TWI727578B - Self-drilling screw - Google Patents

Abstract

A self-drilling screw mainly includes a drilling portion formed at a distal end of a drill body, two opposite tapering portions formed on opposite sides of the drill body and connected to opposite cutting edges, and opposite concave surfaces recessedly formed on opposite sides of the drill body and extending from the drilling portion to the tapering portions. The drilling portion is located at a center of a shank. An included angle of the drilling portion is not more than 60 degrees. A distance between a drilling tip of the drilling portion and a head of the screw is larger than a distance between a tapering tip of the tapering portion and the head. An included angle of the tapering portion is not more than 50 degrees. The drilling portion, the tapering portions, and the concave surfaces combine so that the distal end of the drill body presents a shape of a curved bow riser whereby the drilling portion allows the screw to be placed in position and cutting edges and tapering portions help cut a workpiece and drill into the workpiece quickly and sharply. The concave surfaces and opposite discharge grooves formed on opposite sides of the drill body help quick removal of chips caused by the cutting operation, thereby preventing the drilling resistance and the cracking of the workpiece caused by undue accumulation of the chips.

Description

Self-drilling screw

The invention relates to a screw, especially a self-drilling screw.

1, the conventional self-drilling screw 1 includes a screw head 11, a rod body 12 extending outwards from the screw head 11, and a drill tail part 13 provided on the rod body 12 and opposite to one end of the screw head 11. And a plurality of spiral threads 14 arranged on the rod body 12; wherein, the drill tail portion 13 has a drill body 131 extending outward from the rod body 12, and a drill body 131 extending outward from the drill body 131 in an inclined shape The drill tail 13 has at least one chip flute 133 opened on the drill body 131 and the drill tail 132, and a drill portion 134 located at the edge of the drill tail 132, and the aforementioned chip flute 133 and the drill body 131 Two drill blades 135 are formed at the joint, and the drill blades 135 are separately provided on the two sides of the drill portion 134; therefore, the drill portion 134 is in contact with the surface of the lock compound (not shown) and simultaneously applied The screw head 11 presses down torsion force, through the cooperation of the chip groove 133 and the drill edge 135, so that the drill edge 135 can cut the surface of the lock, and the chips generated during the cutting process can pass from the chip groove 133 is discharged, and has the effect of driving the screws 14 to be screw-locked into the lock compound for positioning.

Furthermore, the design of the included angle 134α of the drill portion 134 will affect the sharpness of the drill edge 135 and the drill portion 134 itself. If the included angle 134α of the drill portion 134 is smaller, the sharpness of the drill portion 134α can be effectively improved. Degree, so that the drill 134α can penetrate into the object more easily, and the preliminary positioning effect is better, but the relative area of the drill blade 135 is smaller The reduction reduces the cutting effect, and even makes it impossible to smoothly drive the tail screw 1 into the lock. Therefore, the included angle 134α is usually designed to be above 120 degrees, but it will relatively cause the sharpness of the drill 134 to decrease, resulting in a positioning effect reduce.

Furthermore, when the self-drilling screw 1 is initially locked, it only forms a point contact with the surface of the lock through the drill portion 134. If the surface of the lock is smooth, the friction generated by it will be reduced Therefore, if the drill portion 134 is not sharp enough, the drill portion 134 cannot be effectively positioned on the lock member, so that the tail drill screw 1 is likely to slip during the screw-locking process and cause deviation. The skew phenomenon causes the lock to be skewed and difficult to lock, and it also causes inconvenience in the lock cooperation industry. At the same time, it also damages the surface of the lock during the locking process. In addition, during the locking process, it uses two drill blades 135 When cutting the lock compound, the chips will be cut from the center of the two drill edges 135 and produce chips, and the chips are easy to accumulate and block at the entrance of the chip flute 133, resulting in increased resistance. At the same time, the chips will also be It is easy to expand and squeeze outwards and cause cracking of the lock compound, which needs to be improved.

Therefore, the object of the present invention is to provide a self-drilling screw, which can achieve accurate, fast and stable locking, and can also reduce the locking resistance and prevent the occurrence of material cracking during the locking process.

Therefore, the tail screw of the present invention is mainly in that the drill body of the drill body has a drill part, which is formed on both sides of the drill body and the tips connected with the cutting edge, and are respectively recessed on the drill body And a concave arc surface extending from the drill portion to the tip portion; wherein the end of the drill portion is formed with a drill tip located on the center of the rod body, and the tip A tip is formed at the end of the tip, and the included angle of the drill does not exceed 60 degrees, and the distance between the tip of the drill and the screw head is greater than the distance between the tip of the tip and the screw head, and the included angle of the tips does not exceed 50 degrees, so A concave arc surface is provided between the drill part and the tip part, and the tail part of the drill can be formed into a chord-cut arc shape from the drill part to the tips on both sides; therefore, the drill part can be positioned on the object at the beginning of locking The sharp parts can be used for planing the object to be screwed in with precise, fast and sharp cutting, and the chips produced by cutting can quickly pass through the concave arc surface and chip flute to quickly evacuate the chips, and at the same time, they can be discharged during the process. The chips can be cut by the cutting edge, which can effectively avoid the resistance and material cracking caused by the entanglement and accumulation of the chips.

[Learning]

1: Self-drilling screw

11: Screw head

12: Rod body

13: Drill the tail

14: Thread

131: Drill Body

132: Drill Tail

133: Chip flute

134: Drill Department

135: Drill Blade

[this invention]

3: Self-drilling screws

31: Screw head

32: Rod body

33: Drill tail

34: Thread

32a: The center of the rod

311: Bottom

331: drill body

332: Chip flute

333: cutting edge

334: concave arc

3311: Drilling Department

33111: drill point

3331: Tip

33311: knife point

4: Object

3311α: included angle of drill

3331α: the angle of the tip

35: cutting groove

Figure 1 is a schematic diagram of a conventional self-drilling screw.

Fig. 2 is a schematic diagram of the first preferred embodiment of this embodiment.

Fig. 3 is a schematic diagram of the tail drilling of the first preferred embodiment of this embodiment.

Fig. 4 is a schematic bottom view of the first preferred embodiment of this embodiment.

Fig. 5 is a cross-sectional view taken along line A-A in Fig. 3.

Fig. 6 is a schematic diagram of the operation of the first preferred embodiment of this embodiment.

Fig. 7 is a schematic diagram of a second preferred embodiment of this embodiment.

The foregoing and other technical content, features, and effects of the present invention will be clearly understood in the following detailed description of the preferred embodiment with reference to the drawings.

2, the first preferred embodiment of the self-drilling screw 3 of the present invention. The self-drilling screw 3 includes a screw head 31, a rod body 32 extending outward from the screw head 31, and a rod body 32 disposed on the rod body 32 On and opposite to the drill tail 33 at one end of the screw head 31, and multiple spirals Thread 34 ringed on the rod body 32; wherein, the drill tail portion 33 has a drill body 331 extending outward from the rod body 32, respectively formed on both sides of the drill body 331 and arranged in staggered chip removal The groove 332 and the cutting edge 333 formed at the junction of the drill body 331 and the chip flute 332.

3, 4, and 5, the drill body 331 has a drill portion 3311, which is respectively provided at the tip portion 3331 of the free end of the cutting edge 333, and is recessed on the drill body 331 and is respectively formed by the drill portion 3311 A concave arc surface 334 extending to the tip portion 3331; wherein the end of the drill portion 3311 is formed with a drill point 33111 located on the center of the rod body 32, and the end of the tip portion 3331 is formed with a knife point 33311, and the drill The included angle 3311 α of the portion 3311 does not exceed 60 degrees, and the optimal range of the included angle 3311 α of the drill portion 3311 is between 30 and 60 degrees, and the distance between the drill point 33111 and the screw head 31 is greater than that of the tool point 33311 and the screw head 31 At the same time, the included angle 3331 α of the pointed parts 3331 does not exceed 50 degrees, and the best range of the included angle 3331 α of the pointed parts 3331 is between 30 and 50 degrees, and the included angle 3311 α is greater than each included angle 3331 α Therefore, the design of the drill portion 3311 and the tip portion 3331 is beneficial to achieve better sharpness and effectively reduce resistance.

As mentioned above, when viewed from the drill body 331 in the direction of the screw head 31, the cutting edge 333 extends counterclockwise, so that the cutting edge 333 is curved in the chip flute 332, that is, when the cutting edge 333 is locked, the cutting edge 333 is The rotation lock direction is the same, so that the cutting edge 333 can cut more smoothly and sharply; in addition, when viewed from the drill body 331 toward the screw head 31, the tip 3331 extends counterclockwise, so that the drill tail 33 forms a chord. Cut into an arc shape (as shown in Figure 4).

Referring to Figure 6, when the self-drilling screw 3 is screwed to an object 4, it should be When the drill body 331 touches the object 4, since the drill portion 3311 protrudes from the tip portion 3331, the drill portion 3311 will contact the object 4 at a single point, and through the sharpness design of the drill portion 3311, It is easier to pierce into the object 4 for positioning. At the same time, when the drill point 33111 is partially submerged in the object 4, the tool point 33311 will be able to contact the object 4, and because the tool point 33311 is set facing the twistlock direction, At this time, a three-point type can be formed for preliminary cutting of the object 4, and at the same time, the drill portion 3311, the tip portion 3331 and the other tip portion 3331 can be formed into a rotary cutting state, and the tip portion 3311 faces the twistlock direction. In addition, as shown in FIG. 2, each concave arc surface 334 extends from the drill tip 33111 toward each tip 3331 to meet the tip 33311 of the tip of the tip 3331, so that the tip 3311 The object 4 can be cut more sharply, and the friction surface between the drill body 331 and the object 4 is reduced, and the resistance of the twist lock is reduced. The chip flute 332 extends from the drill portion 3311 to the outside of the tip portion 3331, In addition, the chips generated during the twist-locking process of the drill portion 3311 and the tip portion 3331 can be directly discharged through the chip groove 332. At the same time, the design of the concave arc surface 334 can reduce the drill body 331 and the object. The contact area of 4 can reduce friction and locking resistance. At the same time, part of the chips can also be discharged into the chip groove 332 through the concave arc surface 334, which effectively improves the smoothness of chip removal and avoids the cracked material caused by chip blockage. Love affairs.

