit 93. A threaded portion 94 spirally surrounds the screw 92. On the outer surface, the nut 91 has a top 95 and a bottom 96. The diameter of the nut 91 decreases from the top 95 to the bottom 96, so that the nut 91 forms an arc, making the conventional The self-tapping screw 9 can be locked into the locked object more easily and smoothly.

As mentioned above, when the conventional self-tapping screw 9 is drilled and locked, the threaded portion 94 can guide the debris generated during the tapping process to the direction of the nut 91. As the screw is locked As the length of entry increases, the amount of these debris also increases and accumulates on the periphery of the keyhole, so that the nut 91 cannot be completely buried in the object to be locked, which will cause the surface of the object to be locked to bulge. Locking the self-tapping screw 9 into the object to be locked will also cause cracks around the keyhole. These protrusions and cracks will not only scratch workers or users, but also affect the overall appearance of the object to be locked.

In view of this, the conventional self-tapping screws do still need to be improved.

In order to solve the above-mentioned problems, the purpose of the present invention is to provide a self-tapping screw, which can cut and refine the chips, so that the chips can be easily removed, so as to avoid the accumulation of chips and cause the surface of the locked object to bulge or produce cracks. .

The directionality described in the full text of the present invention or its similar terms, such as "front", "rear", "left", "right", "up (top)", "down (bottom)", "inner", "outer" , "Side", etc., mainly refer to the directions of the attached drawings, and the terms of directionality or similar terms are only used to assist in the description and understanding of the embodiments of the present invention, and are not intended to limit the present invention.

The elements and components described in the full text of the present invention use the quantifiers "one" or "one" for convenience and to provide the general meaning of the scope of the present invention; in the present invention, it should be construed as including one or at least one, and single The concept of also includes the plural, unless it clearly implies other meanings.

Approximate terms such as "combination", "combination" or "assembly" mentioned in the full text of the present invention mainly include the types that can be separated without destroying the components after being connected, or the components cannot be separated after being connected, which are common knowledge in the field Those can be selected based on the materials of the components to be connected or assembly requirements.

The self-tapping screw of the present invention includes: a rod body with a predetermined length, the rod body is provided with at least one thread part, the thread part starts from the first end of the rod body to the second end Spirally surrounding; a tapping portion located at the first end of the rod; and a cap head located at the second end of the rod, the cap head having a surface and a connecting surface, the surface and the connecting surface There is a thickness between the maximum outer diameter of the connecting surface and the peripheral edge of the cap head, so that a lip is formed between the peripheral edge of the cap head and the outer periphery of the connecting surface. There are two cutting edges, each of the cutting edges has a top, and two sides of the top are respectively provided with a cutting arc surface and an inclined surface.

Accordingly, the self-tapping screw of the present invention can use the cutting edge of the cap head to cut and refine the chip, so that the chip can be easily removed, so as to prevent the chip from accumulating and being locked into the key hole, and then Screw the refined chips into the lock hole by the lip, which can improve the cutting and breaking ability of the self-tapping screw to improve the cutting efficiency of the screw, and can increase the time when the self-tapping screw is combined with the object to be locked. Bonding strength, and can prevent the surface of the object being locked from bulging or cracking.

Wherein, the thickness between the surface and the connecting surface is between 0.5 and 0.9 mm. In this way, it has the effect of improving the structural strength of the cap head.

Wherein, the difference between the maximum outer diameter of the connecting surface and the peripheral diameter of the cap head is between 0.1 mm and 0.5 mm. In this way, it has the effect of improving the bonding strength between the self-tapping screw and the object to be locked.

Wherein, the broken face of the hat head has a central point, and the several cutting edges form equiangular and equidistant rings on the connecting surface, so that there is a gap between the two adjacent cutting edges and the center point of the hat head. A first angle. In this way, it has the effect of improving the cutting efficiency of the screw.

