JPH03113109A - Anchor bolt - Google Patents

Abstract

PURPOSE:To improve resistivity against drawing-out and corrosion of an anchor bolt by inserting an expansion lock ring made of liquid crystal polymer into an annular hollow space between a conical surface of a back-tapered anchor hole and a conical part of a bolt having the same cone angle as that of the anchor hole, and by expanding the expansion lock ring through external force. CONSTITUTION:A bolt 4 is formed so as to have a conical part 2 at its one end and a male screw 3 at its another end. The conical part 2 forms an annular hollow space 9 corresponding to a conical surface 7 of an anchor hole 8 having a required cone angle. An expansion lock ring 6 having longitudinal slots 5 is made of liquid crystal polymer and is inserted into an annular hollow space 9 by expansion caused by the conical part 2 when an external blow is given. Consequently, it is possible to improve its reliability on the basis of the increase of resistivity against drawing-out and corrosion.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an anchor bolt.

[Conventional technology]

Conventionally, a steel anchor bolt a as shown in Fig. 11 has been used.
is used. That is, a trade-shaped anchor hole C is drilled in the concrete b, an anchor bolt a is inserted into the anchor hole C, and a thin cylindrical expansion sheath f having a slit e is struck from the outside, and the bolt body g is The cough sheath body f was expanded by being guided by the cone portion of the cough sheath f, and fixed in the anchor hole C, thereby fixing the anchor bolt a.

By the way, the cone apex angle β of the cone part of the bolt body g is
The angle was approximately 30°, which was extremely gentle.

Furthermore, if the wall thickness of the expansion sheath f is sufficiently small and the outer diameter of the male threaded portion of the bolt body g is d, then t! :i
It was about 0.15·d.

[Problem to be solved by the invention]

Anchor hole C is cylindrical and straight with the same diameter.
At the same time, the cone apex angle β of the cone portion is small,
Moreover, since the wall thickness of the expansion sheath f was as thin as about 0.15 d, a sufficient pulling force could not be obtained. In addition, if repeated vibrations were applied to the anchor bolt a, there was a risk of it coming out from the anchor hole C, and although there was no problem in using it for temporary construction, it lacked reliability and was inappropriate for structural use. .

In addition, because the conventional anchor bolt main body g and expansion sheath f are made of metal such as steel, there is a problem of rusting, and especially large diameter bolts are heavy and inconvenient to transport to the construction site and handle on site. there were.

[Means to solve the problem]

The present invention has a cone portion at one end that is inserted into an anchor hole having a conical surface portion that expands toward the back and forms a ring-shaped cavity corresponding to the conical surface portion, and a male screw portion at the other end. a bolt body having a bolt body, and an expansion lock that is fitted onto the bolt body, has a vertical split, and plunges into the ring-shaped gap while being expanded by the cone part in response to an external impact. The bolt body and the expansion locking ring are made of liquid crystal polymer.

Further, the bolt body and the expansion locking ring are made of high-performance fiber-containing synthetic resin.

[Effect]

The anchor hole is a conical surface portion that expands toward the back, and the expansion locking ring locks in surface contact with the conical surface portion, thereby providing a strong pull-out strength.

Furthermore, since the bolt body and the expansion locking ring are made of liquid crystal polymer or high-performance fiber-containing synthetic resin, the specific gravity is small, making it easy to transport, transport, and handle, and prevents rusting. It is also possible to have a tensile strength higher than that of steel.

〔Example〕

In Figures 1, 2, and 4, the anchor bolt l is
A bolt body 4 having a cone portion 2 at one end and a male threaded portion 3 at the other end, and a thick expansion locking ring 6 that is fitted onto the bolt body 4 and has six vertical splits 5. It is equipped with.

This anchor bolt 1 has a 40° angle as shown in FIG.
It is used by being inserted into an anchor hole 8 in concrete having a conical surface portion 7 which is enlarged toward the back with a conical apex angle of the predetermined angle θ.

That is, the angle θ of the conical apex angle of this conical surface portion 7 is 40°≦
It is better to set θ≦52°, especially 43″≦
It is best to set θ≦47@.

