JPH067846Y2 - Undercut drill drilling position adjustment mechanism - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is applicable to concrete, blocks, bricks, marble,
Drilling position for changing and adjusting the drilling position of the undercut drill used for drilling a drill hole in which the inner wall has a larger diameter inside the hole when embedding a post-installed anchor bolt, etc. into a stone material. Regarding adjustment mechanism.

(Prior Art) FIG. 5 is a front view of a conventional undercut drill and shows a cross section in which the left half is cut away.

As shown in FIG. 5, a conventional undercut drill has a hollow body 3 formed in a drill body 1 having a shank 2 at its upper end, and a wedge center 4 is loosely fitted in the hollow portion 3 to form a wedge center 4. And a stop cylinder 5 attached to the outside of the drill body, and a long hole 6 formed in the middle of the drill body.
The drill body 1 is vertically movable with respect to the wedge center 4 and the stop cylinder 5, and the cutting edge 9 formed in the wing portion 8 at the lower end of the drill body is connected to the wedge center 4 and the stop cylinder 5 through the pin 7. It is configured to move up and down along the protruding jaw 10. Also, the drill body 1
A spring 12 is fitted in the space 11 along the drill body between the stop body 5 and the stop cylinder 5,
And the wedge center 4 and the stop cylinder 5 are urged to keep them in an extended state.

In the case of using the conventional undercut drill having the above-mentioned structure to form a diameter-increased drill hole for anchor bolts in concrete or the like, first, as shown in FIG. 6 (a). As described above, the pilot hole B is previously drilled using another drill. An undercut drill is inserted into the prepared hole B until the lower surface of the stop cylinder 5 contacts the concrete surface A or the tip of the wedge center contacts. Then, as shown in FIG. 6 (b), by pressing the drill body 1 downward, the drill body 1
Is lowered along the wedge center 4, the wing portion 8 at the tip end thereof is expanded, and the diameter of the drill hole C is expanded by the cutting blade 9.
Is perforated.

After the completion of drilling, as shown in FIG. 6 (c), the pressing force on the drill body 1 is released, and the action of the spring 5 causes the drill body 1 to move to the wedge center 4.
Wing portion 8 of the drill body 1 that has risen along with the diameter and expanded
Is restored, and the undercut drill is pulled out from the enlarged drill hole C.

(Problems to be solved by the invention) When using an undercut drill having the above-mentioned conventional configuration to open a diameter-enlarged drill hole for an anchor bolt, the position of the diameter-enlarged drill hole is changed. In this case, or in order to increase the pull-out strength of the anchor drill, it is sufficient to provide a plurality of expanded diameter portions, but it is necessary to form a plurality of expanded drill holes in one pilot hole stepwise. There was a problem in doing so.

That is, in the conventional undercut drill having the above structure, the concrete contact surface is the lower surface of the stop cylinder 5 or the tip of the wedge center. Therefore, change this position, that is, change the drilling position of the expanded drill hole. Means that it is necessary to prepare another undercut drill with a different stop ring length or shoulder length, which results in time-consuming or expensive replacement of the undercut drill. There was such a problem.

(Means for Solving Problems) The drilling position adjusting mechanism of the undercut drill of the present invention is
The present invention has been devised in view of the above problems, and the gist thereof is a wedge center loosely fitted in a hollow portion formed in a drill body having a shank at the upper end and a stop attached to the outside of the body. The cylinder is connected via a pin inserted in a long hole drilled in the middle of the drill body, and the drill body is vertically movable with respect to the wedge center and the stop cylinder, and is formed in the wing part at the lower end of the drill body. In an undercut drill configured to expand the diameter of the cutting edge along the overhanging jaw formed at the lower end of the wedge center, a stopper ring that can be moved stepwise between the wing part of the drill body and the stop cylinder That is wearing.

(Operation) In the undercut drill boring position adjusting mechanism of the present invention, since the stopper ring is mounted so that the position can be moved stepwise between the wing portion of the drill body and the stop cylinder, it corresponds to the desired drill hole position. By mounting the stopper ring at the position, the lower surface of the stopper ring becomes a concrete contact surface, so that it is possible to easily drill an enlarged drill hole for an anchor bolt having a desired depth.

Further, by selecting the position where the stopper ring is mounted, it is possible to easily select and drill the enlarged drill holes for the plurality of anchor bolts at desired positions.

(Example) The drilling position adjusting mechanism of the undercut drill of the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a front view of a drilling position adjusting mechanism for an undercut drill according to the present invention, in which the left half shows a cutaway section, and FIG.
1 is a top view of the ring body of the stopper ring of FIG. 1, FIG. 3 is an exploded perspective view of the stopper ring, and FIG. 4 is similar to FIG. 2 showing another embodiment of the ring body of the stopper ring. It is a top view.

As shown in FIG. 1, the undercut drill used in the present invention is basically the same in construction as the conventional undercut drill, but it is provided between the wing portion 8 of the drill body 1 and the stop cylinder 5. A plurality of annular grooves 14 are formed at intervals. The same components as in a conventional undercut drill have the same reference numbers. 15
Is a ring-shaped stopper ring, and comprises a ring body 16 mounted in the annular groove and a bearing 17 mounted on the lower surface of the ring body 16.

As shown in FIGS. 2 and 3, the ring body 16 is composed of a half ring member, and at the joint portion thereof, a tightening screw 18 and a screw hole 19 corresponding to the tightening screw 18 can be used for tightening and fixing. Is configured.

The bearing 17 is a thrust bearing and is connected to the ring body 16 by a suitable detachable connecting means 20.

Therefore, when the stopper ring having the above structure is mounted in the annular groove at a position corresponding to a desired drilling position of the undercut drill, first, the tightening screw 18 of the ring body 16 is removed, and the upper ring body is removed. 16 are separated, and the ring body 1 is inserted into the annular groove 14 corresponding to the position of the desired drilling depth.
After fitting 6, the tightening screws 18 are tightened, and the ring body 16 is mounted in the annular groove 14. Then, the bearing 17 is attached to the lower surface of the ring body 16.

When the expanded drill hole for the anchor bolt is drilled, the anchor drill in the above state is inserted into the prepared hole that is previously drilled. The bottom surface of the bearing 17 of the stopper ring becomes the concrete contact surface, and the drill body 1 and the ring body 1 are inserted through the shank 2 of the undercut drill.
6 rotates integrally, and a drill hole having an enlarged diameter is bored.

FIG. 4 shows another embodiment of the ring body of the stopper ring, which differs from the ring body of the first embodiment described above in that the half ring member of the ring body 16 is The point is that one seam portion is connected by a pin 21 so that it can be expanded.

(Effect) In the drilling position adjusting mechanism of the undercut drill of the present invention, since the stopper ring is mounted so as to be movable stepwise, by mounting the stopper ring at a position corresponding to a desired drill hole position, Since the lower surface of the stopper ring serves as a concrete contact surface, it is possible to easily form an expanded drill hole for the anchor bolt to a desired depth.

In addition, by selecting the position where the stopper ring is attached, it is possible to easily select and drill the expanded drill holes for a plurality of anchor bolts at the desired position, which is complicated by replacing the drill itself as in the past. This is a very convenient undercut drill boring position adjusting mechanism that does not require time and labor, and has various operational effects.

[Brief description of drawings]

FIG. 1 is a front view of a drilling depth adjusting mechanism of an undercut drill of the present invention showing a cross section with a left half cut away, and FIG. 2 is a top view of a ring body of a stopper ring of FIG.
FIG. 4 is an exploded perspective view of the stopper ring, FIG. 4 is a top view similar to FIG. 2 showing another embodiment of the ring body of the stopper ring, and FIG. 5 is a conventional under view showing a cross section with the left half cut away. The front view of the cut drill and FIGS. 6 (a), (b) and (c) are partial cross-sectional views showing the usage state of the conventional undercut drill. 1 ... Drill body, 2 ... Shank, 4 ... Wedge center,
5 ... Stop cylinder, 7 ... Pin, 8 ... Wing part, 9
... Cutting blade, 10 ... Overhang jaw, 14 ... Annular groove, 15 ... Stopper ring, 16 ... Ring body, 17 ... Bearing, 1
8 ... tightening screw, 19 ... screw hole, 21 ... pin.

Claims (1)

[Scope of utility model registration request] 1. A pin having a wedge center loosely fitted in a hollow portion formed in a drill body having a shank at its upper end and a stop cylinder attached to the outside of the body, inserted through an elongated hole formed in the middle of the drill body. The drill body is vertically movable with respect to the wedge center and the stop cylinder, and the cutting edge formed at the wing portion at the lower end of the drill body is expanded along the overhanging jaw formed at the lower end of the wedge center. In an undercut drill configured to have a diameter, a stopper ring is detachably attached to a plurality of annular grooves formed at intervals between the wing part of the drill body and the stop cylinder, and undercut is made in stages. A drilling position adjusting mechanism for an undercut drill, characterized in that the drilling position can be changed.