JP3079608U - Tapping screw structure - Google Patents

Abstract

(57) [Problem] To provide a structure of a tapping screw which can effectively increase the cutting speed and does not impair the strength of a blade portion. SOLUTION: A head is formed at one end of the screw rod, and two blades extending toward both sides from a center point are formed at the other end of the screw rod. Is formed so that the chip escape groove is formed, and a gentle cutting part is recessed in the part adjacent to the center point of one blade part, so that the tapping speed of the tapping screw can be greatly increased. Have been.

Description

[Detailed description of the invention]

[0001]

[Field to which the invention belongs]

 The present invention relates to the structure of the tapping screw.In particular, the tapping speed of the tapping screw can be increased, and the tapping start speed of the tapping screw can be increased. It relates to the structure of the screw.

[0002]

[Prior art]

 Conventionally, this type is as follows.

[0003] A utility model disclosed in Taiwanese publication No. 340584, "Tapping Screws for Corrugated Plate", has a head and a screw rod integrally joined to the head. The screw rod is provided with one blade portion along one end of the head along the axial direction, and the blade portion is provided with a first screw portion and a second screw portion in the direction of the head in order. The thread pitch of the first thread portion is configured to be smaller than the thread pitch of the second thread portion.

[0004] Further, a utility model disclosed in Taiwanese publication No. 348820, "Improvement of Tapping Screw Structure", has a screw head formed above the main body, and a concave groove for cutting chip escape below. Is provided, and a helical oblique screw having a polygonal, pointed corner is provided between the screw head and the end of the main body.

[0005]

[Problems to be solved by the invention]

 Regarding the structure of the tapping screw disclosed in the aforementioned Taiwanese publication number 340584, it is stated that one end of the head is provided with one blade so as to extend along the axial direction. The two blades are installed at the center of the screw rod so that they are symmetrical. Regarding the structure of the tapping screw disclosed in the above-mentioned publication No. 348820 in Taiwan, a spiral oblique having a polygonal pointed corner between the screw head and the end of the main body. It is formed so that a screw is provided.

[0006] Such tapping screws are often used for tapping a metal corrugated plate or the like, and at least two or more blades of such tapping screws are made of metal at the start of tapping. The cutting speed at the start of tapping is not ideal because it is formed so as to contact the plate. Therefore, in order to increase the cutting speed of tapping in the industry, the cutting speed is increased by using the change of the front oblique angle and the chip clearance angle of the cutting edge. However, some cutting speeds can be increased, but there is still room for improvement. In addition, in addition to the above, if the front oblique angle of the blade portion is too large, the strength of the blade portion is insufficient, and there is a problem that the blade portion is easily broken and broken at the time of tapping cutting. When manufacturing such tapping screws, there was also a problem that the heat treatment work was apt to fail.

The present invention has been devised in view of such problems, and aims at effectively increasing the cutting speed and not impairing the strength of the blade portion. It is intended to provide a structure of a tapping screw.

[0008]

[Means for Solving the Problems]

 To achieve the above object, the structure of the tapping screw according to the present invention is as follows. That is, the structure of the tapping screw is such that a head is formed at one end of the screw rod, two blades are formed at the other end of the screw rod, and the two blades are formed on both sides of the center point of the screw rod. And a first blade portion and a second blade portion are formed respectively, and the first blade portion and the second blade portion are respectively formed with a chip escape groove, and are adjacent to a center point of the second blade portion. A loosely cut portion lower than the surface of the second blade portion is recessed in the portion.

Further, the structure of the tapping screw of the present invention can be configured as follows. 1. The loose cuts can be recessed or formed with different degrees of inclination.

[0010]

[Embodiment of the invention]

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a tapping screw 1 according to an embodiment of the present invention. A head 11 is formed at one end of a screw rod 12 of the tapping screw 1, and two blades are formed at the other end of the screw rod 12. Parts 13 and 14 are respectively formed, and a waste escape groove 15 is extended to each of the two blades 13 and 14.

As shown in FIGS. 2, 3, and 4, the blade portions 13 and 14 are formed so as to extend from the center point 16 of the screw rod 12 to both sides. The part 14 is formed. A loosely cut portion 17 is formed in the second blade portion 14 so that the loosely cut portion 17 is adjacent to the center point 16 and lower than the surface of the second blade portion 14. When the tapping screw 1 rotates around the center point 16 and performs tapping, the loosely cut portion 17 cannot cut a metal plate because the loosely cut portion 17 can be formed in a structure such as a concave notch or a different inclination angle. Absent. Accordingly, when the tapping screw 1 of the present invention starts tapping, tapping is started only by the first blade portion 13 on one side of the center point 16 to cut the metal plate. Since the second blade portion 14 is formed so that the second blade portion 14 does not come into contact with the metal plate when tapping is started due to the provision of the loose cutting portion 17, unnecessary friction is provided. Can be reduced. Accordingly, since the tapping screw 1 can tap a metal plate at a relatively high speed, the speed of cutting and tapping can be increased.

[0013]

[Effect of the invention]

 According to the present invention, when the tapping screw starts tapping, the contact between the blade and the metal plate is loosely cut by forming a loosely cut portion in the blade portion acting at the start of tapping of the tapping screw. Since the friction is reduced by the part, the amount of cutting can be increased, which has the advantage that the speed of cutting and the purpose of labor saving can be achieved. Further, according to the structure of the tapping screw of the present invention, there is an advantage that the strength of the blade portion of the tapping screw is not impaired.

The present invention may be embodied in other ways without departing from its spirit and essential characteristics. Accordingly, the preferred embodiments described herein are illustrative and not limiting.

[Brief description of the drawings]

FIG. 1 is a perspective view of a tapping screw according to an embodiment of the present invention.

FIG. 2 is a front view of the tapping screw according to the embodiment of the present invention;

FIG. 3 is a partially enlarged view of a portion indicated by reference numeral 3 in FIG.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Tapping screw 11 Head 12 Screw rod 13 First blade part 14 Second blade part 15 Dust escape groove 16 Center point 17 Loosely cut part

Claims (2)

[Utility model registration claims] A head (11) is formed at one end of a screw rod (12), and two blades (1) are formed at the other end of the screw rod (12).
3, 14) are formed, and the two blades (13, 14) are formed.
Are located on both sides of the center point (16) of the screw rod (12) and form a first blade part (13) and a second blade part (14), respectively, and the first blade part (13) and the second blade Each of the portions (14) is provided with a chip escape groove (15), and the portion adjacent to the center point (16) of the second blade portion (14) is lower than the surface of the second blade portion (14). Characterized by the fact that a loosely cut portion (17) is recessed. 2. The self-tapping screw structure according to claim 1, wherein the loosely cut portion (17) can be formed by a concave portion or a different inclination.