JP2000009121A - Self-tapping screw structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten resource recycling performance and reduce the demerit of cost, working hours and labor caused by parts replacement by composing self-tapping thread structure of a female screw and a male screw, and providing the female screw with thread cutting function. SOLUTION: A prepared hole 2 is bored in a fixed body 1 of a metal plate, and its internal wall is provided with self-tapping female screw shape 3 with thread cutting function. A male screw 4 has no thread, and a thread forming part 5 is formed in cylindrical shape, while the tip is formed in cone shape with a taper 6 with guide function at the time of screw-fastening. When the tip of the male screw 4 is held to a female screw part 7 of the fixed body 1 to thread-fasten normally, male screw shape 8 is formed on the male screw 4 by the self-tapping female screw part 7, and the male screw 4 is fixed to the fixed body 1. Thread damage in the case of repeating assembly and disassembly is therefore generated onto the male screw side, so that parts replacement of the fixed body 1 is dispensed with, and only the male screw has to be replaced. Cost and replacement time can therefore be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-tapping screw structure, and more particularly to a self-tapping screw structure in which an object itself has a thread cutting function.

[0002]

2. Description of the Related Art Generally, a self-tapping screw structure is:
A male screw has a thread cutting function and forms a female screw by screwing a male screw into a hole of a fixed body. Conventionally, when fixing an object to be fixed composed of a metal plate such as a steel plate with a self-tapping screw, a prepared hole is provided in the object to be fixed and a self-tapping screw is screwed into the hole to plastically deform the prepared hole of the object to be fixed. A female screw was formed. As a result, a strong fastening force is obtained, and at the same time, stable support is obtained by lengthening the protruding hole forming portion, and the valley diameter of the tapered portion gradually increases toward the tip of the tapered portion, so that the screw hole has a tapered portion. The wedge-shaped valleys of the screw threads prevented the shedding.

[0003]

However, the self-tapping screw disclosed in Japanese Patent Application Laid-Open No. 61-184211 has the following problems. JP-A-61-1
In the self-tapping screw disclosed in Japanese Patent No. 84211, when the screw is repeatedly tightened and loosened, the screw has a thread cutting function. In order to repair, the fixed object (structural component) needs to be replaced. As a result, in addition to cost disadvantages, the work time required for replacing parts is enormous, which has been a bottleneck for disassembling the apparatus. In this case, there is no problem if the hardness of the self-tapping screw is more flexible than that of the body to be fixed, but in this case, the self-tapping screw has a There is a disadvantage that it cannot be demonstrated.

[0004] The present invention has been made in view of the above-mentioned problems in the prior art, and has the effect of increasing the reusability of resources and reducing the cost disadvantages. An object of the present invention is to provide a self-tapping screw structure that can reduce labor.

[0005]

According to a first aspect of the present invention, there is provided a self-tapping screw structure comprising a female screw and a male screw, wherein the female screw (shape) has a thread cutting function. And a self-tapping screw structure.

Therefore, according to the self-tapping screw structure of the first invention of the present application, since the female screw (shape) has a thread cutting function, there is an advantage that the fixing can be reliably performed.

The second invention of the present application is characterized in that, in the self-tapping screw structure of the first invention of the present application, an internal wall of a female screw (shape) hole has a thread cutting function.

Therefore, according to the self-tapping screw structure of the second invention of the present application, there is an advantage that the fixing can be reliably performed by the deformation of the male screw due to the insertion of the male screw.

According to a third aspect of the present invention, in the self-tapping screw structure according to the first aspect of the present invention or the second aspect of the present invention, an internal thread (shape) having a thread cutting function is attached to a fixed body. It is characterized by being able to.

[0010] Therefore, according to the self-tapping screw structure of the third invention of the present application, since the fixed body has a thread cutting function, the screw breakage upon repeated assembly and disassembly occurs on the male screw side. In addition, there is no need to replace parts of the fixed body (structure), which has conventionally been performed when a screw is damaged, and only the male screw needs to be replaced. This makes it possible to reduce the cost of replacing parts and reduce the time required for replacing parts. Further, such a fixed body can be made of metal, resin, ceramics, wood, or the like, and the female screw can be attached as a separate body regardless of the material. There is the advantage that it can be applied.

The fourth invention of the present application is characterized in that the screw shaft of the male screw is smooth.

Therefore, according to the self-tapping screw structure of the fourth invention of the present application, since the screw shaft portion of the male screw is smooth, there is an advantage that any screw thread can be formed.

According to a fifth invention of the present application, in the self-tapping screw structure according to any one of the first invention to the fourth invention of the present application, a male screw has a guide function at the end when the screw is screwed. It has a cone shape having a taper to have.

