JP2000126911A - Part clamping device of spindle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily replace a member in a short time when the member such as a collet is broken. SOLUTION: Members such as a retainer 9, a collet 7, a coil spring 10 and a front draw bar 32 screw-coupled with a draw bar main body 31 are stored in a spindle 1 removably from the front end of the spindle 1. A receiving member such as a removable snap ring 12 supporting the rear end of the retainer 9 is provided between the front end of a pedestal 8 on the inner peripheral face of the spindle 1 and the rear end of a taper hole 2a, thus a broken member such as the collet 7 can be replaced and repaired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle component clamping apparatus for clamping a component such as a tool holder having a tool mounted on a spindle of a machine tool such as a machining center.

[0002]

2. Description of the Related Art Conventionally, a taper shank of a tool holder to which a tool is fitted and fixed is fitted to a front end portion of a spindle of a machine tool, and a locking portion of a pull stud projecting from a rear end of the taper shank is fixed to the spindle. In general, a clamp device is used in which a draw bar fitted to the draw bar is locked via a locking member, and the draw bar is pulled rearward by a number of disc springs. In this clamping device, it is preferable to increase the pulling force of the pull stud by the draw bar. For this reason, when the number of the disc springs is increased, the total length of the spindle becomes longer. But easily fatigued and deteriorated. Therefore, a booster mechanism using multiple balls etc. is provided at the rear of the drawbar,
There is also provided an intensifying mechanism for taper-engaging a protruding portion of the rear end inner peripheral surface of the collet fitted on the front portion of the draw bar and a protruding portion protruding on the outer peripheral surface of the draw bar. However, in the former clamping device in which a booster mechanism is provided at the rear part of the drawbar, even if the retraction force is theoretically increased, the drawbar is actually elongated and has little effect. Further, in the clamp device in which the protrusion on the inner peripheral surface of the rear end of the collet and the protrusion on the outer peripheral surface of the draw bar are taperedly engaged to provide a booster mechanism at the front, the opening and closing of the front and rear of the collet are forcibly performed. Since the collet is not divided into four parts, the collet may be divided into a plurality of parts such as four in the circumferential direction, and the collet may be damaged due to excessive force.

[0003] The applicant of the present invention is disclosed in Japanese Patent Application No. 7-23 / 1993.
No. 4898 (Japanese Unexamined Patent Publication No. Hei 9-76105) was filed earlier, and the one provided with a booster mechanism at the front of the drawbar was improved to forcibly open the front of the collet when the drawbar advanced. In addition, the present invention provides a clamp device for a spindle-mounted component such as a tool holder, which can prevent the collet from being damaged by urging the rear end of the collet in the diameter reducing direction.

As shown in a longitudinal sectional view of FIG. 1 and an exploded perspective view of a main part of FIG. If, circumferentially a plurality of divided pieces ₇₁ open capable of dividing a retractable collet 7 fitted on the front outer periphery of the drawbar 3, fitted into the spindle 1 and disposed on the outer peripheral side of the collet 7 The spindle 1 includes a fixed base 8 and a separator 9, also referred to as a retainer, fixed in the spindle 1 and disposed on the front side of the base 8. A tapered portion 5 of a component such as a tool holder 5 is provided in front of the separator 9 of the spindle 1.
a to form a tapered hole 2a into which the draw bar 3 fits.
The engaging portion 3c and the front end portion disposed in front of the engaging portion 3c protrude from the outer peripheral side of the front portion of the collet 7.
The inner peripheral surface of the _1, and the inner protruding portion 7a after engageable with the engaging portion 3c rear drawbar 3, can be engaged with the engaging projection 3d in the front end of the drawbar 3, the engaging projection 3d is projected an inner protrusion 7d before placed in front of the outer peripheral surface of the respective segments 7 ₁ of the collet 7, to form a rear outer protrusion 7e and the front outer protrusion 7f, after the base 8 A rear end tapered surface 8a and a large inner diameter portion 8b are formed at the end and the front end, respectively, and a positioning plate 9b to be inserted between the divided pieces 7 ₁ of the collet 7 is projected behind the annular body 9a of the separator 9,
The positioning plate 9b is engaged with a notch groove 8c formed along the axial direction at the front end of the pedestal 8, and a pull is formed on the rear end face of the front inner protruding portion 7d of the collet 7 to project rearward of the tapered portion 5a of the component. A component clamping device for a spindle 1 adapted to engage and disengage a front end face of a locking portion 6b having a larger diameter than a shaft portion 6a provided at a rear end of a shaft portion 6a such as a stud 6, and which is attached to a draw bar 3 in a retreating direction. by energizing, formed on the engaging and gradually inclined surface 3c ₁ in which the side is small outer diameter after formation of the engagement portion 3c outer peripheral surface, the rear inner protrusion 7a inner peripheral surface of the respective segments 7 ₁ of the collet 7 of the drawbar 3 condensation of boosting mechanism 11 side there is a gradually inclined surface 7a ₁ comprising a small inner diameter to press after installed, and the positioning plates of the annular body of the separator 9, the side after the formation of the respective segments ₇₁ front end of the collet 7 The outer slope comes into contact with the front slope Each is projected Tsu bets 7 expanding projection, if necessary, through a fluid such as cutting fluid in the draw bar 3 is the fluid that is to be supplied to the part forward from the fluid passageway of the part.

