JP4404541B2 - Concrete pin - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a concrete pin used for fixing a metal plate or the like on a concrete surface.
[0002]
[Prior art and its problems]
In the interior construction of a reinforced concrete building, as a post-construction to concrete including high compressive strength, a sheet metal having a thickness of about 0.5 to 0.8 mm is stopped on the concrete. Thus, when a concrete pin is driven to fasten the sheet metal, the volume of the existing concrete pin is large, so that the concrete is cracked or broken, and it is difficult to obtain the necessary fastening force and pulling strength. Therefore, a concrete pin having a long and thin foot portion is known (see, for example, Patent Document 1 and Patent Document 2).
[0003]
In addition, when a concrete pin is driven with a large force instantaneously, cracks often occur due to the breaking strength when entering the concrete. In order to eliminate such drawbacks, a two-stage pin has been proposed in which the head side of the shaft portion of the concrete pin has a large diameter and the tip side has a small diameter (see, for example, Patent Document 2).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-259819 (FIGS. 1, 3, and 6)
[Patent Document 2]
JP 2002-81424 A (FIGS. 1 to 3)
[0005]
[Problems to be solved by the invention]
However, the concrete pin of the above-mentioned patent document 1 is not able to resist the penetration resistance at the beginning of driving (when the tip portion enters the concrete) and bends ahead, which in turn increases the driving load. , There is a problem of floating or being struck diagonally. In addition, as in Patent Document 2, a stepped portion has a strong driving resistance at the stepped portion, and tends to be a factor of destroying concrete.
[0006]
As described above, the conventional one lacks the penetration stability, and has a problem that it cannot cope with a high hardness PC (precast concrete) material (compressive strength: 500 kgf / cm ² ) which has been increasing in recent years. There was a risk of bending and penetrating when driving.
[0007]
An object of the present invention is to solve the above-mentioned problems and to provide a concrete pin having a low penetration resistance at the beginning of driving and having a stable penetration direction.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a concrete pin according to the present invention is a concrete pin formed from an enlarged head, a trunk, and a bullet-shaped toe part, on the outer peripheral surface of the bullet-shaped toe part. At substantially equal intervals, a plurality of grooves having a substantially V-shaped cross section and arcuate sides on both sides and a straight groove bottom are formed leaving the tip of the tip of the foot, and when the tip is driven It is characterized by being formed in a size that does not lose the lead.
[0009]
【The invention's effect】
According to the first aspect of the present invention, since the plurality of grooves are formed at substantially equal intervals on the outer peripheral surface of the toe portion, the cross-section of the toe portion becomes small and the volume during driving is reduced. , Penetration resistance is also reduced. Further, these grooves are formed leaving the tip of the foot tip portion, and the volume of the tip portion of the foot tip portion is sized so as not to lose, so that it does not lose when driving. Therefore, the penetration direction is also stable, and it can sufficiently cope with concrete including high compressive strength.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a front view of a concrete pin according to the present invention, and FIG. 2 is an enlarged end view on line XX of FIG.
[0011]
In the figure, reference numeral 1 denotes a concrete pin. The concrete pin 1 includes an enlarged head portion (not shown), a trunk portion 2 and a tapered foot tip portion 3.
[0012]
The foot tip portion 3 is formed in a cannonball shape, and four grooves 4 are formed on the outer peripheral surface thereof at substantially equal intervals. Both ends of the groove 4 are sharp, both sides are arc-shaped, the cross section is substantially V-shaped, and the groove bottom 4a is formed in a straight line. Therefore, as shown in FIG. 2, the cross-sectional area of the cross section at each part of the foot portion 3 is scraped by the groove 4 compared to the cross-sectional area without the groove 4 (cross-sectional area of the inner portion of the dotted line). It is smaller by the amount.
[0013]
The groove 4 is formed on the body 2 side, leaving the tip 5 of the foot 3.
[0014]
The tip portion 5 is formed in a conical shape with a size that does not lose the hardness of the concrete when the concrete pin 1 is driven. Usually, if the diameter of the base of the conical tip 5 is about 0.4 mm or more, there is no loss.
[0015]
Next, an example in which the concrete pin 1 having the above configuration is driven into high-hardness concrete will be described. First, when the concrete pin 1 is loaded into the nailing machine and driven toward the concrete, the bullet-shaped toe portion 3 of the concrete pin 1 enters and is driven into the concrete.
[0016]
By the way, the toe portion 3 of the concrete pin 1 is formed in a bullet shape, but since four grooves 4 are formed on the outer peripheral surface thereof, as shown in FIG. The cross-sectional area is reduced by the amount removed.
[0017]
Thus, compared with the conventional concrete pin 1 which does not have the groove 4, the volume of the foot part 3 becomes small, and driving resistance is also reduced. For this reason, destruction occurs in the concrete as the toe portion 3 enters the inside, but since the volume is small and the destruction progresses gradually, the propagation of impact is reduced and the destruction is reduced. Therefore, the concrete pin 1 and the concrete are in close contact with each other after being driven, and the contact area between the concrete and the concrete pin 1 is increased by the groove 4, so that the necessary fastening force and pulling strength can be sufficiently secured.
[0018]
Moreover, as shown in FIG. 1 and FIG. 3, the tip 5 of the foot tip 3 is formed in a size that does not lose the tip, so the tip 5 does not bend at the beginning of driving.
[0019]
Moreover, since the groove 4 is formed at equal intervals, the penetration direction is stabilized.
[0020]
Further, as shown in FIG. 3, in the cross section of each part of the foot tip portion 3, a protrusion 6 is formed between adjacent grooves 4, and these protrusions are the same as the reinforcing ribs. Therefore, the portion where the groove 4 is formed is not bent.
[0021]
As described above, since the penetration resistance into the concrete is reduced, it becomes easier to maintain the verticality of the machine during driving, and the volume during penetration is small, so that the area that collides with hard grease in the concrete during driving is reduced. , The frequency of defective driving is reduced. Therefore, the penetration performance at the time of driving improves, and the concrete pin 1 can be surely penetrated even to high-hardness concrete.
[0022]
In addition, although the above-mentioned embodiment is an example which formed the four groove 4 in the outer peripheral surface of the foot part 3 at equal intervals, the groove 4 is not limited to four. For example, as shown in FIGS. 4 and 5, six grooves 4 may be formed, or three, five, seven or more may be used.
[0023]
Even with the above configuration, since the cross-sectional area is reduced by the amount scraped off by the groove 4, the driving resistance is reduced, the driving is smooth and stable, and the concrete pin 1 and the concrete are in close contact after driving, Necessary fastening force and pulling strength can be secured.
[Brief description of the drawings]
FIG. 1 is a front view of a foot side of a concrete pin according to the present invention. FIG. 2 is an enlarged end view on line XX in FIG. Enlarged bottom view of the part [Fig. 4] Front view of the foot side of another concrete pin [Fig. 5] Enlarged cross-sectional view on the YY line of [Fig.
1 Concrete Pin 2 Body 3 Foot Toe 4 Groove 5 Tip

Claims (1)

In a concrete pin formed from an enlarged head, a body, and a bullet-shaped toe part, the outer peripheral surface of the above-mentioned bullet-shaped toe part is substantially V-shaped in cross section and arc-shaped on both sides. In addition, a plurality of grooves having a straight groove bottom are formed leaving the tip of the tip of the foot, and the tip is formed in a size that does not lose when driving. Concrete pin.

Images