JP2986394B2 - Drilling tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling tool used for providing relatively large holes such as large-diameter holes required for piping of an air conditioner on a wall of a building, for example.

[0002]

2. Description of the Related Art A drilling tool of this type has a cylindrical drilling cylinder mounted on a tool shaft having a shank at a base end and a center drill mounted at a distal end through a disk-shaped cylinder holder. It is mounted concentrically. In such a drilling tool, it is necessary to take out the material clogged in the drilling cylinder after the drilling operation. Therefore, it is preferable that the drilling cylinder is configured to be detachable from the cylinder holder.

FIG. 9 shows a conventional tool configured as described above. In this tool 40, a cylinder holder 41 and a hole machining cylinder 42 are formed separately, and the connection between these two members 41, 42 is screwed to the tip of a tool center shaft body 43 penetrating the cylinder holder 41. Expansion / contraction operation wheel 44
And an expansion / contraction wheel 45 disposed between the expansion / contraction operation wheel 44 and the hole processing cylinder 42.

That is, the tool center shaft 43 and the cylinder holder 4
When the tool center shaft 43 is rotated clockwise in the tube holder 41, the expansion / contraction operation wheel 44 screwed to the tip of the tool center shaft 43 comes close to the tube holder 41. It has become. For this reason, the expansion / contraction operation wheel 44
The expansion / contraction wheel 4 is connected to the wedge-shaped inclined surface via the inclined surface.
5 is expanded in the radial direction and pushed between the cylinder holder 41 and the cylinder holder 41 and the hole processing cylinder 42 are fixed.

[0005] In the conventional tool 40, when removing the material clogged in the bored cylinder 42 after the drilling operation,
The hole drilling cylinder 42 can be removed from the cylinder holder 41 by rotating the tool center shaft body 43 counterclockwise relative to the expansion / contraction operation wheel 44. However, in this tool 40, the screw engagement between the tip of the tool center shaft 43 and the expansion / contraction operation wheel 44 is strongly tightened by the rotational force applied to the shank 46 of the tool center shaft 43 during the drilling operation. However, when trying to loosen the expansion / contraction operation wheel 44 as described above, it is necessary to rotate the tool shaft 43 with a strong force, and there is a problem that the operation is difficult and complicated.

In order to solve such a problem, there is, for example, one disclosed in Japanese Patent Application Laid-Open No. Hei 5-253721. In this prior art, a member that is capable of being screwed onto a tool center shaft body and displaceable between the first position and the second position along the axial direction on the tube holder, By providing a pressing member having a pressing surface that expands and contracts the expansion and contraction ring when in the first position, and a release surface that allows the expansion and contraction ring to reduce in diameter when in the second position, the cylinder holder Therefore, the pressing member for fixing the drilling cylinder is not directly affected by the rotation of the tool, so that the drilling cylinder can be easily removed from the cylinder holder.

[0007]

However, in this conventional tool as well, the cylinder holder provided with the pressing member is screwed to the tool center shaft, and the rotation of the tool causes a gap between the tool center shaft and the cylinder holder. Since the screw engagement is strongly tightened, it is extremely difficult to disassemble these two members, and the attachment / detachment replacement operation of the tube holder is complicated.

Therefore, the present invention is intended to facilitate not only the work of removing the cylinder holder and the bored cylinder but also the work of removing the tool center shaft and the cylinder holder. Aim.

[0009]

In order to achieve the above object, the present invention takes the following technical measures. That is, the drilling tool of the present invention has a tool shaft having a shank on the base end side,
A boss of a cylindrical holder for holding one end of a cylindrical hole processing cylinder is inserted through a boss portion of the boss portion so as to be detachable from a shaft tip side, and a tool is provided between the tool center shaft and the boss portion. A rotation restricting member for restricting the rotation of the cylinder holder with respect to the center shaft is provided, and a nut member is screwed on the outer periphery of the tool center shaft at the base end side of the cylinder holder, and on the shaft tip side of the cylinder holder.
Is provided with an expansion / contraction wheel fitted into the hole processing cylinder,
At least a nut member is fastened to the shaft tip side of the expansion / contraction wheel.
When operating, against the cylinder holder together with the tool shaft
It is provided at the tip of the tool shaft to move in the axial direction.
The expansion and contraction operation wheel is arranged, and the nut member is fastened.
When the cylinder holder and the expansion / contraction operation wheel are relatively close to each other
The tapered surface that pushes and expands the expansion / contraction ring in the radial direction
It is characterized in that it is provided on the outer periphery of a slider or an expansion / contraction operation wheel .

