JPS61169543A - Method and apparatus for attaching insert metal jig in concrete product - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for attaching an insert fitting to a forming form for various concrete products using concrete balls and the like.

<Prior art> Fig. 2 shows a state in which an insert fitting 1 as a receiving fitting for a scaffolding bolt to be incorporated into a conventional centrifugal curvature stress concrete pole is attached to a formwork 3 for centrifugal forming, and 2 is a concrete product. It shows.

In this figure, the inner surface of the insert metal fitting 1 has a threaded part with a pitch P, and a metal fitting mounting bolt 6 is attached to the threaded part of a nut part 5 fixed by means such as welding to the outside of the opening 4 provided in the formwork 3.
The male thread of the large diameter part 8 of the bolt 6 is screwed into the threaded part of the insert metal fitting 1, and a ring-shaped leakage prevention member made of rubber or the like is attached to the lower end surface of the large diameter part 8 of the bolt 6. I am wearing 7.

When assembling, screw the small diameter part 9 of the metal fittings mounting bolt 6 into the inserter 1 to the metal fitting 1 and screwing the entertainment mounting bolt 6 into the nut part 5 using an impact wrench or the like that is engaged with the hexagonal head 10. , the metal insert 1 is made to protrude into the formwork 3 through the opening 4.

Also, the pitch of the threaded part of the insert fitting 1 and the nut part 5
The pitch is the same as the pitch P of the threaded portion.

After the product 2 has hardened, the metal fitting bolt 6 is removed from the insert metal fitting 1 and the nut part 5, and the product 2 is removed from the formwork 3, and the insert metal fitting 1 is embedded in the product 2.
Moreover, the outer end of the metal fitting 1 is flush with the surface f of the product 20.

<Problems to be Solved by the Invention> The conventional method described above has the following problems.

<a) When screwing the insert metal fitting 1 and metal fitting mounting bolt 6 set in the formwork 3 into the nut part 5 with an impact wrench, etc., the inner metal fitting 1 and the small diameter part 9 are tightened by the action of the impact wrench etc. As a result, the outer end of the insert metal fitting 1 sinks below the surface f of the product 2, which tends to result in the production of defective products.

(b) Threaded part of insert metal fitting 1 and mounting bolt 6
The pitch P of the small diameter part of the small diameter part of the product 2, the small diameter part of the mounting bolt 6, and the thread part of the large diameter part 8 are the same, but the mounting bolt 6 is the same as the thread part of the product 2.
After hardening, the screws are removed and used many times, and the tightening and loosening operations are performed by applying impact using an impact wrench, etc., resulting in severe wear on the threaded portions.

For this reason, the pitch increases by the backlash generated in the threaded portion, which results in unnecessary force being applied to the metal insert 1 during demolding after concrete hardens, resulting in breakage of the metal insert 1.

<Means for Solving the Problems> The present invention has been made to solve the above-mentioned problems, and the small diameter portion of a metal fitting bolt having a small diameter portion having an elastic body fixed to the outer periphery is fixed to an elastic body. After press-fitting the metal insert into the threaded part of the metal insert using the elastic deformation of the body, screw the threaded part of the large diameter part of this metal fitting mounting hole 1 into the nut part fixed to the formwork, and attach the metal insert to the formwork. The present invention provides a method and device for fixing the device in a state in which it protrudes inward.

<Operation> The present invention is as described above. First, the small diameter portion of the metal fitting mounting bolt is press-fitted into the threaded portion on the inner periphery of the metal insert using the elastic deformation of the elastic body on the outside thereof.

Then, while inserting the insert metal fixed to the metal fitting bolt through the opening of the formwork having the nut part, the male screw of the large diameter part of the metal fitting bolt is screwed into the nut part using an impact wrench or the like.

Thereafter, a concrete product is formed in the formwork, and after the product is allowed to harden, the metal fixture mounting bolts are removed from the formwork together with the elastic body.

Embodiment Example In FIG. 1, the same parts as in FIG. 2 are given the same reference numerals.

The metal fitting bolt 6 has a threaded portion in its large diameter portion 8, but its small diameter portion 9 does not have a threaded portion and is instead surrounded by an elastic body 11 such as rubber.

This elastic body 11 is fixed to the small diameter portion 9 by adhesive, welding, baking, etc., and the outer diameter of the elastic body 11 is slightly larger than the inner diameter of the threaded portion on the inner circumference of the metal insert 1.

Furthermore, although the leakage prevention member 7 of the concrete product is shown integrated with the elastic body 11 in the figure, it may be separate from the elastic body 11. Furthermore, the metal fitting bolt 6 has an air vent hole 12.
will be established.

In this embodiment, the elastic body 11 on the outside of the small diameter portion 9 of the metal fitting bolt 6 is press-fitted and fixed into the threaded part of the metal insert 1 using its elastic deformation, and then the insert 1 to the metal fitting 1 are attached to the formwork 3. into the opening 4 of the nut part 5 and screw the large diameter part 8 into the nut part 5.

Then, the concrete product 2 is centrifugally formed, and after the product 2 is hardened, the metal fitting mounting bolt 6 is removed from the nut part 5 and the insert metal fitting 1.

<21I Results> As described above, the present invention fixes an elastic body integrally to the outside of the small diameter portion of the metal fitting mounting bolt, and uses the elasticity of this elastic body to push the elastic body into the threaded part of the insert metal fitting. deforms elastically and bites firmly into the threaded part of the insert metal fitting. Therefore, when screwing the large diameter part of the metal fitting mounting bolt 1~ into the nut part of the formwork using an impact wrench, etc., the impact is buffered by the elastic body, so the metal fitting bolt loosens and the outer end of the insert metal part is attached to the product. This has the effect of producing an excellent concrete product without the risk of it sinking in from the surface.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a longitudinal cross-sectional view showing a conventional mounting state of an insert fitting. 1... Insert metal fittings 2... Concrete product 3... Formwork 4... Opening 5...
・Nut parts 6...Bracket mounting bolt 8...
・Large diameter part 9...Small diameter part 11...Elastic body

Claims (2)

[Claims] (1) After press-fitting the small diameter part of a metal fitting mounting bolt with an elastic body fixed to the outer periphery into the threaded part of the insert fitting by utilizing the elastic deformation of the elastic body, the large diameter part of this metal fitting mounting bolt is pressed. 1. A method for installing an insert fitting in a concrete product, which comprises screwing into a nut part provided in an opening of a formwork and fixing the insert fitting in a state in which it protrudes into the formwork. (2) A metal fitting mounting bolt having a small diameter part with an elastic body fixed to the outer periphery and a large diameter part having a threaded part on the outer periphery, and an insert metal fitting having a threaded part on the inner periphery into which the elastic part of the metal fitting bolt is press-fitted; On the outer periphery of the opening into which the insert fitting fits,
A device for attaching an insert fitting in a concrete product, comprising a formwork to which a nut part having a threaded portion inside into which the large diameter portion of the fitting attaching bolt is screwed is fixed.