Therefore, according to the self-tapping screw structure of the fifth invention of the present application, the male screw is characterized in that it has a tapered cone shape at its tip to have a guide function at the time of screw tightening. Has the advantage that it can be performed reliably.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A self-tapping screw structure according to an embodiment of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a configuration diagram showing a self-tapping screw structure according to an embodiment of the present invention. As shown in FIG. 1, a pilot hole 2 is provided in a fixed body 1 formed of a metal plate such as a steel plate. Have. On the other hand, the external thread 4 does not have a conventional thread, and the thread forming portion 5 is formed in a cylindrical shape. In addition, the tip has a cone shape having a taper 6 for providing a guide function when screwing. In this case, since the male screw 4 is formed with a screw thread by the screw cutting function at the time of screw tightening, the male screw 4 is an object to be fixed to the fixed body in the process of forming the screw thread.

FIG. 2 illustrates the operation of the self-tapping screw structure according to one embodiment of the present invention. As shown in FIG. 2, the tip of the male screw 4 is applied to the female screw part 7 of the fixed body 1. Thereafter, when a normal screw tightening operation is performed, a male screw shape 8 is formed on the male screw 4 by the female screw portion 7 for self tapping. Further, since the male screw 4 in this case fixes the fixed body 1 by this operation, in the self-tapping structure of the present invention, the male screw 4 functions as a member for attaching some member to the fixed body.

Embodiment 2 As an example in which the material of the fixed body has a characteristic, as an example where the fixed body 9 is formed of a thin metal plate, FIG.
As shown in FIG. 5, the self-tapping structure of the present invention can be applied by forming the prepared hole portion 10 into a burring shape and forming a female screw shape 3 for self-tapping having a threading function inside the prepared hole portion.

Third Embodiment Next, an embodiment different from the first and second embodiments in the self-tapping structure of the present invention will be described below with reference to FIG. This is a case where the female screw is attached separately from the fixed body. For example, when the fixed body 11 is formed of resin, as shown in FIG. To metal insert 1
2 and the outer diameter 13 of the female screw insertion portion and the fixed body 11
The holes can be fixed to the resin-fixed body 11 by matching the hole inner diameters 14 with each other and inserting and bonding them. That is, since the female screw is attached separately from the fixed body, the self-tapping structure of the present invention can be applied even if the fixed body is, for example, wood or ceramic.

Fourth Embodiment Next, an embodiment different from the first, second and third embodiments in the self-tapping structure of the present invention will be described with reference to FIG. When the female screw 15 is inserted into a fixed body 19 having no threading function (hereinafter, a fixed body), as shown in FIG.
6 and the female screw outer wall 17 are provided with a thread cutting function, and the female screw 15 is inserted into the fixed body hole 18 so that the fixed body hole 18 and the female screw 15 can be securely fixed. After the female screw 15 is inserted, the fixed member 18 can be fixed by inserting the male screw 4 into the hole 20 of the female screw 15.

[0021]

[Brief description of the drawings]

FIG. 1 is a sectional view showing a basic configuration of a self-tapping structure according to the present invention.

FIG. 2 is a cross-sectional view illustrating an operation of a self-tapping structure according to the present invention.

FIG. 3 is a sectional view showing an example of a self-tapping structure according to the present invention.

FIG. 4 is a sectional view showing an example of a self-tapping structure according to the present invention.

FIG. 5 is a sectional view showing an example of a self-tapping structure according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 To-be-fixed body 2 Preparatory hole 3 Female screw shape 4 Male screw 5 Thread forming part 6 Taper 7 Female screw part 8 Male screw shape 9 Thin metal plate fixed body 10 Burring-shaped prepared hole 11 Resin fixed body 12 Metal insert 13 Insertion part outer diameter 14 Fixed body hole inner diameter 15 Female screw 16 Female screw hole inner wall 17 Female screw outer wall 18 Fixed body hole 19 Fixed body without screw cutting function 20 Female screw hole

Claims (5)

[Claims] 1. A self-tapping screw structure comprising a female screw and a male screw, wherein the female screw (shape) has a thread cutting function. 2. The self-tapping screw structure according to claim 1, wherein the inner wall of the female screw (shape) has a thread cutting function. 3. The method according to claim 1, wherein a female screw having a thread cutting function, which is separate from the fixed member, is attached.
Or the self-tapping screw structure according to claim 2. 4. The self-tapping structure according to claim 1, wherein the surface of the screw shaft portion of the male screw is smooth. 5. The self-tapping device according to claim 1, wherein the male screw has a tapered cone shape since the male screw has a guide function at the time of screw tightening. Screw structure.