Among them, the number of the cutting edges is an even number and is arranged symmetrically. In this way, it has the effect of improving the locking balance of the screw.

Wherein, the number of the cutting edges is six, so that the angle between the cutting edges is 60 degrees. In this way, the self-tapping screw has the effect of improving the cutting and damaging capabilities of the self-tapping screw.

Wherein, the plurality of cutting edges each have a first end and a second end, the first end is adjacent to the end of the second thread part but not connected to each other, and the second end extends to the peripheral edge of the cap head , So that the second end of the cutting edge protrudes from the lip. In this way, the system has the effect of increasing the cutting ability and making the surface of the object to be locked smoother.

Wherein, the top of each cutting edge is a straight line, and the straight line is inclined and not parallel to the axial center line, so that the straight line has a second included angle when projected on the axial center line. In this way, the cutting edge can firstly cut and refine the chips, which has the effect of avoiding the accumulation of chips.

Wherein, the second included angle is between 5 and 35 degrees. In this way, the cutting edge can firstly cut and refine the chips, which has the effect of avoiding the accumulation of chips.

Wherein, each of the cutting edges respectively has a cutting arc and an inclined surface on two sides of the top, the radial section of the rod body has an arc, and the normal line of the arc through the top forms a datum line, the There is a first angle between the cutting arc and the reference line, and there is a second angle between the inclined surface and the reference line, and the second angle is greater than the first angle. In this way, the two sides of the cutting edge are asymmetrical to each other and form a claw shape, which has the effect of improving the cutting efficiency of the screw.

Wherein, the first angle is between 15 and 20 degrees. In this way, it has the effect of increasing the cutting force and destructive force of the screw.

Wherein, the second angle is between 30 and 37 degrees. In this way, it has the effect of improving the cutting efficiency of the screw.

In order to make the above and other objectives, features and advantages of the present invention more comprehensible, the following describes the preferred embodiments of the present invention in conjunction with the accompanying drawings in detail as follows:

Please refer to Figures 2 and 3, which is a preferred embodiment of the self-tapping screw of the present invention, which includes a rod body 1, a tapping portion 2 and a cap head 3, the tapping portion 2 is located on the rod At the first end of the body 1, the head 3 is located at the second end of the rod body 1.

The rod body 1 has a predetermined length and has an axial centerline X. The rod body 1 has at least one thread portion, and the thread portion starts from the first end of the rod body 1 toward the second In this embodiment, the rod body 1 has a first thread portion 11 and a second thread portion 12, and the first thread portion 11 is formed by the first end of the rod body 1. Starting to spiral around the second end, the second thread portion 12 is connected to the tail end of the first thread portion 11, and continues to spirally loop toward the second end, so that the first thread portion 11 and the The second thread portion 12 is continuously wound around and protrudes on the outer surface of the rod body 1. Preferably, there may be a plurality of chip flutes 13 between each of the first screw thread portions 11, and the chip flutes 13 are surrounded in a continuous spiral and recessed on the outer surface of the rod body 1. , In order to discharge the debris generated in the process of tapping towards the direction of the cap head 3.

The penetration portion 2 is located at the first end of the rod body 1. The penetration portion 2 is the part that first contacts the object to be locked. The penetration portion 2 can be used to create an initial hole on the surface of the object to be locked. Position the screw on the object to be locked to facilitate subsequent tapping. The tapping part 2 can select cutting tails or shovel tailings according to the function, and the present invention is not limited, and only needs to be convenient for the worker to use as the principle.