Furthermore, by the urging force of the backward direction of the drawbar 3, and gradually inclined surface which side is small outer diameter after forming the engaging portion 3c the outer peripheral surface of the drawbar 3, the respective segments ₇₁ of the collet 7 A booster mechanism 11 is provided, in which a rear side formed on the inner peripheral surface of the rear inner protruding portion is pressed against a gentle slope having a small inner diameter,
Further, between the positioning plates of the annular body 9a of the separator 9, projecting projections for expanding the collet 7 are formed at the front end of each of the divided pieces 7 ₁ of the collet 7 and the outer inclined surface comes into contact with the inclined surface at the front end which is reduced in diameter at the rear side. is, optionally, passed through a fluid such as cutting fluid in the draw bar 3, and from the fluid passage of the part of the fluid can be supplied to the parts forward, further, the split pieces 7 of the collet 7 optionally ₁ A rear end protruding portion 7g protruding rearward of the rear inner protruding portion 7a and the rear outer protruding portion 7e is formed, and a rear portion of the collet 7 is radially reduced in a concave groove 7h provided on an outer periphery of the rear end protruding portion 7g. The annular coil spring 10 that urges the spring was fitted.

[0006]

However, in the above-described spindle component clamping device, the clamping components including the collet are usually assembled from the rear end side opposite to the tapered portion of the spindle. When the tool holder or tool is fast-clamped and fast-forwarded, the collet or retainer may be damaged.In this case, remove all members of the component clamping device from the rear end of the spindle and replace the damaged member. Since it is necessary, there is a problem that the work is troublesome and the restoration takes a long time. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a spindle component clamping device capable of easily replacing and repairing a damaged member such as a collet in a short time.

[0007]

According to a first aspect of the present invention, a tapered hole is formed at a front end of a spindle of a machine tool, into which a tapered portion of a component such as a tool holder fits, and the tapered hole is inserted into the spindle to advance and retreat. The drawbar is connected to the tip of the drawbar body by detachably screwing the front drawbar to the front end of the drawbar main body, and protruding the engaging portion on the outer peripheral side of the front drawbar and the front end arranged in front of the engaging portion. And a rear inner projection that can be engaged with the rear side of the engaging portion on the inner peripheral surface of each of the divided pieces of the retractable collet that is fitted on the outer peripheral side of the front end of the front draw bar and that can be engaged with the front side portion. A plurality of engaging projections, a rear outer projection and a front outer projection are formed on the outer peripheral surface of each of the divided pieces, and the collet rear part is contracted into a concave groove provided on the outer periphery of the rear end of each of the divided pieces. An annular coil spring that urges in the radial direction is fitted on the outer periphery of the collet. A rear end tapered surface and a large inner diameter portion are respectively formed at a rear end portion and a front end portion of a cylindrical pedestal which is placed and fixed in the spindle, and a rear side of the annular body of a retainer disposed in front of the pedestal in the spindle. The positioning plate to be inserted between each of the divided pieces is protruded, the positioning plate is engaged with a notch groove formed along the axial direction at the front end of the pedestal, and the component is mounted on the rear end face of the inner protruding portion of the collet. After engaging the large diameter front end face of the locking portion provided at the rear end of the shaft portion such as a pull stud projecting rearward of the tapered portion, after forming on the outer peripheral surface of the engaging portion of the draw bar by retreating the draw bar Between the positioning plate of the retainer and a gently inclined surface having a small outside diameter on the side and a gently inclined surface having a small inside diameter on the rear side formed on the inner peripheral surface of the rear inner protruding portion of each of the split pieces of the collet. To each of the divided pieces A collet enlarging projection in which an outer inclined surface is in contact with a front end inclined surface formed at a front end and reduced in diameter to a rear side is projected, so that the retainer, the collet, the coil spring, and the draw bar can be taken in and out from the front end of the spindle. A removable receiving member for supporting the rear end of the retainer is provided between the front end of the pedestal and the rear end of the tapered hole on the inner peripheral surface.

