JPH0129646B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a percussion drilling device that generates rotational motion and reciprocating motion in a blade body, and is called an undercut in which the diameter of the deep hole is larger than that of the opening. This relates to a hammer drill or vibration drill for drilling holes.

By the way, when planting an anchor bolt in solidifying concrete, a blind end hole of a predetermined depth is drilled in the concrete, and the bolt base is inserted into the hole into a seated cylindrical body with a notch in the longitudinal direction. Methods such as screwing in and expanding the diameter to create frictional resistance between the anchor bolt and the hole wall have been taken, but the pullout strength of an anchor bolt installed on a concrete surface depends on the bonding strength between the hardening agent and the hole wall. The pull-out strength can be greatly increased by planting the hole in an undercut hole where the diameter at the back of the hole is larger than the opening, but with conventional hammer drill bits,
There was no structure that could drill undercut holes.

In addition, conventional rotary drills have been made so that the diameter can be expanded by making vertical cuts at regular intervals around the tip of the cylindrical body for drilling, and after drilling a hole of the same diameter from the opening to the bottom of the hole. A truncated cone-shaped guide member is inserted into the hole, and the drilling cylinder is rotated while expanding the diameter of the tip so that the guide member is placed on top of the guide member, thereby drilling an undercut hole. However, since it is a rotary drill, its drilling efficiency in concrete is lower than that of a hammer drill, and the diameter of the tip of the drilling cylinder is expanded by placing it on the guide member, so the wall of the drilling cylinder is It is necessary to reduce the thickness, and the tip blade plate is easily damaged, resulting in a lack of durability.Also, it is difficult to first drill a hole of the same diameter using another drilling device and then enlarge the deep part of the hole. Since it is necessary to make the diameter, there are drawbacks such as inconvenience in handling and poor work efficiency.

This invention was made in view of the above points, and is a convenient hammer drill and vibration drill that can continuously drill undercut holes for installing anchor bolts in objects such as concrete, and has good workability. The purpose of the present invention is to provide a percussion drilling device such as a drill.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In Figures 1 to 3, 1 is a main blade body, and this main blade body 1 has a V-shaped tip to form a cutting blade 2, and following this cutting blade 2, an overhanging jaw 3 is formed. A pair of vertically elongated guide grooves 4 are formed at the tip.

Reference numeral 5 denotes a sub-blade body for cutting the hole wall, and this sub-blade body 5 cuts both sides of the tip of the tubular body into cutting grooves 6 to form a pair of opposing blade plates 7, and a cutting blade is provided at the tip of the double-blade plate 7, respectively. A blade 8 is provided, and a part of the cutting blade 8 is made to protrude inward so that this protrusion 8a can be fitted into the guide groove 4, and the main blade 1 is inserted into the secondary blade 5. The protruding part 8a is inserted into the guide groove 4, and the double blade bodies 1 and 5 always rotate together, and the cutting blade 8 of the secondary blade body 5 is attached to the rear of the protruding jaw 3 of the main blade body 1. From this position, the blade plate 7 is gradually expanded along the inclined surface at the rear of the overhanging jaw 3, and finally the cutting blade 8 is configured to be movable relative to the axis to a position where it extends outward beyond the overhanging jaw 3. do.

Reference numeral 9 denotes a holding holder for the double-edged bodies 1 and 5, which has the following configuration. That is, the cylindrical case 10 has six longitudinally elongated engaging parts 10a formed at equal intervals in the circumferential direction on the upper part of the inner circumferential wall, and three engaging parts 10 at the upper end opening.
b are protruded at equal intervals in the circumferential direction, and the base end of the sub-blade body 5 is screwed to the lower end of the hollow mounting body 11, and the vertically elongated engaging portion 10a of the case 10 is attached to the upper end of the outer peripheral wall of the hollow mounting body 11. It is fitted into the case 10 so as to be rotatable and axially movable, and is biased upward by a spring 12.

Further, on the inner circumferential wall of the hollow mounting body 11, three engaging portions 11b are formed at predetermined intervals below the upper end opening, and at equal intervals in the circumferential direction, and further below the engaging portions 11b. Six vertically long engaging portions 11c are continuously formed at equal intervals in the circumferential direction. The base end of the main blade body 1 is screwed onto the lower end of the attachment body 13,
An engaging portion 13a corresponding to the vertically elongated engaging portion 11c is provided at the upper end of the outer circumferential wall thereof, and is fitted into the hollow mounting body 11 so as to be rotatable and axially movable therewith. The intermediate member 14 has an engaging portion 14a corresponding to the longitudinally elongated engaging portion 11c at the lower end of the outer circumferential wall, and the upper half 15 has an outer diameter reduced to form three engaging portions 15a on the outer circumferential wall in the circumferential direction. They are formed at equal intervals and are fitted onto the mounting body 13 in the hollow mounting body 11 so as to rotate together with the hollow mounting body 11 and to be able to move axially.

A rotation control body 17 having a shank 16 integrally connected to the upper end is attached to the upper half 1 of the intermediate member 14 at the center of the lower end.
A lumen 18 is formed into which the lumen 1 can be inserted.
The lower end opening of 8 has an engaging portion 15 of the upper half portion 15.
An engaging portion 18a corresponding to the portion a is formed at the lower end of the outer peripheral wall of the rotation control body 17, and an engaging portion 17a corresponding to the engaging portion 11b of the hollow mounting body 11 is formed. The outer circumferential wall above the portion 17a corresponds to the upper end opening engaging portion 10b of the case 10, and is sequentially engaged in the rotational direction by rotating the rotation control body 17 by a predetermined angle with the rotation control body 17 inserted into the case 10 by a predetermined dimension. three-stage engagement portion 17b,
17c and 17d are formed. Reference numeral 19 denotes a ring body that is relatively rotatably mounted at the position of the cutting waste discharge port 20 bored at the lower end of the case 10. By suctioning through the opening 19a of this ring body 19, waste generated during drilling work is sucked through the opening 19a of the ring body 19. The cutting waste passes through the cut groove 6 of the sub-blade body 5, through the gap between the main blade body 1 and the sub-blade body 5, and further passes through the discharge port 21 at the lower end of the mounting body 13, the gap between the mounting body 13 and the hollow mounting body 11, and the hollow mounting body. 11 is configured to be discharged to the outside via a discharge hole 20 in the middle part. Further, 23 is a bellows-shaped protective cover for the rotation control body 17, which covers the lower end of the shank 16 and the case 10.
It is placed between the top ends. 24 is a pressure spring,
It is interposed between the upper end of the inner cavity 18 of the rotation control body 17 and the intermediate member 15 .

Next, the drilling operations for the embodiment of the above construction will be explained in order according to FIGS. 4A to 4F.

FIG. 4B The hollow mounting body 11 is located at the upper end of the case 10, the mounting body 13 is inserted into the lower end of the hollow mounting body 11, and the upper half 15 of the intermediate 14 is connected to the rotation control body 17.
The cutting blade 8 of the secondary blade body 5 is inserted between the lower end surface of the rotation control body 17 and the upper end surface of the mounting body 13, and the cutting blade 8 of the secondary blade body 5 is inserted into the protruding jaw of the main blade body 1. 3. Start drilling work with the main blade 1 on the object to be drilled A while being located at a distance from the rear.

In this state, the engaging portion 10b at the upper end of the case 10 and the first stage engaging portion 17b of the rotation control body 17 are engaged, and the shank 16, the case 10, and the hollow mounting body 1 are engaged with each other.
1. The mounting body 13 and the intermediate piece 14 rotate together, and the impact force of the shank 16 is applied to the mounting body 13 via the intermediate piece 14 and directly to the hollow attachment body 11.
and the case 10 via this hollow mounting body 11.
By being transmitted to the double-edged bodies 1 and 5 respectively,
rotates and reciprocates to drill a hole to a depth _L1 , and the tip of the case 10 comes into contact with the surface A of the object to be drilled.

4B When the main blade 1 continues drilling from the state shown in FIG. 4A, the hollow mounting body 11 advances inside the case 10 against the spring 12 and
When a space is formed at the upper end of the case 10 and a hole of a predetermined depth _L2 is made, the engaging part 10b at the upper end of the case 10
The engagement relationship between the rotation control body 17 and the first stage engagement portion 17b is released, and the rotation control body 17 rotates relative to the case 10 by a predetermined angle α° to engage the engagement portion 1.
The second stage engaging portion 17c engages with 0b. In this state, the engaging part 15a of the upper half 15 of the intermediate member 14 and the engaging part 18a of the lower end of the inner cavity 18 of the rotation control body 17
The engagement relationship with the upper half 1 of the meson 14 is released.
5 can be inserted into the inner cavity 18 of the rotation control body 17.

FIG. 4C: During the process in which the upper half 15 of the meson 14 enters the inner cavity 18 of the rotation control body 17, the impact force is not transmitted from the shank 16 to the main blade 1, and the drilling work by the main blade 1 is not performed. The impact force is transmitted only to the secondary blade 5 which rotates together with the main blade 1, and the secondary blade 5 continues to move forward, and its cutting blade 8 moves forward along the inclined surface at the rear of the overhanging jaw 3. As the process progresses, cutting of the hole wall begins.

In this state, the hollow mounting body 11 further moves down inside the case 10 against the spring 12.

When the cutting operation of the hole wall is continued by the sub-blade 5 from the state shown in Fig. 4D and Fig. 4C, the cutting blade 8 of the sub-blade 5 moves forward a distance _L3 and eventually the overhanging jaw 3 reach the outside,
At this point, the upper half 15 of the intermediate member 14 has finished retracting into the inner cavity 18, and the advance of the sub-blade 5 is also stopped. In this state, the engagement relationship between the second stage engagement portion 17c of the rotation control body 17 and the engagement portion 10b at the upper end of the case 10 is released, and the rotation control body 17 rotates relative to the case 10 by a predetermined angle α°. Then, the third stage engaging portion 17d engages with the engaging portion 10b, and the engagement relationship between the engaging portion 17a at the lower end of the rotation control body 17 and the engaging portion 11b of the hollow mounting body 11 is also released. The rotation control body 17 can be axially moved within the hollow mounting body 11.

Fig. 4 E In this state, the transmission of the impact force from the shank 16 to the sub-blade cavity 5 is stopped, and the impact force is again transmitted to the main blade 1, and the main blade 1 starts the drilling operation to a predetermined depth. When L ₄ is drilled and its forward movement is stopped and the drilling operation is completed, the sub-blade 5 is in its original position with respect to the main blade 1, that is, the cutting blade 8 is behind the overhanging jaw 3 of the main blade 1. They are located far apart from each other.

By pulling out the shank 16 upward in the state shown in FIG.

Then, in the state shown in FIG.
The case 1 is released by disengaging the engagement portion 17d of the third stage of the rotation control body 17 from the engagement portion 10b at the upper end.
When the rotation control body 17 is rotated by a predetermined angle α° with respect to When energized, the upper half 15 is pulled out of the lumen 18. In this state, the rotation control body 1
7 relative to the case 10 by a predetermined angle α°, the intermediate member 14 is rotated relative to the engaging portion 18a of the inner cavity 18.
The engaging portion 15a of the upper half portion 15 of is engaged, and the state returns to the original state at which the drilling operation is started, that is, the state shown in FIG. 4A.

As explained above, the impact drilling device of the present invention performs drilling with the main blade, and then uses the secondary blade for hole wall cutting, which rotates together with the main blade, to drill a hole deep inside the hole. The series of operations of expanding the diameter of the wall and making it possible to extract the double-edged body is configured to be performed continuously through the engagement and disengagement mechanism between the rotation control body and other structural members. Because of this, it is possible to efficiently drill undercut holes for planting anchor bolts in concrete, etc. in an extremely short time, and the workability is also good. When drilling, the forward drilling of the preceding main blade is stopped and the secondary blade performs cutting using the main blade as a guide, so regardless of the properties of the object to be drilled, reliable and accurate diameter expansion cutting of the hole wall is possible. This also prevents damage to the cutting edge portion of the auxiliary blade, allowing for stable use over a long period of time.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of a main blade and a sub-blade showing an embodiment of the present invention, FIG. 2 is an overall sectional view, and FIG. C line sectional view,
Figure B is a sectional view taken along the line B-B in Figure 2, and Figure C is a cross-sectional view of Figure 2.
D is a cross-sectional view taken along the line EE in Figure 2, E is a cross-sectional view taken along the F-F line in Figure 2, and F is a cross-sectional view taken along the line G-G in Figure 2. Figure 4 is a sectional view taken along line H--H in Figure 2, Figure 4 is a sectional view taken along II-I in Figure 2, and Figure 4 A to F are drilling operation modes and engagement of the upper end of the case. The engaging portion 17b of the portion 10b and the rotation control body
17d is a cross-sectional view showing the engagement relationship with 17d. 1... Main blade body, 2... Cutting blade, 3... Projecting jaw, 4, 8a
...An engaging part between the main blade body 1 and the sub-blade body 5, 5...A sub-blade body,
6... Cutting groove, 7... Blade plate, 8... Cutting blade, 9... Holding holder, 10... Case, 11... Hollow mounting body, 12
... Spring, 13 ... Mounting body, 14 ... Intermediate, 1
5...Upper half, 16...Shank, 17...Rotation control body, 10b, 17b, 17c, 17d...Case 1
0 an engagement mechanism between the upper end and the rotation control body 17, 18...inner cavity, 24...pressing spring.

Claims (1)

[Claims] 1 A pair of opposing main blades each having a V-shaped cutting blade at the tip and a protruding jaw following the cutting blade, and cutting grooves on both sides of the tip of the tube. The blade plate is inserted into the secondary blade body for hole wall cutting, each of which has a cutting blade, and both blade bodies rotate together, and the blade plate can be pushed and expanded along the rearward slope of the protruding jaw. A joint is provided between the two blade bodies, and a hollow mounting body to which the base end of the secondary blade body is attached is placed in a cylindrical case that forms a part of the holding holder for the double blade bodies, and is urged upward by a spring to make the connection. The mounting body, which is fitted into the cylindrical case so that it can rotate together with the hollow mounting body and can move relative to the shaft, and the base end of the main blade is fixed in the hollow mounting body, and the intermediate member can rotate together with the hollow mounting body and can move along the relative axis. A rotation control body, which has a shank integrally connected to the upper end thereof and a bore portion into which the upper half of the intermediate member is inserted so as to be rotatable as a unit and movable relative to each other in a relative axis, is inserted between the intermediate members. A process of inserting a pressure spring into the hollow mounting body from the upper end of the cylindrical case, and inserting the rotation control body into the cylindrical case between the outer peripheral surface of the rotation control body and the upper end of the cylindrical case. An engaging portion is provided that rotates through a predetermined angle to change the engaging position in stages, and is configured to selectively control relative axial movement of the main blade body and the secondary blade body at each engaging position. A percussion perforation device for undercut perforation, characterized by the following.