JPH04336984A - Power rotation impact tool - Google Patents

Abstract

PURPOSE:To provide a power rotation impact tool which can mount and demount a drill bit easily to an adapter provided to a driving shaft of the power tool or its extension shaft, and furnishes a combining means to transmit the rotation shock force in a high efficiency. CONSTITUTION:Balls 21 are held to an adapter 11 to allow to project to the inner side surface and to the outer side surface, an engaging groove 19 for fitting balls 21 extending in the axial direction of the shank 5 of a drill bit 4 is provided, and at the same time, a presser ring member 22 furnishing spaces 23 for inserting the balls 21 has been installed movable in the axial direction to the adapter 11. By fitting the balls 21 to the engaging groove 19 by the presser ring member 21, the drill bit 4 and the adapter 11 are combined, and by inserting the balls to the spaces 23, the drill bit 4 is to be separated.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a power-driven rotary impact tool for drilling mounting holes for fastening machines and instruments in structures made of plastic materials, and more specifically, the present invention is a power-driven rotary impact tool that is easy to attach and detach. The present invention relates to a power-driven rotary impact tool that includes means for connecting a drill bit and an adapter with high transmission efficiency of rotational impact force.

0002

[Prior Art] A drill bit is attached directly to the drive shaft of an electric or other power tool or via an extension shaft, and rotational force and impact force are applied to the drill bit to produce plastic materials such as concrete, brick, and stone. It is well known that machines and instruments can be attached by drilling mounting holes in a built-in structure and fixing bolts or the like in the mounting holes.

The shank of a drill bit is generally tapered and is attached to an adapter at the tip of a drive shaft or an extension shaft by a tapered fit. As a result, slipping occurs at the tapered contact area between the shank and the adapter, which inevitably reduces the transmission efficiency of rotational force and impact force, and when driven continuously for long periods of time, frictional heat due to circumferential and axial slipping occurs. This causes a problem in that the tapered portion becomes extremely hot, changes the material, and deteriorates durability. Also, when replacing a drill bit, it is not only a hassle to insert the drift key and hit it with a hammer to remove it from the adapter, but also a loose drill bit may pull out from the adapter and fall, causing harm to people below depending on the location. There is a concern that.

On the other hand, there are some drill bits with straight shank, but since they are attached to the adapter with screws or chucks, it is not only difficult to attach and detach, but also there is a risk that the shank may come loose due to rotation or impact reaction force. Therefore, it is necessary to inspect the bolts as appropriate and retighten them if necessary, which is extremely troublesome.

[0005]

[Problems to be Solved by the Invention] The problem to be solved by the present invention is that it is possible to attach and detach a drill bit to an adapter very easily and quickly, and to obtain high transmission efficiency of rotational impact force without worrying about slippage or loosening. The problem was that there was no means to connect the drill bit to the adapter.

[0006]

[Means for Solving the Problems] As a means for solving the above problems, the present invention provides an adapter for connecting the shank of a drill bit and the distal end of a drive shaft of a power tool or an extension thereof to each other from the distal and proximal sides. A ball that is integrally inserted in an axially movable manner and rotatably coupled to the adapter as one body, and that holds the shank and the adapter so that it can protrude to the inner and outer surfaces of the adapter, and a ball that extends in the axial direction provided on the shank. The main feature is that the adapter is removably connected by a clutch mechanism consisting of an engagement groove for fitting and a holding ring member that is movable in the axial direction on the outer surface of the adapter and has a cavity for inserting the ball. The object of this invention is to be able to attach and detach the drill bit to the adapter very easily and quickly, and to apply rotational impact force to the drill bit with high transmission efficiency.

[0007] The shank and the adapter are preferably connected by a key in addition to the clutch mechanism to reduce the torque load on the clutch mechanism and to facilitate the alignment of the ball and groove when connected. Further, the tip of the drive shaft or its extension shaft and the adapter are movable in the axial direction with a predetermined stroke by a guide groove extending in the axial direction of the tip and a stopper of the adapter fitted thereto, and furthermore, these need to be separated. Since there is almost no friction, a clutch mechanism similar to that described above may be used for coupling, but it is preferable to provide a rectangular portion at the tip and the insertion hole of the adapter so that they rotate together.

