JP2005125432A - Adjustable diameter boring tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid an enlargement by surely fixing a holder to a tool body with a simple constitution and a structure. <P>SOLUTION: A tapered part 10 is formed in a shank of the holder 3. The tapered part 10 is arranged on the rear side of a flange 11 projected in a base part of the shank by forming a diameter larger than that part, and is formed in a tapering-off shape by expanding a diameter up to gradually becoming the same diameter as the flange 11 for reaching the rear end side in the axis direction from there by forming the tip side in the smallest diameter. A fitting hole 12 has an inner diameter corresponding to the largest outer diameter of the tapered part 10. When the shank is fitted to a shank installing hole of a tool body 2 and the tapered part 10 is fitted to the fitting hole 12, the holder 3 is fixed to the tool holder 2 by being fastened by a clamp screw 16. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a diameter-adjustable drilling tool, and more particularly, to a diameter-adjustable drilling tool suitable for changing the diameter dimension by adjusting the blade tip position in the radial direction.

  In this type of hole drilling tool, it has been proposed to improve the accuracy and workability of the positioning operation of the cutting edge of the cutting edge. Therefore, in the conventional hole drilling tool, it is provided in the shank portion. There has been proposed an eccentric sleeve type that includes an eccentric sleeve for adjusting the blade tip position and that supports the eccentric sleeve so as to be rotatable about an axis (see, for example, Patent Document 1).

The one described in Patent Document 1 (hereinafter referred to as the prior art) defines a drill insertion limit by engaging with a drill holding hole provided in a holder body as a tool body in a relatively non-rotatable manner with a drill tongue. The worm wheel is provided, and the worm wheel is engaged with a worm held by the holder main body so as not to move in the axial direction of the worm wheel, so that the drill can be moved back and forth in the axial direction. The worm wheel can be engaged with the worm regardless of the axial position, and the insertion depth of the drill into the holder body can be adjusted. The load torque applied to the drill during processing is received by the holder main body via the worm wheel and the worm, and the relative rotation of the drill with respect to the holder main body is reliably prevented.
Japanese Patent Laid-Open No. 10-071512 (page 3-8, FIGS. 1 to 5)

  By the way, in the prior art shown above, the drill can be inserted into the drill holding hole of the tool main body up to the specified position, but as a means for realizing it, only a worm wheel and a worm are provided. There is a problem that the drill holding part requires a large number of parts such as an oil passage, plug, cylinder bore, piston, operating screw, auxiliary oil chamber, etc., and has a complicated structure. There is also a problem that the hole drilling tool itself becomes large due to the number of parts and the complicated structure.

  The present invention has been made in consideration of such circumstances, and its object is to be able to securely fix the holder to the tool body with a simple configuration and structure, and to avoid the increase in size. An object of the present invention is to provide a diameter-adjustable drilling tool.

In order to achieve the above object, the present invention proposes the following means.
The invention according to claim 1 is provided with a tool main body provided with a shank mounting hole eccentric to the center axis on the front end surface, a cutting edge provided at the front end, and an axial extension extending at the rear end. And a holder that is fitted and fixed in a shank mounting hole of the tool body, and the radial direction of the cutting blade is based on the eccentric distance between the center axis of the tool body and the axis of the holder. In the diameter-adjustable drilling tool adapted to adjust the position of the holder, a taper portion is formed at the midway position in the axial direction of the holder with an inclined surface that is tapered along the axial direction on the outer periphery, When the tool body is formed with a fitting hole for fitting with the taper, the shank of the holder is fitted into the shank mounting hole of the tool body, and the taper portion is fitted into the fitting hole. , The tool body Characterized by fixing the path portion by a clamp screw.

  According to the first aspect of the present invention, the holder can be securely fixed to the tool body by tightening the clamp screw after the shank of the holder is fitted to the tool body, so that the number of parts can be greatly reduced. Not only can the structure be simplified, but also the increase in size of the tool can be reliably avoided, and the assembly reliability between the shank and the tool body can be increased. .

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are views showing a diameter-adjustable drilling tool according to a first embodiment of the present invention. FIG. 1 is an overall view showing a diameter-adjustable drilling tool, and FIG. 3 is a side view seen from the left side, FIG. 3 is an enlarged sectional view taken along line AA in FIG. 1, and FIG. 4 is an enlarged view taken along line BB in FIG.
This diameter-adjustable drilling tool 1 shown in FIG. 1 includes a tool body 2 and a holder 3 having a cutting edge 4 provided at the tip, and a shank 5 of the holder 3 is attached to the tool body 2. When fitted and fixed, the tool main body 2 is driven and rotated together with the holder 3 so that the cutting edge 4 of the holder 3 makes a desired hole in the work material.

The tool body 2 has a base side attached to the main shaft of the machine tool and rotated around the central axis O by a drive source of the main shaft, has a substantially cylindrical shape, and protrudes laterally at the tip thereof. Part 6 is provided.
As shown in FIG. 1, the holder 3 has a multi-stage columnar shape, and a cutting edge 4 is provided at a front end portion thereof, and a shank 5 is extended and provided at a rear end portion thereof. As shown in FIG. 2, the cutting blade 4 is provided on two throwaway tips (hereinafter referred to as “tips”) composed of an inner tip 7 </ b> A and an outer tip 7 </ b> B attached to the holder 3. At the time of machining, by rotating about the central axis O of the tool body 2, the inner tip 7A will pierce the inner portion of the machining hole provided in the work material, and the outer tip 7B will pierce the outer portion of the machining hole. It has become. The inner side tip 7A and the outer side tip 7B are attached to the holder 3 so as to be exchangeable with mounting screws.

As shown in FIG. 1, the shank 5 has a cylindrical shape extending along the axial direction at a position centering on the axis P of the holder 3 at the rear end of the holder 3, and is formed in the tool body 2. When fitted in the shank mounting hole 8, the holder 3 is fixed to the tool body 2 by fixing means described later. However, in FIG. 1, since the center axis O of the tool main body 2 and the axis P of the holder 3 are plotted on the horizontal line, the center axis O and the axis P are located on the same line.
The shank mounting hole 8 is for fitting the shank 5 and is provided along the axial direction at a position slightly decentered from the central axis O on the tip surface of the tool body 2.

  Accordingly, the axis P of the holder 3 (shank 5) is fitted with a distance L from the center axis O of the tool body 2 as shown in FIG. 3, and the shank 5 is rotated. At the same time, based on the distance L between the central axis O and the axis P of the holder 3, the cutting edges 4 of the chips 7A and 7B in the holder 3 are displaced in the radial direction, thereby adjusting the position of the cutting edge 4 in the radial direction. It has come to be.

  In this embodiment, a tapered portion 10 having a diameter larger than that of the shank 5 is formed on the shank 5 of the holder 3. As shown in FIG. 1, the taper portion 10 is sized to fit into a fitting hole 12 provided in the flange portion 6 of the tool body 2, and specifically, at the base portion of the shank 5. It is provided on the rear side of the flange 11 projecting with a diameter larger than that of the shank 5, and the tip end side has the smallest diameter, and gradually extends from the flange 11 along the axial direction to the rear end side. It is formed into a tapered shape by being expanded to the same diameter, and therefore the outer periphery thereof is an inclined surface 10a. As shown in FIGS. 1 to 3, the fitting hole 12 is provided inside the flange portion 6 of the tool body 2 and has an inner diameter corresponding to the largest outer diameter of the tapered portion 10.

  When the shank 5 of the holder 3 is fitted into the shank mounting hole 8 of the tool body 2 and the tapered portion 10 is fitted into the fitting hole 12, the tapered portion 10 is used as a fixing means in the tool body 2. The holder 3 is fixed to the tool body 2 by tightening with the clamp screw 16. As shown in FIG. 3, the clamp screws 16 are screwed into screw holes 17 that are radially engraved in the flange portion 6 of the tool body 2, so that there are three clamp screws 16 at an equally spaced angle (an angle of 120 °). Is provided.

The shank 5 is provided with a worm wheel 14 and a worm 15 for rotating the worm wheel 14 is rotatably attached to the tool body 2 to form a so-called wall gear configuration.
As shown in FIG. 1, the worm wheel 14 is provided at the rear portion of the tapered portion 10 and has a diameter slightly smaller than the maximum diameter of the tapered portion 10. Is arranged. Therefore, the fitting hole 12 has a size capable of fitting the tapered portion 10 and the worm wheel 14 in the axial direction. In addition, although the worm wheel 14 of this example is being fixed to the shank 5 by inserting the shank 5 in the center of the inner side, you may form integrally with the shank 5. FIG.
As shown in FIG. 4, the worm 15 has a gear that meshes with the gear of the worm wheel 14. The worm 15 is rotatably supported on the flange portion 6 of the tool body 2 by a support shaft 20 and rotates. As the worm wheel 14 rotates about the axis P together with the shank 5, the position of the cutting edge 4 provided on the holder 3 can be adjusted in the radial direction.

At this time, as shown in FIG. 2, a plurality of markings 18 representing a memory are provided on the front surface of the flange portion 6, and a marking 19 is also provided on the front surface of the flange 13, and the positions of the markings 19 with respect to the plurality of markings 18 are determined. By confirming, the rotation angle of the holder 3 can be recognized.
As shown in FIG. 4, the support shaft 20 is rotatably held by a holding portion 21 provided in the collar portion 6, and an operator inserts a tool or the like into a concave portion 22 provided at the distal end to turn the support shaft 20. The worm 15 is rotated. In FIG. 1, reference numeral 23 denotes a second cutting blade, which is attached to the middle thick portion 3 b having a diameter larger than that of the shank 5 and the tip diameter portion 3 a of the holder 3 and smaller than that of the taper portion 10. Counterbore processing can be performed on the processed part.

Since the diameter-adjustable drilling tool 1 of this embodiment is configured as described above, the handling thereof will be described below.
First, after attaching the tool main body 2 to the spindle of a machine tool (not shown), the holder 3 to which the inner side tip 7A having the cutting edge 4 and the outer side tip 7B are previously attached is attached to the tool main body 2.

In that case, after fitting the shank 5 provided in the holder 3 in the shank mounting hole 8 of the tool body 2, inserting the worm wheel 14 in the fitting hole 12 and fitting the tapered portion 10, The holder 3 is fixed to the tool body 2 by tightening the clamp screw 16 as a fixing means.
Thereby, since the taper part 10 provided in the shank 5 of the holder 3 is formed in a tapered shape as shown in FIG. 1 and the outer periphery is an inclined surface 10a, when the taper part 10 is tightened with the clamp screw 16, Since the tapered portion 10 is pushed into the fitting hole 12 so as to be pulled toward the rear (back) side, the holder 3 can be accurately fixed to the tool body 2. Thereby, the tool main body 2 is driven by the machine tool and the holder 3 rotates, so that the cutting edge 4 provided at the tip of the holder 3 can perform a hole in the work material.

  Therefore, according to this diameter-adjustable drilling tool 1, the holder 3 can be securely fixed to the tool body 2 by tightening the clamp screw 16 after the shank 5 of the holder 3 is fitted to the tool body 2. Compared with the prior art, not only can the number of parts be greatly reduced, but also the structure can be simplified, and further, the increase in size of the tool can be surely avoided, and the shank can be avoided. Assembling reliability between 5 and the tool body 2 is increased.

In addition, after attaching the tool main body 2 to the machine tool beforehand, the holder 3 was fixed to this, However, You may attach the tool main body 2 to which the holder 3 was fixed beforehand to the main axis | shaft of a machine tool. .
Of course, when the shank 5 is fitted into the shank mounting hole 8, the worm wheel 14 is inserted with the gear of the worm wheel 14 meshed with the worm 15 attached to the tool body 2.

On the other hand, when the above-described hole machining is performed, if the radial direction of the cutting edge 4 is smaller than the target machining hole, it is necessary to adjust the tip of the cutting edge 4 to be large.
At this time, first, the clamp screw 16 is loosened, and the worm 15 is rotated in that state. When the worm wheel 14 is rotated accordingly, the tapered portion 10 is rotated in the fitting hole 12. Since the shank 5 is rotated around the axis P in the shank mounting hole 8 of the tool body 2, the rotation results in a distance L between the center axis O of the tool body 2 and the axis P of the holder 3. Based on this, the cutting edge of the cutting edge 4 is gradually expanded in the radial direction at the tip of the holder 3, and the cutting edge of the cutting edge 4 is slightly shifted and adjusted in the radial direction.

That is, according to this diameter-adjustable drilling tool 1, the holder 3 is rotated about the axis P in the tool body 2 by the worm gear composed of the worm wheel 14 and the worm 15 interposed between the tool body 2 and the holder 3. By being moved, the cutting edge 4 can be slightly displaced in the radial direction, so that fine adjustment of the cutting edge 4 can be performed satisfactorily.
In addition, the worm wheel 14 and the worm 15 are each appropriately selected from the constituent elements such as leads, modules, the number of teeth, and the pressure angle, so that the holder 3 can be rotated by a slight angle by operating the worm 15. Thereby, the whole holder 3 can be rotated little by little.

  Thus, after the diameter of the cutting blade 4 is finely adjusted by slightly rotating the shank 5 by the worm gear, the holder 3 can be assembled and fixed to the tool body 2 by tightening the clamp screw 16. Therefore, after performing normal drilling, fine adjustment of the cutting edge 4 as described above enables finishing drilling with the same tool, improving the workability of drilling. be able to.

  Furthermore, during the fine adjustment, markings 18 and 19 are provided on the front surfaces of the flange portion 6 of the tool body 2 and the flange 11 of the holder 3 so as to display the rotation angle of the holder 3 with respect to the tool body 2. When making fine adjustments with the worm gear, the amount of protrusion in the radial direction as the position of the cutting blade 4 can be visually confirmed in spite of fine adjustment by using both markings as a guideline. Workability increases.

5 and 6 show a diameter-adjustable drilling tool according to a second embodiment of the present invention.
The diameter-adjustable drilling tool 1 is different from the first embodiment in that an adjustment screw 30 provided in the tool body 2 and a notch 32 provided in the shank 5 of the holder 3 are provided.
That is, as shown in FIG. 6, the adjustment screw 30 is screwed into a screw hole 31 formed in the outer peripheral portion of the flange portion 6 of the tool body 2, and the tip thereof is provided so as to face the shank 5. ing. On the other hand, as shown in FIG. 6, the notch 32 is provided with a contact surface 33 formed linearly in a direction substantially parallel to the diameter from the outer peripheral side to the taper portion 10 of the shank 5. The tip of the adjusting screw 30 is arranged in this space by inclining and cutting away from the inner end of the taper portion 10 toward the outside of the taper portion 10 in a slightly lower right state.

  Then, when the adjustment screw 30 is rotated and the adjustment screw 30 presses the contact surface 33 of the notch 32 provided in the taper portion 10 with the clamp screw 16 loosened, the taper portion 10 changes its axis P. The cutting edge 4 is rotated in the fitting hole 12 of the tool main body 2 as the center, and the cutting edge of the cutting edge 4 is brought into contact with the holder 3 based on the distance L between the central axis O of the tool main body 2 and the axis P of the holder 3. Since the tip portion is gradually expanded in the radial direction, the cutting edge of the cutting edge 4 is adjusted in a minute amount.

Therefore, according to this diameter-adjustable drilling tool 1, the cutting edge 4 has a cutting edge by rotating the shank 5 around the axis P in the tool body 2 with the adjusting screw 30 screwed into the tool body 2. Can be finely adjusted in the radial direction, fine adjustment of the cutting blade 4 can be performed satisfactorily, and basically the same effects as those of the first embodiment can be obtained.
Moreover, the adjustment screw 30 is considerably thinner than the diameter of the shank 4 and the taper portion 10 and its lead and screw pitch are very small. By slightly moving forward, the shank 5 can be rotated little by little. Therefore, in general, in the case of an eccentric amount of 0.1 mm, it can be adjusted to about 0.2 mm, but in this embodiment, it is adjusted with a subtle amount of eccentricity over a range of 0.01 to 0.5 mm. The effect which can be done is acquired.

  In the above embodiment, an example in which a tool body attached to a machine tool and a holder fixed to the tool body are provided to configure a diameter-adjustable drilling tool is shown. It is not limited to the examples shown. In particular, as the cutting edge provided at the tip of the holder, an example in which the cutting edge is configured by replacing the inner tip and the outer tip in an exchangeable manner has been shown. By applying to what is provided directly, the same effect can be obtained, and is not limited to the illustrated example.

  Since the present invention can securely fix the holder to the tool body with a simple configuration and structure in the diameter-adjustable drilling tool, and can avoid an increase in size, the present invention can be used industrially. Is recognized.

1 is an overall view showing a diameter-adjustable drilling tool according to a first embodiment of the present invention. It is the side view seen from the left side of FIG. It is an expanded sectional view of the AA line of FIG. It is an enlarged view of the BB line of FIG. It is a general view which shows the diameter adjustment type | formula drilling tool which concerns on 2nd Embodiment of this invention. FIG. 6 is an enlarged cross-sectional view corresponding to line CC in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Diameter adjustment type | formula drilling tool 2 Tool main body 3 Holder 4 Cutting blade 5 Shank 10 Tapered part 10a Inclined surface 16 Clamp screw

Claims (1)

A tool body provided with a shank mounting hole eccentrically with the central axis on the front end surface, and a shank provided with a cutting edge at the front end and extending in the axial direction at the rear end, A holder that fits and is fixed to the shank mounting hole, and adjusts the radial position of the cutting blade based on the eccentric distance between the center axis of the tool body and the axis of the holder. In diameter-adjustable drilling tools,
In the middle of the holder in the axial direction, a taper portion having a tapered inclined surface along the axial direction is formed on the outer periphery, and a fitting hole for fitting the taper is formed in the tool body. ,
When the shank of the holder is fitted into the shank mounting hole of the tool body, and when the tapered portion is fitted into the fitting hole, the tapered portion is fixed to the tool body with a clamp screw. Diameter-adjustable drilling tool.

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