According to a second aspect of the present invention, in the spindle component clamping device according to the first aspect, the receiving member is attached to and detached from an annular groove formed between the front end of the pedestal and the rear end of the tapered hole on the inner peripheral surface of the spindle. It is a snap ring that engages as much as possible.

According to a third aspect of the present invention, in the spindle component clamping device according to the first aspect, the receiving member is formed at an appropriate position between the front end of the pedestal and the rear end of the tapered hole on the inner peripheral surface of the spindle. A receiving ring having a thread formed on its outer periphery is removably fastened to the portion.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. In FIG. 3, reference numeral 1 denotes a spindle of a machine tool such as a machining center. A plurality of disc springs for inserting a draw bar 3 into a through hole 2 formed in the spindle 1 so as to be able to advance and retreat, and urging the draw bar 3 rearward at the rear of the draw bar 3. (Not shown), and a hydraulic cylinder mechanism (not shown) for pushing the draw bar 3 forward is provided at the rear end of the draw bar 3, and the spindle 1 is integrally formed with a spindle head 4 of a machine tool. .

A tapered hole 2a is formed in the large diameter portion 1a at the front end of the spindle 1 through the front end of the through hole 2 and the inside of the annular inner projection 1b. A tool (not shown) is formed in the tapered hole 2a. The taper shank 5b protruding to the rear side of the grip portion 5a of the tool holder 5 to which is mounted is configured to be detachably fitted. The rear surface of the inner projection 1b connected to the rear side of the tapered hole 2a is orthogonal to the axial direction of the spindle 1.

A pull stud 6 protrudes from the tool holder 5 behind the taper shank 5b.
a A locking portion 6b having a larger outer diameter is provided integrally with the rear end, and the locking portion 6b forms a truncated conical portion having a rear end portion having a smaller diameter on the rear side, and a front end surface is formed behind the shaft portion 6a. It protrudes outward from the end at right angles to the axial direction. The position in the axial direction of the spindle 1, the sleeve 1c is fixed in the through hole 2, to form a large-diameter portion 1c ₁ on the front end of the sleeve 1c, the sleeve 1c
In the front through-hole 2, as described later, a draw bar 3 is provided.
The collet 7 is fitted on the outer peripheral side of the front part of the collet 7, and the pedestal 8 is fitted on the outer peripheral side of the collet 7 while being fixed to the inner peripheral surface of the spindle 1. Housed in

[0013] The drawbar 3, the rear portion of the drawbar body 3 ₁ front drawbar 3 ₂ detachably allowed screw fitted a fluid, such drawbar body 3 ₁ and the front drawbar 3 air or the cutting fluid in the center of ₂ formed to be continuous passage 3 _3, the passage 3 ₃ is opened to the distal end of the front drawbar 3 _2, forms a front draw bar 3 ₂ of the tip regular hexagonal operating recess 3 ₄ cross section in and a side annular groove 3a after the outer peripheral surface of the front drawbar 3 _2, to form a short front annular groove 3b than this, provided with an engagement portion 3c therebetween, slightly larger outer diameter than that The front end 3d is provided in front of the front annular groove 3b. The engaging portion 3c and the front end 3d have their front and rear surfaces respectively at 45 ° to the axis.
Inclined to the rear of the outer peripheral surface of the engaging portion 3c at an angle of 10 ° with respect to the axis.
Forming a gradually inclined surface 3c ₁ degree, it is the shapes rear end becomes small outer diameter.

[0014] As the collet 7 shown in FIG. 4, 4 divided by equally circumferentially on the inner peripheral surfaces of the divided piece _71, from the rear side toward the front side, the rear inner protrusion 7a, protruding guide portions 7b, respectively are protruded engaging projection 7c, or the anteromedial protrusions 7d provided axially spaced, on the outer peripheral surface of the respective segments _71, the rear inner protrusion 7a, A rear outer protruding portion 7e and a front outer protruding portion 7f are respectively protruded so as to face the front inner protruding portion 7d in the axial direction.

Further, the front surface of the rear inner protrusion 7a, the front and rear surfaces of the guide protrusion 7b and the engagement protrusion 7c, and the rear outer protrusion 7c.
e, the front and rear surfaces of the front and outside protrusions 7f are inclined at 45 degrees with respect to the axis, respectively, and the front surface of the front and inside protrusion 7d is inclined at 45 degrees with respect to the axis at the front and has a small diameter toward the rear.
Are formed, and the rear surface of the front inner protruding portion 7d is perpendicular to the axial direction.

Then, on the outer peripheral surface of the rear inner protruding portion 7a,
Rear side becomes small inner diameter, a gradually inclined surface 7a ₁ which engages the gradually inclined surface 3c ₁ formed in the engaging portion 3c of the front drawbar 3 constituting the boosting mechanism 11, is inclined about 10 ° to the axis , Has been formed. Furthermore, each divided piece 7 ₁ of the collet 7
A rear end protruding portion 7g is formed on the rear side of the rear inner protruding portion 7a and the rear outer protruding portion 7e, and a concave groove 7h is formed on an outer peripheral surface of the rear end protruding portion 7g.
Is formed.

The collet 7 is formed by cutting the protruding portions 7a to 7g and the concave groove 7h on a cylindrical metal material by cutting or the like, and then cutting the entire length in the axial direction to divide it into four in the circumferential direction. _Have created _one . An annular coil spring 10 having both ends connected to each other is fitted in a concave groove 7h provided in each of the divided pieces 7 ₁ of the collet 7 to urge the rear part of each of the divided pieces 7 _{1 in} the diameter reducing direction. ing.

As shown in FIG. 5, the coil spring 10 has annular connecting portions 10b and 10c which are wound twice at both ends of an elastic metal wire material 10a which is wound tightly in a coil shape, and which project perpendicularly. Hook and coil spring 10
Are connected, and the coil spring 10 is annular.

The pedestal 8 is, as shown in FIGS.
A rear end tapered surface 8a having a large inner diameter on the rear side is formed at the rear end of the metal cylinder, and a large internal diameter portion 8b is formed at the front end of the inner peripheral surface of the cylinder. An inner diameter portion 8b and a rear surface thereof are inclined at 45 ° with respect to the axis, and a notch groove 8 is formed at four positions in the circumferential direction at equal intervals along the axial direction at the front portion of the pedestal 8.
c, and these grooves 8c are opened at the front end of the cylinder. The pedestal 8 is arranged such that its rear end is in contact with the front end of the sleeve 1c of the spindle 1 and its front end is in contact with the inner projection 1b of the spindle 1.

The retainer 9 is made of metal.
As shown in FIG. 4, there is an annular body 9a, and four rectangular positioning plates 9b are radially projected on the rear surface of the annular body 9a at regular intervals, and the outer ends of the positioning plates 9b are outside the annular body 9a. The collet 7 is located at the peripheral edge, and a right-angled triangular collet 7 expanding projection 9c is projected from the rear surface of the annular body 9a. These expanding projections 9c are respectively arranged at the centers between the positioning plates 9b.

The widening projection 9c is formed such that one side of the annular body 9a which is perpendicular to the rear surface periphery of the tapered hole 9d having a large diameter on the front side of the annular body 9a stands upright on the annular body 9a, and the other side sandwiching the right angle is an annular body. 9a
Is fixed to the rear surface, and the oblique side is inclined by about 50 ° with respect to the axis, and an outer inclined surface is formed so that the rear side is lowered, and is disposed at a portion near the center of the annular body 9a. A retainer 9 and a pedestal 8 are provided at the front of the through hole 2 formed in the spindle 1.
And the front end of the positioning plate 9b of the retainer 9 is brought into contact with the rear surface of the inner projection 1b of the spindle 1, and
The positioning plate 9b is engaged with the notch groove 8c of the pedestal 8, and the front end of the pedestal 8 is brought into contact with the rear surface of the inner projection 1b.

[0022] fitted with a collet 7 of a coil spring 10 is mounted within the base 8, by inserting the positioning plate 9b of the retainer 9 between the divided pieces ₇₁ of the collet 7, and the inner projections 1b and the sleeve 1c of the spindle 1 The pedestal 8 and the retainer 9 are fixed to the front part of the spindle 1 by this.

The retainer 9 has an outer diameter capable of being taken in and out from the front end of the spindle 1. An annular groove 2c is formed between the front end of the pedestal 8 on the inner peripheral surface of the spindle 1 and the tapered hole 2a. The snap ring 12 is detachably engaged as a receiving member, and the rear surface of the snap ring 12 supports the front surface of the annular body 9 a of the retainer 9. The portion of the inner peripheral surface of the spindle 1 on the front side of the annular groove 2c is less protruded toward the center. Further, the outer peripheral portion 15a of the lid 15 is supported at the rear end of the spindle 1 and a plurality of bolts 1
6, the outer peripheral portion 15a is fastened to the spindle 1, and the lid 1
5 of the center hole 15b with inserting the drawbar body 3 ₁ slidably sleeve intermediate portion 15c of the lid 15 1
c is supported at the rear end.

