JPH0515605Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a knurled nail in which the valley of the knurling formed in the intermediate portion is a curved surface so that stress concentration does not occur and the shear strength is improved.

(Prior art and its problems) In general, knurled nails are known in which knurling is carved on the outer peripheral surface of the shaft part to increase the frictional force with the material to be driven in order to improve the pull-out strength after nail driving. There is. For example, conventional knurled nails, such as those disclosed in Japanese Utility Model Publication No. 53-4349, are manufactured using a rolling method in which the knurled portion is formed by locally applying pressure while rotating the nail material using a mold, roll, die, etc. Since the knurling formed on the outer circumferential surface of the shaft is formed by machining, the cross-sectional shape of the knurling on the outer circumferential surface of the shaft portion is composed of sharp ridge lines in both valleys and peaks.

However, when conventional knurled nails are subjected to external force (shearing force) from the lateral direction on the shaft, stress concentration occurs in the troughs of the ridgeline, making them extremely weak in terms of strength. When nailed, the knurled portions may sag when subjected to shocks such as earthquakes, resulting in loss of adhesion to the supported external wall panels, resulting in a problem of unreliable nailing work. .

(Purpose of the invention) The present invention solves the above-mentioned problems, in particular, by making the valley of the knurling carved on the outer peripheral surface of the nail shaft into a curved surface.
The purpose is to provide a knurled nail that is resistant to impacts, etc., while avoiding concentration of stress on the troughs.

(Means for Solving the Problems) In order to achieve the above object, the knurled nail according to the present invention has a head, a shank, and a pointed end, in which a knurl is carved on the outer peripheral surface of the shank, and It is characterized in that the valley of the knurling is formed of a curved surface.

Further, the knurling is formed in an intermediate portion of the shaft excluding a portion on the head side and the tip side,
Further, the knurled portion and the non-knurled portion may be connected by a tapered knurling whose outer diameter gradually changes.

(Example) Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

In FIGS. 1 to 3, the symbol A indicates a knurled nail. The knurled nail A is composed of a head 1, a shaft 2, and a pointed end 3, and the head 1 may have any shape such as a flat head, a semi-round head, a round head, or a large flat head, but in the illustrated example, it has a flat head. be. A knurl is formed in the intermediate portion of the shaft portion 2 excluding a portion of the head 1 side and a portion of the tip portion 3 by rolling, thereby forming a knurl portion 4.

Incidentally, the cross section of this knurling portion 4 is composed of a valley portion A and a peak portion B, and the valley portion A is formed as a curved surface 5. Incidentally, the ridge portion R is also formed as a curved surface.

The pointed end 3 is processed into a diamond cut shape and has a sharpened end.

Next, straight non-knurled parts 7 and 8 having a smaller diameter than the knurled part 4 are formed between the head 1 and the knurled part 4 and between the tip part 3 and the knurled part 4, respectively. Further, the knurled portion 4 and the non-knurled portions 7, 8 of the shaft portion 2 are continuous through tapered knurled portions 4', 4' whose outer diameter gradually changes. The troughs and peaks of the knurled portions 4', 4' are formed as curved surfaces in cross-section.

As mentioned above, since the valleys A of the knurled portions 4, 4' are formed into curved surfaces, no concentrated stress is generated in the valleys A when an impact is received.

Similarly, there is a tapered knurled portion 4' on the head 1 side.
By forming this, it is possible to avoid stress concentration when subjected to impact, and by providing a tapered knurled portion 4' on the tip 3 side, penetration resistance during nail driving is reduced and smooth nail driving is achieved. Can drive nails.

Furthermore, by providing the straight portion 7 on the side of the head 1, when a plate material is driven and receives an impact, the direct impact force of the material to be driven can be avoided.

Next, according to FIG. 4, the knurled nail A of the present invention
The results of a drop test using a conventional knurled nail (curved surface R of the valley = 0.4 mm) and a conventional knurled nail are shown below.

In this test, both knurled nails were
This was done by using a 1.62 kg impact object and dropping it from a certain height onto both nails with the nails protruding by 1.5 mm and tilted at an angle of 15 degrees.

As a result, it was observed that conventional knurled nails cracked or broke when the falling height was 400 mm or less, but in contrast, with the knurled nail A of the present invention, the knurled nails of the present invention cracked or broke when the falling height was 600 mm or more. Conditions such as cracks and breakage were not observed, and it was verified that no concentrated stress was generated in the troughs of the knurled portions 4, and that the knurled portions 4 exhibited sufficient resistance to impact.

(Effects of the invention) Since the knurled nail according to the invention has a curved valley in the knurling on the outer peripheral surface of the shaft, stress concentration will occur even if an external force is applied from the lateral direction to the knurled part. However, the shear strength is greatly improved, so if the exterior wall panels are stopped during construction,
Even if the knurling part is subjected to an impact such as an earthquake, it will not easily break, so the reliability of nailing work can be improved.

In addition, a knurl is formed in the middle part of the shaft,
In addition, by connecting the knurled part and the non-knurled part with a tapered knurl whose outer diameter gradually changes, the penetration resistance into the object to be driven is reduced during nail driving, making it easier to drive the nail.
Further, it is possible to obtain the practical effect that stress concentration can be avoided even when subjected to impact.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of the knurled nail according to the present invention, Fig. 2 is an enlarged view of the knurled part, Fig. 3 is a sectional view taken along the line X-X shown in Fig. 2, and Fig. 4 is a conventional knurled nail. FIG. 3 is a diagram showing the results of a drop test between the product and the product of the present invention. Symbols: 1... Head, 2... Shaft, 3... Tip, 4... Knurled part, 4', 4'... Tapered knurled part, 7, 8... Non-knurled part.

Claims (1)

[Claims for Utility Model Registration] (1) A nail having a head, a shaft, and a pointed end,
In addition to carving a knurl on the outer peripheral surface of the shaft,
A knurled nail characterized in that the valley portion of the knurling is composed of a curved surface. (2) the knurling is formed in an intermediate portion of the shaft excluding a portion of the head side and the tip side;
Claim (1) above, characterized in that the knurled portion and the non-knurled portion are connected by a tapered knurling whose outer diameter gradually changes.
Knurled nails as described.