JPH09108914A - Cutting rotary tool and its holder structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To vibrate an edge part by a twist of an elastic part, and enhance cutting efficiency by vibration by forming the elastic part to give vibration by a twist to the edge part between a shank and the edge part. SOLUTION: Plural groove-shaped recessed places 4 extending in the axial direction are respectively formed at equal intervals in parallel to each other on an outer peripheral surface between an edge part 2 and a shank 3. A part forming the recessed parts 4 becomes an elastic part. In this cutting rotary tool 1, when the edge part receives a load from a work when the work is cut in rotation, the elastic part is twisted, and when the load reduces, this twist returns. That is, since the load changes when chips are continuously and repeatedly compressed and sheared in stages in a prescribed length, the edge part 2 vibrates in the rotational direction, and cutting efficiency is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary tool for cutting such as a drill blade that vibrates by itself with rotation and a holder structure for holding the rotary tool for cutting.

[0002]

2. Description of the Related Art Conventionally, it has been known that when a workpiece is cut with a rotary cutting tool such as a drill blade, the cutting efficiency is improved by vibrating the rotary cutting tool.

As a means for vibrating the cutting rotary tool, a method is provided in which a cutting device to which the cutting rotary tool is attached is provided with an oscillating mechanism so as to forcibly vibrate the cutting rotary tool. An input shaft driven by a main shaft, such as the cutting device disclosed in Japanese Patent Laid-Open No. 4-210306,
There is a method in which a vibrating unit including a movable oscillator and a spring is provided between an output shaft having a grip portion of a cutting rotary tool and the output shaft and the cutting rotary tool are vibrated in accordance with the rotation of the input shaft. .

[0004]

By the way, a cutting device provided with an oscillating mechanism is large and expensive because the oscillating mechanism is generally large and expensive.

Further, since the cutting device having the vibration unit provided between the input shaft and the output shaft has a complicated structure, the assembly cost is high. Therefore, the cutting device is not as expensive as the cutting device having the vibration oscillating mechanism, but the price is still low. high.

Therefore, in order to vibrate the rotary cutting tool and improve the cutting efficiency, there is a problem that the expensive cutting device as described above must be purchased.

Therefore, the present invention is intended to provide a rotary tool for cutting that vibrates during rotary cutting even if it is attached to a cutting device having no special mechanism or unit.

[0008]

In order to solve the above-mentioned problems, the present invention provides a rotary tool for cutting by forming an elastic portion between the shank and the blade portion, which gives vibration to the blade portion due to twisting. Configured. The elastic portion of the cutting rotary tool may be formed by providing a plurality of recesses on the outer peripheral surface.

Further, the rotary tool for cutting may be provided with a hollow portion extending from the end on the shank side to the tip of the elastic portion, or the recess may be formed in a direction inclined with respect to the axis. May be.

Further, a sleeve covering the elastic portion may be slidably covered on the outer peripheral surface, and one end of the covered sleeve may be fixed to the outer peripheral surface.

In order to hold such a rotary tool for cutting, an input shaft which is rotationally driven by a main shaft of a cutting device, and an output shaft which is connected to the input shaft and holds a shank of the rotary tool for cutting. A cylindrical frame provided on the output shaft or the input shaft to surround the elastic portion of the cutting rotary tool, and a pressing member attached to the cylindrical frame for pressing the outer peripheral surface of the cutting rotary tool. Then, by inserting the tip of the pressing member into the recess formed in the cutting rotary tool, the holder structure is configured so as to limit the amount of twist of the cutting rotary tool. Further, a tubular member may be attached inside the tubular frame of this holder structure.

In the rotary tool for cutting according to the present invention, when the blade portion is pressed against the work piece while the shank is gripped and rotationally driven, the elastic portion is twisted by the load received from the work piece to the blade portion. The blade vibrates in the direction of rotation during rotary cutting.

Further, when the hollow portion as described above is provided, the elastic portion is more twisted, so that the blade portion vibrates more.

When the recess is formed in a direction inclined with respect to the shaft center, the elastic portion is twisted and extends in the shaft center direction during rotary cutting, so that the blade portion vibrates in the rotation direction and the shaft center direction. To do.

Further, when a sleeve covering the elastic portion is slidably covered on the outer peripheral surface of the cutting rotary tool and only one end of the sleeve is fixed to the outer peripheral surface, the bending rigidity of the elastic portion in the axial direction is improved. At the same time, the elastic portion can be twisted during rotary cutting with the sleeve covered.

In the holder structure as described above, the amount of twist of the cutting rotary tool can be limited by inserting the tip of the pressing member into the recess of the outer peripheral surface of the cutting rotary tool or the cylindrical member. The amplitude of the torsional vibration of the blade is constant.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of a rotary tool for cutting and its holder according to the present invention will be described with reference to the accompanying drawings.

A rotary tool for cutting 1 shown in FIG.
Is a drill blade used for drilling.

In this rotary tool for cutting 1, a blade portion 2 having two cutting edges is formed at the tip end portion by two spiral grooves, and a shank 3 which is held by a holder of a cutting device is formed at the rear end portion. ing.

On the outer peripheral surface between the blade portion 2 and the shank 3, as shown in FIG. 1A, a plurality of groove-shaped recesses 4 extending in the axial direction are formed in parallel at equal intervals. Has been done.

When the shank 3 is attached to the holder of the cutting device and rotated, and the blade 2 is pressed against the workpiece to perform rotary cutting, the rotary tool 1 for cutting twists at the portion where the recess 4 is formed. So that the depth is set. Therefore, the part where the recess 4 is formed becomes the elastic part.

As described above, in the rotary tool for cutting 1, when the blade 2 receives a load from the work when the work is rotationally cut, the elastic portion is twisted, and when the load is light, the twist is returned, that is, Since the load fluctuates as the chips are repeatedly compressed and sheared in a predetermined length step by step, the blade 2 vibrates in the rotation direction. Even when mounted on the machine, self-excited vibration improves cutting efficiency.

Further, as shown in FIG. 1 (b), a circular recess may be provided on the outer peripheral surface between the blade portion 2 and the shank 3 of the rotary cutting tool 5 to form the recess 6. .

The recesses 6 form rows arranged at equal intervals in the axial direction, and the rows of the recesses 6 are parallel to each other in the circumferential direction of the rotary tool for cutting 5 at equal intervals. It is arranged.

The rotary tool for cutting 7 shown in FIG. 1 (c) is provided with a hollow portion 8 extending from the end on the shank 3 side to the tip of the groove-shaped recess 4. The recess 4 is a through hole reaching the hollow portion 8.

The hollow portion 8 causes the rotary tool 7 for cutting to be twisted more greatly in the elastic portion, so that the rotary tool 7 vibrates more during rotary cutting of the work, thereby improving the cutting efficiency.

A rotary tool for cutting 9 shown in FIG. 1 (d).
Is a groove-shaped recess 10 extending in a direction inclined with respect to the axis.
Are formed.

The recess 10 is formed so as to be approximately parallel to the direction of the twist groove of the blade 2.

In this rotary tool 9 for cutting, since the recess 10 is formed in the so-called twist direction, when the blade 2 receives a load from the work during rotary cutting, the elastic portion is twisted and the axial direction. Extend to.

That is, in the rotary tool 9 for cutting, the elastic portion is twisted and displaced in the rotational direction and the axial direction during rotational cutting of the work, so that the blade portion 2 vibrates in the rotational direction and the axial direction. As a result, the cutting efficiency is further improved.

Further, as shown in FIG. 2A, a large number of circular depressions may be arranged on the outer peripheral surface of the cutting rotary tool 11 in a direction inclined with respect to the axial direction.

As shown in FIGS. 2 (b) and 2 (c), when the hollow parts 8 as described above are provided in the rotary cutting tools 12 and 13, the elastic parts are apt to be twisted, and the rotary parts during rotary cutting are rotated. Since the vibration in the axial direction and the axial direction becomes larger, the cutting efficiency is further improved.

The rotary cutting tool 14 shown in FIG. 2 (d).
The sleeve 15 is slidably covered on the elastic portion.

This sleeve 15 is a rotary tool 14 for cutting.
Is formed to have a length that completely covers the recess 10 and enhances the rigidity of the rotary cutting tool 14 against bending in the axial direction. Further, the sleeve 15 has a pair of upper and lower pin insertion holes 15a which are formed at the rear end of the sleeve 15 and which match the vertical through holes formed in the rear of the recess 10 of the rotary cutting tool 14.

This pin insertion hole 15a and the rotary tool for cutting 1
One stop pin 15b is driven into the through hole 4 and the stop pin 15b fixes the sleeve 15 to the outer peripheral surface of the cutting rotary tool 14.

As described above, since only the rear end of the sleeve 15 is fixed to the cutting rotary tool 14 by the retaining pin 15b, the elastic portion of the cutting rotary tool 14 is twisted during rotary cutting. In this case, since the outer peripheral surface slides with respect to the inner peripheral surface of the sleeve 15, it is possible to vibrate in the rotational direction and the axial direction with the sleeve 15 covered.

FIG. 3 shows the rotary tools for cutting 1, 5, 7,
The holder structure for holding 9, 11, 12, 13, 14 is shown.

The holder 16 shown in FIG. 3 includes an input shaft 18 which is rotationally driven by a main shaft of a cutting device, a collet chuck 19 which is fixed to the tip of the input shaft 18 and serves as an output shaft, and the input shaft. The cylindrical frame 20 extends forward from the outer peripheral surface of 18 and surrounds the collet chuck 19.

The collet chuck 19 is formed so that it can hold the shank 3 of the rotary cutting tool 9.

The tubular frame 20 has a rear end portion which is the input shaft 18.
Is screwed to the outer peripheral surface of the collet chuck 19, and the tip portion is located further ahead of the tip of the collet chuck 19. The tip end of the tubular frame 20 projects inward and surrounds the recess 10 of the rotary cutting tool 9 held by the collet chuck 19 at a predetermined interval.

A rotary tool 9 for cutting held by a collet chuck 19 and a tip end of the cylindrical frame 20 projecting inward.
A cylindrical bush 21 is fitted between and.

The bush 21 protrudes forward and backward from the tubular frame 20 in a fitted state, and a protruding stopper 22 is formed at a rear end portion of the bush 21 to prevent the stopper 21 from protruding outward. A screw hole 23 that penetrates in the radial direction is formed in the portion.

The rotary cutting tool 9 held by the collet chuck 19 is fixed to the bush 21 by being tightened with a set screw 24 screwed into the screw hole 23 of the bush 21.

Further, the bush 21 is formed so that the inner diameter of the portion behind the screw hole 23 is larger than the inner diameter of the front end portion, and the cutting rotary tool 9 is twisted at the elastic portion.

At the tip of the cylindrical frame 20, one screw hole 25 penetrating in the radial direction is provided. A metal ball 26 is movably accommodated in the screw hole 25, and an adjusting screw 27 for pressing the metal ball 26 against the outer peripheral surface of the bush 21 is screwed into the screw hole 25.

Further, a conical recess 28 that partially accommodates the metal ball 26 is formed in the outer peripheral surface portion of the bush 21 pressed by the metal ball 26.

When the adjusting screw 27 is turned and the bush 21 is tightened via the metal ball 26, the bush 21 cannot move in the circumferential direction with respect to the tubular frame 20, so that the elastic portion of the cutting rotary tool 9 is prevented. Since twisting is prevented, rotary cutting without vibration is possible.

Further, the adjusting screw 27 is loosened, and the bush 2
When 1 is properly rattled against the tubular frame 20,
As shown in FIG. 4, since the bush 21 can be moved in the circumferential direction and the cutting rotary tool 9 is twisted by the elastic portion and vibrates appropriately, the user must adjust the tightening amount of the adjusting screw 27. With this, it becomes possible to suppress the vibration to a certain value or less and perform the rotary cutting in a desired vibration condition. Further, since the metal balls 26 roll in the depressions 28, friction is unlikely to occur between the bush 21 and the metal balls 26.

According to this holder structure, vibrations having a constant amplitude are applied to the blade portion 2 of the cutting rotary tool 9,
The rotary cutting becomes stable, and the rotary tool 9 for cutting is damaged by being excessively twisted by the elastic part even if the blade part 2 receives an excessive load due to clogging of chips during rotary cutting. There is no such thing.

The holder 17 shown in FIG. 5 has a collet chuck 19 as compared with the holder 16 shown in FIG.
Instead of providing, set screw 30 on input shaft 29,
The shank 3 of the rotary cutting tool 31 is directly fixed to the input shaft 29, and the outer peripheral surface of the tip of the recess 10 of the rotary cutting tool 31 is adjusted by the adjusting screw 32 and the metal ball 33 without using the bush 21. It is designed to be pressed directly.

This rotary tool 31 for cutting is used for the metal ball 3
A recess 34 that partially accommodates the metal ball 33 is formed in the portion pressed by 3.

Also in this holder structure, the adjusting screw 3
2 makes it possible to adjust the vibration of the rotary cutting tool 31.

[0053]

[Effect] The rotary tool for cutting according to the present invention is configured as described above, so that the elastic portion is twisted and the blade portion vibrates during rotary cutting, so that there is no special vibration mechanism for the cutting device. It is possible to improve the cutting efficiency due to vibration without the provision of. Further, in the holder structure according to the present invention, by inserting the tip of the pressing member into the recess formed on the outer peripheral surface of the rotary tool for tip or the cylindrical member, the magnitude of vibration of the blade portion of the rotary tool for cutting is increased. Therefore, stable rotary cutting can be performed with the vibration degree desired by the user.

Furthermore, since this holder structure can limit the amplitude of the cutting rotary tool, it is possible to prevent damage due to excessive twisting of the elastic portion.

[Brief description of the drawings]

FIG. 1A is a side view showing an embodiment of a cutting rotary tool according to the present invention. FIG. 1B is a side view showing a cutting rotary tool in which an elastic portion is formed by a circular recess. Partially cutaway side view showing the provided rotary tool for cutting (d) Side view showing a rotary tool for cutting with a recess inclined with respect to the axial direction

FIG. 2 (a) is a side view showing a rotary tool for cutting in which circular recesses are arranged in a direction inclined with respect to the axial direction to form an elastic portion. (B) For cutting of FIG. 1 (d) Partially cutaway side view showing a rotary tool for cutting in which a hollow part is provided in a rotary tool (c) Partial cutaway side view showing a rotary tool for cutting in which a hollow part is provided in the rotary tool for cutting shown in FIG. d) Sectional view showing a rotary cutting tool with a sleeve

FIG. 3 is a sectional view showing a rotary tool holder for cutting according to the present invention.

FIG. 4 is a sectional view showing the movement of the bush with respect to the tubular frame.

FIG. 5 is a sectional view showing another embodiment of the cutting rotary tool holder according to the present invention.

[Explanation of symbols]

1,5,7,9,11,12,13,14,31 Rotary tool for cutting 2 Blade part 3 Shank 4, 6, 10 Recess 8 Hollow part 15 Sleeve 15a Pin insertion hole 15b Stop pin 16, 17 Holder 18 , 29 Input shaft 19 Collet chuck 20 Cylindrical frame 21 Bush 22 Stopper 23, 25 Screw hole 24, 30 Set screw 26, 33 Metal ball 27, 32 Adjustment screw 28, 34 Recess

Continued Front Page (72) Inventor Tamada Isoda, 4-11-5 Shinji, Higashinari-ku, Osaka

Claims (7)

[Claims] 1. A rotary tool for cutting, wherein an elastic portion is formed between the shank and the blade portion to give vibration to the blade portion due to twisting. 2. The rotary tool for cutting according to claim 1, wherein the elastic portion is formed by providing a plurality of recesses on an outer peripheral surface thereof. 3. The rotary tool for cutting according to claim 1, wherein a hollow portion is provided from the end on the shank side to the tip of the elastic portion. 4. The rotary tool for cutting according to claim 2, wherein the recess is formed in a direction inclined with respect to the axis. 5. A sleeve for covering the elastic portion is slidably covered on the outer peripheral surface, and one end of the covered sleeve is fixed to the outer peripheral surface. Rotary tool for cutting. 6. An input shaft which is rotationally driven by a main shaft of a cutting device, an output shaft which is connected to the input shaft and holds a shank of a rotary tool for cutting according to claim 1, and the output shaft or the input. A cylindrical frame provided on the shaft and surrounding the elastic portion of the cutting rotary tool, and a pressing member attached to the cylindrical frame for pressing the outer peripheral surface of the cutting rotary tool, the tip of the pressing member. A holder structure for a cutting rotary tool, wherein the amount of twist of the cutting rotary tool is limited by inserting the above into a recess formed in the cutting rotary tool. 7. A tubular member is fitted between the tubular frame and the outer peripheral surface of the cutting rotary tool, and the tubular member is slidably attached to the tubular frame and cut into the tubular member. By providing the cylindrical member with fixing means for fixing the rotary tool for use, forming a recess on the outer peripheral surface of the cylindrical member into which the tip of the pressing member is inserted, and inserting the tip of the pressing member into this recess. A holder structure for a cutting rotary tool, wherein the amount of twist of the cutting rotary tool is limited.