According to the present invention, the drilling cylinder can be removed from the cylinder holder by loosening the nut member, and by removing the nut member from the tool center shaft, the tool center shaft can be moved from the boss portion of the tube holder toward the shaft tip. It can be removed. Further, the rotation of the cylinder holder with respect to the tool center member is restricted by the rotation restricting member, and the rotational force of the tool center member is transmitted to the drilling cylinder through the rotation restricting member. Since there is no screw engaging portion in the force transmission path, the screw engaging portion is not strongly tightened by the rotation of the tool. That is, the nut member is not strongly tightened by the rotation of the tool, so that not only the removal of the drilling cylinder from the cylinder holder, but also the removal of the cylinder holder from the tool shaft can be easily performed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A center drill, which is located on the axis of a drilling cylinder, is usually removably mounted on the tip end of a tool center shaft so that the centering of the tool during drilling can be reliably performed. To improve. The rotation restricting member is attached to the boss portion in a radially inwardly protruding shape, and an engagement groove extending in the axial direction with which the rotation restricting member engages is formed on the outer periphery of the tool center shaft so that the rotation of both of them is restricted. However, it is also possible to provide a rotation restricting member on the tool center shaft so as to protrude radially outward, and form an engagement groove on the inner periphery of the boss portion.

As a cylinder fixing mechanism, an expanding / reducing body fitted in the bored cylinder is disposed on the shaft end side of the cylinder holder, and at least a nut member is provided on the shaft end side of the expanding / reducing body. An enlargement / reduction operation wheel provided at a distal end portion of the tool center shaft is disposed so as to move in the axial direction with respect to the cylinder holder together with the tool center shaft during the fastening operation, and the cylinder is operated by fastening the nut member. The tapered surface that pushes and expands the expansion and contraction wheel body in the radial direction when the holder and the expansion and contraction operation wheel are relatively close to each other,
It may be provided on the outer periphery of the cylinder holder and the expansion / contraction operation wheel. The tapered surface may be provided only on one of the cylinder holder and the expansion / contraction operation wheel. The expansion / contraction operation wheel provided at the tip of the tool center shaft may be provided integrally with the tool center shaft or may be provided separately.

In this cylinder fixing mechanism, when the nut member is fastened, the tool center shaft is axially moved toward the base end with respect to the tube holder, and the expanding / reducing operation wheel is axially moved with the tool center shaft toward the base end. Is done. That is, the cylinder holder and the enlargement / reduction operation wheel are relatively close to each other, and the expansion / contraction ring body is pushed and expanded in the radial direction by the tapered surface formed on the cylinder holder and the enlargement / reduction operation wheel. Is firmly fixed.

On the other hand, in this fixed state, the cylinder holder is strongly tightened in the axial direction between the expansion / contraction operation wheel provided at the tip of the tool center shaft and the nut member screwed to the tool center shaft. Therefore, the fastening of the nut member and the cylinder holder are also performed by the fastening operation of the nut member described above. In such a cylinder fixing mechanism, the structure of the constituent members is simple, and the number of components can be reduced, so that productivity can be improved, assembling work efficiency can be improved, and costs can be reduced. Also, the thread groove is formed at one place where the tool center shaft body and the nut member are screwed together, and the number of thread groove machining points is smaller than that of the invention described in JP-A-5-253721. This also contributes to improving productivity and reducing costs.

[0015] Further, a circumferential groove is formed on the inner peripheral surface of the hole processing cylinder,
If a convex portion is provided on the outer periphery of the expansion / contraction operation wheel to be engaged with the peripheral groove when it is pushed and expanded in the radial direction, when the nut member is fastened to fix the bored cylinder to the cylinder holder, the convex is formed. By the engagement between the portion and the peripheral groove, it is possible to reliably prevent the holed cylinder from coming out of the cylinder holder.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 show a drilling tool 1 according to an embodiment of the present invention. The tool 1 has a shank 4 on a base end side and a drill mounting barrel shaft 3 on a distal end side. A center shaft 5 is provided. The shaft 5 is made of carbon tool steel.