Please refer to Figure 3, the cap head 3 is located at the second end of the rod body 1 for the user to rotate and press the self-tapping screw into the locked object. The cap head 3 can be In order to be familiar with various structures and shapes, the present invention is not limited. In this embodiment, the cap head 3 is illustrated by taking a circular shape as an example. The cap head 3 has a surface 3a and a connecting surface 3b. There is a thickness T between the surface 3a and the connecting surface 3b. The thickness T is preferably between 0.5 and 0.9 mm to improve the structural strength of the cap head 3. The surface 3a has a lock groove G that can be combined with a driving tool so that the worker can use The driving tool easily rotates the self-tapping screw to screw the cap head 3 into the object to be locked. The lock groove G can be a conventional slot or cross groove, which is not limited by the present invention for the convenience of the worker. The principle is sufficient; the connecting surface 3b is connected to the rod body 1, and the connecting surface 3b is generally arc-shaped and decreases in diameter toward the rod body 1, so that the self-tapping screw can be locked into the object to be locked more easily and smoothly.

Please refer to Figure 4, the maximum outer diameter of the connecting surface 3b and the peripheral edge of the hat head 3 have a diameter difference W, so that a lip is formed between the peripheral edge of the hat head 3 and the outer periphery of the connecting surface 3b In the portion 31, the diameter difference W is preferably between 0.1 and 0.5 mm, so as to improve the bonding strength between the self-tapping screw and the object to be locked. The connecting surface 3b is provided with a plurality of cutting edges 32 in the ring. The cutting edges 32 are used to destroy larger chips or fibers. The cutting edges 32 can form equiangular and equidistant rings. The connecting surface 3b has a first included angle θ1 between the two adjacent cutting edges 32 and the center point M of the hat head 3. Preferably, the number of the cutting edges 32 is an even number and arranged symmetrically, so that the locking balance of the self-tapping screw can be increased. More preferably, the number of the plurality of cutting edges 32 is six, so that the first included angle θ1 between the plurality of cutting edges 32 is 60 degrees at the same time, which can improve the chip cutting and chip cutting of the self-tapping screw. Destructive ability and the effect of increasing the balance of screw locking.

Please refer to FIG. 5, each of the cutting edges 32 has a first end 32a and a second end 32b. The first end 32a is adjacent to the end of the second thread portion 12 but is not connected to each other. The second end 32b extends to the periphery of the cap head 3 so that the second end 32b of the cutting edge 32 protrudes from the lip 31.

Please refer to Fig. 6, each of the cutting edges 32 has a top portion 321. The top portion 321 can be a straight line or a curved line segment. The present invention is not limited, and can effectively reduce the chip cutting as a principle; In this embodiment, the top portion 321 is a straight line, and the straight line is inclined and not parallel to the axial centerline X, so that when the straight line is projected on the axial centerline X, there is a second included angle θ2, and the second The angle θ2 is preferably between 5 and 35 degrees.

Please refer to Figure 7, the cutting edge 32 has a cutting arc surface 322 and an inclined surface 323 on both sides of the top 321 respectively. The normal line of the arc K forms a reference line S, the cutting arc surface 322 and the reference line S have a first angle ø1, the inclined surface 323 and the reference line S have a second angle ø2, the The second angle ø2 is greater than the first angle ø1, so that the two sides of the cutting edge 32 are asymmetrical to each other and form a claw shape to improve cutting efficiency. Preferably, the first angle ø1 is between 15 and 20 degrees, and the second angle ø2 is between 30 and 37 degrees.

In summary, the self-tapping screw of the present invention can use the cutting edge of the cap head to cut and refine the chips, so that the chips can be easily removed, so as to prevent the chips from accumulating and being locked into the lock hole. , And then use the lip to screw the refined debris into the key hole, which can improve the cutting and destruction capabilities of the self-tapping screw to improve the cutting efficiency of the screw, and can increase the coupling of the self-tapping screw to the object to be locked The combination of time and strength, and can prevent the surface of the locked object from bulging or cracking.

Although the present invention has been disclosed using the above-mentioned preferred embodiments, it is not intended to limit the present invention. Anyone who is familiar with the art without departing from the spirit and scope of the present invention may make various changes and modifications relative to the above-mentioned embodiments. The technical scope of the invention is protected. Therefore, the scope of protection of the invention shall be subject to the scope of the attached patent application.

﹝this invention﹞ 1: Rod body 11: The first thread part 12: The first thread part 13: Chip flute 2: Invasion Department 3: hat head 3a: surface 3b: Connection surface 31: Lips 32: cutting edge 32a: first end 32b: second end 321: top 322: Cutting arc 323: Slope G: lock slot K: arc M: center point S: Baseline T: thickness W: Diameter difference X: axial centerline θ1: The first included angle θ2: second included angle ø1: first angle ø2: second angle ﹝Used ﹞ 9: Known self-tapping screws 91: Nut 92: screw 93: Drill 94: Threaded part 95: top 96: bottom

[Picture 1] A picture of a conventional self-tapping screw. [Figure 2] A perspective view of a preferred embodiment of the present invention. [Figure 3] A front view of a preferred embodiment of the present invention. [Picture 4] A cross-sectional view along the line A-A in Fig. 3. [Picture 5] A cross-sectional view along the line B-B in Fig. 4. [Figure 6] A partial enlarged view of the head part of a preferred embodiment of the present invention. [Picture 7] Part C of Fig. 4 is enlarged.

1: Rod body

11: The first thread part

12: The first thread part

13: Chip flute

2: Invasion Department

3: hat head

3a: surface

3b: Connection surface

31: Lips

32: cutting edge

32a: first end

32b: second end

321: top

322: Cutting arc

323: Slope

Claims (12)

A self-tapping screw, including: A rod body having a predetermined length, the rod body is provided with at least one threaded portion, and the threaded portion starts from the first end of the rod body and spirally surrounds the second end; A tapping part located at the first end of the rod body; and A hat head is located at the second end of the rod body. The hat head has a surface and a connecting surface. There is a thickness between the surface and the connecting surface. The peripheral edge has a diameter difference, so that a lip is formed between the peripheral edge of the cap head and the outer periphery of the connecting surface. A plurality of cutting edges are arranged around the connecting surface, and each cutting edge has a top part. The sides are respectively provided with a cutting arc surface and an inclined surface. Such as the self-tapping screw of claim 1, wherein the thickness between the surface and the connecting surface is between 0.5 and 0.9 mm. Such as the self-tapping screw of claim 1, wherein the difference between the maximum outer diameter of the connecting surface and the peripheral diameter of the cap head is between 0.1 mm and 0.5 mm. For example, the self-tapping screw of claim 1, wherein the fracture surface of the cap head has a center point, and the several cutting edges form equiangular and equidistant rings on the connecting surface, so that the adjacent two cutting edges and There is a first included angle between the center points of the hat head. Such as the self-tapping screw of claim 1, wherein the number of the cutting edges is an even number and is set symmetrically. Such as the self-tapping screw of claim 1, wherein the number of the cutting edges is six, so that the angle between the cutting edges is 60 degrees. For example, the self-tapping screw of claim 1, wherein each of the cutting edges has a first end and a second end, and the first end is adjacent to the end of the second thread portion but not connected to each other, the first The two ends extend to the periphery of the cap head, so that the second end of the cutting edge protrudes from the lip. For example, the self-tapping screw of claim 1, wherein the top of each cutting edge is a straight line, and the straight line is inclined and not parallel to the axial centerline, so that when the straight line is projected on the axial centerline, there is a second Angle. Such as the self-tapping screw of claim 8, wherein the second included angle is between 5 and 35 degrees. For example, the self-tapping screw of claim 8, wherein each of the cutting edges has a cutting arc and an inclined surface on two sides of the top, and the radial section of the rod has an arc, and the arc passing through the top The normal line of to forms a reference line, and there is a first angle between the cutting arc and the reference line, and there is a second angle between the inclined surface and the reference line, and the second angle is greater than the first angle. For example, the self-tapping screw of claim 10, wherein the first angle is between 15 and 20 degrees. For example, the self-tapping screw of claim 10, wherein the second angle is between 30 and 37 degrees.

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