JP2834422B2 - 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.

[0002]

2. Description of the Related Art Conventionally, as one of drilling tools, there is a drilling tool having a large diameter hole (commonly called a core drill), which is frequently used, for example, for drilling holes required for piping of an air conditioner or the like on the wall of a building. . As illustrated in FIG. 8, the drilling tool includes a center drill 42, a center trunk 43,
A plurality of cutting blades 46 are provided along the annular end portions on both sides in the longitudinal direction in such a manner as to surround the center drill 42 with respect to the tool center shaft body 45 provided with the tool 4 (a portion to be chucked by a rotary hammer drill or the like). Is provided, and a cylindrical hole processing cylinder 47 provided with a hole is held.

The shank 44 is provided with a rotary torque transmitting groove 48 and a keyway-like stroke regulating groove 49 which can be mounted (chucked) on the hammer drill (see FIG. 9) alternately at two intervals of 90 degrees. Have been. In addition, the drilling cylinder 47 is provided with the tool shaft 4
5 allows easy attachment and detachment.

As shown in FIG. 9, the hammer drill 50 has a sleeve 52 having a shank accommodating hole 53 at a tip end of a spindle 52 extending from one end of a hammer casing 51 and capable of reciprocating in the axial direction. 54 is externally fitted, and on the inner surface of the shank receiving hole 53 of the sleeve 54,
A rotational torque transmitting ridge 55 is projected, and a through hole 56 is provided in the radial direction. A locking sphere 57 that gives a shank stroke is fitted in the through hole 56.

The projection 55 is fitted in the torque transmission groove 48 of the shank 44, and the locking sphere 57 is
In the stroke regulating groove 49. Also,
As shown in FIGS. 10 and 11, a shank 44 of a drilling tool to be mounted on a normal electric rotary vibration drill (not shown) has a shank so that it can be mounted on a drill chuck having three claws. 44 at equal intervals in the circumferential direction (1
The torque transmitting surface 58 is formed flat at an interval of 20 degrees).

[0006]

In the above-mentioned prior art, the structure of the shank 44 is different between the rotary hammer drill 50 and the rotary vibration drill.
On the side of providing the tool, the tool is provided by replacing the shank 44 according to the drill held by the purchaser, and this operation is complicated and troublesome. Further, it is sufficient to prepare a drilling tool that can be mounted on each drill, but there is a problem in terms of inventory management and economy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and has as its object the provision of a shank that can be attached to both a rotary hammer drill and a rotary vibration drill with a single shank structure. To provide a drilling tool.

[0008]

According to the present invention, the following technical measures have been taken in order to achieve the above object. That is, the present invention relates to a drilling tool having a cutting blade at a front end portion and a shank at a rear end portion, wherein an outer peripheral surface of the shank has a mounting torque on a rotary hammer drill parallel to its axis. A transmission groove and a tool stroke restriction groove, and a torque transmission surface for mounting on a rotary vibration drill are provided.

In the present invention, the torque transmitting grooves and the tool stroke regulating grooves are alternately provided at 90 ° intervals, and the three torque transmitting surfaces are provided at equal circumferential intervals.
The circumferential center of one of the surfaces is aligned with the center in the width direction of the regulating groove.

[0010]

According to the present invention, when the working tool is mounted on the rotary hammer drill, the torque transmission groove of the shank and the stroke regulating groove are engaged, and when the working tool is mounted on the rotary vibration drill, the torque of the shank is used. What is necessary is just to clamp using a transmission surface.

[0011]

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.

The shank 4 of the tool center shaft 5 has, on its outer peripheral surface, a torque transmitting groove 15 for mounting to a rotary hammer drill having a key groove shape parallel to the axis at substantially two full-length intervals of 180 degrees. 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 ° 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 vibration drill at equal circumferential intervals (120 ° intervals). The center of the stroke regulating groove 16 is aligned with the center of the stroke regulating groove 16 in the width direction.
Are provided on both sides in the axial 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 a rotary hammer drill and a rotary vibration drill. The cylinder holder 6 includes a holder body 6
A and an expanding / contracting ring 7 separate from the main body 6A.
A boss 19 having a central portion formed with a threaded hole 18 screwed into the small diameter screw portion 12 of the center shaft body 5, and a radial direction (radially outward) from the outer peripheral end of the boss portion 19. And a ring-shaped expanding and contracting ring body receiving portion 21 protruding from the outer peripheral portion of the flange portion 20 to the opposite side of the boss portion 19.

The outer peripheral side of the expanding and contracting wheel body 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 body 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 state between the two 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 fork 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 has a ring shape, and a tapered surface 36 is formed on the outer peripheral surface thereof so as to fit into the tapered surface 8 B 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 held in a non-rotatable state by rotating the nut member 10 in the screw tightening direction and tightening it, the expansion / reduction operation drive wheel 11 is moved to the flange of the tube 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 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 held 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, but can be applied to a drill bit having the same simple structure as the center drill 2 for drilling a small diameter hole.

[0028]

As described above, the present invention relates to a drilling tool provided with a cutting blade at the front end and a shank at the rear end, wherein the outer peripheral surface of the shank is parallel to its axis. It is characterized by having a torque transmitting groove for mounting to a rotary hammer drill and a tool stroke regulating groove, and a torque transmitting surface for mounting to a rotary vibration drill. Can be attached to both hammer drill and rotary vibration drill.

In the present invention, the torque transmitting grooves and the tool stroke regulating grooves are alternately provided at 90 ° intervals, and the three torque transmitting surfaces are provided at equal intervals in the circumferential direction.
Because the circumferential center of one of the surfaces is aligned with the center in the width direction of the regulating groove,
Even if the shank is formed with a torque transmitting groove for mounting to a rotary hammer drill and a tool stroke regulating groove, and a torque transmitting surface for mounting to a rotary vibration drill, the torque transmitting groove for mounting to a rotary hammer drill and The torque transmitting function can be sufficiently exerted without impairing the torque transmitting function of the tool stroke regulating groove.

[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 a partially exploded enlarged sectional view of 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 longitudinal sectional view of a conventional example.

FIG. 9 is a sectional view showing a main part of an example of a rotary hammer drill.

FIG. 10 is a front view of a main part of another conventional example.

FIG. 11 is a top plan view of FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drilling tool 4 Shank 15 Torque transmitting groove 16 Tool stroke regulating groove 17 Torque transmitting surface 26 Cutting blade

Claims (1)

(57) [Claims] 1. A drilling tool having a cutting blade at a front end and a shank at a rear end, wherein an outer peripheral surface of the shank is transmitted to a rotary hammer drill in parallel to an axis thereof. Grooves and tool stroke regulating grooves are provided alternately at 90 degree intervals,
On the outer peripheral surface of the shank, three torque transmitting surfaces for mounting to the rotary vibration drill are provided at equal intervals in the circumferential direction,
A hole machining tool, wherein a center in a circumferential direction of one of the surfaces is aligned with a center in a width direction of the restriction groove.