JPH0128654B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing architectural anchor bolt sleeves used in concrete or lightweight concrete, particularly small diameter sleeves, and provides anchor bolt sleeves with excellent anchoring effects at low cost with less material loss. It is intended to.

Generally, this type of anchor bolt sleeve is
A tapered part is formed at the inner depth of the sleeve body, and an axial slit is provided at the end of the body on the side of this tapered part.By driving a wedge into the sleeve body, the wedge and the tapered part are formed. The end of the main body expands due to the action of

In the conventional manufacturing method, a large diameter sleeve is formed with a tapered part using a boring tool, but for a small diameter sleeve, as shown in FIGS. A tapered part 22 is formed by drilling holes in sequence with a drill to gradually taper the holes.
However, since the tapered part requires several steps, not only is the manufacturing efficiency not improved, but the cutting process also results in a large amount of material loss. In addition, in this conventional manufacturing method, in order to reduce the number of steps, the opening is not intentionally formed at the tip of the sleeve body by drilling, but a cross-shaped slit 23 is formed as shown in FIG. 8B. The intersection of the slits serves as an opening at the tip of the sleeve. Therefore, when a wedge is driven in, the sharp cut around the opening comes into contact with the wedge, and if there is a discrepancy in the accuracy of forming the opening or the slit, the end of the sleeve will spread evenly radially. Otherwise, the desired anchor effect may not be achieved.

To solve this problem, it is conceivable to cut the tip of the drill with a shape that matches the shape of the tapered part, but this would cause seizure and other problems, making it difficult to cut properly, and this would be impractical.

The present invention provides a method for manufacturing a sleeve for an anchor bolt that can eliminate the above-mentioned conventional drawbacks by utilizing the malleability of the material. , by forming a sleeve material having a wedge insertion hole and with a solid portion remaining at the bottom of the hole, and applying a striking force of a circular area smaller in diameter than the wedge insertion hole to the solid portion from the outer end surface of the sleeve material. The solid portion is removed by shearing, and the sleeve material is then drawn to obtain a long and small diameter sleeve body,
Thereafter, a slit and a threaded portion are formed in the sleeve body.

The details of the present invention will be explained based on the embodiments shown in FIGS. 1 to 4. FIG. 1 shows a sleeve for an anchor bolt obtained by the manufacturing method of the present invention, in which 1 is the sleeve body, 2 is a wedge insertion hole, and 3 is a sleeve for an anchor bolt obtained by the manufacturing method of the present invention.
4 is a tapered surface continuous to the inner depth of the wedge insertion hole 2; 4 is an opening continuous to the tapered part of the tapered surface 3;
5 is a slit formed in the axial direction of the sleeve body 1 from the side of the opening 4, 6 is a retaining convex portion, 7 is a threaded portion formed on the outer periphery of the sleeve body 1 on the side opposite to the slit 5, and 8 is a wedge. It is.

However, in order to manufacture the above-mentioned sleeve, first, a solid bar with excellent malleability is cut into a predetermined length, and then held in a homer, and processed by cutting it inward in the axial direction from one end of the bar. In addition to drilling a wedge insertion hole 2' that reaches deep, a circular blind center hole 4' is formed on the other end surface of the bar, and a thick wall is formed between the wedge insertion hole 2' and the blind center hole 4'. A solid portion 9 is left, thereby obtaining an original sleeve 1' having a larger diameter and shorter length than the sleeve main body 1 to be manufactured, as shown in FIG.
The inner diameter of the blind central hole 4' is approximately half that of the wedge insertion hole 2'.

Next, a homer pin is applied to the solid portion 9 through the blind center hole 4' to apply a striking force. Then, a shear fracture in the shape of a truncated conical circumferential surface as shown by the dotted line in FIG. the solid part 9 inside this shear fracture surface is removed from the sleeve base body 1';
A tapered surface 3' having a tapered and inverted truncated conical peripheral surface shape is formed on the sleeve original body 1' side. This tapered surface 3' is a rough surface and continues deep inside the wedge insertion hole 2', and its tapered end continues to the blind center hole 4', and the blind center hole 4' becomes an opening that communicates with the inside and outside. (See Figure 3). Note that it is not necessary to apply the shear impact force after providing the blind center hole 4', and the impact force may be applied directly to the solid portion. After this, the sleeve material 1'
The sleeve body 1 as shown in FIG. 4 is obtained by drawing the entire sleeve to make it long and small in diameter. As a result, not only the diameter of the whole becomes small, but also the wedge insertion hole 2 becomes small in diameter, and the tapered surface 3 also becomes elongated and its slope becomes gentle.

After that, a threaded portion 7 is formed on the outer periphery of one end of the sleeve body 1, and a retaining protrusion 6 is formed on the side with the tapered surface 3, and the sleeve body 1 is divided so as to divide the retaining protrusion 6. Several slits 5, . . . are cut in the axial direction from one end, thus obtaining the sleeve shown in FIG.

The anchor bolt sleeve of the present invention manufactured in this way is half-buried in an anchor hole drilled in concrete or the like with the threaded portion 7 exposed, in the same manner as conventional products, and then inserted into the wedge insertion hole. Insert the wedge 8 from 2 and press fit it. The tip of the wedge 8 hits the tapered surface 8 and pushes it apart, and the sleeve body 1
The part held by the slit 5 expands. In addition, in the illustrated example, the sleeve body 1 is formed with a male thread, but
A female thread may be provided on the inner peripheral surface of the wedge insertion hole 2.

Figures 5 to 7 show each process of another embodiment, in which a bar of a predetermined length is held in a homer as in the previous embodiment, and the bar is shaped by machining. A wedge insertion hole 12' is drilled from one end to reach the inner depth in the axial direction, and a hole whose diameter becomes smaller in stages is subsequently drilled at the back of the wedge insertion hole 12' to form a stepwise tapered portion 13'. A solid part 19 is left between the tapered part 13' and the outer circumferential surface of the bar material, thereby obtaining a sleeve body 11' as shown in FIG. 5. Next, a wedge insertion hole is formed. When a pin having the same diameter as the inner diameter of the tapered part 13' is applied from the end face opposite to the tapered part 12' and a striking force is applied, the solid part 19 is sheared and removed as shown in FIG. An opening 14' is formed at the end of the sleeve body 11'. After that, this sleeve body 11' is drawn to form a long and small diameter sleeve body 11 as shown in FIG.
get. Forming the retaining protrusion and the slit in the sleeve body 11 is the same as in the example shown in FIGS. 1 to 4. 12 is a wedge insertion hole in the sleeve body 11, 13 is a tapered portion, and 14 is an opening. The width of the slit is made smaller than the diameter of the opening 14.

As described above, the present invention involves forming a sleeve material with a solid portion remaining at the bottom of the wedge insertion hole by homing processing, shearing off the solid portion, and then drawing the sleeve material. This method produces a small-diameter sleeve by making it long and small in diameter, and then forming a slit and a threaded part.Since it can be processed almost while being set in the homer, it is not necessary to drill holes in sequence with several drills to form the tapered part as in the conventional method. Compared to the case where the product was manufactured using
Since fewer steps are required, manufacturing efficiency is improved, and material loss is extremely low, small-diameter sleeves can be obtained at low cost.

In addition, when the solid part is sheared into an inverted truncated cone shape, the tapered surface is formed into a conical surface and the contact area with the wedge is large, so the bonding force with the wedge is strong and the anchor effect due to vibration etc. There is no such thing as a decrease in the value.

Furthermore, a relatively large-diameter opening is formed at the tip of the sleeve body, and the diameter of the opening is larger than the width of the slit, so the tip of the wedge is guided through this opening and reaches the center of the sleeve body. There is no risk of poor expansion.

[Brief explanation of drawings]

Fig. 1 is a half-cut sectional view of a sleeve obtained by the manufacturing method of the present invention, Figs. 2 to 4 are sectional views of semi-finished products at each manufacturing process, and Figs. 5 to 7 are semi-finished products at each process in other embodiments. FIGS. 8A and 8B are a sectional view of a main part and a bottom view of a conventional product. 1, 11... Sleeve body, 1', 11'... Sleeve original body, 2, 12, 2', 12'... Wedge insertion hole, 3, 3'... Tapered surface, 13, 13'... Taper Part, 5...Slit, 7...Thread part, 8...
Wedge, 9, 19...solid part.

Claims (1)

[Claims] 1. Form a sleeve material from a solid bar material by homing processing, which has a wedge insertion hole and a solid portion remains at the bottom of the hole, and insert a diameter smaller than the wedge insertion hole into the solid portion from the outer end surface of the sleeve material material. The solid portion is sheared off by applying a striking force with a circular area of , and then the sleeve material is drawn to form a long and small diameter sleeve body, and then a slit and a threaded portion are formed in this sleeve body. A method for producing sleeves for anchor bolts, which is characterized by: