JPH0440805Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a drill shaft mounting structure for mounting the drill shaft to a drive device.

(Conventional technology) Conventionally, concrete, asphalt, tile,
To attach a drill used for drilling blocks, humid pipes, ceramic pipes, etc. to the drive device, as shown in FIG. The inner wall surface on the opening side of the shaft hole 33 is formed into a conical shape expanding toward the opening side, and a female screw 34 is provided on the bottom side of the shaft hole 33. On the other hand, the base 3 of the drill 35
6 has a conical portion 37 formed at its root portion 36.
and a cylindrical portion 3 formed at the tip of the conical portion 37
8 is provided with a male screw 39, and the mounting portion 3 of the drive device 31 is
The male screw 39 is screwed into the female screw 34 provided in 2,
By strongly tightening, the drill 35 can be attached to the attachment portion 32 of the drive device 31.

(Problems to be Solved by the Invention) In the conventional drill shaft mounting structure described above, since it is mounted only by the tightening force of screwing, it is easy to loosen due to vibrations on the drive device 31 side, and the base of the drill shaft 36 is the drive device 3
Since the conical part 37 must be formed to match the conical inner wall surface formed in the mounting part 32 of the first mounting part 1, there are problems such as processing becomes difficult.

The present invention was developed in view of the above-mentioned problems, and the technical problem set for solving the above-mentioned problems is to tighten the tip of a cylindrical collet chuck so that it bends toward the drill side. To provide a drill shaft mounting structure that ensures the mounting of a drill and simplifies the shape of the drill to facilitate manufacturing.

(Means for solving the problem) In the present invention, as a means to solve the above problem, in configuring the mounting structure of the drill shaft, a groove is formed in a conical shape with the outer diameter decreasing toward the tip side. A drill shank is provided around the periphery, and a distal end fitted onto the drill shank is formed so as to be able to engage with the groove by bending, and the outer circumferential surface of the distal end has a larger diameter than the central portion and has a tapered conical shape. a collet formed, a mounting portion on the driving device side having a hole drilled into which the collet is fitted, and an inclined surface that is fitted onto the drill shank, is screwed onto the mounting portion, and comes into contact with the outer circumferential surface of the tip portion. The structure includes a nut that presses the tip of the collet toward the groove side of the drill shank by an inner wall surface.

(Function) With the above structure, the present invention has the nut fitted externally into the drill shank and screwed into the mounting part on the drive device side, thereby pressing the tip of the collet fitted externally into the drill shank against the groove side of the drill shank. Then, the tip part is bent toward the groove side of the drill shank, and the collet is engaged with the drill shank in a biting state to prevent the drill shank from coming off from the attachment part on the drive device side. The drill shank only needs to be formed with a groove into which the tip of the collet can be narrowed, which simplifies the shape, and the drill shank can be attached or removed by tightening or loosening the nut, making it easy to attach and detach.

(Example) Hereinafter, an example according to the present invention will be described in detail based on FIGS. 1 to 7.

As shown in Fig. 1, the mounting structure consists of fitting a collet 2 onto a hollow cylindrical drill shank 1, fitting the collet 2 into a hole 4 drilled in a mounting part 3 on the driving device side, and attaching the collet 2 to the drill shank 1 in advance. The fitted nut 5 was screwed into the male screw 6 of the mounting part 3, and the tip 8 of the collet 2 was carved on the outer circumferential surface of the drill shank 1 using the inclined inner wall surface 7 provided at the deepest part of the inner surface of the nut 5. The drill shank 1 is formed into a shape that prevents it from slipping out from the mounting portion 3 on the drive device side by pressing it toward the groove 9 side.

As shown in FIG. 2, the drill shank 1 has an elongated groove 12 parallel to the axial direction carved in an end 11 facing the drive device, and an end 11 with the groove 12 carved therein.
A groove 9 is carved in a conical shape with an outer diameter decreasing from the end 11 side where the groove 12 is carved toward the opposite side.

As shown in FIGS. 3 and 4, the collet 2 is provided with a tip 8 having a larger outer diameter than the center of the collet 2 at one end and formed into a tapered conical shape. A narrow groove 13 parallel to the axis is carved in the shaft, and an elongated groove 14 parallel to the axial direction is carved in the opposite end so as to have the same width as the groove 12 of the drill shank 1.

As shown in FIGS. 5 and 6, the mounting portion 3 on the drive device side has a main shaft 15 formed hollow and connected to a rotating shaft of a motor (not shown) as a drive device. A grip part 16 with a knurled outer surface is provided at one end,
A male screw 6 is formed with a smaller outer diameter than the grip portion 16 on the tip side of the grip portion 16, and the male screw 6 is formed on the tip side of the grip portion 16.
A hole 4 is coaxially drilled from the distal end surface of the drill shank to the gripping part 16 side, so that a collet 2 fitted onto the drill shank 1 can be inserted therein. A pin 17 is provided at a position closer to the male screw 6 side of the gripping part 16 so as to protrude toward the hole 4 side, and the amount of protrusion toward the hole 4 side is determined by the distance between the drill shank 1 and the collet 2 when the collet 2 is fitted into the drill shank 1. The combined thickness is made to protrude so that the drill shank 1 inserted into the hole 4 and the grooves 12 and 14 provided in the collet 2 can engage.
To prevent a drill shank 1 and a collet 2 from rotating during drilling.

As shown in FIG. 7, the nut 5 has an inclined inner wall surface 7 at one end of which a hole 19 is provided with a female screw 18 that is screwed into the male screw 6, and whose hole diameter decreases toward an end surface 20.
A hole 21 with an inner diameter slightly larger than the outer diameter of the drill shank 1 is formed in the immediate vicinity of the end face 20, and an O-ring groove 22 is provided around the hole 21 to prevent inflow of dust or cooling medium. An O-ring 23 for preventing leakage can be fitted.

When using the mounting structure configured in this way, the nut 5 is fitted into the drill shank 1 with the end of the nut 5 on the O-ring 23 fitting side facing the end face 20 of the drill shank 1, and then the nut 5 is fitted onto the drill shank 1.
Align the circumferential and axial directions so that the groove 12 of the collet 2 matches the groove 14 of the collet 2, fit the collet 2 onto the drill shank 1, and insert the collet 2 together with the drill shank 1 into the hole 4 of the mounting part 3 on the drive device side. Insert the collet 2, engage the pin 17 protruding into the hole 4 with the groove 12 of the drill shank 1 and the groove 14 of the collet 2 to prevent it from rotating around the axis, and insert the drill shank 1 and the collet 2 into the hole 4 of the mounting part 3. When the nut 5 is tightened by inserting the nut 5 into the deepest part of the mounting part 3 and tightening the nut 5, the inclined inner wall surface 7
comes into contact with the tip 8 of the collet 2 and presses the tip side so as to bend toward the groove 9 side of the drill shank 1, thereby preventing the drill shank 1 from coming off from the attachment part 3 side.

As described above, in the above embodiment, the tip 8 of the collet 2 is clamped in the groove 9 of the drill shank 1,
The drill shank 1 can be prevented from coming off from the mounting part 3 on the driving device side, and the pin 17 can be engaged with the groove 12 of the drill shank 1 and the groove 14 of the collet 2, so that the drill shank 1 can be rotated around the axis of the mounting part 3. It is possible to prevent relative rotation.
By pressing the collet 2 toward the drill shank 1 with the nut 5 and bending the tip 8 of the collet 2, a reaction force always acts between the collet 2 and the nut 5, which reduces vibration during cutting. to prevent loosening.

Further, the shape of each part is simplified to a cylindrical hollow part, and there is no need to make the conical wall surfaces formed on the collet 2 and the nut 5 parallel wall surfaces, making manufacturing easy and inexpensive.

Further, once the drill shank 1 is installed, the drill shank 1 can be pulled out from the mounting part 3 by loosening the nut 5, or it can be fixed by inserting the drill shank 1 into the mounting part 3 and tightening the nut 5. , attaching and detaching the drill shank 1 becomes extremely easy.

Note that the groove 9 may have any shape as long as the collet 2 can fit therein, and may be stepped.

(Effects of the invention) As described above, in the present invention, the collet is pressed toward the drill shank by the nut screwed into the mounting portion on the driving device side, and the tip of the collet is bent toward the drill shank. A reaction force always acts between the collet and the nut, which prevents loosening due to vibration during cutting and prevents the drill shank from coming off from the mounting part.

Further, the shape of each part is simplified to a cylindrical hollow part, and there is no need to make the conical wall surfaces formed on the collet and nut parallel to each other, making manufacturing easy and inexpensive.

Furthermore, the drill shank can be installed or removed by tightening or loosening a nut, making it easy to install or remove.

[Brief explanation of the drawing]

1 to 7 are drawings showing an embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view showing the assembled state of the mounting structure, and FIG. 2 is a longitudinal half sectional view showing the drill shank. , FIG. 3 is a longitudinal half-sectional view showing the collet, and FIG. 4 is a front view showing the collet.
FIG. 5 is a vertical half sectional view showing the mounting part on the drive device side, FIG. 6 is a front view showing the mounting part on the drive device side, FIG. 7 is a vertical half sectional view showing the nut, and FIG. is a partially sectional side view showing a conventional mounting structure. 1...Drillshank, 2...Collect, 3...
... Attachment part on the drive device side, 4 ... hole, 5 ... nut, 6 ... male screw, 7 ... inclined inner wall surface, 8 ... tip, 9 ... groove.

Claims (1)

[Scope of utility model registration request] A drill shank is provided with a conical groove whose outer diameter decreases toward the tip side, and the drill shank is fitted onto the outside of the drill shank so that the tip thereof can be engaged with the groove by bending. a collet whose outer circumferential surface is formed in a tapered conical shape with a diameter larger than that of the central portion; a mounting portion on the driving device side having a hole into which the collet is inserted; A mounting structure for a drill shaft consisting of a nut that is screwed onto a part of the drill shaft and presses the tip of the collet toward the groove of the drill shank by means of an inclined inner wall surface that abuts the outer peripheral surface of the tip.