As shown in FIG. 2 (and FIG. 4), the cone apex angle of the cone portion 2 of the bolt body 4 is also set within the range of the above-mentioned predetermined angle θ. As shown in FIG. 6, when the anchor bolt 1 is inserted deep into the anchor hole 8 in the concrete surface, the cone portion 2 corresponds parallel to the conical surface portion 7, and a ring-shaped cavity 9 is formed. In FIG. 6, IO is an insert rond, which applies an impactful external force (blow) as indicated by arrow F to the outer end surface of the expansion locking ring 6.

When the expansion locking ring 6 receives such a blow from the outside, it plunges into the ring-shaped cavity 9 while being guided to expand by the cone portion 2, becomes fixed as shown in Figure 7, and expands. The outer peripheral surface of the locking ring 6 is strongly fixed to the conical surface portion 7 of the anchor hole 8 through surface contact.

In other words, as shown in FIG. 7, 401≦θ≦526, preferably 43°≦θ≦47
An anchor hole 8 having a conical surface portion 7 whose inner part is enlarged with a conical apex angle of angle θ shown by @, and a cone portion 2 having the same conical apex angle forming a ring-shaped cavity 9 corresponding to the conical surface portion 7. a bolt body 4 having a bolt body 4, and an expansion lock that is fitted onto the bolt body 4 and has a loose split 5, and expands and plunges into the umbrella-shaped ring-shaped cavity 9 upon receiving a blow from the outside. The ring 6 constitutes an anchor bolt structure.

Next, as shown in FIG.
If the female threaded part 10 is screwed into the male threaded part 3 of the bolt body 4 which is fixed in the inner part of the bolt body 4, and fixed,
The female threaded portion 11 is now provided on the concrete surface 13, and the bolt can be brought close to the female threaded portion 11 together with the illustrated detailed work piece and screwed into the female threaded portion 11.

Next, FIGS. 8 to 10 show another embodiment, which is a so-called male anchor bolt structure in which a male threaded portion 3 is provided protruding from a concrete surface 13. That is, the bolt body 4 is sufficiently long and has a cone portion 2 having a conical apex angle of the predetermined angle θ at one end, and a male screw portion 3 at the other end. The entire length of the bolt body 4 is longer than the anchor hole 8, and the expansion locking ring 6 is formed integrally with the driving cylindrical portion 14. That is, the expansion locking ring 6 and the driving cylindrical part 14 are connected to each other via the thin wall part 15 so as to be easily plastically deformed. Specifically, by forming the outer circumferential groove 16,
It is assumed that the thin wall portion 15 is formed. The vertical splits 5 are formed to reach the thin wall portion 15, but they may also be formed to extend beyond the full width W of the thin wall portion 15 and reach the cylindrical portion 14.

Due to the existence of this thin portion 15, the thick expansion locking ring 6 is smoothly guided to the cone portion 2, expanded, and easily deformed to the state shown in FIG. 8. The value of this width W is such that the upper end of the expanded locking ring 6 is connected to the cylindrical portion 14 as shown in FIG.
You just need to set it so that it doesn't hit the bottom edge of the screen, or only lightly (just enough to hit it).

In addition, the wall thickness dimension T1 of the thin wall portion 15 and the expansion locking ring 6
The relationship between the wall thickness dimension T2 is set as shown in the following equation.

0.2 ・Tt≦T1 ≦0.35・T2...■Now, returning to FIGS. 2 and 3, the dimensions of each part and their relationships will be explained as follows.

0.2 ・T2≦T, ≦0.4・Tt …■′T2
ζ(D-d)/2...■0.25・d≦T
2≦0.4・d…■0.04・S2≦S,≦0.1
・S2...■T2: Wall thickness dimension of expansion locking ring 6 D: Outer diameter dimension of expansion locking ring 6 d: Outer diameter dimension of male threaded portion 3 In the conventional anchor bolt shown in FIG. 11, t -0,1
5·d, it can be seen that in this embodiment, the expansion locking ring 6 is sufficiently thick as shown in the above formula (2).

The reason why such a thick expansion locking ring 6 can be expanded to a large angle such as the above-mentioned angle θ is that the cross-sectional area and dimensions of the remaining wall portion 17 are It is set sufficiently small to facilitate the plastic deformation from FIG. 6 to FIG. On the other hand, when it is fixed as shown in FIG. 7, FIG. 4, or FIG. 8, the pulling force is strong. In other words, there is no need to worry about the phenomenon of so-called l' slippage, which existed in the conventional example shown in FIG. 11.

In Figure 4 or Figure 8, (with an apex angle of about 90')
The two-dot chain line indicates the position of the fracture surface of the concrete, and according to the present invention, the strength of the anchor bolt structure depends on the conical fracture area (area of the two-dot chain line) and the strength of the concrete. It is now possible to accurately calculate the yield strength, and it can be used as a structural bolt. Moreover, even if vibrations or repeated loads are applied, the bolt will not be pulled out at all.

The anchor bolt structure of the present invention exhibits strong yield strength (pulling force) as described above due to its shape, dimensions, and structure. Furthermore, in order to increase the strength of the layer and reduce its weight, it is desirable that the bolt body 4 and the expansion locking ring 6 be made of liquid crystal polymer. As the liquid crystal polymer, resins such as epoxy, polyester (polyarylate), polyimide, and polyamide are preferred. The specific gravity is approximately 2.6, making it significantly lighter than conventional iron M (specific gravity 7.8). Moreover, it has the advantage that it can be manufactured in large quantities and at low cost by injection molding or the like.

Although the bolt body 4 and the expansion locking ring 6 are formed of high-performance fiber-containing synthetic resin, it is preferable to use aluminum fibers such as polyarylate or polyamide, or inorganic fibers such as carbon fiber or silicon carbide fiber. Alternatively, metal fibers are mixed into various synthetic resins. FRM containing metal fibers (specific gravity 3.6) is particularly preferred.

Note that it is also possible to put the adhesive in the capsule into the anchor hole 8 in advance, then insert and drive the anchor bolt 1, break the capsule, and insert the adhesive to further increase the strength. Furthermore, the number of vertical splits 5 in the ring 6 can be increased or decreased as desired.

Further, it is also preferable that the tension sleeve 12 is also made of the same material.

〔Effect of the invention〕

The present invention is configured as described above, and includes liquid crystal polymer or
Since the bolt body 4 and expansion locking ring 6 are made of high-performance fiber-containing synthetic resin, there is no need to worry about rusting, and the mechanical strength is equal to or higher than that of steel, despite its light weight. I can do it. In addition, since it is lightweight, it is easy to transport, transport, and work, making it convenient to handle.

Furthermore, an expansion locking ring 6 is attached to the conical surface portion 7 of the anchor hole 8.
are firmly held in surface contact, and there is no risk of slippage even with materials such as liquid crystal polymers, and this is combined with the increase in mechanical strength provided by this material to produce a significant effect.

[Brief explanation of drawings]

FIG. 1 is a front view of an embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a schematic front plan view of the expansion locking ring.
Fig. 4 is a sectional view of the usage state, Figs. 5, 6, and 7 are explanatory diagrams of how to use it, and Fig. 8 is a sectional view of another embodiment of the usage state.
FIG. 9 is a front view of the main part, and FIG. 10 is a sectional view of the main part. FIG. 11 is a partially cutaway explanatory view showing a conventional example. θ...predetermined angle, 1... anchor bolt, 2... cone part, 3
...Male thread part, 4...Bolt body, 5...Vertical split, 6...Expansion locking ring, 7...Circle S (6 side part, 8...Anchor hole, 9...Ring-shaped cavity. Anchor hole, 9... Ring-shaped cavity.

Claims (1)

[Claims] 1. A cone portion 2 is inserted into an anchor hole 8 having a conical surface portion 7 expanding toward the back, and has a cone portion 2 at one end forming a ring-shaped cavity 9 corresponding to the conical surface portion 7. and a bolt body 4 having a male threaded portion 3 at the other end; and a bolt body 4 that is fitted onto the bolt body 4 and has vertical splits 5, so that the ring-shaped cavity 9 receives an external blow. fart,
An expansion locking ring 6 that expands and enters at the cone portion 2, the bolt body 4 and the expansion locking ring 6.
An anchor bolt characterized by being made of liquid crystal polymer. 2. The cone part 2 is inserted into the anchor hole 8 having a conical surface part 7 that expands toward the back, and has a cone part 2 at one end that forms a ring-shaped cavity 9 corresponding to the conical surface part 7, and a male part at the other end. A bolt body 4 having a threaded portion 3, which is externally fitted onto the bolt body 4 and has vertical splits 5, so that it receives an external blow and enters the ring-shaped cavity 9.
An expansion locking ring 6 that expands and enters at the cone portion 2, the bolt body 4 and the expansion locking ring 6.
An anchor bolt characterized by being made of high-performance fiber-containing synthetic resin.