JP2839755B2 - Rotary punch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drilling tool suitable for drilling work in a reinforced concrete building, sampling work for soil investigation, and the like.

[0002]

2. Description of the Related Art Conventionally, as a rotary piercing tool for performing this kind of piercing operation, for example, there is a rotary piercing tool previously proposed by the present applicant (Japanese Patent Application No. 1-136154). The rotary punch has an adapter mounted on the electric motor, an inner cylinder attached to the distal end of the adapter, and having a plurality of cutting blades at the distal end, and an outer cylinder externally fitted and fixed to the inner cylinder. Consists of
Then, the adapter, the inner cylinder and the outer cylinder are integrally driven to rotate by an electric motor, and a hole is drilled in the drilled object at the cutting blade portion.

[0003] Further, in the above-mentioned rotary piercing tool, in order to prevent the cutting powder from staying in the cutting blade portion and forming cutting resistance,
Compressed air is supplied to a flow passage formed between the inner cylinder and the outer cylinder, and the supplied compressed air is injected to the cutting powder.
Then, the cutting powder blown out from the perforated portion by the injection of the compressed air is sucked by the operation of the suction device or the like, and is discharged to the outside through the inner cylinder and the adapter.

[0004]

However, in the above-described conventional rotary punch, the inner cylinder has a large diameter and a long shape. It is difficult to make the inside of the cylinder a sufficiently large negative pressure state. Therefore, the cutting powder stays in the inner cylinder, and the cutting powder cannot be efficiently discharged out of the rotary drilling tool. Such a problem becomes a problem particularly when a cutting powder having a large specific gravity is generated, such as a drilling operation in a reinforced concrete building.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a rotary piercing tool capable of efficiently sucking and discharging cutting powder regardless of the specific gravity of the cutting powder. To provide.

[0006]

According to a first aspect of the present invention, there is provided an adapter connected to a rotating shaft of a motor, a cylindrical body attached to the adapter, and a tip of the body. A cutting blade that cuts and pierces the object to be pierced by rotation, sucks the cutting powder staying in the vicinity of the cutting blade with a negative pressure, and discharges the inside of the body portion and a discharge path provided in the adapter. In the rotary drilling tool configured to discharge the cutting powder to the outside of the adapter, a guide pipe for guiding the cutting powder generated by the cutting blade to a discharge path of the adapter is disposed in the body. One end of the guide tube is fixed to the adapter, and at least a part of the guide tube is provided with an extendable portion that can extend and contract in the longitudinal direction of the body portion.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, a dust collecting head is attached to a distal end of the guide tube, and the dust collecting head has a communication passage for communicating an outer peripheral surface of the dust collecting head with the inside of the guide tube. Is provided.

In a third aspect of the present invention, in addition to the configuration of the second aspect, a rotary support is provided at the center of the tip of the dust collecting head to prevent the torsion of the guide tube by making point contact with the surface of the drilled object. Part is provided.

[0009]

In the first aspect of the invention, when the adapter and the body are integrally rotated with the driving of the electric motor, the object to be drilled is cut by the cutting blade at the tip of the body to make a hole. At this time, cutting powder tends to stay in the vicinity of the cutting blade, but this cutting powder is sucked by negative pressure and discharged to the outside of the adapter through the inside of the body and the discharge path of the adapter.
A guide tube is provided in the body, and one end of the guide tube is fixed to the adapter. Therefore, the opening at the distal end of the discharge passage of the adapter approaches the pierced object substantially by the length of the guide tube. Moreover, this guide tube has a smaller diameter than the body portion. For this reason, compared with the case where the guide tube is not provided in the inner cylinder, a large negative pressure acts on the perforated portion, and the cutting powder near the cutting blade is efficiently sucked.

Further, since the guide tube is provided with a telescopic part, when the drilling operation proceeds and the body portion enters the object to be drilled, the guide tube contracts. For this reason, it is possible to always make the distal end opening of the guide tube close to the surface of the drilled object.

