JP3265335B2 - Tool holder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool holder for holding both a drill and a cutting tool other than the drill.

[0002]

2. Description of the Related Art Conventionally, there has been known a tool holder for holding both a drill and a cutting tool other than the drill. The tool holder has a cylindrical shape having an axial through hole, a holder body having at least one cutting tool holding portion on an outer peripheral portion of the through hole, and a drill holding device for holding a drill in the through hole. And As shown in FIG. 14, a drill 204 is fitted into the through hole 202 of the holder main body 200, and the cutting tool holding portion at the tip end of the holder main body 200 is used as a different cutting tool from the drill 204 for chamfering. A chamfering tip 206 with a cutting edge and a counterbore tip 208 with a counterbore cutting edge are held respectively. If the holder body 200 is rotated, the drill 20
4. The chamfering chip 206 and the counterbore chip 208 are rotated. As a result, the pre-drilling, chamfering, and end face cutting are performed simultaneously.

[0003]

However, when drilling is performed by a tool held by a conventional tool holder, there is a problem that the processing accuracy is low. Also,
There was also a problem that the tool life was short. This is because the drill 204 is fixed (side-locked) to the holder body 200 by screwing a side bolt (not shown) into the female screw hole 210 for the side bolt extending in the radial direction. That is, since the drill 204 is fixed to one side of the through hole 202 by the side bolt, the drill 204
And the center axis of the holder main body 200 and the center axis of the main shaft 212 are displaced from each other, and the processing accuracy is reduced. In addition, a radial unbalance force acts on the drill 204 and the tool holder during machining, and vibration is generated.
The life of the entire tool including the drill 204, the chips 206, 208 and the like is shortened, and particularly the life of the drill 204 is shortened. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tool holder having high machining accuracy and a long tool life.

[0004]

The gist of the present invention resides in that a tool holder is (1) formed into a cylindrical shape having an axial through hole, and a tapered inner peripheral surface is formed in a part of the through hole. And (2) a drill gripper having a taper outer peripheral surface corresponding to the taper inner peripheral surface and a straight inner peripheral surface for gripping a drill. (3) a collet moving device that is provided on the holder body , engages with the engaging portion at the rear end of the collet, and moves the collet in the axial direction. Include and move collet
The apparatus includes (i) an outer peripheral surface and an inner peripheral surface of a rear end portion of the collet.
And (ii) a generally cylindrical shape
(A) a second threaded portion to be screwed to the first threaded portion, and (b) a second threaded portion.
Provided inside the rear end of the body,
A rotating tool engaging portion, and an inner peripheral surface of the holder main body.
A core that is held so that it can rotate relatively and cannot move relatively in the axial direction.
Together shall include a cmdlet operating member, said insert
A depth adjusting device (i) disposed inside said collet,
Out of the collet through the slot formed in the peripheral wall of the collet
Part of the holder body at the projecting part.
Female having a female screw hole coaxial with the collet
A screw member; (ii) disposed inside the collet,
While being screwed into the female screw hole, at the rear end, the cylindrical
Engage with a rotating tool inserted through the collet operating member
In the the this <br/> as including a male screw member having a that tool engaging portion. Further, the gist of the invention of claim 2, wherein the collet
A first annular groove with a semicircular cross section is formed on the outer peripheral surface of the
And the first annular surface on the inner peripheral surface of the holder body.
Forming a second annular groove having a symmetrical cross-sectional shape with the groove,
From the first annular groove and the second annular groove
A collet operating member, thereby
Maintained so that it can rotate relative to the body and cannot move relative to the axis.
It is to make. The gist of the invention of claim 3 is that the insertion depth adjusting device is provided inside the collet,
Protrude from the collet through the long hole formed in the peripheral wall of the collet.
The protrusion is engaged with the holder body so as to be relatively movable and non-rotatable in the axial direction at its protruding portion, abuts against the male screw member at a rear end portion, and engages with the drill at a front end portion so as not to rotate relative to the drill. Including matching driving members
It is in having done. The gist of the invention according to claim 4 is that the female screw member is a rod-shaped member fitted into a female screw member fitting hole formed through the peripheral wall of the holder body in the radial direction.

[0005] Here, in the collet, the drill gripping portion and the collet moving device engaging portion may be formed integrally or separately. Also,
They may be formed of the same material or different materials.

[0006]

According to a first aspect of the present invention, there is provided a tool holder including a collet for holding a drill, and a tool holding portion for holding a tool. The drill is held in the drill holding portion at the tip of the collet by the diameter reduction of the collet inside the through hole. Since the collet is reduced in diameter while maintaining coaxiality with the holder main body, there is almost no misalignment of the drill. The cutting tool is held by a cutting tool holding portion provided on the outer peripheral portion of the through hole at the tip of the holder body. The number of blade holders may be one or plural. If the machining is performed by the tool held by the tool holder of the present invention, the pre-drilling with the drill and the machining with a cutting tool different from the drill (for example, chamfering) are simultaneously performed.

The collet moving device for reducing the diameter of the collet is engaged with a collet moving device engaging portion at the rear end of the collet. The collet moving device is the rear end of the collet
First threaded portion formed on one of the outer peripheral surface and inner peripheral surface of the portion
And a second screw portion to be screwed with the first screw portion.
A collet operating member, and a holder main body.
Relative to the inner peripheral surface of the
To be held inside the rear end of the collet operating member.
The rotating tool is engaged with the rotating tool engaging portion provided in
If the collet moves in the axial direction
The diameter is reduced or expanded. The drill is gripped by the diameter reduction, and the grip of the drill is released by the diameter expansion.
Furthermore, in the tool holder according to the first aspect of the present invention,
It is provided in the axial middle part of the collet,
And a female screw member fixed to the main body.
The screw mechanism of the combined male thread member
The insertion depth into the holder body is adjusted.

[0008] In the tool holder according to the second aspect of the present invention,
The first annular groove on the outer peripheral surface of the collet operating member is
Arranged over the second annular groove on the inner peripheral surface of the rudder body
A plurality of balls move in the axial direction while allowing relative rotation between them.
To prevent relative movement of As a result, the collet operating member
Screw mechanism with first and second threaded portions as they rotate
Thereby, the collet is moved in the axial direction. Claim 3
In the tool holder according to the invention, the insertion depth adjusting device
Includes a drive member that transmits the rotation of the holder body to the drill.
The drill is indirectly connected to the drill
Abuts on the holder member and regulates the insertion depth into the holder body.
You.

In the tool holder according to the fourth aspect of the present invention, a rod-shaped member as a female screw member is fitted into a female screw member fitting hole formed through the holder body in the radial direction, and is fixed to the holder body. You. When the collet moving device is provided on the rear end side of the collet, it is difficult to directly screw the male screw member into the holder body while avoiding interference with the collet moving device. When the male screw member is provided inside the collet, how to avoid interference between the collet and the portion of the holder body that holds the male screw member is another problem.

[0010] Assuming that the inner surface of the through hole of the holder body is inside.
Integrally formed with a protrusion protruding toward
By forming a screw hole, the male screw member can be screwed and held,
Also, the collet is provided with an opening to avoid interference with the protrusion.
If possible, it is possible to avoid interference with the collet
However, it is difficult to form a projection. In contrast, the present invention
In such a tool holder, the female screw member of the holder body is fitted.
The rod-shaped member is fitted into the mating hole and held by the holder body.
Since it functions as a part of the
Processing is easier than forming a protrusion integrally with the body
Become. Also, when the male screw member is provided inside the collet,
If the collet is fitted into the holder body,
Material into the female screw member fitting hole and open the collet.
If you protrude into the collet through the mouth,
Can be screwed with a male screw member. The stick
The internal thread member is circular even if its cross section is polygonal.
You may.

[0011]

As described above, if the hole is drilled by the tool held by the tool holder of the present invention, the misalignment hardly occurs in the drill, so that the processing accuracy is improved.
In addition, the effect of extending the life of the drill and the tool provided with a different cutting tool is obtained. Furthermore, the tip of the holder body
Tool holding part and collet moving device engaging part provided in
And interference with the collet moving device can be avoided
You.

[0012]

Preferred Embodiments of the Invention Preferred embodiments of the present invention will be listed below, and explanations relating to each will be given as necessary.

(1) It has a cylindrical shape with an axial through hole.
And has a tapered inner peripheral surface in a part of the through hole.
Holder body with at least one cutting tool holder at the end
And a taper outer peripheral surface corresponding to the taper inner peripheral surface and a drill
Drill gripper having a straight inner peripheral surface for gripping
Collet that has a tip and holds the drill by reducing the diameter
Provided on the inner peripheral side of the rear end of the holder body,
Engage with the engaging part at the rear end of the collet and move the collet
A collet moving device for moving the collet
Tool holder. (2) the tool holder comprises an insertion depth adjustment device for adjusting the insertion depth into the holder main body of the drill (1) term
Tool holder according to. (3) The insertion depth adjusting device comprises: (a) a female screw member fixed to the holder body and having a female screw hole coaxial with the collet; and (b) a male screw member screwed into the female screw hole.
(c) a driving member which is held by the holder main body so as to be relatively movable and non-rotatable in the axial direction, abuts against the male screw member at a rear end portion, and engages the drill at a front end portion so as to be relatively non-rotatable. Tool holder according to (1) or (2) .

(4) The driving member is fitted to the inner peripheral surface of the collet so as to be relatively movable in the axial direction, and the male screw member is moved relative to the collet in the axial direction inside the collet. The tool holder according to (3) , wherein the tool holder is freely and relatively rotatable. A collet moving device is engaged with the collet at a position rearward of a tip portion for gripping the drill. According to this aspect, it is easy to dispose the insertion depth adjusting device at an intermediate portion between the drill gripping portion at the front end portion of the collet and the engaging portion of the collet moving device at the rear end portion.

For example, when the collet moving device is a so-called rotary type moving device provided with a screw mechanism, the collet moving device cannot be provided near the distal end. This is because the collet moving device interferes with the cutting tool holder provided at the distal end of the holder body. If the collet is lengthened in the axial direction and the collet moving device is mounted near the rear end of the collet, interference with the blade holder can be avoided, and the driving member and the male screw member are provided inside the collet. For example, the insertion depth adjusting device can be easily disposed at an intermediate portion between the drill grip portion and the collet moving device engaging portion. (5) The tool holder according to (4) , wherein the female screw member is a rod-shaped member fitted into a female screw member fitting hole formed through the peripheral wall of the holder body in a radial direction.

(6) Female screw member fitting holes are formed at two places in the peripheral wall of the holder main body which are separated in the diameter direction, and both ends of the rod-like female screw member are fitted into the female screw member fitting holes. The tool holder according to the above mode (5) .
Since the rod-shaped female screw member is supported by the holder main body at both ends thereof, the supporting strength and stability of the female screw member with respect to the holder main body can be improved.

(7) The female screw member is a columnar member, and at the inner peripheral edge of the female screw member fitting hole, a first notch having a semicircular cross section is formed parallel to the fitting hole.
A second notch formed symmetrically with the first notch was formed on the outer peripheral edge of the female screw member, and a columnar rotation preventing member was fitted over the first notch and the second notch. The tool holder according to the above mode (5) or (6) . The rotation preventing member can prevent the female screw member from rotating relative to the holder body. If the cross section of the female screw member fitting hole is made circular, machining of the female screw member and the female screw member fitting hole becomes easy. However, in this case, rotation of the female screw member inside the female screw fitting hole must be prevented.
The female screw member rotates inside the fitting hole, the center axis of the female screw hole is displaced from the center axis of the collet, and the male screw member cannot be properly screwed into the female screw hole, or the insertion depth is properly adjusted. Because it can no longer be done. In addition, a thread may be formed on the inner peripheral surface of the first notch or the second notch, and the rotation preventing member may be a male screw member.

(8) The collet moving device comprises: ( e) a first thread portion formed on one of an outer peripheral surface and an inner peripheral surface of a rear end of the collet; and (f) a generally cylindrical shape. Having a second screw portion screwed to the first screw portion, and a rotary tool engaging portion for engaging the rotary tool, and held by the holder main body so as to be relatively rotatable and relatively immovable in the axial direction. The tool holder according to any one of the above items (1) to (7) , further comprising a collet operating member.

[0019]

(9 ) The holder main body has a head having the cutting tool holding portion on the distal end side, a hollow shaft portion formed with the tapered inner peripheral surface, and the head and the hollow shaft portion can be separated. (1) or including a coupling device for coupling
The tool holder according to any one of the above items (8) . The tapered inner peripheral surface is formed at the head side end of the hollow shaft portion. Therefore, if the head and the hollow shaft can be separated from each other, it becomes easy to taper the through hole.

The through hole in the head can be formed separately from the through hole in the hollow shaft. When the head and the hollow shaft are integrally formed, a through-hole must be formed across both the head and the hollow shaft. On the other hand, in this embodiment, the through hole in the head can be formed separately from the through hole in the hollow shaft portion, so that the degree of freedom of the shape of the through hole increases and the formation of the through hole becomes easy. . For example, it is easy to make the through hole in the head smaller in diameter than the through hole in the hollow shaft portion, and the cutting edge of the cutting tool held by the head and the cutting edge of the drill are in relative positions close to each other in the radial direction. It becomes easy to form.

(10) The coupling device according to item (9) , wherein the coupling device includes an engagement protrusion provided at one of the eccentric positions and an engagement recess provided at the other. Tool holder. By the engagement of the engagement projection and the engagement recess at the eccentric position, the rotational torque can be transmitted to the head satisfactorily. When the head and the hollow shaft portion are fitted by the fitting projection and the fitting recess which are concentric with each other and are brought into contact with end faces perpendicular to the central axis, or with end faces perpendicular to the central axis. In the case of simple contact, the transmission of rotational torque from the hollow shaft portion to the head is due to the frictional force between the two portions, which tends to be insufficient. According to the engagement with the collision portion, the transmission of the rotational torque can be reliably performed.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a tool holder according to the present invention will be described in detail with reference to the drawings. In FIG. 1, reference numeral 10 denotes a holder main body, and reference numeral 12 denotes a collet. The holder main body 10 has a generally cylindrical shape, and includes a head portion 14 and a hollow shaft portion 16. Through holes 18 and 20 are formed in the head 14 and the hollow shaft portion 16, respectively.
The drill 22 is inserted into the inside of 0.

The head 14 is provided with a cutting tool holder 23 at the outer peripheral tip (left end in the figure). The blade holder 23 includes a tip mounting seat 24, a clamp member 25, a bolt 26, and the like. A chamfered tip 28 having a chamfering cutting blade 27 is seated on the tip mounting seat 24 formed on the head 14. The clamp member 25 and the bolt 2
6 and pressed and held. The collet 12 is fitted into the through hole 20 of the hollow shaft portion 16. As shown in FIG. 8, the head 14 and the hollow shaft 16 are connected by a connecting device 38 including bolts 30 and 32, drive pins 34 and 36, and the like.

The through hole 2 formed inside the hollow shaft portion 16
In the case of 0, the tip portion is a tapered portion 40, and the rear side from the tip portion is a straight portion. The tapered portion 40
The diameter of the hollow shaft portion 16 is the largest at the end surface on the head 14 side. The inner diameter of the large diameter portion is larger than the inner diameter of the through hole 18 of the head 14 described above.

The collet 12, as shown in FIGS.
It has a long shape in the axial direction, and the drill gripper 4 at the tip
4 and an engagement portion 46 at the rear end. Middle part 48
Is provided with an insertion depth adjusting device 50 for adjusting a relative position (insertion depth) of the drill 22 with respect to the holder main body 10.

The outer surface of the drill gripper 44 is a tapered outer surface, the inner surface is a straight cylindrical surface, and the outer surface is tapered by the tapered portion 40 of the through hole 20.
Is the same as the taper. On the other hand, the drill gripper 44
Are formed with four slits 56 (see FIGS. 3 and 5) extending in the axial direction from the distal end surface, and the drill gripping portion 44 is moved along the tapered portion 40 so that the drill gripping is performed. The portion 44 can be reduced in diameter and expanded in diameter. If the collet 12 is moved to the rear end side (referred to as rearward), the drill gripper 44 is forcibly reduced in diameter and becomes a state of gripping the drill 22, and if moved to the distal end side (referred to as frontward). , Elastic expansion is allowed,
The state in which the grip of the drill 22 is released is brought about. Collet 12
Is moved by the collet moving device 58.

The collet moving device 58 includes a collet operating member 62 having a cylindrical shape.
Are engaged with the outer peripheral surface of the engaging portion 46 of the collet 12. A male screw portion as a first screw portion is formed on the outer peripheral surface of the engaging portion 46 of the collet 12, whereas a female screw portion as a second screw portion is formed on the inner peripheral surface of the distal end portion of the collet operating member 62. A part is formed. Collet operation member 6
An annular groove 66 having a semicircular cross section is formed on the outer peripheral surface of the rear end of the holder 2, and an annular groove 6 having a symmetrical sectional shape with the annular groove 66 is formed on the inner peripheral surface of the holder body 10.
A plurality of balls (not shown) are provided in an annular space having a circular cross section formed by the annular grooves 66 and 68 in a state of being in close contact with or close to each other. The ball is, as shown in FIG.
Is inserted through a ball insertion hole 70 penetrating in the radial direction, and the ball insertion hole 70 is later closed by a plug.

As a result, the collet operating member 62 is engaged with the holder main body 10 via the ball, so that the collet operating member 62 is relatively rotatable with respect to the holder main body 10 and is not relatively movable in the axial direction. Further, the frictional force generated between the collet operating member 62 and the holder main body 10 is reduced by the ball.

The inside of the rear end of the collet operating member 62
As shown in FIG. 6, the cross-sectional shape is polygonal, and the rotary tool engaging portion 72 is used. If the collet operating member 62 is rotated by engaging the rotary tool with the rotary tool engaging portion 72 (specifically, fitting the rotary tool into a non-rotatable manner), the collet 12
Is moved relative to the holder body 10 in the axial direction.

As shown in FIG. 3, two elongated holes 74 extending in the axial direction are formed on the peripheral wall of the intermediate portion 48 of the collet 12 so as to be spaced apart in the diameter direction. The two long holes 74
Each has a wide portion 76 having a large width and a narrow portion 78 having a small width. Further, a circular female screw member fitting hole 8 is provided in a portion corresponding to the wide portion 76 of the elongated hole 74 of the holder body 10.
0 are formed at two locations in the diametrical direction (only one is shown in FIGS. 1 and 2), and a long hole 82 extending in the axial direction is fitted in the portion corresponding to the narrow portion 78 with a female screw member. Hole 80
Similarly, it is formed in two places.

The insertion depth adjusting device 50 disposed inside the intermediate portion 48 includes a female screw member 84, a male screw member 85, a driving member 86 and the like. The female screw member 84 is a rod-shaped member having a circular cross section, and can be fitted into the above-mentioned two female screw member fitting holes 80 formed in the holder body 10. A female screw hole 88 is formed at an intermediate portion thereof, and both ends are fitted into the female screw member fitting hole 80 via the wide portion 76 of the long hole 74 of the collet 12 and fixed. The center axis of the female screw hole 88 is parallel to the center axis of the collet 12 (coaxial in this embodiment).

Further, at the outer peripheral edge of both ends (one end is also acceptable) of the female screw member 84, a semi-circular first notch 91 is formed, and at the inner peripheral edge of the female screw member fitting hole 80. Is formed with a second notch 92 having a symmetrical sectional shape with the first notch 91. In a state in which the first notch 91 of the female screw member 84 faces the second notch 92 of the holder body 10, the rotation preventing member 94 is fitted across the notches 91 and 92. The rotation preventing member 94 prevents rotation of the female screw member 84 in the female screw member fitting hole 80.
It is also a phase defining member that defines the phase of the female screw member 84. Further, the rotation preventing member 94 is press-fitted across the first notch 91 and the second notch 92, and also functions as an axial movement preventing member for preventing the female screw member 84 from moving in the axial direction. As described above, the female screw member 84 is fixed to the holder main body 10 and functions as a part of the holder main body 10 after fixing.

A male screw member 85 is screwed into the female screw hole 88. As a result, the male screw member 85 is moved to the collet 12
Are disposed so as to be relatively movable in the axial direction with respect to the collet 12 and to be relatively rotatable. Drive member 8
The rear end surface of the drill 6 can be brought into contact with the front end surface of the male screw member 85, and the front end portion can be engaged with a tongue 98 as a torque transmitting portion of the drill 22. The driving member 86 is a generally cylindrical member, and has a rectangular-shaped engaging groove extending along the diameter at the tip end surface thereof, and the tongue 98 of the drill 22 abuts on the bottom surface in this engaging groove. By fitting, the movement limit of the drill 22 toward the drive member 86 is defined, and the relative rotation with respect to the drive member 86 is prevented. The tongue 98 does not contact the bottom surface of the engagement groove, and the rear end surface of the drill 22 where the tongue 98 protrudes comes into contact with the front end surface of the drive member 86 where the engagement groove is formed. , The movement limit of the drill 22 toward the drive member 86 may be defined.

A shaft member fitting hole 100 is formed in the driving member 86 in the diameter direction.
The shaft member 102 is press-fitted to zero. Thereby, the shaft member 102 is fixed to the drive member 86 in a state where both ends protrude from the outer peripheral surface, and both ends thereof pass through the narrow portion 78 of the long hole 74 of the collet 12 and the long hole of the holder body 10. 8
2 is fitted. Therefore, the holder body 10
Is rotated with the rotation of the main shaft 106 of the machine tool, the rotation torque is transmitted to the drill 22 via the shaft member 102 and the drive member 86. The driving member 86 constitutes a torque transmitting device together with the shaft member 102 and the elongated hole 82.

The narrow portion 7 of the elongated hole 74 of the collet 12 described above.
Since the width of the shaft member 8 is only slightly larger than the outer diameter of the shaft member 102, the shaft member 102 also has a function as a detent member for the collet 12. In addition,
The width of the wide portion 76 may be slightly larger than the outer diameter of the female screw member 84 so that the female screw member 84 functions as a rotation preventing member for the collet 12.

At the rear end of the head 14, a fitting hole 110 is formed. The inner diameter of the fitting hole 110 is slightly larger than the outer diameter of the distal end portion of the hollow shaft portion 16, and the head portion 14 and the hollow shaft portion 16 are fitted by fitting the hollow shaft portion 16 into the fitting hole 110. Are positioned coaxially. Also, the head 14
In addition, a not-shown bolt hole for the bolts 30 and 32 and a pin hole for the drive pins 34 and 36 are formed, and a female screw is formed at a position corresponding to the bolt hole on the distal end surface of the hollow shaft portion 16. Pin holes are formed at positions corresponding to the holes and the pin holes, respectively. The pins 34 and 36 are press-fitted into the pin holes of the hollow shaft portion 16 and can be inserted into and detached from the pin holes of the head 14, but can be reversed.

Therefore, when the head 14 and the hollow shaft portion 16 are fitted to each other in the fitting hole 110, the two are aligned with each other. 14 and the hollow shaft portion 16 are aligned, and the head 1 is tightened by tightening bolts 30 and 32.
The axial relative movement between the shaft 4 and the hollow shaft 16 is prevented,
Both are completely fixed. The drive pins 34 and 36
Together with the bolts 30 and 32, the head 14 and the hollow shaft 16 are connected to each other, and also function as a rotation transmitting member that transmits the rotational torque of the hollow shaft 16 to the head 14.

As described above, since the head 14 and the hollow shaft 16 are separable, the chamfering tip 28
Can be simplified in the vicinity of the drill 22. Since the chamfering tip 28 is a cutting tool for chamfering the opening periphery of the hole formed by the drill 22, the inner peripheral end of the cutting blade 27, that is, the end closest to the center axis of the tool holder is formed by the drill 22. It is indispensable to be located on the center axis side from the rotation trajectory of the cylindrical surface circumscribing the outer peripheral edge of the main cutting edge of the drill 22. Therefore, the blade holder 23 for holding the chamfering tip 28 is
It is necessary that the inner diameter of the through-hole 18 of the head 14 be
It is desirable to have a size close to the outer diameter of

On the other hand, since the tapered portion 40 is a portion for holding the drill 22 via the drill gripping portion 44 of the collet 12, the inner diameter is necessarily two times the thickness of the drill gripping portion 44 than the outer diameter of the drill 22. It becomes larger by double. Therefore,
Usually, the inner diameter of the tapered portion 40 is considerably larger than the inner diameter of the through hole 18 of the head portion 14. If the head portion 14 and the hollow shaft portion 16 are formed integrally, the through hole 1
It is necessary to form a tapered portion 40 having a larger inner diameter at the back of 8. The machining of the tapered portion 40 is very difficult, and the collet 12 cannot be fitted to the tapered portion 40 even if it is forcibly machined. Not only can the fitting from the through hole 18 side be impossible, but the tapered portion 40 has a larger diameter nearer the through hole 18 side, and therefore cannot be fitted from the opening on the opposite side.

After all, when the head 14 and the hollow shaft portion 16 are integrally formed, the inner diameter of the through hole 18 is made larger than the inner diameter of the tapered portion 40 so that the collet 12 is fitted to the tapered portion 40. There is no other way to make it possible. Therefore, it is necessary to take measures such as attaching the chip holding member to the head 14 in a state of protruding inward and holding the chamfered chip 28 on the chip holding member. Inevitably becomes complicated. On the other hand, in the present embodiment, since the inner diameter of the through hole 18 can be made smaller than the inner diameter of the tapered portion 40, the chamfering tip 28 can be directly held by the blade holder 23 formed near the through hole 18. The configuration can be simplified.
The chamfering tip 28 is attached to the cutting tool holder 23 by the clamp member 2.
4 and the clamp bolt 25 fix it removably.

In this embodiment, as shown in FIG.
The inner peripheral end of the chamfering cutting edge 27 is located closer to the center axis than the rotation locus of the outer peripheral end of the main cutting edge of the drill 22. However, since the shank of the drill 22 is thinner than the rotation locus of the inner peripheral end of the chamfering cutting blade 27, the drill 22 can be attached to the tool holder without interfering with the chamfering tip 28.

As shown in FIG. 7, engagement projections 120 are formed on the outer peripheral surface of the holder main body 10 at two positions separated in the diametrical direction. When the holder main body 10 is fitted into the main shaft hole 121 formed in the main shaft 106 with a certain relative phase, the engaging protrusion 120 is fitted into an engaging notch formed in the axial direction from the end surface of the main shaft 106, When the main body 10 is rotated by a predetermined angle, the main body 10 is engaged with an engagement groove formed on the inner peripheral surface of the main shaft, thereby preventing the holder main body 10 from separating from the main shaft 106.

A flange 122 is formed on the outer peripheral surface of the holder main body 10 so as to extend radially outward and can abut on the end surface of the main shaft 106.
The engagement notches 124 are formed at two places separated in the diametric direction. As shown in FIG. 7, the engagement notch 124 is formed at a phase different from that of the engagement protrusion 120 by 90 degrees.

A switch collar 126 is fitted to a portion of the holder body 10 that is closer to the tip than the flange 122. Engagement projections 128 are respectively formed at two positions diametrically separated from each other on the main shaft side end surface of the switch collar 126, and are fitted into the engagement notches 124. The switch collar 126 is urged by a spring 132 disposed between the switch collar 126 and a spring retainer 130 disposed on the outer peripheral surface of the holder body 10 in a direction in which the switch collar 126 contacts the flange 122.

When the holder main body 10 is attached to the main shaft 106, the engagement protrusion 128 of the switch collar 126
Engages over the engagement notch 124 of the holder body 10 and the engagement notch allowing the engagement of the engagement protrusion 120 of the main shaft 106, thereby preventing relative rotation between the main shaft 12 and the holder main body 10. The rotation of the main shaft 106 is transmitted to the holder body 10. If the switch collar 126 is disengaged from the notch engaged with the main shaft 12 against the urging force of the spring 132, the main shaft 1
Relative rotation between the holder 2 and the holder body 10 is allowed.

Next, the assembling work of the main part of the tool holder will be described. First, the hollow shaft portion 16 separated from the head portion 14
Then, the collet 12 is fitted from the tapered portion 40 side, and the collet moving member 62 is fitted from the opposite side and screwed into the engaging portion 46 of the collet 12. Thereafter, the collet operating member 62
Is attached to the holder body 10 via a ball. next,
The head 14 and the hollow shaft 16 are connected. The hollow shaft portion 16 is fitted into the fitting hole 110 of the head portion 14, and the drive pins 34 and 36 fixed to the hollow shaft portion 16 are fitted into the pin holes of the head portion 14. A bolt 30 is attached to the shaft 16,
Fix by 32.

Subsequently, the insertion depth adjusting device 50 is assembled. The driving member 86 is inserted into the collet 12 from the engaging portion 46 side, and the shaft member 102 is pressed into the driving member 86 through the elongated holes 82 and 74. The female screw member 84 is inserted into the female screw member fitting hole 8.
0 and the wide portion 76, and the male screw member 85 is screwed into the female screw hole 88 of the same. The rotation preventing member 94 is press-fitted across the first and second notches 91 and 92, and the female screw member 86 is fixed to the holder body 10. Since the assembling work of the other parts is obvious, the description is omitted.

After the assembly is completed, the drill 22 is connected to the holder body 10.
Then, the tongue 98 is inserted into the collet 12 from the head 14 side, and the tongue 98 is engaged with the engagement groove of the drive member 86 inside the collet 12. As a result, the driving member 86 and the drill 22 cannot rotate relative to each other. In this state, the insertion depth of the drill 22 is adjusted by rotating the male screw member 85, the rotating tool is engaged with the rotating tool engaging portion 72 of the collet operating member 62, and the collet operation is performed in the direction of retracting the collet 12. When the member 62 is rotated, the diameter of the drill gripping portion 44 is reduced by the tapered portion 40, and the drill 22 is gripped.

When the tool holder 10 holding the drill 22 in this manner is mounted on the main shaft 106, first, the phase of the engagement projection 120 of the holder main body 10 and the engagement notch of the main shaft 106 are matched. To be inserted into the main shaft 106. In this state, the engagement protrusion 12 of the switch collar 126 is
8 is 90 degrees out of phase with the engagement notch of the main shaft 106, so that it comes into contact with the end surface of the main shaft 106 and
Is moved toward the distal end of the holder body 10 against the urging force of the spring 132.

When the holder main body 10 is inserted into the main shaft hole 121 until the flange 122 abuts on the end surface of the main shaft 106, the axial position of the engaging protrusion 120 and the engaging groove formed on the inner peripheral surface of the main shaft 106 is changed. Match, the holder body 10
And the main shaft 106 are relatively rotated to engage the engagement protrusion 120 with the engagement groove. Due to this engagement and the contact of the flange 122 with the end face of the main shaft, the holder main body 10 cannot move in the axial direction with respect to the main shaft 106. Holder body 10 and spindle 10
6 is rotated by 90 degrees relative to the main shaft 1.
06, is fitted into the engagement notch by the urging force of the spring 132, and the holder body 10 and the main shaft 106
This is a state in which relative rotation with is prevented.

When processing a workpiece, the spindle 106
The holder body 10 and the drill 2
2 is rotated and advanced. The hole is machined by the drill 22, and then the opening edge of the hole is chamfered by the chamfering cutting blade 27.

During machining, the drill 22 is accurately held on the center axis of the tool holder by the collet 12, so that misalignment can be avoided and machining accuracy can be improved. Further, since a part of the main cutting edge of the drill 22 and a part of the chamfering cutting edge 27 overlap in the radial direction, the drill 2
The chamfering of the opening edge of the hole processed by 2 is performed without any trouble by the chamfering cutting blade 26.

When replacing the drill 22, the tool holder is removed from the main shaft 106, the collet 12 is expanded by the rotation of the collet operating member 62, and the drill 22 is removed. The next drill 22 is inserted into the through holes 18 and 20 to reduce the diameter of the collet 12. When adjusting the insertion depth of the drill 22, the male screw member 85 may be rotated.

Next, a method of manufacturing the collet 12 used in the above embodiment will be briefly described with reference to FIGS. The cylindrical member 140 shown in FIG. 9 is manufactured. The cylindrical member 140 is provided with a neck 142 and a head 144 in front of the drill grip 44 of the collet 12. In this state, as shown in FIG. 10, the drill gripper 44 is moved from the neck 142 by a circular cutter (not shown).
, Four slits 146 are formed. Before or after the formation of the slit 146, the elongated hole 74 is formed. Thereafter, if the neck 142 and the head 144 are cut off, the collet 12 is obtained. Slit 146 with circular cutter
Is formed, a neck 142 and a head 144 are provided in order to prevent the opening end of the drill gripper 44 from expanding.

In the above embodiment, the collet 1
2 includes a drill gripping portion 44, an intermediate portion 48, and an engaging portion 46.
Was formed integrally from the same material,
These may be separately formed of different materials, fixed and integrated. Since the diameter of the drill grip portion 44 is repeatedly reduced and increased, it must be made of a material having high flexibility and high strength. As such, these materials are generally expensive. However, since the intermediate portion 48 and the engaging portion 46 do not need to be elastically deformed, ordinary steel materials may be used.

In the above embodiment, the collet operating member 62 is screwed to the outer peripheral surface of the collet 12, but may be screwed to the inner peripheral surface. As shown in FIG. 12, the collet operating member 150 is a stepped cylinder having a small diameter portion 152 and a large diameter portion 154, and the large diameter portion 154.
In the above, as in the case of the above embodiment, the holder body 10 is connected via a ball, and the outer peripheral surface of the small diameter portion 152 is screwed with the inner peripheral surface of the collet 156. In this case, a male screw portion is formed on the collet operating member 150, and a female screw portion is formed on the inner peripheral surface of the collet 156. By rotating the collet operating member 150, the collet 156 is moved in the axial direction.

It is also possible to form a male screw portion and a female screw portion on the surfaces where the collet operating members 62 and 150 and the holder body 10 are fitted to each other, and connect them by screwing.
Collet 12, 156 of collet operating member 62, 150
If the screw pitch of the screw portion of the collet operating member 6 and the screw pitch of the screw portion of the screw portion with the holder body 10 are different from each other, or if the screw directions of both screw portions are opposite to each other, the collet operating member 6
2,150 rotational motion can be converted into axial relative movement of the collets 12,156 with respect to the holder body 10.

Further, in the above embodiment, the female screw member 84, which is a component of the insertion depth adjusting device 50, is fixed to the holder body 10 at both ends, but when the peripheral wall of the holder body 10 is thick, etc. May be fixed only at one end. Further, in the above embodiment, only one blade holder 23 is provided, but two blade holders may be provided as shown in FIG. For example, cutting tool holding portions 170 and 172 are provided, and respectively hold chamfering chips 174 and counterbore chips 176.

Also, if the drill 178 is held by the tool holder, and a cutting tool other than the drill 178 such as the chamfering tip 174 and the counterbore tip 176 is attached to the tool holder, the shank is made thinner like the drill 22. There is no need to use a general purpose drill. The inner peripheral end of the chamfering tip 174, the counterbore tip 176, etc. should be located in the chip removing groove of the drill 178. Even if only one tool other than the drill is provided, or even if two tools are provided, they are not provided at positions spaced apart in the diameter direction. For example, the drill is provided at two places with a phase difference of 90 degrees, and the drill is used as a holder. A general-purpose drill can be used even when it is possible to avoid interference between the drill shank and the cutting tool by slightly inclining the main body. After the drill shank has passed the cutting tool, interference with the cutting tool is avoided by the groove of the drill.

Further, if the tip mounting seat 24 is formed on the inner diameter side of the cutting tool holding portion 23, it can be mounted so that the chamfered tip 28 is located in the groove of the drill 22. In that case, the distance between the cutting edge of the drill 22 and the cutting edge 27 of the chamfering tip 28 in the relation direction can be reduced.

Although not specifically exemplified, the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief description of the drawings]

FIG. 1 is a front view showing a cross section of a part of a tool holder according to an embodiment of the present invention.

FIG. 2 is a plan view of a holder main body which is a component of the tool holder.

FIG. 3 is a plan view of a collet which is another component of the tool holder.

FIG. 4 is a front sectional view of the collet.

FIG. 5 is a left side view of the collet.

FIG. 6 is a right side view of the tool holder.

FIG. 7 is a sectional view of the tool holder taken along line VIII-VIII in FIG. 1;

FIG. 8 is a left side view of the tool holder.

FIG. 9 is a cross-sectional view of a cylindrical member that is a material of the collet.

FIG. 10 is an explanatory view showing a state in which a slit is formed in the cylindrical member.

FIG. 11 is a plan view of the cylindrical member.

FIG. 12 is a sectional view of a collet moving device for a tool holder according to another embodiment of the present invention.

FIG. 13 is a front view showing a part of a tool holder according to still another embodiment in section.

FIG. 14 is a front view showing a cross section of a part of a conventional tool holder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Holder main body 12 Collet 23 Cutting tool holding part 34, 36 Drive pin 40 Taper part 44 Drill gripping part 46 Engaging part 48 Intermediate part 58 Collet moving device 62 Collet operating member 72 Tool engaging part

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Manabu Kiji 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Mitsuhiro Shiota 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Takesasa Sasamori 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Tahiro Takasaki 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (56) References Real 60-183104 (JP, U) Actually open 64-30105 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23B 31/00-31/20 B23Q 3/12

Claims (4)

(57) [Claims] 1. A holder body having a cylindrical shape with an axial through hole, a tapered inner peripheral surface in a part of the through hole, and at least one cutting tool holding portion at a tip end; A collet for gripping the drill by reducing the diameter, having a drill gripper having a taper outer peripheral surface corresponding to the taper inner peripheral surface and a straight inner peripheral surface for gripping the drill at a distal end portion , provided on the holder body, A collet moving device that engages with an engaging portion at a rear end of the collet and moves the collet in an axial direction; and the engagement with the drill gripping portion of the collet.
The holder body of the drill, provided at an intermediate portion with the part
An insertion depth adjustment device for adjusting the insertion depth into the
The collet moving device is formed on one of an outer peripheral surface and an inner peripheral surface of a rear end of the collet.
The first threaded part, and a second thread that is generally cylindrical and (a) is screwed into the first threaded part
And (b) the rear end of the rotating tool
And a rotary tool engaging portion for engaging the
Relative rotation to the inner peripheral surface of the main body and no relative movement in the axial direction.
A collet operating member held in the
An adjusting device is disposed inside the collet, and is provided on a peripheral wall of the collet.
A protrusion protruding outside the collet from the formed slot
Protruding part, fixed to the holder body at the protruding part
And a female screw portion having a female screw hole coaxial with the collet.
Material, which is disposed inside the collet and is screwed into the female screw hole.
And at the rear end, the cylindrical collet operating member
Tool engaging part that engages with the rotating tool inserted through
And a male screw member . 2. A cross-section of the outer peripheral surface of the collet operating member is half.
A circular first annular groove is formed and the holder
Has a symmetrical cross-sectional shape on the inner peripheral surface of the body with its first annular groove
A second annular groove is formed and straddles the first annular groove and the second annular groove.
Therefore, several balls double is disposed, whereby, before
Whether the collet operating member can rotate relative to the holder body
2. The motor according to claim 1, wherein the shaft is held so as not to be relatively movable in the axial direction.
Tool holder. 3. The collet according to claim 1, wherein said insertion depth adjusting device is provided with
Elongated hole arranged inside and formed on the peripheral wall of the collet
From the collet to the outside of the collet.
The holder body brought axially together relatively movable and relatively unrotatably engaged Te abutting said male screw member at the rear end, comprising a drive member non-rotatably engage the drill at the tip claims Item 3. The tool holder according to item 1 or 2 . Wherein said internally threaded member, to one of the claims 1 a fitted rod-like member into the female screw member fitting hole formed through the radially peripheral wall of the holder body 3 <br The tool holder described in />.