TW201428192A - Structure and manufacturing method of self-tapping screws - Google Patents

Abstract

The structure and manufacturing method of self-tapping screws are mainly directed to the manufacturing method and structure improvement of chip grooves in self-tapping screws. The manufacturing method of a chip groove uses molds for compression molding, structurally characterized in that the chip groove is installed at the top end of the self-tapping screw, and the chip groove is a symmetric bevel groove which is helpful to remove chips and without causing chip obstruction to affect the operation.

Description

Self-tapping screw structure and manufacturing method

The invention relates to a structural improvement of a self-tapping screw. When a self-tapping screw is drilled into a workpiece, a waste material generated in a drill portion thereof is formed, and a chip flute is designed at a rear end portion of the cutting bit to prevent accumulation of waste. The self-tapping screw drills into the workpiece and enhances its cutting speed and the hole that slides out of the workpiece. The invention relates to a self-tapping screw having a screw head, a self-drilling cutting tip and a chip flute connecting the tip and the shank.

According to the conventional case, the patent number I311505 "a type of tail screw forming method" is that a head is punched from the upper end of a rod-shaped blank, and a tail is punched out at the lower end, and the tail end has a tapered surface. There are two symmetrical flutes and cutting edges on the tail of the drill, and then the two clamps respectively clamp the rod-shaped blank and the end of the drill tail, so that one of the clamps rotates at an angle to make the flute of the drill tail And the cutting edge is twisted to form a symmetrical spiral shape, and then the external thread is formed on the outer edge of the rod-shaped blank to form a finished screw with a spiral chip flute and a cutting edge.

A drill tail screw having a head at the upper end, an external thread on the shaft body, a drill tail portion at the lower end, and a tapered surface at the end of the drill tail, characterized in that the drill tail has two symmetric spiral flutes and cutting The blade is convenient for the locking action.

In the above-mentioned conventional patent case, the main method is to manufacture the method and structure of the chip flute of the self-tapping screw, but in the process of processing, it is necessary to perform secondary processing work, and there is a way to make the chip flute forming, and to achieve two symmetry. The self-tapping screws of the spiral flutes, therefore, the process of the self-tapping screws is too slow and the processing cost is high, and the competition in the market has yet to be tested. Moreover, the flutes are rotated by the clamps. Spiral chip flutes, which also have problems with the flute structure. Because they are spiral flutes that rotate radially around the screw, they form a space for arranging a circle of debris, which will cause waste. The chips are stuck in the swirling space of the flutes, so the waste can not be completely discharged.

Self-tapping screws are usually drilled directly into the workpiece, for example, concrete or similar wood or steel, and the scraps stuck in the flutes cannot be effectively removed. All the debris, this result may affect the pre-drilling process, including the speed, quality of the hole, or the hole wall that is inserted into the hole of the workpiece that may not be fastened by the self-tapping screw. unit.

In order to effectively and improve the drilling speed of the self-tapping screw, and to effectively discharge the waste to securely insert the workpiece, it is necessary to improve the manufacturing method and structure of the chip flute of the existing self-tapping screw, and the main method of the present invention The purpose is to provide a self-tapping screw with a better chip removal function at the processing end and a self-tapping screw with a chip evacuation structure in a quick process.

The invention provides a self-tapping screw having a screw head, a self-drilling tip, a threaded portion and a smoothing handle; the threaded portion abuts the smoothing handle, the smoothing handle is directly adjacent to the screw head, and follows the threaded portion to the self-drilling tip There is a chip flute between them, the main feature is that the chip flute is formed by two symmetrical but staggered inclined arc grooves.

The self-drilling tip has two oblique cutting edges to facilitate drilling into the workpiece and cutting the workpiece into the hole. The scraped material from the workpiece during the drilling process will slide from the flute. Out.

The main feature of the present invention is the chip flute structure, wherein the center of the self-drilling tip is a circumferential reference line, and the reference line is an axial extension. The chip flute starts from the lowest point of the self-drilling tip cutting line and extends obliquely. Crossing the reference line, a diagonal arc groove surface is formed, and the opposite side of the chip flute starts from the lowest point of the self-drilling tip blade cutting surface in a symmetrical cross direction, and extends obliquely across the reference line to form an oblique line. The torsion arc groove surface is twisted for about half a circle; in addition, the edge line of the side edge of the thread portion is started from the lowest point of the blade edge on both sides of the blade front surface, and is an extension of an angle of 5 degrees to 10 degrees. The edges are also symmetrically staggered and become the facet lines outside the flutes.

The fourth figure is another embodiment of the structure and the manufacturing method of the self-tapping screw of the present invention. As shown in the fourth figure, the oblique arc groove of the chip flute 13 extends from the front side to the other side, and the other side of the inclined chip flute 14 is also relatively staggered from the opposite side to the front.

The method of the present invention improves the structure and the manufacturing method of the conventional patent number I311505 "a type of tail screw forming method", which adopts a cutting edge on a drill tail, and clamps a rod-shaped blank and a tail end with two clamps respectively. In the segment, one of the clamps is rotated by an angle, so that the chip flute and the cutting edge of the drill tail are twisted to form a symmetrical spiral shape, and the method requires secondary processing, and cannot be formed quickly, and the processing process is slow to increase the processing cost. The molding method of the chip groove of the invention does not need to be formed by secondary processing, but is formed by press molding of the mold up and down. In other words, when the self-tapping screw of the self-tapping screw is made, the mold is pressurized by the chip flute. After the molding, the subsequent processing of the thread portion is performed, and the processing method can not only process a large amount of fast processing, but also the chip flute formed is extended to the thread portion by about a half turn, so that the chip flute has a small angle. Shape and waste discharge, so that the waste can be discharged quickly and smoothly.

A‧‧‧iron wire

B‧‧‧screw body

C‧‧‧ Self-tapping screw body

D‧‧‧ finished product

1‧‧‧ Self-drilling pointed

11‧‧‧ Blade front

12‧‧‧ Blade front

13‧‧‧chip flute

14‧‧‧ chip flute

15‧‧‧Blank line

2‧‧‧Threading Department

3‧‧‧Smooth handle

4‧‧‧ screw head

The first figure is a self-tapping screw manufacturing process of the present invention.

The second figure is a front view of the self-tapping screw of the present invention.

The third figure is a side view of the self-tapping screw of the present invention.

The fourth figure is another embodiment of the self-tapping screw of the present invention.

In order to fully understand the present invention, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The statements in this specification are hereby implemented and are not intended to limit the technical scope of the invention.

A self-tapping screw has a screw head 4, and the preparation method thereof is referred to as shown in the first figure. First, the iron wire A is press-formed by a mold to produce a screw head 4, and the base cylinder 3 is a screw body B, and enters The second step presses the screw body B again with another mold to pressurize the screw body B The self-drilling tip 1, the chip flutes 13, 14 are self-tapping screw body C, and the third step is to tap the self-tapping screw body C into the tapping die machine to perform the tapping process of the thread portion 2, that is, the finished product D The molding method of the chip flutes 13 and 14 of the present invention does not need to be formed by secondary processing, but is formed by pressing up and down the screw body B, in other words, when the self-drilling tip 1 of the self-tapping screw is manufactured, The mold is press-formed to form the chip flutes 13, 14 and the subsequent processing of the tapping portion 2 is performed after the molding. Such a processing method can not only process a large number of fast processing, but also the chip flutes 13, 14 are circumferentially formed. One-fourth of the more than some of the grooves of the curved arc-curved surface, so the chip flutes 13, 14 are extended obliquely from the self-drilling tip 1 to the spiral portion 2, so that the waste can quickly discharge the hole of the workpiece. .

Continuing with the structure of the present invention, as shown in the second and third figures, the self-tapping screw has a screw head 4, a self-drilling tip 1, a threaded portion 2 and a smoothing handle 3; the threaded portion 2 Adjacent to the smoothing handle 3, the smoothing handle 3 is directly adjacent to the screw head 4, and the chip flutes 13, 14 are arranged between the threaded portion 2 and the self-drilling tip 1, the main feature is that the chip flutes 13, 14 It is formed by two symmetrical but staggered oblique arc-shaped flutes 13, 14.

The self-drilling tip 1 is formed by two opposite cutting faces of the inclined blade faces 11, 12 for facilitating drilling into the object to be processed, and cutting the workpiece into the hole, and during the drilling process, the object to be processed is The scraped bits will slide out of the flutes 13, 14.

The main feature of the present invention is the structure of the chip flutes 13, 14 with the center of the self-drilling tip 1 as a circumferential reference line, and the reference straight line is an axial extension. The chip flute 13 is formed by a self-drilling tip 1 blade front surface 11, Starting from the lowest point of the tangential line, extending over the reference line with an oblique arc, forming a skewed arc-shaped flute 13 of about half a turn, and the flutes 14 of the other side of the opposite side are also self-drilled in a symmetrical cross direction. The tip 1 starts at the lowest point of the blade faces 11, 12, and extends over the reference line with a diagonal arc to form a skewed arc-shaped chip flute 14 of about half a turn; and the lowest of the blade faces 11 and 12 of the self-drilling tip 1 The point starts to the side crimp line 15 between the threaded portions 2, which is inclined at an angle of 5 degrees to 10 degrees, and the two side crimping lines 15 are also symmetrically staggered and become outside the flutes 13, 14. Cut the noodle line.

The crimp line 15 refers to a mold clamping line 15 which is produced by clamping the upper mold and the lower mold.

The fourth figure is another embodiment of the structure and the manufacturing method of the self-tapping screw of the present invention. As shown in the fourth figure, the oblique arc groove of the chip flute 13 extends from the front side to the other side, and the other side of the inclined chip flute 14 is also relatively staggered from the opposite side to the front.

In conclusion, it is only a preferred embodiment of the invention, and is not intended to limit the scope of the invention. That is, the equivalent changes and modifications made by the scope of the patent application of the present invention are covered by the scope of the invention.

1‧‧‧ Self-drilling pointed

11‧‧‧ Blade front

12‧‧‧ Blade front

13‧‧‧chip flute

14‧‧‧ chip flute

2‧‧‧Threading Department

3‧‧‧Smooth handle

4‧‧‧ screw head

Claims (6)

A self-tapping screw structure and manufacturing method, comprising a screw body integrally composed of a screw head, a self-drilling tip, a threaded portion and a smoothing handle; the smoothing handle is arranged between the threaded portion and the self-drilling tip than the adjacent screw head The chip flute is mainly characterized in that the chip flute is formed by two symmetrical but staggered oblique arc flutes. The self-tapping screw structure and method according to claim 1, wherein the self-drilling tip is formed by two oblique cutting surfaces of the cutting edge to facilitate drilling into the workpiece, and will be The machined object cuts out the hole, and the scraped material from which the workpiece is cut during the drilling process will slide out of the chip flute. The self-tapping screw structure and the method according to claim 1, wherein the center of the self-drilling tip is a circumferential reference line, and the reference line is an axial extension, and the chip flute is formed by a self-drilling tip blade. The lowest point of the tangent begins to extend across the reference line in an oblique arc, forming an oblique arc-shaped flute that is twisted about half a turn. The self-tapping screw structure and the manufacturing method according to claim 1, wherein a bottom line between the lowest point of the self-drilling tip blade and the threaded portion is provided with a crimping line for presenting a 5 degree angle to 10 The inclination of the angle is also symmetrically staggered on both sides, and becomes the cut line outside the chip flute. The self-tapping screw structure and the manufacturing method according to the fourth aspect of the invention, wherein the crimping line refers to a clamping line formed by clamping the upper mold and the lower mold. A self-tapping screw manufacturing method, the first step is to press the iron wire into a mold to produce a screw head, and the basic cylinder is a screw body; In the second step, the screw body is pressed again by another die to press the screw body out of the self-drilling tip and the chip flute body is a self-tapping screw body body; the third step is to insert the self-tapping screw body into the tapping die The tapping process of the threading part of the machine is the finished product.