[0011] In the second aspect of the present invention, the opening at the distal end of the guide tube approaches the perforated portion by an amount corresponding to the communication passage provided in the dust collecting head. For this reason, the suction efficiency is further improved. Third
In the invention of (1), at the time of the drilling operation, the rotary support at the center of the tip of the dust collecting head makes point contact with the surface of the drilled object. At this time, the friction generated between the rotation support portion and the object to be drilled is small, and the torsion of the guide tube is prevented.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. First, the basic configuration of the rotary punch according to the present embodiment will be described. As shown in FIG. 1, the rotary piercing tool 1 includes an adapter 3 mounted on an electric motor 2 and a body attached to a distal end of the adapter 3. The body portion includes an inner cylinder 4 and an outer cylinder 5 fitted and fixed to the inner cylinder 4. A plurality of diamond segments 6 as cutting blades are fixed to the tip of the inner cylinder 4. The adapter 3, the inner cylinder 4 and the outer cylinder 5 are integrally rotated by the electric motor 2 to make a hole in the object 7 to be drilled at the diamond segment 6. In the rotary punch 1,
In order to prevent cutting powder (solid particles such as dust) 8 generated at the time of drilling from accumulating in the diamond segment 6 to cause cutting resistance, the cutting powder 8 is compressed into the flow passage 9 between the inner cylinder 4 and the outer cylinder 5. Air 10 is supplied, and the supplied compressed air 10 is blown against the cutting powder 8 (see FIG. 5). Then, the cutting powder 8 blown out from the perforated portion by the blowing of the compressed air 10 is sucked at a negative pressure and discharged to the outside through the inner cylinder 4 and the adapter 3.

Next, each part of the rotary punch 1 will be described in detail. As shown in FIGS. 1 and 2, a screw hole 11 is formed at a base end (the right end in FIG. 1) of the adapter 3, and a rotary shaft 12 of the electric motor 2 is screwed into the screw hole 11. . A first swivel joint 13 is provided on the rotating shaft 12.
Are supported so as to be relatively rotatable. The compressed air 10 supplied from outside the first swivel joint 13 flows into the screw hole 11 through the rotary shaft 12.

From the inner bottom surface of the screw hole 11, a plurality of small-diameter holes 14 extend at equal angular intervals toward the distal end of the adapter 3 in the axial direction (see FIG. 6). These small holes 1
Reference numeral 4 denotes an opening at the distal end surface of the adapter 3. The opening at the end of each small-diameter hole 14 is closed by a screw 15.
A communication hole 16 extends radially outward from the tip of each small diameter hole 14. The communication hole 16 opens in an annular groove 17 formed on the outer peripheral surface of the adapter 3. In the present embodiment, the compressed air 1 supplied from the base end side of the adapter 3 is formed by the screw hole 11, the small diameter hole 14, and the communication hole 16.
A fluid supply path 18 that guides 0 to the annular groove 17 is formed.

At the approximate center of the adapter 3, a large-diameter hole 19 which is open at the distal end face and extends in the axial direction toward the base end side is formed. A plurality of communication holes 20 extend radially outward from the inner end of the large-diameter hole 19 at equal angular intervals. These communication holes 20 are open on the outer peripheral surface of the adapter 3, and the outer peripheral surface opening portion serves as a discharge port 21. In this embodiment, the large-diameter hole 19 and the communication hole 20 constitute a discharge path 22 for guiding the cutting powder 8 to the discharge port 21.

On the outer peripheral surface of the adapter 3, a second swivel joint 23 is rotatably supported. The entire outlet 21 is covered by the second swivel joint 23. Second
A suction pipe 25 is connected to the swivel joint 23 via a connection fitting 24. A suction device (not shown) is connected to the suction pipe 25. Therefore, by the operation of the suction device, the discharge passage 22, the second swivel joint 23,
The cutting powder 8 is sucked out of the adapter 3 in the order of the connection fitting 24 and the suction pipe 25.

On the outer peripheral surface of the adapter 3, a flange portion 26 is integrally formed near the discharge port 21. Further, the adapter 3 is provided near the base end side of the communication hole 20.
A stopper 27 is screwed onto the outer periphery of the. The flange portion 26 and the stopper 27 restrict the axial movement of the second swivel joint 23.

As shown in FIGS. 1 and 3, the adapter 3 has a cylindrical inner cylinder 4 open at both ends. The inner cylinder 4 includes a small-diameter portion 29 and large-diameter portions 28 and 30 formed on the proximal and distal ends of the small-diameter portion 29.
A female screw 31 is threaded on the inner peripheral surface of the large diameter portion 28 on the proximal end side, and the female screw 31 is screwed to a male screw 32 on the outer peripheral side on the distal end side of the adapter 3. In addition, an O-ring 33 for ensuring a sealing property is interposed between the adapter 3 and the inner cylinder 4 on the distal end side of the screw portion.

A suitable number of notches 34 extending toward the base end side are formed in the front end surface of the large diameter portion 30 on the front end side of the inner cylinder 4.
Are formed at equal angles. The diamond segment 6 is fixed to the front end face between a pair of adjacent notches 34 by brazing or the like. At the base end portion of the inner cylinder 4 corresponding to the annular groove 17 of the adapter 3, a plurality of communication holes 35 for communicating the inside and the outside of the inner cylinder 4 are formed at equal angles and are provided therethrough. Further, a guide groove 36 extending in the axial direction from each of the communication holes 35 toward the notch 34 is formed on the outer peripheral surface of the inner cylinder 4.

The outer cylinder 5 is externally fixed on the outer peripheral surface of the small diameter portion 29 of the inner cylinder 4. The outer cylinder 5 has a substantially cylindrical shape and is formed to have a slightly smaller diameter than the small diameter portion 29 of the inner cylinder 4. The outer cylinder 5 is provided with a linear slit 37 extending in the axial direction. Therefore, the outer cylinder 5 can be increased in diameter and reduced in diameter. When the outer cylinder 5 is enlarged in diameter and externally fitted to the small-diameter portion 29 of the inner cylinder 4, the outer cylinder 5 comes into close contact with the small-diameter portion 29 by its own elastic restoring force. Then, the outer cylinder 5 is adjusted so that the slit 37 does not coincide with the guide groove 36.
The outer cylinder 5 is fixedly welded to the inner cylinder 4 in a state where the outer cylinder 5 is fitted over the inner cylinder 4.

Accordingly, in the state where the outer cylinder 5 is externally fitted and fixed to the inner cylinder 4 as described above, the gap between the inner peripheral surface of the outer cylinder 5 and the guide groove 36 of the inner cylinder 4 is increased as shown in FIG. The flow passage 9 will be formed in the air passage. The flow passage 9 guides the compressed air 10 discharged from the communication hole 16 of the adapter 3 to the diamond segment 6 at the tip of the inner cylinder 4.

In the present embodiment, the following configuration is employed in order to increase the efficiency of discharging the cutting powder 8 generated in the diamond segment 6. As shown in FIGS. 1 and 2, a guide tube 38 having both ends opened and having a smaller diameter than the inner cylinder 4 is provided in the inner cylinder 4. The guide tube 38 is connected to the adapter 3 at the base end. That is, the mounting bracket 39 is fixed to the opening of the large-diameter hole 19 in the adapter 3, and the base end of the guide tube 38 is externally fixed to the mounting bracket 39. Therefore, when using the rotary punch 1,
The guide tube 38 can rotate integrally with the adapter 3, the inner tube 4, the outer tube 5, and the like.

Further, in order to make the length of the guide tube 38 variable according to the depth of drilling by the rotary punch 1, the guide tube 3
8 is provided with a telescopic part 40. In the present embodiment, most of the guide tube 38 except for both ends is formed in a bellows-like shape to form a telescopic portion 40.
0 is extendable in the axial direction. And this guide tube 3
8 is set to a length such that it is close to the diamond segment 6 when it is most extended.

Further, a dust collecting head 41 is attached to the distal end of the guide tube 38. The main body portion 42 of the dust collecting head 41 has a substantially disk shape, and a central portion thereof has a concave portion 43 which is open at the rear surface. A plurality of small-diameter communication passages 44 extend radially outward from the recess 43 at equal angular intervals, and these communication passages 44 are open on the outer peripheral surface of the main body 42.

A metal tip 45 as a rotation support is fixed to the center of the distal end surface of the main body 42 of the dust collecting head 41. The tip of the tip 45 is sharp and makes point contact with the surface of the pierced object 7, thereby reducing the friction between the pierced object 7 and the dust collecting head 41 during the piercing operation.
The guide tube 38 is prevented from being twisted. Note that a locking hole 46 is formed in the outer periphery of the chip 45. The locking hole 46 is a hole for hooking a wire or the like (not shown) when the guide tube 38 contracted by the perforation operation is pulled out after the perforation operation.

Next, a description will be given of the operation and effect of the case where the drilling operation is performed on the drilled object 7 such as a reinforced concrete building using the rotary drilling tool 1 configured as described above. First,
Prior to the drilling operation by the rotary punch 1, the guide tube 38 contracted in the inner cylinder 4 is extended. Then, in this state, the electric motor 2 is operated to rotate the rotating shaft 12. Then, the adapter 3 connected to the rotating shaft 12,
The inner cylinder 4, the outer cylinder 5, the guide tube 38 and the like rotate integrally. In this way, the diamond segment 6 is pressed against the object 7 while rotating the rotary punch 1. Then, the object 7 to be drilled is cut by the diamond segments 6, and cutting powder 8 is generated. At this time, the tip of the tip 45 of the dust collecting head 41 is in point contact with the surface of the drilled object 7. At this time, since the friction generated between the drilled object 7 and the tip 45 is small, the guide tube 38 rotates smoothly without twisting.

As the drilling operation proceeds, the cutting powder 8 generated as described above tends to stay in the diamond segment 6. Therefore, the compressed air 10 is supplied from outside the first swivel joint 13 and the suction device is operated. Then, the compressed air 10 is supplied to the rotating shaft 12 of the electric motor 2 and the screw hole 1.
1, through the small-diameter hole 14, the communication hole 16 and the annular groove 17, it is supplied to the communication hole 35 of the inner cylinder 4. The compressed air 10 flows through the flow passage 9 between the guide groove 36 of the inner cylinder 4 and the inner peripheral surface of the outer cylinder 5.
And is injected toward the diamond segment 6 side.

On the other hand, the operation of the suction device causes
Air is sucked in the inside, the guide tube 38, the dust collecting head 41, etc., so that a large negative pressure acts on the vicinity of the dust collecting head 41 and in the hole formed by the diamond segment 6. The negative pressure at this time is larger than that in the related art in which the air in the entire space in the inner cylinder 4 is sucked without using the guide tube 38 and the dust collecting head 41. This is because the guide tube 38 is much smaller in diameter than the inner cylinder 4, and the dust collecting head 41 is always located near the surface of the drilled object 7, and sucks near the location where the cutting powder 8 is generated. Because. In addition, in the present embodiment, the dust collecting head 41 has a substantially disc shape slightly smaller in diameter than the inner cylinder 4, and a communication passage 44 is opened on the outer peripheral surface, and this opening portion serves as a suction port. I have. Therefore, the suction port approaches the perforated portion by the amount of the communication passage 44, and the cutting powder 8 in the perforated portion can be more efficiently sucked.

Due to the negative pressure, the cutting powder 8 is brought into the dust collecting head 41 and the guide pipe 3 together with the air outside the drilled object 7.
8, the suction is efficiently performed into the suction pipe 25 through the large diameter hole 19, the communication hole 20 , the second swivel joint 23, and the connection fitting 24 of the adapter 3. For this reason, the cutting powder 8 generated at the time of drilling is quickly sucked and collected by the suction device without staying in the opened hole. Therefore, the cutting powder 8 can be prevented from becoming a resistance during cutting.

Further, in the present embodiment, since a large negative pressure can be generated as described above, even though the perforated object 7 is a reinforced concrete building and the specific gravity of the cutting powder 8 is large, this cutting operation is performed. The powder 8 can be effectively sucked and discharged.

The guide tube 38 has a bellows-like expansion and contraction portion 4.
0 is formed, even if the drilling operation proceeds and the inner cylinder 4 and the outer cylinder 5 are immersed in the pierced object 7, the expansion / contraction portion 40 contracts, and the dust collection head 41 is moved to the pierced object. 7 surface. Therefore, the cutting powder 8 can always be efficiently discharged regardless of the drilling depth.