Next, the use of the component clamping device for a spindle according to the first embodiment will be described. Wherein actuating the hydraulic cylinder mechanism, the advancing a plurality of the dishes drawbar 3 against the spring force of the spring, as shown in FIG. 6 (1), the front draw bar 3 ₂ of front end 3d of the drawbar 3 in the forward position engaged with the engaging portion 7c of the respective segments 7 ₁ of the collet 7, the front end inclined surface 7i of the rear side of the front inner protrusion 7d of the collet 7 becomes small the spreading projection 9c of the retainer 9 and is supported on the outer inclined surface, the respective segments ₇₁ of the collet 7 is the front end is stopped while maintaining the inclined state of expansion.

In this state, the gripper 5 of the tool holder 5, which is a part, is operated by the operation of an automatic tool changer (not shown).
a, the taper shank 5b is fitted into the taper hole 2a of the spindle 1, and the shaft portion 6a of the pull stud 6 projecting from the rear end of the taper shank 5b is loosely inserted into the annular body 9a of the retainer 9 (FIG. 3). see), the locking portion 6b which is provided at the rear end of the shaft portion 6a is positioned in front inwardly protruded portions 7d behind each divided piece 7 ₁ of the collet 7, the front end portion 3d of the drawbar 3 a rear surface of the locking portion 6b Abut the front of the

After that, the gripper 5a of the tool holder 5 by the automatic tool changer is released, and the operation of the hydraulic cylinder mechanism is released, whereby the drawbar 3 is retracted by the spring force of the plurality of disc springs. As shown in 6 (2),
The front drawbar 3 _second engagement portion 3c rear is supported on the inwardly projecting portion 7a front after the split pieces ₇₁ of the collet 7, and divided pieces ₇₁ of the engaging projecting front drawbar 3 ₂ of front end 3d parts 7c is positioned in the rear, slightly to separate the front drawbar 3 ₂ of front end 3d behind the locking portion 6b of the pull stud 6. The automatic tool changer having released the grip of the grip 5a is returned to the position before the operation.

[0027] Then, when the draw bar 3 continues to retract, this collet 7 is retracted together, as shown in FIG. 6 (3), the respective segments ₇₁ of the front outer protrusion 7f of the collet 7 of the pedestal 8 Retreats rearward of the large inner diameter portion 8b formed at the front end,
The respective segments ₇₁ are front side substantially parallel state from the state where the flared. As the draw bar 3 and the collet 7 continue to retreat, as shown in FIG.
_The rear surface of the front inner protruding portion 7d is the locking portion 6 of the pull stud 6.
b It is in the state of being locked on the front surface.

Further, as the draw bar 3 continues to retreat, the taper shank 5b of the tool holder 5
Of the tool holder 5 by pressing against the peripheral surface of the tapered hole 2a of the tool holder 5.
a when the rear surface contacts the front end surface of the spindle 1 (see FIG. 3).
See), runs onto the rear surface inclined rear face of the front drawbar 3 ₂ of the engaging portion 3c is inclined inner protrusion 7a after forming the divided piece ₇₁ of the collet 7 as shown in FIG. 7 (5).

[0029] Subsequently, as shown in FIG. 7 (6), the front draw bar 3 ₂ split piece ₇₁ after the inner projection of the gradually inclined surface 3c ₁ collet 7 formed on the outer peripheral surface rear portion of the engaging portion 3c Part 7a
Pressed against the gradually inclined surface 7a ₁ formed in the inner peripheral surface, the drawbar 3 is divided piece 7 ₁ of the collet 7 into the outer peripheral surface of the front end portion 3d
Is brought into a retracted state in which the inner peripheral surface of the guide projection 7b is fitted and supported.

When the draw bar 3 is retracted,
FIG. 1 shows a plurality of disc springs that are biased rearward in the axial direction.
0, front drawbar 3_Two Outer periphery of the engaging portion 3c
Slowly inclined surface 3c formed so that the rear side has a small outer diameter on the surface₁
And each divided piece 7 of the collet 7 ₁Inner circumference of rear inner protruding part 7a
Slowly inclined surface 7a formed on the surface so that the rear side has a large inner diameter ₁
Is pressed at a small inclination angle of about 10 °,
As shown by arrow α in FIG._Two Perimeter
Is large, and the engaging portion 3c
Strongly presses the rear inner protruding portion 7a to
5 is clamped.

[0031] Then, by expanding the rear end of the respective segments _71,
The front surfaces of the rear outer protrusions 7e projecting to the outer peripheral side of the rear inner protrusions 7a are pressed against the rear end tapered surface 8a of the pedestal 8 fixed to the spindle 1 at an inclination angle of 45 °. A booster mechanism 11 capable of locking the locking portion 7b of the pull stud 6 by increasing the force several times the spring force of the spring.
It will be exerted at the front drawbar 3 _2. Therefore,
Wherein the pedestal 8 can strongly fix the divided pieces 7 ₁ of the collet 7 and said disc spring also can be used as thin fatigue is small, there is no need to increase the number of disc springs.

In the clamp state of the tool holder 5 described above,
By rotating the spindle 1, machining such as cutting is performed on the workpiece by the tool mounted on the tool holder 5, and each member such as the spindle 1 is returned to the position before machining and stopped, and the tool is automatically changed. In this automatic exchange, the gripper 5a of the tool holder 5 in the clamped state shown in FIG. 3 and FIG. 7 (6) is gripped by operating the automatic tool changer, and the drawbar 3 is advanced by operating the hydraulic cylinder mechanism. Let
As shown in FIG. 8 (7), the front end portion 3d front of the drawbar 3 is supported on the engaging protrusion 7c rear surface of the respective segments 7 ₁ of the collet 7, the rear projecting portion 7e of the respective segments 7 ₁ by the spring force of the annular coil spring 10 fitted into the groove 7h, slightly tilting the respective segments ₇₁ as the rear of the collet 7 becomes small, the front draw bar 3 ₂ of front end 3d front than the collet the inserted front within 7 to form a slight gap between the divided pieces _71.

As the draw bar 3 continues to move forward,
As shown in (8), each divided piece 7₁Front of the engagement projection 7c
Drawbar 3_Two Extruded at the front end 3d of the collet
7 and advance each divided piece 7₁Of the front inside projection 7d
Separate from the front surface of the engaging portion 6b of the pull stud 6, and
7₁The front surface of the rear outer protruding portion 7e is connected to the rear end tapered surface 8 of the base 8.
a, and each divided piece 7₁Front outer butt
The front end inclined surface 7i of the protrusion 7f is expanded by the collet 7 of the retainer 9.
Each split piece 7 is brought into contact with the outer inclined surface of the open projection 9c. ₁Before
The rear surface of the inner protruding portion 7d is in front of the locking portion 6b of the pull stud 6.
Separate from the surface.

Furthermore, by advancing the drawbar 3, as shown in FIG. 9 (9), by extruding the divided pieces _71, the outer protrusion 7e outer peripheral plane of these rear inner peripheral surface of the pedestal 8 is fitted and supported, anterolateral protrusion 7f of respective segments 7 ₁
Sliding the rear surface on the inclined rear surface of the large inner diameter portion 8b of the pedestal 8,
And the spring force of the coil spring 10, by the expansion of the respective segments ₇₁ front end by the outer inclined surface of the expansion projection 9c,
These are inclined so that the front side opens.

[0035] When the front drawbar 3 ₂ is advanced to the advanced end shown in FIG. 8 (10), and the rear end surface of the front drawbar 3 ₂ of the front end face of the front end portion 3d of the pull stud 6 engaging portion 6b contact, anterolateral protrusion 7f outer surface of the respective segments 7 ₁ of the collet 7 is brought into contact with the large-diameter portion 8b inner peripheral surface of the base 8, the inner circumferential surface of the front inner protrusion 7d of the respective segments 7 ₁ Purusutatto 6 on the outer peripheral side of the outer peripheral surface of the locking portion 6b.

Subsequently, the automatic tool changer is operated, the grip 5a of the tool holder 5 is gripped, and the tool holder 5 and the pull stud 6 are pulled out of the front end of the spindle 1 (to the right in FIG. 7). After that, another tool holder held by the automatic tool changer is replaced with the one shown in FIGS. 6 (1) to (3) and FIG.
It is mounted on the spindle 1 by the above-described operations shown in (4) to (6).

In the component clamping device according to the first embodiment of the present invention, the right triangular collet 7 expanding projections 9c are projected from the plate-like annular body 9a of the retainer 9, and the outer inclined surfaces of these expanding projections 9c. When the collet 7 advances, the front end inclined surfaces 7i formed on the front inner protruding portions 7f of the divided pieces 7 ₁ are engaged with each other, so that each divided piece 7 ₁ is moved as shown in FIG. Can be opened reliably.

Further, by fitting the annular coil spring 10 of the groove 7h provided on the rear protrusion 7g of the divided pieces ₇₁ of the collet 7, so as to shrink the rear end portion of the respective segments 7 ₁ since the front side becomes the rear side is a smaller diameter at the forward of the collet 7 can tilt the divided piece ₇₁ so that the large diameter, it is stable expanded operation of the front end of the collet 7, the engagement of the pull stud 6 Attachment / detachment of the stopper 6b to / from the collet 7 can be performed without any trouble.

Usually, the collet 7 and the retainer 9
The clamping member constituted by, for example, is assembled from the rear end side of the spindle 1. However, when the user sets the tool holder 5
If the collet 7 or the like is damaged by fast-forwarding while the tool or the tool is clamped and the tool collides with the workpiece, the tool holder 5 or the tool is removed from the front end side of the spindle 1 and the snap ring 12 as the receiving member is removed. Annular groove 2 of spindle 1
c, then retainer 9, front drawbar 3
_2. After removing the coil spring 10 and the collet 7 from the front end side of the spindle 1, replace the damaged member such as the collet 7 and assemble the removed member into the spindle 1 and put the ring 12 into the annular groove 2c. By engaging,
It can be easily restored in a short time.

[0040] Incidentally, the front draw bar 3 _2, the regular hexagonal operating recess 3 ₄ formed on the tip portion, at least the operation end is fitted with a regular hexagon control rod, draw bar body 3 front draw bar 3 ₂ Pull out from ₁ and front drawbar 3 ₂
With extracts the collet 7 with the coil spring 10 to the front end outside of the spindle 1, then replace the damaged member, front draw bar 3 _2, coil spring 10, the collet 7
The assembly may be tightened by a front draw bar 3 ₂ causes screw fitted into the front end of the drawbar body 3 _1. Further, the spindle part clamping device according to the first embodiment of the present invention includes a fluid passage 3 such as air or cutting fluid in the draw bar 3.
₃ is formed, since the passage 3 ₃ was opened at the front end of the front drawbar 3 _2, blow timely cleaning air from the fluid passage 3 _3, or and supplies the cutting fluid during machining of a workpiece that Can be. In the present invention, air,
Fluid passage 3 ₃ of the cutting fluid may be omitted.

[0041] Figure 11 shows a modification of the receiving member according to the present invention, to form the threaded portion ₃₅ between the base 8 front and tapered hole 2a rear end of the inner peripheral surface of the spindle 1, the screw part 3 ₅ is formed, on the threaded portion _35, fastening detachably a threaded portion 13a provided on the outer periphery of the ring 13, the ring 1
3 supports the positioning plate 9b of the retainer 9 and, if necessary, a rig 13 caused by vibration during processing.
Lock bolt 14 to prevent ring
May be tightened to the screw hole 13b penetrating in the radial direction of the bolt, and the inner end of the bolt 14 may be pressed against the screw portion 13a.

In the present invention, the spring for urging the draw bar forward has a booster mechanism at the front of the draw bar, so that a coil spring may be used instead of a plurality of disc springs.

[0043]

The component to be clamped by the present invention is not limited to the tool holder of the above-described embodiment, and even if it is a tool or a workpiece, the shaft protrudes behind the tapered portion 5a,
What is necessary is just to form a locking part with a larger outer diameter than the shaft part.

[0045]

As described above, the spindle component clamping device according to the first aspect of the present invention provides a retainer, a collet, a coil spring, and a front draw bar by using a taper hole formed at the front end of the spindle to form a tool holder or the like. With the parts removed, it is possible to insert and remove from the front end of the spindle, so that parts such as tool holders are clamped and fed in a short time, and when collets etc. are damaged, replacement or repair of damaged parts is short time Easily.

According to the second aspect of the present invention, since the receiving member for supporting the rear end of the retainer is a snap ring which engages with the annular groove, the ring can be quickly and easily attached and detached. In the described invention, since the receiving member is detachably screwed to the inner peripheral surface of the spindle, the rear end of the retainer can be reliably supported.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a conventional spindle component clamping device.

FIG. 2 is an exploded perspective view of a main part of the component clamping device shown in FIG.

FIG. 3 is a longitudinal sectional view showing a spindle component clamping device according to the first embodiment of the present invention.

FIG. 4 is an exploded perspective view of a main part of the component clamping device shown in FIG.

FIG. 5 is a front view of a coil spring used in the component clamping device shown in FIG. 3;

FIG. 6 is an explanatory view of the component clamping device shown in FIG. 3, wherein (1) to (3) are explanatory views of a clamping operation.

FIG. 7 is an explanatory view of the component clamping device shown in FIG. 3, wherein (4) to (6) are explanatory views of a clamping operation.

FIG. 8 is an explanatory view of the component clamping device shown in FIG. 3, wherein (7) and (8) are explanatory views of a clamp releasing operation.

FIG. 9 is an explanatory view of the component clamping device shown in FIG. 3, wherein (9) and (10) are explanatory views of a clamp releasing operation.

FIG. 10 is an explanatory view of a booster mechanism of the component clamping device shown in FIG. 3;

FIG. 11 is a longitudinal sectional view of a main part showing a spindle component clamping device according to a second embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 spindle 2 through hole 2a taper hole 2c annular groove 3 draw bar 3 ₁ Drawbar body 3 ₂ Front drawbar 3 ₄ Operation recess 3 ₅ Screw part 7 Collet 7 ₁ Divided piece 9 Retainer 9a Annular body 9b Positioning plate 9c Collet 7 Expansion protrusion 10 Coil spring 11 Boost mechanism 12 Snap ring 13 Ring

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuhiro Shimono 1-6-153 Motomachi, Higashi-Osaka-shi, Osaka F-term in Niken Corporation (reference) 3C016 BA08 CA07 FA05 3C032 AA01 AA06 AA13 AA15

Claims (3)

[Claims] 1. A taper hole in which a taper portion of a component such as a tool holder fits is formed at a front end portion of a spindle of a machine tool, and a draw bar which is inserted into the spindle and advances and retracts is provided at a front end portion of a main body of the draw bar. The drawbar is detachably screw-fitted and connected, and the engaging portion and the front end disposed in front of the engaging portion are projected to the outer peripheral side of the front drawbar, and the drawbar is connected to the outer peripheral side of the front end of the front drawbar. A rear-inside protruding portion engageable with the rear side of the engaging portion and an engaging protruding portion engageable with the front side portion are projected on an inner peripheral surface of each of the split pieces of the fitted retractable collet, An annular coil spring that forms a rear outer protrusion and a front outer protrusion on the outer peripheral surface of each split piece and urges the collet rear in the radial direction in a concave groove provided on the rear end outer circumference of each split piece. Fitted, placed on the outer periphery of the collet and fitted and fixed inside the spindle A rear end taper surface and a large inner diameter portion are respectively formed at a rear end portion and a front end portion of the cylindrical pedestal, and positioning is performed between the divided pieces at a rear side of an annular body of a retainer disposed in front of the pedestal in the spindle. Extend the board,
The positioning plate is engaged with a notch groove formed in the front end of the pedestal along the axial direction, and the rear end of a shaft portion such as a pull stud protruding rearward of the tapered portion of the component at the rear end surface of the inner protruding portion of the collet. A large-diameter engaging portion front end surface provided in the engaging portion is engaged, and the rear side formed on the outer peripheral surface of the engaging portion of the draw bar by the retraction of the draw bar has a small outer diameter on the rear side; A rear end formed on the inner peripheral surface of the rear inner protruding portion is provided with a booster mechanism that is pressed against a gently inclined surface having a small inner diameter on the rear side, and formed at the front end of each of the divided pieces between the positioning plates of the retainer and reduced in diameter on the rear side The projections for expanding the collet that the outer inclined surface abuts on the front end inclined surface
A detachable receiving member for supporting the rear end of the retainer between the pedestal front end of the inner peripheral surface of the spindle and the rear end of the tapered hole, so that the retainer, the collet, the coil spring, and the draw bar can be taken in and out of the front end of the spindle. A component clamping device for a spindle, wherein the component clamping device is provided. 2. The snap ring according to claim 1, wherein the receiving member is a snap ring which is detachably engaged with an annular groove formed between a front end of the pedestal and a rear end of the tapered hole on the inner peripheral surface of the spindle. A device for clamping parts of a spindle as described. 3. A receiving ring having a thread formed on an outer periphery thereof is detachably fastened to a threaded portion formed at an appropriate position between a front end of a pedestal and a rear end of a tapered hole on an inner peripheral surface of a spindle. The spindle component clamping device according to claim 1, wherein: