JP2802047B2 - Drilling tools - 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 forming a relatively large hole such as a large diameter hole required for piping of an air conditioner on a wall of a building, for example.

[0002]

2. Description of the Related Art Conventionally, a drilling tool (commonly called a core drill) of this kind having a large diameter hole is known as shown in FIG. The tool 41 is attached to a tool center shaft 45 having a center drill 42, a center shaft 43, and a shank 44 (a portion chucked by a rotary drill or the like) so as to surround the center drill 42 at both ends in the axial direction. A cylindrical drilling cylinder 47 having a large number of cutting blades 46 in a portion is detachably held.

The central shaft portion 43 of the center shaft 45 has a small-diameter portion 43A and a large-diameter portion 43B, and a screw portion 48 is provided at an end of the small-diameter portion on the center drill 42 side.
A cylindrical holder 49 is fitted outside the large diameter portion 43B. The cylinder holder 49 includes a boss 51 having a shaft hole 50.
A flange portion 52 extending radially from one end of the boss portion 51; and an expanding / reducing ring portion 53 extending from the outer peripheral end of the flange portion 52 to a side opposite to the boss portion 51 in the axial direction.

The expanding and contracting ring portion 53 is fitted in the hole forming cylinder 47, has an inner surface formed as a tapered surface 53A, and has a slit 54 extending from the axially extending end to the flange portion 52. Many are provided over the circumference. The screw portion 48 of the center shaft 45 has a screw hole 5 at its center.
An expansion / contraction drive disk 56 having an outer periphery tapered is screwed. The disk 56 is fitted on the tapered surface 53A of the expansion / contraction ring portion 53 of the cylinder holder 49, and is movable in the axial direction.

Therefore, when the tool center shaft 45 is rotated in the screw tightening direction while holding the cylinder holder 49 in a non-rotatable state, the expansion / reduction driving disk 56 is rotated by the cylinder holder 49.
To expand the expansion / contraction ring portion 53 outward in the radial direction, and is pressed and fixed to the inner surface of the hole processing cylinder 47 all around. Conversely, when the tool center shaft 45 is rotated in the direction in which the screw is loosened, the entire body can be disassembled.

[0006]

By the way, in the above-mentioned prior art, the rotation direction when tightening the tool center shaft 45 into the cylinder holder 49 is the rotation direction (rotation direction) when drilling using the machining tool 41. (Rotation direction of drill etc.) to prevent screw loosening. Accordingly, with the use of the processing tool 41, the tool center shaft 45 is increasingly tightened to the expansion / reduction drive disk 56, and it is very difficult to remove the hole drilling cylinder 47 from the tool center shaft 45 and the tube holder 49. Problem.

In order to solve this problem, the axial movement of the expansion / reduction drive disk 56 can be performed by another screw mechanism without using a direct screwing structure between the tool center shaft 45 and the expansion / reduction drive disk 56. However, if the expansion / reduction drive disk 56 is moved in the axial direction by another screw mechanism, there is a possibility that the bored cylinder 47 may come off the cylinder holder 49 due to loosening of the screw.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and an object of the present invention is to enable easy and quick attachment and detachment of a drilling cylinder to and from a tool center shaft. Another object of the present invention is to provide a drilling tool in which the drilling cylinder is not loosened during the drilling operation and does not come off the cylinder holder.

[0009]

According to the present invention, the following technical measures have been taken in order to achieve the above object. That is, the present invention provides a tool center shaft in which a center drill, a center shaft, and a shank are provided on one axis along a rotation axis, a cylinder holder held on the outer periphery of the center shaft of the center shaft, and a tool center shaft. In a drilling tool comprising a cylindrical drilling cylinder held by the holder in a state surrounding the center drill of the body, the cylinder holder has a boss portion screwed to a central shaft portion of a tool center shaft body, A flange portion extending in a radial direction from this is provided, and an expanding / contracting ring body fitted into the hole machining cylinder provided on the outer periphery of the flange portion is provided. At the inner end of the expansion / contraction operation member of the expansion / contraction wheel inserted into the holder, an expansion / reduction operation drive wheel having a tapered surface provided on the outer periphery is locked. Nut member for driving expansion and contraction on the outer peripheral side The expansion / contraction operation drive wheel is fitted to the tapered inner surface of the expansion / contraction wheel, and the outer peripheral surface of the expansion / contraction wheel and the inner peripheral surface of the hole processing cylinder are locked in the axial direction via the uneven portion. It is characterized by having become.

Further, the present invention is characterized in that the expanding and contracting ring body of the cylinder holder is formed separately from the flange portion, and both are in contact with each other on a tapered surface.
Further, in the present invention, the flange portion of the cylinder holder,
A locking ball is fitted to face the nut member, and the locking ball is constantly urged toward the nut member by the urging means, and the locking ball contact surface of the nut member has irregularities. It is characterized by having.

[0011]

According to the present invention, the tool center shaft is screwed to the boss of the cylinder holder, and does not screw the expansion / contraction operation member and the expansion / contraction operation drive shaft. The expansion ring is not expanded or contracted. That is, the expansion and contraction of the expansion and contraction wheel is performed by rotating the nut member and thereby moving the expansion and contraction operation drive wheel together with the expansion and contraction operation member in the axial direction. Then, the engagement between the outer peripheral surface of the expansion / reduction ring of the cylinder holder and the concave / convex portion with the hole processing cylinder restricts the axial movement of the hole processing cylinder by the expansion / reduction ring, and the cylinder holder is pulled out of the hole processing cylinder. There is no.

Further, the nut member screwed to the expansion / contraction operation member is locked to the cylinder holder via the locking ball by the urging force of an elastic body such as a spring, so that the nut member does not loosen. Also, there is no possibility that the diameter of the expanding and contracting ring body is reduced and the bored cylinder is detached.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 7 show an embodiment of the present invention,
Is a tool center shaft 5 in which a center drill 2, a center shaft 3 and a shank 4 are provided on one axis along a rotation axis.
A cylinder holder 6 held by the central shaft portion 3, a hole processing cylinder 7 held by the holder 6, an expansion / contraction ring body 8 fitted externally to the holder 6, an expansion / contraction operation member 9, Member 9
And an expansion / reduction operation drive wheel 11 fixedly connected to the inner end of the operation member 9.

The center shaft 3 of the tool center shaft 5 has a small diameter portion 12 on the center drill 2 side and a large diameter portion 13 on the shank 4 side.
And a male screw portion (hereinafter, referred to as a small-diameter screw portion 12) is formed on the outer peripheral surface of the small-diameter portion 12. A center drill fixing bolt 14 is screwed to the small diameter portion 13 so that the drill 2 is detachable and replaceable.

On the outer peripheral surface of the shank 4 of the tool center shaft member 5, a torque transmitting groove 15 for mounting to a rotary hammer drill having a key groove shape parallel to the axis is provided at intervals of two 180 degrees over substantially the entire length thereof. A tool stroke regulating groove 16 is provided between the grooves 15 in parallel with each other 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). But 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, and allows them to function sufficiently. And can be attached to both rotary hammer drills and rotary drills. The cylinder holder 6 is composed of a holder body 6A and an expanding / contracting ring body 7 which is separate from the holder body 6A. A boss portion 19 formed in a penetrating shape;
9, a flange portion 20 extending radially outward from the outer peripheral end of the flange 9, and a ring-shaped expanding and contracting ring body receiving portion 21 protruding from the outer peripheral portion of the flange portion 20 on the opposite side to the boss portion 19.
And

The outer peripheral side of the expanding / reducing wheel receiving portion 21
A tapered surface 21A whose diameter is reduced toward the edge is formed so that the tapered surface 21A can be fitted into the hole processing cylinder 7, and one tapered surface 8A of the expanding / reducing ring body 8 comes into contact with the tapered surface 21A. It has become. In the flange portion 20 of the holder 6, arc-shaped through-holes 22 are respectively provided at two symmetrical positions around the boss portion 19 and on the outer peripheral side thereof. A ball fitting portion 23 is provided, and an elastic body 24 made of a coil spring and a locking ball 25 are fitted in the fitting portion 23. And
A part of the locking ball 25 slightly protrudes from the end surface of the flange portion 20 on the boss portion 19 side, and is constantly urged toward the boss portion 19 by the elastic body 24 (FIGS. 3, 5, and 6).
reference).

Further, the flange portion 20 of the holder 6
The outer peripheral portion is provided with a number of cutting blade fitting notches 27 corresponding to the number of cutting blades 26 provided at both axial end portions of the hole processing cylinder 7. In addition, on the inner peripheral surface of both ends in the axial direction of the hole processing cylinder 7, a ring-shaped engagement annular groove 28 concave portion is provided. The expanding and contracting ring body 8 is provided with a slit 29 at one position on the outer peripheral portion so as to reach both ends in the axial direction, and is a C-shaped split ring.
At both ends in the axial direction of the inner peripheral surface, there are tapered surfaces 8A and 8B whose diameters are reduced from the end edges toward the central portion, and a number of shallow grooves 30 are provided obliquely with respect to the axial line on the outer periphery. At the same time, engagement projections 31 are provided at the end of the tapered surface 8B side, respectively, and the projections 31 are fitted into and engaged with the annular grooves 28 of the hole processing cylinder 7.

Therefore, the expansion and contraction wheel 8 and the hole processing cylinder 7 are restrained from moving in the axial direction by the annular groove 28 and the engagement projection 31, and the engagement between them is reliably maintained. The expansion / contraction ring body 8 does not come out of the hole processing cylinder 7. As shown in FIG. 3, the expansion / contraction operation member 9 is provided with a threaded portion 32 at one end outer periphery and an annular groove 33 at the other end periphery using a pipe material, leaving an axial end of the threaded portion 32. A notch 34 is formed, and the bifurcated piece 9A having an arc-shaped cross section left therethrough can be inserted into the through hole 22 provided in the flange portion 20 of the cylinder holder 6.

The expansion / contraction operation member 9 is provided with a bifurcated piece 9
A is inserted into the through hole 22 of the flange portion 20 from the boss portion 19 side, is fitted to the boss portion 19 and is axially movable, and the nut member 10 is attached to the screw portion 32. It is screwed. As shown in FIGS. 3 and 4, the nut member 10 is provided with a large number of irregularities 35 on the entire end surface thereof (the engaging surface of the locking ball) facing the flange portion 20. Locking ball 2
5, the nut member 10 is prevented from loosening naturally.

As shown in FIG. 3, the expansion / reduction operation drive wheel 11 is formed in a ring shape and a tapered surface 36 is formed on the outer peripheral surface thereof so as to fit into the tapered surface 8B of the expansion / reduction wheel body 8. The bifurcated piece 9A of the enlarging / reducing operation member 9 is fitted in the driving wheel 11 through a C-ring 38 fitted in the groove 33 as shown by a two-dot chain line in FIG. Of the drive wheel 11
Are driven in a direction to expand the diameter of the expanding / contracting member 8 (a direction indicated by an arrow A in FIG. 3).

In the above embodiment, when assembling the hole drilling tool 1, first, the fork 9A of the expansion / contraction operation member 9 is inserted through the through hole 22 of the cylinder holder 6, and is externally fitted to the boss portion 19 and its screw portion is formed. 32, the nut member 10 is screwed in. Then, the expanding / reducing wheel 8 is fitted in the ring body receiving portion 21 of the cylinder holder 6, and then the expanding / reducing operation drive wheel 11 is fitted in the hole 37 of the bifurcated piece 9A. Then, the C ring 38 is fitted into the annular groove 33 to prevent the ring from coming off.

Next, the tool center shaft 5 is inserted into the screw hole 18 of the cylinder holder 6 from the center drill 2 and the small-diameter screw portion 12 is fitted and fixed in the screw hole 18.
Is fitted around the expansion / contraction wheel 8 and the expansion / contraction operation drive wheel 11 of the cylinder holder 6. At this time, the cutting blade 26 is provided with a notch 27 provided on the outer periphery of the flange 20 of the cylinder holder 6.
To provide a provisional detent function of the cylinder holder 6 and the hole processing cylinder 7, a positioning function and a protection function of the cutting blade 26.

When the nut member 10 is rotated in the direction in which the screws are tightened while holding the drilling cylinder 7 by hand and holding it in a non-rotatable state, the expansion / reduction operation drive wheel 11 is moved to the flange of the cylinder holder 6. 3 (in the direction indicated by the arrow A in FIG. 3), whereby the expanding and contracting ring body 8 is pushed and expanded, and the engaging convex portion 31 of the expanding and contracting ring body 8 is brought into the annular groove 28 of the hole processing cylinder 7. At the same time, the outer peripheral surface of the expanding / reducing wheel body 8 is pressed against the inner peripheral surface of the hole processing cylinder 7 in a tight manner, so that the entire 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
The locking ball 25 is pushed in against the urging force of No. 4, and the nut member 10 can be easily rotated. And
When the nut member 10 loosens naturally, the locking ball 2
5 is completely fitted into the unevenness 35, the rotation of the nut member 10 is restrained with respect to the cylinder holder 6, and an effect of preventing loosening is produced.

On the other hand, when removing the drilling cylinder 7 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. Is reduced by its elasticity, and pushes the expanding / reducing operation drive wheel 11 in a direction away from the cylinder holder 6, and a gap is generated between the outer peripheral surface of the expanding / reducing wheel body 8 and the inner peripheral surface of the hole processing cylinder 7. The processing cylinder 7 can be easily extracted.

In the above embodiment, the cylinder holder 6
Can be integrally protruded on the outer periphery of the flange portion 20 and can be divided into a plurality of divided rings in the circumferential direction. By providing a screw portion on the outer periphery of the piece 9A, the screw portion can be inserted into the through hole 22 of the flange portion 20 from the side of the drive wheel 11 opposite to the above and fixed by the nut member 10.

The present invention is not limited to the above embodiment, and the design can be changed as appropriate, for example, by integrating the expansion / contraction operation member 9 and the expansion / contraction operation drive wheel 11 into one body.

[0030]

According to the present invention, as described above, the center drill, the center shaft, and the shank are provided on a single axis along the rotation axis, and the tool is held by the outer periphery of the center shaft of the center shaft. In the drilling tool consisting of a cylindrical holder and a cylindrical drilling cylinder held by the holder in a state surrounding the center drill of the tool center shaft, the tube holder has a center shaft portion of the tool center shaft. A boss portion to be screwed, a flange portion extending in a radial direction from the boss portion, and an expanding / contracting ring fitted into the hole processing cylinder provided on the outer periphery of the flange portion are provided, and are externally fitted to the boss portion. Along with the inner end of the expansion / contraction operation member of the expansion / contraction wheel that penetrates through the flange portion and enters the cylindrical holder, an expansion / contraction operation drive wheel having a tapered surface on the outer periphery is locked, and The outer peripheral surface extends to the outer peripheral side of the boss. Operation drive nut is screwed,
An expansion / contraction operation drive wheel is fitted to the tapered inner surface of the expansion / contraction wheel, and the outer peripheral surface of the expansion / contraction wheel and the inner peripheral surface of the drilling cylinder are locked in the axial direction via the uneven portion. Since the tool center shaft and the expansion / contraction operation drive wheel do not become a direct screw mechanism, the use of a machining tool does not make it difficult to detach the hole machining cylinder. The exchange workability can be improved, and the expansion / reduction operation drive wheel is not formed by a direct screw mechanism between the tool center shaft and the expansion / reduction operation drive wheel, but by the expansion / reduction operation member and the nut member screwed to the outer peripheral surface thereof. Even when the hole processing cylinder is moved in the axial direction, the outer peripheral surface of the expansion and contraction ring body and the inner peripheral surface of the hole processing cylinder are locked in the axial direction via the uneven portion, so that the hole processing cylinder is moved in the axial direction. There is no fear of getting out.

Further, the present invention is characterized in that the expansion / contraction ring body of the cylinder holder is separate from the flange portion and both are in contact with each other on a tapered surface. Is easy to manufacture, and the outer peripheral surface of the expanding and contracting wheel body can be brought into close contact with the inner peripheral surface of the bored cylinder with uniform pressing force, so that the fixing strength of both can be increased. Further, in the present invention, a locking ball is fitted on the flange portion of the cylinder holder so as to face the nut member, and the locking ball is constantly urged in the direction of the nut member by urging means. Since the unevenness is formed on the engaging ball contact surface of the member, the nut member can be prevented from loosening, and the holed cylinder can be prevented from falling out of the cylinder holder.

[Brief description of the drawings]

FIG. 1 is a central longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an exploded enlarged vertical sectional view of a main part in the embodiment.

FIG. 4 is an end view of the nut member in the embodiment.

FIG. 5 is an enlarged plan view of the cylinder holder in the embodiment.

FIG. 6 is a sectional view taken along line BB of FIG. 5;

FIG. 7 is a partial development of the outer peripheral surface of the expanding and contracting wheel body in the embodiment.

FIG. 8 is a central sectional view of a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 drilling tool 2 center drill 3 center shaft 4 shank 5 tool center shaft 6 cylinder holder 7 hole drilling cylinder 8 expansion and contraction body 8A taper surface 8B taper surface 9 expansion and contraction operation member 10 nut member 11 expansion and reduction operation drive wheel 12 small diameter screw Part 18 Screw hole 19 Boss part 20 Flange part 22 Through hole 23 Locking ball fitting part 24 Elastic body 25 Locking ball 28 Annular groove 31 Engagement projection 35 Irregularity 36 Tapered surface

Claims (3)

(57) [Claims] 1. A tool center shaft in which a center drill, a center shaft, and a shank are provided on a single axis along a rotation axis, a cylinder holder held on the outer periphery of the center shaft of the center shaft, and a tool center shaft. A drilling tool comprising a cylindrical drilling cylinder held by the holder in a state surrounding the center drill, wherein the cylinder holder has a boss portion screwed to a central shaft portion of a tool center shaft body; A flange portion extending in a radial direction, and an expansion / contraction ring body fitted into the bored cylinder provided on the outer periphery of the flange portion, the cylinder holder being externally fitted to the boss portion and penetrating through the flange portion. An expansion / reduction operation drive wheel having a tapered surface on the outer periphery is locked to an inner end of the expansion / contraction operation member of the expansion / reduction wheel body inserted into the inside, and an outer peripheral surface of the boss portion is provided on an outer peripheral surface of the expansion / contraction operation member. A nut member for driving the expansion / contraction operation on the side The expansion / contraction operation drive wheel is fitted to the tapered inner surface of the expansion / contraction wheel body, and the outer peripheral surface of the expansion / contraction wheel body and the inner peripheral surface of the hole processing cylinder are locked in the axial direction via the uneven portion. A drilling tool characterized in that: 2. The drilling tool according to claim 1, wherein the expansion and contraction wheel body of the cylinder holder is formed separately from the flange portion, and both are in contact with each other on a tapered surface. 3. A locking ball is fitted to the flange portion of the cylinder holder so as to face the nut member, and the locking ball is constantly urged in the direction of the nut member by urging means,
The hole machining tool according to claim 1, wherein the locking ball contact surface of the nut member is formed with irregularities.