The present invention is not limited to the configuration of the above-described embodiment, and may be arbitrarily changed without departing from the spirit of the present invention, for example, as follows. (1) Diamond segment 6 in the above embodiment,
The number of the small-diameter holes 14, the communication holes 16, 20, 35, the guide grooves 36, and the like may be appropriately changed. (2) A V-ring may be used instead of the O-ring 33 in the above embodiment. (3) The rotary piercing tool 1 of the present invention can also be used when performing a sampling operation for soil investigation. (4) The present invention may be applied to a rotary piercing tool of a type in which a cutting blade is provided at the tip of the outer cylinder 5 instead of the inner cylinder 4. (5) In the above-described embodiment, the entirety of the guide tube 38 except for both ends is formed in a bellows-like shape as the elastic portion 40. However, the elastic portion 40 may be provided only in a part of the guide tube 38.

[0033]

As described above in detail, according to the first aspect, the cutting powder can be efficiently sucked and discharged regardless of the specific gravity of the cutting powder.

According to the second aspect, in addition to the effect of the first aspect, the suction efficiency of the cutting powder can be further improved.
According to the third invention, in addition to the effect of the second invention, it is possible to prevent the guide tube from being twisted during the drilling operation.

[Brief description of the drawings]

FIG. 1 shows an embodiment embodying the present invention,
It is sectional drawing of the rotary piercing tool which abbreviate | omits a part of outer cylinder and a guide tube.

FIG. 2 is an exploded perspective view showing a part of an adapter and a guide tube in one embodiment in a cutaway manner.

FIG. 3 is an exploded perspective view showing a part of the inner cylinder and the outer cylinder in one embodiment in a cutaway manner.

FIG. 4 is an enlarged cross-sectional view of a mounting portion of the inner cylinder to the adapter in one embodiment.

FIG. 5 is an enlarged sectional view of the distal end portions of the inner cylinder and the outer cylinder in one embodiment.

FIG. 6 is a sectional view taken along line AA in FIG.

[Explanation of symbols]

Reference numeral 2 denotes an electric motor, 3 denotes an adapter, 4 denotes an inner cylinder that constitutes a part of the body part, 5 denotes an outer cylinder that constitutes a part of the body part, 6 denotes a diamond segment as a cutting blade, 7 denotes an object to be pierced, and 8 …
Cutting powder, 12: rotating shaft, 22: discharge path, 38: guide tube, 40: telescopic part, 41: dust collecting head, 44: communication path,
45 Tip as rotation support

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) E02D 25/00-25/18 E02D 10/02-10/66 B28D 1/00-7/04

Claims (3)

(57) [Claims] An adapter (3) connected to a rotating shaft (12) of an electric motor (2); and a cylindrical body (4) attached to the adapter (3).
5), and a cutting blade (6) fixed to the tip of the body portion (4, 5) and cutting and piercing the object to be pierced (7) by rotation, staying near the cutting blade (6). The cutting powder (8) to be sucked is sucked at a negative pressure, and the inside of the body (4, 5) and the adapter (3)
A rotary piercing tool configured to discharge the cutting powder (8) to the outside of the adapter (3) through a discharge path (22) provided in the body (4, 5); The cutting powder (8) generated by the cutting blade (6) is discharged to the discharge path (22) of the adapter (3).
A guide tube (38) for guiding the guide tube (38) is provided, one end of the guide tube (38) is fixed to the adapter (3), and at least a part of the guide tube (38) has a body portion (4, 4). 5) A rotary piercing tool provided with a telescopic part (40) that can expand and contract in the length direction. 2. A dust collecting head (41) is attached to the tip of a guide tube (38), and a communication passage (41) for communicating the outer peripheral surface of the dust collecting head (41) with the inside of the guide tube (38). The rotary punch according to claim 1, wherein 44) is provided. 3. The guide pipe (3) is brought into point contact with the center of the tip of the dust collecting head (41) at the surface of the object to be pierced (7).
3. The rotary piercing tool according to claim 2, further comprising a rotary support (45) for preventing the twisting of (8).