[0008]

[Operation] When the shank of the drill bit is inserted into the adapter, the ball fits into the engagement groove by the holding ring member, allowing the shank to rotate integrally with the adapter, and the axis line with a stroke corresponding to the length of the engagement groove. directionally movably coupled. When the drive shaft or its extension shaft is rotated by the power tool, the adapter rotates together with the adapter and the drill bit also rotates together with the clutch mechanism. Further, when the drive shaft or its extension shaft is reciprocated in its axial direction, the drill bit also reciprocates together, applying an impact. When the presser ring member is moved on the outer surface of the adapter to position the cavity outside the ball and the drill bit is extracted, the ball is pushed out of the engagement groove and fitted into the cavity, and the drill bit is extracted. Conversely, the shank is inserted into the adapter with the ball fitted into the cavity, and then the ball that moves the presser ring member is fitted into the engagement groove and the drill bit is coupled to the shank.

[0009]

[Embodiment] An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, an extension shaft 3 is connected to the tip of a drive shaft 2 of a portable hand-held electric power tool 1. A drill bit 4 is attached by an adapter 11. This device is suitable for drilling a mounting hole in a high ceiling surface, and allows the worker to work stably while standing on the floor without getting on a stepladder. Needless to say, it may be directly attached to the drive shaft 2 in some cases.

FIG. 2 and below show the extension shaft 3 and drill bit 4.
This figure shows the details of the connection between the adapter 11 and the adapter 11.
The adapter 11 has a cylindrical main body 12, a mounting hole 13 in the front part of a hollow part penetrating the main body 12, and an insertion hole 14 in the rear part. The diameter is slightly smaller, and a stepped portion 15 is formed between them. In addition, two keys 16 protrude from the mounting hole 13 so as to face each other across the central axis, and a square hole 17 whose diameter is the diagonal line extends to an appropriate length in the middle of the insertion hole 14. It is formed.

The shank 5 of the drill bit 4 has a straight shape with a circular cross section, and has two key grooves 18 extending in the axial direction from its tail end surface at symmetrical positions across the central axis, and at right angles to the key grooves 18. Two engaging grooves 19 extending an appropriate length in the axial direction are provided at positions sandwiching the central axis.

Holding holes 20 extending an appropriate length in the axial direction are formed at positions perpendicular to the key 16 of the main body 12, that is, at positions overlapping the two engaging grooves 19, and one ball 21 is fitted into each holding hole 20. It's included. This ball 21
has a diameter equal to the sum of the wall thickness of the main body 12 and the depth of the engagement groove 19, and when fitted into the engagement groove 19 of the shank 4 tightly inserted into the mounting hole 13, the outer surface It is made to be flush with the outer peripheral surface of the main body 12.

[0013] In the front part of the main body 12 from the stepped part 15,
A retaining ring member 22 having an annular cavity 23 open to the inner circumferential surface is attached so as to be slidable in the axial direction, and the protective sleeve 2
The main body 12 is fixed in contact with a stopper 26 provided near the tip of the main body 12 by a compression spring 25 which is a compression coil spring and is inserted between the main body 12 and the stepped portion 15 .

The engagement groove 19, the ball 21, the presser ring member 22, and the presser spring 25 constitute a clutch mechanism 27, and the ball 21 is inserted into the cavity 23 of the presser ring member 22 and then inserted into the mounting hole 13. Insert key 1 into key groove 18 while the
6 and inserting the shank 5 into the mounting hole 13, the ball 21 and the engagement groove 19 match, and the presser ring member 22
The ball 21 is moved toward the proximal end to release the ball 21 sandwiched between the cavity 23 and the holding hole 20, and then the presser ring member 22 is returned to contact with the stopper 26 by the spring force of the presser spring 25, thereby releasing the ball 21. is pushed into the engagement groove 19 to connect the adapter 11 and the drill bit 4.

When separating the drill bit 4, move the presser ring member 22 toward the proximal end, position the cavity 23 on the outside of the ball 21, and pull out the drill bit 4.
The ball 21 pushed out from the tail end of the ball 9 fits into the cavity 23 and can be completely removed, and by returning the presser ring member 22, the ball 21 is sandwiched between the cavity 23 and the holding hole 20. Retained. The above-mentioned state of the ball 21 when the drill bit 4 is attached and detached is shown in FIG.

Next, at the tip of the extension shaft 3, a square shaft part 31 is formed which is tightly fitted into the square hole part 17 and extends over a length longer than the square hole part 17. A striking shaft portion 32 is formed to protrude from the shaft portion 31, and a guide groove 33 of an appropriate length extending in the axial direction is provided on two opposite sides of the square shaft portion 31.

At the rear of the stepped portion 15 of the main body 12, two flat stoppers 34 are fitted into mounting grooves 35 extending in the axial direction at symmetrical positions across the central axis and project into the square hole portion 17. At the same time, it is held down by a retaining ring 36 to prevent it from falling out.

The square shaft portion 3 at the tip inserted into the insertion hole 14
1 is fitted into the square hole 17, and the stopper 34 is fitted into the guide groove 33, and the striking shaft 32 is inserted into the mounting hole 13, and its tip surface contacts the tail end surface of the shank 5. ing.

[0019] In this embodiment having such a configuration, the power tool 1
When the extension shaft 3 is rotated, the adapter 11 rotates together due to the engagement between the square shaft portion 31 and the square hole portion 17, the guide groove 33, and the stopper 34, and the adapter 11, clutch mechanism 27, and key 16 are rotated together. , the drill bit 4 connected by the keyway 18 also rotates together to cut and drill the structure. Furthermore, when the extension shaft 3 is linearly reciprocated by the driving tool 1, the maximum stroke of the extension shaft 3 is the difference in length between the guide groove 33 and the stopper 34 or the difference in length between the key groove 18 and the key 16. A linear reciprocating motion is performed and the drill bit 4 is pushed to perform impact drilling of the structure.

The shank 5 and the adapter 11 may be movably connected in the axial direction only by the clutch mechanism 27, and the tip of the drive shaft 2 or its extension shaft 3 and the adapter 11 may be connected by the same clutch mechanism as described above. Alternatively, they may be connected movably in the axial direction using a spline or the like. Furthermore, the clutch mechanism 27
The retaining ring member 22 may be screwed to the main body 12 and moved back and forth while being rotated to cause the ball 21 to fit into and disengage from the engagement groove 19.

[0021]

[Effects of the Invention] According to the present invention, the adapter for attaching the drill bit to the drive shaft or its extension shaft is connected movably in the axial direction by a clutch mechanism consisting of a guide groove, a ball, and a retaining ring member. Not only is attachment/detachment extremely easy and quick, but slippage only occurs in the axial direction upon impact, and no loosening occurs between the drill bit and adapter at that time, resulting in less frictional heat generation and increased durability. Not only does it not deteriorate, it also provides high transmission efficiency of rotational force and impact force, and the clutch mechanism does not become loose, so it can be used while maintaining a stable connected state.

Furthermore, when the drill bit is connected to the adapter with a key in addition to the clutch connection, the torque load on the clutch mechanism is reduced, eliminating the risk of damage, and the positioning of the clutch mechanism during connection is facilitated, resulting in quick attachment and detachment. This is something that can be measured.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an overall embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing an embodiment of the main part of the present invention.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a sectional view taken along line BB in FIG. 2;

FIG. 5 is a sectional view taken along line CC in FIG. 2;

FIG. 6 is a partial longitudinal cross-sectional view of the drill bit when it is attached and detached.

[Explanation of symbols]

1 Power tools 2 Drive shaft 3 Extension shaft 4 Drill bit 5 Shank 11 Adapter 13 Mounting hole 14 Insertion hole 16 key 17 Square hole part 18 Key groove 19 Engagement groove 21 Ball 22 Presser ring member 23 Blank space 27 Clutch mechanism 31 Square shaft part 33 Guide groove 34 Stopper

Claims (3)

[Claims] 1. A shank of a drill bit and a distal end of a drive shaft of a power tool or an extension shaft thereof are inserted into the adapter from the proximal end side and the distal end side, so that they are movable together in the axial direction, and each of the adapters The shank and the adapter are integrally rotatably coupled to each other, and the shank and the adapter include a ball held in the adapter so as to be able to protrude to the inner and outer surfaces, and a locking member provided on the shank and extending in the axial direction into which the ball is fitted. The powered rotation is detachably coupled by a clutch mechanism comprising a fitting groove and a holding ring member having a hollow space into which the ball is inserted and is attached to the outer surface of the adapter so as to be movable in the axial direction. impact tool. 2. A power-driven rotary impact tool, in addition to the structure according to claim 1, wherein the shank and the adapter are rotatable together by key coupling. 3. The drive shaft or its extension shaft is movable in the axial direction with a predetermined stroke by a guide groove extending in the axial direction provided at the tip thereof and a stopper provided on the adapter and fitted in the guide groove. Claim 1, wherein the tip and the adapter are rotatably coupled together by fitting into a square hole formed in the tip.
2. The powered rotary impact tool according to any one of the above.