As shown in FIGS. 1, 2 and 4, the shank 4 of the tool center shaft body 5 has a torque transmission groove 15 for mounting on a rotary hammer drill having a key groove shape parallel to the axis. Are provided over substantially the entire length thereof at intervals of two 180 degrees, and tool stroke regulating grooves 16 are provided between the grooves 15 in parallel and at equal intervals near the shaft end.
The restricting groove 16 restricts the axial movement amount and the return amount, that is, the stroke of the tool 1 when hit by a hammer drill. The groove bottom is as shown in FIG. 2 so that the locking ball can be engaged. And both ends in the axial direction are closed.

That is, the torque transmitting grooves 15 and the stroke regulating grooves 16 are provided alternately at 90-degree intervals. Further, the shank 4 is further provided with three torque transmitting surfaces 17 that can be mounted on a chuck (not shown) of the rotary drill at regular intervals in the circumferential direction (120-degree intervals). The center is the stroke regulating groove 1
6 are provided on both sides in the axial direction of the regulating groove 16 so as to coincide with the center in the width direction.

Therefore, the formation of the torque transmitting surface 17 slightly lowers the height of a part of the side walls of the two grooves 15 and 16, but does not hinder the torque transmission and the stroke regulation at all. It can be attached to both rotary hammer drill and rotary drill. A center drill 2 is inserted into and held by the drill mounting cylinder shaft portion 3 of the tool center shaft body 5 from the shaft tip side. The drill 2, the cylinder shaft portion 3 and the shank 4 are arranged on one axis along the rotation axis. ing. Further, a drill fixing bolt 14 is screwed to the cylindrical shaft portion 3, and the drill 2 is fixed to be detachable and replaceable.

A nut member 10 screwed to the cylindrical shaft portion 3 from the base end side of the outer peripheral portion of the cylindrical shaft portion 3 of the tool center shaft member 5, a cylindrical holder 6 held by the cylindrical shaft portion 3, An expansion / reduction wheel 8 externally fitted to the holder 6 and an expansion / reduction operation wheel 11 provided at the tip of the cylindrical shaft portion 3 are provided. Further, a cylindrical hole processing cylinder 7 is fitted around the cylinder holder 6 coaxially with the center drill 2.

An external thread 12 is formed on the outer peripheral surface on the base end side of the cylindrical shaft portion 3, and the external thread 12 and the nut member 1 are formed.
A female screw portion formed on the inner peripheral surface of the “0” is screw-engaged. The shank 4 of the tool center shaft 5 has the smallest diameter. The diameter of the cylindrical shaft 3 is gradually increased from the base end to the distal end. The provided flange portion 13 has the largest diameter.

As shown in FIGS. 6 and 7, the cylinder holder 6 has a boss portion 19 in the center of which a through hole 18 into which the cylinder shaft portion 3 of the center shaft body 5 is inserted is formed in a penetrating manner. The flange 20 extends radially from the outer peripheral end of the boss 19. In addition, the boss portion 19 protrudes to the base end side from the flange portion 20. Also, on the outer peripheral portion of the flange portion 20, the side opposite to the boss portion 19 (that is, the shaft tip side).
And a ring-shaped expanding / contracting ring body receiving portion 21 that is integrally provided.

As shown in FIG. 1, the outer peripheral side of the expanding / reducing ring body receiving portion 21 can be removably fitted into the hole processing cylinder 7 and has a diameter reduced toward the shaft tip side end edge. A tapered surface 21A is formed, and a tapered surface 8A formed on the base end side peripheral edge of the expanding / reducing wheel body 8 comes into contact with the tapered surface 21A. The boss 19 of the cylinder holder 6 is also provided.
, A screw-shaped rotation restricting member 22 is screwed from the outside of the diameter, and the member 22 projects slightly inward from the inner peripheral surface of the boss portion 19. On the other hand, as shown in FIG. 4, a concave groove 22 a extending in the axial direction from the base end toward the distal end is provided on the outer peripheral surface of the cylindrical shaft portion 3 of the center shaft body 5,
The rotation of the cylinder holder 6 with respect to the center shaft body 5 is regulated by the engagement of the regulating member 22 into the concave groove 22a, but relative movement in the axial direction is allowed.

