JPH0416803Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an improvement of a so-called insert, which is an embedded fitting in concrete for attaching a member.

<Prior art> As a type of insert 1, a bolt hole (not shown) into which a bolt for mounting a member is screwed is bored in the length direction of a shaft portion 3 having a flange 2 at the lower end, as shown in FIG. , there is a threaded insert on the inner surface of the bolt hole. In this case, the screw is usually cut with a tap, so if the tip is closed like this bolt hole, the screw cannot be cut all the way to the tip of the hole. Therefore, the screws do not reach the flange part.

By the way, as a request regarding insert 1,
It is desired to reduce the weight, but if the thickness of the shaft portion 3 is made thinner for this purpose, a drawback arises in that the tensile strength is reduced.

By the way, if the bolt 4 is screwed into the insert 1 and the bolt is pulled in this state, if the insert 1 is weaker than the bolt, the insert 1 will be cut off at the shaft portion 3 corresponding to the tip of the screwed bolt. This was experimentally known.

In this experiment, as shown in FIG. 2, an insert 1 into which a bolt 4 was screwed was supported by a support plate 5.
Grasp bolt 4 with chuck 6 and pull chuck 6 downward. Then, if the insert 1 is weaker than the bolt 4, the insert 1 will be cut at the shaft portion 2 of the portion 7 corresponding to the tip of the bolt 4. Experimental data regarding this is shown in the attached reference material.

As is clear from this experiment, when the bolt is pulled, it is the root of the shaft corresponding to the tip of the bolt that is cut. Therefore, when reducing weight, the first problem is to strengthen this part.

<Problems to be Solved and Means Therefor> The present invention attempts to solve the above-mentioned problems, and is configured as follows for this purpose.
In other words, in an insert that has bolt holes drilled in the length direction of the shaft for screwing bolts for attaching components, an inverted truncated conical flange with a wide upper surface and a concave side on the buried side is provided below the shaft all around the circumference. This is an insert in which a protruding part is provided on the lower surface of the flange, the bolt hole extends to the protruding part, and a thick part is provided at the base of the shaft part.

<Function> This insert is provided with an inverted truncated conical flange around the entire circumference below the shaft, and has a thick wall at the base of the shaft that is easy to cut. Therefore, even if the thickness of the shaft portion other than the thick portion is the same, a much larger tensile strength is generated compared to the conventional product.

<Examples> Examples of the present invention will be described below based on the drawings. As shown in FIG.
A flange 13 is provided at the bottom of 2. Flange 13
Contrary to the conventional product shown in FIG. 3, the shape is an inverted cone that tapers at the bottom, and three notches 14 are provided on the outer periphery to support the flange 13 from below. A thick part 15 is provided at the root of the shaft part 12 which is connected to the flange 13. For example, the thick portion 15 has the inner diameter of the shaft portion 12.
In a 12 mm insert 11, the wall thickness of the thick wall portion 15 is made 1 mm thicker than the shaft portion 12. A protruding portion 16 is provided below the flange 13, and a bolt hole 18 is provided in the length direction of the shaft portion 12 into which a bolt 17 for attaching a member is screwed. A screw 19 is carved into the inner surface of the bolt hole 18.

The method of use is exactly the same as the conventional product.

<Effects of the Invention> As explained above, in the present invention, an inverted truncated conical flange is provided below the shaft portion over the entire circumference, and a thick portion is provided at the root of the shaft portion. For this reason, the parts that are easy to break when stretched are reinforced, so
An extremely effective effect was produced for the insert, in which the tensile strength was much higher than that of an insert with the same wall thickness except for the thick part.

[Brief explanation of drawings]

FIG. 1 is a partially longitudinal front view showing an insert of the present invention, FIG. 2 is an explanatory view showing a tensile strength experiment, and FIG. 3 is a front view showing a conventional insert. 11... insert, 12... shaft section, 13...
Flange, 15... Thick part, 17... Bolt, 1
8...Bolt hole.

Claims (1)

[Scope of utility model registration request] In an insert in which a bolt hole for screwing a bolt for attaching a component is drilled in the length direction of the shaft part, an inverted truncated conical flange with a wide upper surface and a concave side on the buried side is provided below the shaft part all around the circumference, This insert has a protruding part on the lower surface of the flange so that the bolt hole extends to the protruding part, and a thick part is provided at the base of the shaft part.