As mentioned above, when the chips are discharged to the chip flute 332, since the cutting edge 333 is provided on the edge of the chip flute 332, when the chips are discharged through the chip flute 332, the cutting edge 333 will be able to Cut the chips to prevent the chips from being entangled on the drill body 331, reduce the locking resistance and increase the locking speed, plus smooth chip evacuation and avoid fiber entanglement in the chips, so the tail screw 3 is no matter the cutting It has significant effects on reducing process resistance, increasing locking speed and preventing material splitting.

7 is a second preferred embodiment of the self-drilling screw 3 of the present invention. The self-drilling screw 3 includes a screw head 31, a rod body 32 extending outward from the screw head 31, and a rod body 32 disposed on the rod body. 32 and opposite to the drill tail portion 33 at one end of the screw head 31, and a plurality of components such as the screw thread 34 arranged on the rod body 32, and the foregoing components are the same as the first embodiment, and will not be described in detail, especially : In this embodiment, the bottom surface 311 of the screw head 31 is provided with a plurality of cutting grooves 35. Therefore, when the self-drilling screw 3 is locked to the screw head 31, the cutting grooves 35 can level the chips. The tightness of the locking screw 31 is better.

Summarizing the foregoing, the main feature of the drill tail screw of the present invention is that the drill tail is provided with a drill part, a tip, a cutting edge, a concave arc surface, etc.; wherein, the end of the drill tail is formed with a drill part, and the cutting edge end is formed with a tip Therefore, the design of the drill and the tips on both sides will make the tail end of the drill form a chord cutting state, so that the two tips can be accurately, quickly and sharply cut and screwed into the outside under the positioning of the drill, and through The concave arc surface and chip flute can quickly provide chip removal, effectively avoiding resistance and material cracking caused by chip accumulation.

However, what has been described above is only to illustrate the preferred embodiments of the present invention, and should not be used to limit the scope of implementation of the present invention, that is, simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the description of the invention. , Should still fall within the scope of the invention patent.

3: Self-drilling screws

31: Screw head

32: Rod body

33: Drill tail

34: Thread

32a: The center of the rod

331: drill body

332: Chip flute

333: cutting edge

334: concave arc

3311: Drilling Department

33111: drill point

3331: Tip

33311: knife point

3311α: included angle of drill

3331α: the angle of the tip

Claims (4)

A self-drilling screw, which is locked into an object in a twisting direction, includes a screw head, a rod body extending outward from the screw head, and an end on the rod body opposite to the screw head The tail part of the drill body, and a plurality of spiral threads arranged on the rod body; wherein, the tail part of the drill body has a drill body extending outward from the rod body, respectively formed on both sides of the drill body and arranged in staggered rows Chip flutes, and cutting edges respectively formed at the junction of the drill body and the chip flutes; characterized in that: the end of the drill body is formed with a drill part, which is respectively formed on both sides of the drill body and is connected to the cutting edge The tip portion and the concave arc surface respectively recessed on the drill body and extending from the drill portion to the tip portion; wherein the end of the drill portion is formed with a drill tip located on the center of the rod body, and the The tip of the tip is formed with a tip that is connected to the cutting edge, and the included angle of the drill is 30-60 degrees, and the distance between the drill tip and the screw head is greater than the distance between the knife tip and the screw head, and the The included angle of the tip is 30-50 degrees, the included angle of the drill is greater than the included angle of the tips, and each concave arc surface extends from the drill tip toward each tip to meet the knife at the end of the tip tip. The self-drilling screw according to item 1 of the scope of patent application, wherein the cutting edge extends counterclockwise when viewed from the drill body in the direction of the screw head, so that when the drill body is locked, the cutting edge faces the spinlock direction. According to the self-drilling screw described in item 1 of the scope of patent application, when viewed from the drill body in the direction of the screw head, the tip extends counterclockwise so that the drill body can be locked When it is time, the tip of the knife faces the direction of the twist lock. According to the self-drilling screw described in item 1 of the scope of patent application, the bottom surface of the screw head is provided with a plurality of cutting grooves.

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