The boss portion 19 is provided with locking ball fitting holes 23 at a plurality of positions (four in the illustrated embodiment) in the circumferential direction, and a coil spring is provided in the fitting holes 23. The elastic body 24 and the locking ball 25 are housed. A part of the locking ball 25 slightly protrudes from the proximal end face of the boss 19 and is constantly urged by the elastic body 24 in the protruding direction (proximal side).

Further, on the outer peripheral portion of the flange portion 20 of the cylinder holder 6, a large number of cutting notches 27 are provided so as to correspond to a large number of cutting blades 26 provided at both ends in the axial direction of the hole forming cylinder 7 in the circumferential direction. The engagement between the cutting blade 26 and the notch 27 ensures that the relative rotation between the cylinder holder 6 and the hole machining cylinder 7 is reliably restricted. A peripheral groove 28 having a concave cross section is provided on an inner peripheral surface near both ends in the axial direction of the hole processing cylinder 7.

As shown in FIG. 3, the expanding and contracting ring body 8 is formed as a C-shaped split ring provided with a slit 29 at one position on the outer peripheral portion so as to reach both ends in the axial direction. At both ends in the axial direction, there are tapered surfaces 8A and 8B whose diameters are reduced from the end edges toward the center, respectively. On the outer periphery, a number of shallow grooves 30 are provided obliquely with respect to the axis, and the tapered surfaces are formed. At the end portions on the 8B side, engaging projections 31 are provided, respectively, and the projections 31 are fitted into and engaged with the peripheral grooves 28 of the hole processing cylinder 7, so that the hole processing cylinder 7 is securely removed from the cylinder holder 6. It is designed to block.

As shown in FIG. 5, the nut member 10 is provided with a large number of irregularities 35 all around its end surface (the end surface on the shaft tip side) facing the boss portion 19, and is engaged with the recessed portion. The locking ball 25 is fitted and locked, and the nut member 1 is locked.
0 is prevented from loosening naturally. The expansion / contraction operation wheel 11 has a disk shape, and has a central portion provided with an insertion hole 11a into which the cylindrical shaft portion 3 of the tool center shaft body 5 is fitted. On the other hand, a flange portion 13 is protruded from the outer periphery of the distal end portion of the cylindrical shaft portion 3, and the flange portion 13 is in contact with the shaft distal end side end surface of the expansion / contraction operation wheel 11.
0 by operating the center shaft 5 against the cylinder holder 6.
When the is moved in the axial direction to the base end side, the expansion / contraction operation wheel 11 is configured to relatively move to the base end side together with the center shaft body 5. In the illustrated embodiment, the expansion / contraction operation wheel 11 is connected to the cylindrical shaft portion 3.
Although the configuration is made separately, the expansion / contraction operation wheel 11 may be provided integrally with the distal end portion of the cylindrical shaft portion 3.

A tapered surface 36 fitted to the tapered surface 8B of the expansion / contraction wheel 8 is provided on the outer peripheral surface of the expansion / contraction operation wheel 11.
Is formed, and when the flange portion 20 of the cylindrical holder 6 and the expansion / contraction operation wheel 11 are relatively close to each other by tightening the nut member 10, the expansion / contraction operation wheel 11 pushes and expands the expansion / contraction wheel body 8 in the radial direction. Thus, the cylinder holder 6 and the hole processing cylinder 7 are fixed via the expansion / contraction ring 8.

In the above embodiment, when assembling the drilling tool 1, first, the expanding / reducing wheel 8 is externally fitted to the wheel receiving portion 21 of the cylindrical holder 6, and the expanding / reducing operation wheel is mounted on the shaft tip side of the wheel 8. 11 is fitted. The cylindrical holder 6, the expansion / reduction wheel 8, and the expansion / reduction operation wheel 11 are inserted through the center of the through-hole into the mounting hole from the tip of the shaft (from below in FIGS. 1 and 3).
The tool center shaft 5 is inserted. At this time, the rotation regulating member 2
2 is engaged with the concave groove 22a provided in the cylindrical shaft portion 3.

The male screw 12 formed on the cylindrical shaft 3
Is exposed more proximally than the boss 19 of the cylinder holder 6, the nut member 10 is lightly screwed into the male screw 12,
The nut member 10 prevents the tool center shaft 5 from coming off the cylinder holder 6. In addition, as described above, the nut member 1
In a state where 0 is lightly screwed, the expansion and contraction wheel 8 is configured not to be pushed and expanded in the radial direction.

Next, one end of the hole forming cylinder 7 is
And fitted around the expansion / contraction operation wheel 11. At this time, the cutting blade 26 is fitted into a notch 27 provided on the outer periphery of the flange portion 20 of the cylinder holder 6 to prevent the rotation of the cylinder holder 6 and the hole processing cylinder 7, the positioning function, and the protection function of the cutting blade 26. And can be obtained. Then, while holding the hole processing cylinder 7 by hand and holding it in a non-rotatable state, by rotating the nut member 10 in the direction in which the screw is tightened, the expansion / contraction operation wheel 11 is moved toward the flange portion 20 side of the cylinder holder 6. As a result, the expansion and contraction wheel 8 is pushed and expanded, and the engaging projection 31 of the ring 8 is fitted into the peripheral groove 28 of the hole processing cylinder 7 and the outer peripheral surface of the expansion and contraction wheel 8 is formed by drilling. It is pressed against the inner peripheral surface of the cylinder 7 in close contact, and the overall assembling relationship is fixed.

At this time, the unevenness 3 on the end face of the nut member 10
5, a locking ball 25 is locked, but the elastic body 2
Since the locking ball 25 is pushed in against the urging force of No. 4, the nut member 10 can be easily rotated. When the nut member 10 is to loosen naturally, the locking ball 25 fits into the unevenness 35, thereby preventing the rotation of the nut member 10 with respect to the cylinder holder 6, and an effect of preventing loosening is produced.

When the drilling cylinder 7 is to be removed from the cylinder holder 6, the nut member 10 is rotated in the direction in which the screw is loosened while the drilling cylinder 7 is kept in a non-rotatable state, so that the expanding and contracting wheel 8 is rotated. The diameter is reduced by elasticity, and the expansion / contraction operation wheel 1
1 in the direction away from the cylinder holder 6,
A gap is formed between the outer peripheral surface of the hole and the inner peripheral surface of the hole drilling cylinder 7, so that the hole drilling cylinder 7 can be easily extracted. In addition,
When performing the work of removing the material clogged in the bored cylinder 7 after the drilling work, it is only necessary to remove the bored cylinder 7, so it is not necessary to completely remove the nut member 10 from the barrel shaft 3. . However, when performing attachment / detachment / replacement work of the cylinder holder 6 attached to the tool center shaft 5, the nut member 1
0 may be completely removed from the cylindrical shaft portion 3 and the center shaft body 5 may be removed from the cylindrical holder 6.

The present invention is not limited to the configuration of the above-described embodiment, and the design can be changed as appropriate. For example, the expansion / contraction wheel 8
Can be integrally protruded from the outer periphery of the flange portion 20 of the cylinder holder 6, or can be a divided ring body divided into a plurality in the circumferential direction. Further, a retaining ring for preventing the tool from being pulled out from the boss 19 of the cylinder holder 6 toward the tip of the shaft can be detachably attached to the tool center shaft 5.

[0035]

According to the present invention, the tool center shaft having the shank on the base end side is attached to the boss of the cylindrical holder for holding one end of the cylindrical drilling cylinder from the tip end of the boss. A rotation restricting member that restricts rotation of the cylinder holder with respect to the tool center shaft is provided between the tool center shaft and the boss portion while being inserted so as to be freely inserted and removed. A nut member is screwed on the outer periphery of the center shaft body, and a cylinder fixing mechanism for fixing the hole processing cylinder to the tube holder by fastening the nut member and fixing the cylinder holder to the tool center body. Because it has
The rotational driving force of the tool is not transmitted to the nut member for performing both the fixing of the hole processing cylinder to the cylinder holder and the fixing of the cylinder holder to the tool center body, so that the nut member is not firmly tightened. Therefore, the operation of loosening the nut member can be easily performed, so that not only the work of removing the bored cylinder from the tube holder but also the work of removing the cylinder holder from the tool shaft can be easily performed.

As a cylinder fixing mechanism, an expanding / reducing body fitted into the bored cylinder is disposed on the end of the shaft of the cylinder holder, and at least a nut member is fastened to the end of the shaft of the expanding / reducing body. The expansion / contraction operation wheel provided at the tip of the tool center shaft is disposed so as to move in the axial direction with respect to the cylinder holder together with the tool center shaft, and the nut member is tightened to operate the cylinder holder and the expansion / contraction operation wheel. Since the tapered surface that pushes and expands the expansion / contraction wheel in the radial direction when it is relatively close to each other is provided on the outer circumference of the cylinder holder or the expansion / contraction operation wheel, the above-described effects can be achieved while reducing the number of components and simplifying the structure Can be achieved,
It is possible to improve productivity and reduce costs.

Further, a peripheral groove is formed on the inner peripheral surface of the hole processing cylinder,
In the outer periphery of the expansion and contraction operation wheel, provided with a convex portion that engages with the circumferential groove when pushed and expanded in the radial direction, it is possible to reliably prevent the hole processing cylinder from coming off the cylinder holder in the axial direction. it can.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a drilling tool according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of the shank, and is a cross-sectional view taken along line AA of FIG.

FIG. 3 is an exploded vertical sectional view of the tool.

FIG. 4 is a side view of a tool center shaft.

FIG. 5 is a bottom view of the nut member.

FIG. 6 is a plan view of a tube holder.

FIG. 7 is a sectional view taken along the line BB of FIG. 6;

FIG. 8 is a side view showing a part of the expansion and contraction wheel.

FIG. 9 is a cross-sectional view illustrating an example of a conventional drilling tool.

[Explanation of symbols]

 Reference Signs List 1 drilling tool 4 shank 5 tool center body 6 cylinder holder 7 drilling cylinder 8 expansion / reduction wheel 10 nut member 11 expansion / reduction operation wheel 19 boss portion 22 rotation regulating member 28 peripheral groove 31 convex portion 36 tapered surface

Claims (2)

(57) [Claims] 1. A tool center shaft (5) having a shank (4) on the base end side is attached to a boss (19) of a cylinder holder (6) for holding one end of a cylindrical drilling cylinder (7). The boss (19) is inserted through the shaft tip side so as to be freely inserted and removed, and between the tool center shaft (5) and the boss (19),
A rotation restricting member (22) for restricting rotation of the cylinder holder (6) with respect to the tool center shaft (5) is provided, and a nut is provided on the outer periphery of the tool center shaft (5) on the base end side of the tube holder (6). A member (10) is screwed in, and an expanding / reducing wheel (8) fitted in the bored cylinder (7) is disposed on the shaft tip side of the tube holder (6). ) On the shaft tip side,
An expansion / contraction operation wheel provided at the tip of the tool center shaft (5) so as to move in the axial direction with respect to the cylinder holder (6) together with the tool center shaft (5) at least when the nut member (10) is tightened. (11) is provided, and when the nut member (10) is tightened and the cylinder holder (6) and the expansion / contraction operation wheel (11) are relatively close to each other, the expansion / contraction wheel (8) is moved in the radial direction. A drilling tool characterized in that a tapered surface (21A, 36) for expanding is provided on an outer periphery of a cylinder holder (6) or an expansion / contraction operation wheel (11). 2. A hole processing cylinder (7) on the inner peripheral surface of the circumferential groove (2
8) is formed, and the outer periphery of the expansion / contraction operation wheel (11) is provided with a convex portion (31) that engages with the peripheral groove (28) when pushed and expanded in the radial direction. The drilling tool according to claim 1, wherein: