JP4349576B2 - Tool holder - Google Patents

Description

The present invention relates to a tool Hol da detachably mounted on a spindle of a machine tool.

In the conventional tool holder, the shank part is formed in a taper with a small outer diameter on the rear side, a tapered hole with a small inner diameter on the rear side is formed in the front end of the spindle of the machine tool, and the shank part of the tool holder is moved back by a retracting member. The tool holder is mounted on the spindle by pulling it to the side.
However, a gap is provided between the flange portion provided on the front side of the shank portion of the tool holder and the front end surface of the spindle, and the shank portion is formed only by the outer peripheral surface having a taper of the shank portion and the inner peripheral surface of the tapered hole of the spindle. Since the part was restrained, the shank part could not be held with a large force, and satisfactory cutting could not be performed in high-speed rotation or low-speed heavy cutting.
Therefore, by restricting the end surface of the front end surface of the spindle against the rear end surface of the flange portion provided on the front side of the shank portion of the tool holder in addition to the constraint by the outer peripheral surface having the taper and the inner peripheral surface of the tapered hole, Some of them tried to increase their power.

However, in order to make the configuration as described above, the manufacturing tolerance must be severe, which increases the cost, and if the spindle is used for a long period of time, the taper hole needs to be re-polished. Since the taper hole is enlarged in the re-polished one, only the restriction by the flange portion of the tool holder and the end surface of the spindle is restricted, the taper portion does not contact, and the tool swings and cannot be used.
Further, when the spindle is rotated at a high speed, the front end portion of the spindle is expanded by centrifugal force due to the taper hole, the restraining force due to the taper hole is reduced, the tool held by the tool holder is vibrated, and the machining accuracy is lowered.

  Therefore, a straight portion is provided in the shank portion of the holder main body of the tool holder having the flange portion, a taper cone is fitted therein, and a disc spring is interposed between the rear end surface of the cone and the front end surface of the shank portion, so that the taper cone By applying a preload, the outer peripheral surface of the tapered cone whose rear side has a small outer diameter is pressed against the inner peripheral surface of the tapered hole whose rear side has a small outer diameter, so that the holder body is pulled into the rear side of the spindle. Although some results can be obtained and the manufacture is relatively easy, the taper cone cannot be sufficiently restrained by the inner peripheral surface of the taper hole unless the pull-in force of the holder body is increased.

  In addition, a large-diameter end portion and a small-diameter end portion are formed on the outer periphery of the shank portion of the holder main body to form a two-step straight portion, and the straight small-diameter end portion and the large-diameter end portion correspond to the end portion on the inner periphery of the tapered cone. Although some have a diameter end portion, the inner peripheral surface of the taper cone is straight, so that there is a problem that a sufficient effect cannot be obtained unless the holder body is pulled with a strong pulling force.

So, even if the pull-in force of the holder main body is relatively small, the above-mentioned problems are solved, and the cutting is performed by inclining with the axial direction over the entire length of the outer peripheral surface of the shank portion of the holder main body and the taper cone closely fitted thereto. Formed and filled with an elastic body such as fluorine-based rubber in the cut, the taper hole inner peripheral surface of the spindle whose rear side has a small diameter and the taper angle of the taper cone outer peripheral surface are smaller than the taper angle. By forming the taper, the outer peripheral surface of the shank has a locking function by a so-called wedge effect with respect to the tapered cone, and the lining force of the outer peripheral surface of the tapered cone acts on the inner peripheral surface of the tapered hole of the spindle. Tool holder that can hold the tool holder mounted in the hole with a large restraining force and can withstand high-speed rotation and low-speed heavy cutting For, the present inventors have already proposed by Japanese Patent No. 3083291.
Patent No. 3083291

  However, as described above, in the taper cone in which a slit is formed by inclining with the axial direction over the entire length of the taper cone, and a plate-like elastic body formed of fluorine rubber or the like is filled between the cut surfaces of the slit. In the recent high-pressure center-through coolant type machine main shaft, as shown in FIG. 7, the coupling with the tip of the coolant supply cylinder 10b connected to the upper part of the coolant communication hole 10a of the pull stud 10 is a taper connection. In some cases, the seals such as the O-ring 10c disposed in the joint portion may be damaged during operation, and in the case of damage, pull studs may be used. There is a risk that the high-pressure coolant leaks out from the upper part of the connection with the spindle 20 where 10 is located. In such a state, when cutting is finished and the tool holder 1 is in an unclamped state, the high-pressure coolant has a sharp arrow between the inner peripheral surface 21a of the tapered hole of the spindle 20 and the outer peripheral surface of the tapered cone 8 toward the rear side. Since the plate-like elastic body 30 filled in the slit 8a of the tapered cone 8 is moved to the outer peripheral side due to the influence of the centrifugal force at the time of high-speed rotation by the high-pressure coolant because it flows out like A, both There is a problem that it flows out or protrudes from the cut 8a, and there is a problem that repair or replacement is troublesome.

In order to further improve the above-described problems, the present invention improves the shape of the elastic body filled in the taper cone cut and the shape of the cut formed on the inner peripheral surface of the taper cone so that the elastic body rotates at high speed or, for example. Even when high-pressure coolant leaks, the elastic body attached to the taper cone's slit can be securely held without falling off or protruding , and when the taper cone is reduced in diameter It is an object of the present invention to provide a tool holder that can prevent a sealing effect and a taper cone from coming off from a shank .

The invention according to claim 1 is characterized in that a taper cone fitted to a taper hole formed on the spindle of a machine tool so as to have a smaller diameter as it goes rearward from the front end of the spindle, and fitted to the taper cone so as to be relatively movable in the axial direction. A holder main body having a combined shank, a flange provided integrally with the holder main body and in contact with a front end surface of the spindle, and an elastic member provided between the flange and the front end surface of the taper cone A stopper member that abuts the rear end surface of the taper cone and that pre-loads the elastic member by screwing and tightening to the rear end of the shank portion, and the outer peripheral surface of the taper cone is the inner periphery of the taper hole of the spindle. A tapered surface having an angle equal to the surface of the taper cone, and an inner peripheral surface of the tapered cone and the shank portion fitted to the inner peripheral surface. At least a portion of the peripheral surface is formed in a tapered surface whose diameter as it goes rearward, and a tool holder in which the said tapered surface on loose angle than the angle of the outer circumferential surface of the taper cone, the thickness of the taper cone to the tapered cone is penetrating in the direction, and the cut-split inclined against the axial direction of the taper cone formed over the entire length of the taper cone, along a wide recess from the cut-split to the inner surface of the front side of the taper cone in the longitudinal direction of the cut-split forming Te, wherein a wide recess from the cut-split to the inner surface of the side formed along the longitudinal direction of the cut-split after taper cone, forming such a fluorine based rubber having a plate-like portion to be inserted fills the cut-split retaining part and an elastic member disposed along said cut-split was to engage the in each recess in the end portion of the plate-like portion facing the inner surface of the taper cone A stepped portion is formed on the outer peripheral surface of the rear end portion of the tapered cone, which is formed over the entire length of the plate-like portion, and the stopper member abuts, and a stepped portion of the tapered cone is formed on the inner peripheral surface of the front end side of the stopper member. A stepped portion to be engaged is formed, and the stepped portion is configured to engage with each other when the stopper member is screwed and tightened to the rear end of the shank portion .

The invention of claim 2 is the tool holder according to claim 1, loose outer peripheral surface and the rear on the inner peripheral surface of the front portion of the taper cone of the front portion of the front alkoxy Yanku portion from each other equal angles whose diameter tapered the respectively formed, said shank portion front portion of the tapered cone is fitted to the front part of, a gap is provided between the intermediate portion outer peripheral surface and the intermediate inner peripheral surface of the taper cone of said shank portion, said shank side outer peripheral plane of the section and provided with a straight portion each side inner peripheral surface after the taper cone, characterized in that the sides fitted after the taper cone to the rear side of the shank portion.

A third aspect of the present invention, the tool holder according to claim 1 or 2, an annular recess is formed in the rear end surface of the flange portion facing the front end face of the shank portion, the elastic member in the annular recess is accommodated, the front end surface of the taper cone the elastic member and is in contact, wherein the elastic member is composed of a plurality of disc springs and these plates the front side and the rear side of at least one the superimposed washer spring and said that you are.

  According to a fourth aspect of the present invention, in the tool holder according to any one of the first to third aspects, the stopper member is a nut that engages with a screw formed at a rear end portion of the shank portion. And

The invention of claim 5 is the tool holder according to any one of claims 1 to 4, the rear end surface of the flange portion located on an outer peripheral side of the annular recess, viewed from the arc-shaped pair of The shim plate is detachably fixed, and the shim plate is brought into contact with the front end surface of the spindle.

Claim 6 invention, the tool holder according to any one of claims 1 to 5, wherein the holder body, characterized in that subjected to rust-preventive treatment to the members constituting the tool holder, such as the taper cone .

The present invention is fitted to a spindle of a machine tool so as to be relatively movable in the axial direction, and a tapered cone fitted into a tapered hole formed so as to have a smaller diameter as it goes rearward from the front end of the spindle. A holder body having a shank portion; a flange portion provided integrally with the holder body and in contact with a front end surface of the spindle; an elastic member provided between the flange portion and the front end surface of the taper cone; A tool holder provided with a stopper member that abuts against the end face and is screwed into and tightened to the rear end of the shank portion to preload the elastic member, and penetrates the taper cone in the thickness direction of the taper cone, and a cut-split inclined against the axial direction of the taper cone formed over the entire length of the taper cone, the Te A wide recess from the cut-split to the inner surface of the front side of Pakon formed along the longitudinal direction of the cut-split, the wide recesses along the longitudinal direction of the cut-split from the cut-split to the inner surface of the rear side of the taper cone formed, the elastic body formed like fluorine-based rubber having a cut-split inserted filled the plate-like portion disposed along said cut-split, the the end of the plate-like portion facing the inner surface of the taper cone A retaining portion that engages with each concave portion is formed over the entire length of the plate-like portion, and a step portion is formed on the outer peripheral surface of the rear end portion of the tapered cone with which the stopper member abuts, and the front end side of the stopper member a step portion engaging the step portion of the taper cone formed on the inner peripheral surface, wherein the two step portions are configured to engage one another when the stopper member at the rear end of the shank portion tightened screwed By pulling the holder main body to the rear side by the pulling member provided in the spindle, the taper cone is expanded by a taper in which the outer peripheral surface of the shank portion and the inner peripheral surface of the taper cone are equal to each other and the rear side is smaller in diameter. Press the outer peripheral surface against the inner peripheral surface of the tapered hole of the spindle, and even if the pulling force of the holder body is weak, the outer peripheral surface of the taper cone is brought into close contact with the inner peripheral surface of the tapered hole, and the taper cone is sufficiently restrained and held firmly can, and accuracy can heavy cutting by a tool attached to the tool holder by the drive of the spindle can be highly machined, further Ru can prevent inadvertent from the shank portion of the sealing effect and taper cone when the taper cone has a reduced diameter.

  Further, the outer peripheral surface of the shank portion has a so-called wedge effect locking function with respect to the tapered cone, and the lining force of the outer peripheral surface of the tapered cone acts on the inner peripheral surface of the tapered hole of the spindle. It can be restrained while maintaining the pulling force, and the tool holder mounted in the taper hole of the spindle is held in close contact with a large restraining force, providing an excellent damping effect and capable of withstanding high speed rotation and low speed heavy cutting. It can be.

  In addition, a so-called T-shape formed by a fluorine-based rubber having a cut-off shape having a retaining portion held in the recess at one end and a plate-like portion inserted and filled in the cut portion at the other end Since the elastic body of the shape is filled, the elastic body filled in the cut of the taper cone is securely held, it can be prevented from protruding or peeling off together due to liquid leakage, etc., and diameter expansion and contraction are possible, The taper cone can be brought into close contact with the taper hole of the spindle, and the rear end surface of the flange portion can be securely adhered to the front end surface of the spindle.

  In addition, a loose taper is formed only on the outer peripheral surface of the front side portion of the shank portion and the front side portion of the inner peripheral surface of the taper cone, so that the area to be tapered is small, and the rear side portion of the outer peripheral surface of the shank portion and the inner peripheral surface of the taper cone Since the taper cone is fitted in the shank part, it is easy to process, but with less vibration during processing and high-precision cutting, and used for spindles with a 7/24 taper taper hole. It is preferable to do.

Further, since the elastic material such as T-shaped fluorine-based rubber is filled and bonded to the cut, it has a dustproof function.
In addition, since a plurality of disc springs and at least one of the front side and the rear side are configured with a washer, the taper cone can be biased to the rear side, and by changing the number and thickness of the washers, The position of the taper cone in the front-rear direction can be adjusted.

  Further, a nut that is screw-fitted to the outer periphery of the rear end portion of the shank portion is disposed on the rear end portion side of the taper cone so as to support the rear end of the taper cone, so that different pull studs can be used. Further, when the pull stud is removed from the rear end side of the shank portion when not in use, it is possible to prevent the taper cone fitted to the shank portion from falling off from the shank portion and falling apart.

In addition, a pair of arc-shaped shim plates are detachably fixed to the rear end surface of the flange portion so as to come into contact with the front end surface of the spindle, so that the holder body can be used effectively over a long period of time and is required. By using a shim plate having a thickness of 5 mm, it is possible to absorb the difference in clearance between the spindle end surface of the machine tool and the rear end surface of the tool holder flange.
Moreover, since each member which comprises tool holders, such as a holder main body and a taper cone, was rust-proofed, a holder main body, a taper cone, etc. can be used over a long period of time.
Further, a notch stepped portion is provided on the outer peripheral surface of the rear end portion of the tapered cone, and the stepped portion formed on the inner peripheral surface of the front end side of the stopper member is engaged with the stepped portion. Even in a state where the shank portion is clamped to the spindle and the tapered cone is reduced in diameter and moved to the rear end side, a sealing effect can be achieved by the engagement of the two step portions.

  The present invention is a tool holder that is detachably fitted in a tapered hole of a spindle of a machine tool having a tapered hole whose rear side has a small outer diameter, and has a large outer diameter on the front side of a shank portion provided on the rear side part of the holder body. The flange portion is provided, an elastic member is interposed between the rear end surface of the flange portion and the front end surface of the taper cone fitted to the shank portion, the taper cone having a small outer diameter on the rear side, and the rear end surface of the taper cone as the shank portion. The front side portion of the shank portion is supported by a provided stopper member, and a loose taper of the same angle is formed on the outer peripheral surface of the front side portion of the shank portion of the holder main body and the inner peripheral surface of the front side portion of the tapered cone. The front side part of the taper cone is fitted to the intermediate part of the shank part, and a gap is provided between the intermediate part of the shank part and the intermediate part of the taper cone. The straight portion is provided on the side inner peripheral surface, it is applied to the tool holder having the structure fitted to the rear side of the taper cone to the rear side of the shank portion.

  FIG. 1 shows a tool holder according to a first embodiment of the present invention. As shown in FIG. 1, the tool holder 1 is provided with a shank portion 3 on the rear end side of the holder body 2, and the front end of the shank portion 3. A large-diameter flange portion 4 is provided on the side.

  An annular recess 4c is formed in the rear end surface 4a of the flange portion 4, and an elastic member 7 is fitted in the annular recess 4c. A taper cone 8 is rotatably fitted on the outer periphery of the shank portion 3, and is attached to the rear end portion of the shank portion 3. Is provided with a stopper member 9 for adjusting the preload.

As shown in FIG. 2, the taper cone 8 is formed with a 7/24 taper tight taper on the entire outer peripheral surface, and the front side portion 8g of the inner peripheral surface is 1/10 to 1/100 taper. The intermediate portion 8h, which is formed with a loose taper of 1/50 taper, is slightly protruded toward the center via a step, and a straight portion is formed on the rear side portion 8i of the intermediate portion 8h. A stepped portion 8k that engages with a stepped portion 9a formed on the front end side inner peripheral surface of the stopper member 9 is formed on the outer peripheral surface of the narrow-diameter end portion that is the rear end portion of the tapered cone 8.

Said shank portion 3, 1 / 10-1 / 100 taper equal to the front portion 8g of the taper cone 8, preferably a front portion 3c having a loose tapered outer peripheral surface of 1/50 taper slightly to Ri Tsurana the front portion 3c an intermediate portion 3d comprising a small outer diameter, and an intermediate portion connected to 3d side straight portion 3e after the straight cylindrical, that has a rear end portion 3f having a male screw portion continuous to the rear straight portion 3e.
The taper cone 8 is fitted to the shank portion 3, the front side portion 8 g of the taper cone 8 is fitted to the front side portion 3 c of the shank portion 3, and the inner peripheral surface of the intermediate portion 8 h of the taper cone 8 and the outer periphery of the intermediate portion 3 d of the shank portion 3. A gap a in the radial direction and a gap b in the front-rear direction are formed between the surface and the rear side portion 8 i that is the straight portion of the tapered cone 8 is fitted to the straight portion 3 e of the shank portion 3.

The stopper member 9 is made of a nut screwed onto the male threaded portion of the rear end portion 3f of the shank portion 3 which projects from the rear end surface of the taper cone 8, the rear end surface peripheral surface of the taper cone 8 at the front end inner peripheral surface of the nut A step portion 9a that engages with the step portion 8k formed on the rear end portion 3f is formed, and a nut is screwed and tightened to the male screw portion of the rear end portion 3f, thereby engaging with the step portion 8k formed on the rear end surface of the taper cone 8 with each other. combined, and is pressed against the taper cone 8 to the flange portion 4 side described later.
Further, on the outer peripheral surfaces of the front side portion 3c and the straight portion 3e of the shank portion 3, a lubricant enclosing groove 3a and a lubricant enclosing groove 3g are formed in a circumferentially continuous mountain shape, respectively, and these enclosing grooves 3a, 3g A lubricant such as grease is put in

A taper hole 21 that opens to the front end surface of the spindle 20 of the machine tool is formed, and a 7/24 taper taper with a small rear diameter is formed on the inner peripheral surface 21a of the taper hole 21.
A shank portion 3 is provided on the rear end side of the holder body 2, a large outer diameter flange portion 4 is provided on the front end side of the shank portion 3, and a front end portion 6 is formed in series on the front end side of the flange portion 4. .

Rear end surface 4a of the flange portion 4 is perpendicular to the axial direction formed toward the center from the outer peripheral side, the arm (not shown) of the automatic tool changer on the outer peripheral surface of the flange portion 4 is disengageably engaged the trapezoidal groove 4b which case formed, the rear end surface 4a of the flange portion 4 is formed an annular recess 4c, the elastic member 7 described later in the annular recess 4c is that is inserted. 4e and 4e are key grooves.

Wherein the outer periphery of the shank portion 3 front facet taper cone 8 constituting the taper shank abuts slidably fitted in the radial direction and axial direction in the elastic member 7, described later to a rear end of the taper cone 8 A stopper member 9 made of a preload adjusting nut is fixed to the shank portion 3 by screwing. The taper cone 8 is pressed against the elastic member 7 through the stopper member 9, and the elastic member 7 is compressed to give a preload. Yes.

The taper cone 8, as shown in FIG. 2, penetrates in the thickness direction of the taper cone 8, and cut-split 8a to loose rather inclined with respect to the axial direction of the taper cone 8 is formed over the entire length of the taper cone 8, in this cut-split 8a An elastic body 30 such as fluorine-based rubber is filled so as to be elastically deformable in the radial direction.
Cut-split 8a than wider recesses 8j on the inner surface of the front side portion 8g of the taper cone 8 except the middle portion 8h is formed along the longitudinal direction of the cut-split 8a, further cut-split 8a on the inner surface after the side 8i of the taper cone 8 A wider recess 8j is formed along the longitudinal direction of the slit 8a.
Then, as shown in FIG. 3, the cut 8 a having the above shape has a plate-like portion 30 b inserted and filled in the cut-off portion 8 a and an end portion of the plate-like portion 30 b facing the inner surface of the taper cone 8 to the full length of the plate-like portion 30 b. The elastic body 30 has a T-shaped transverse shape, and has a retaining portion 30a that is formed across and engages with each recess 8j .

Incidentally, before Ki凹 portion 8j is preferably provided in the cut-split 8a entire length of the taper cone 8, when processing the inner circumferential surface of the intermediate portion 8h of the taper cone 8 is difficult, the front portion of the taper cone 8 8i and after Even if it is formed only on the side portion 8g, since the gap a is provided between the inner peripheral surface of the taper cone 8 intermediate portion 8h and the intermediate portion 3d of the shank portion 3, Even if the retaining portion 30a is not flush with the inner circumferential surface of the tapered cone 8, the fitting of the tapered cone 8 to the shank portion 3 is not hindered. Further, when the plate-like portion 30b of the elastic body 30 is filled and attached to the cut 8a of the tapered cone 8, it may be fixed to the opposing surface of the cut 8a using an adhesive to have a dustproof function.

The elastic member 7 is formed by stacking a plurality of annular disc springs made of an elastic metal plate such as a steel plate and a thin plate made of an annular metal plate, etc., and at least a part of these is accommodated in the annular recess 4c. Te, that is interposed between the front end surface of the bottom and taper cone 8 of the recess 4c.

Further, lubricant enclosing grooves 3a and 3g are formed in a circumferentially continuous mountain shape on the outer peripheral surface of the shank portion 3 into which the tapered cone 8 is fitted, and a lubricant such as grease is formed in the enclosing grooves 3a and 3g. The relative movement between the shank portion 3 and the tapered cone 8 is made smooth over a long period of time.

  A tapered hole 11 for holding a collet and a straight hole 12 extending to the rear end side of the tapered hole 11 are formed between the axially intermediate portion and the front end of the holder main body 2. Has a bolt support portion 14 formed with a small-diameter bolt insertion hole 13 projecting annularly toward the center side, and forming a rear end hole 15 opening on the rear end face of the holder body 2 on the rear end side of the bolt insertion hole 13. A female threaded portion 15 a is formed at an appropriate position in the axial direction of the rear end hole 15, and the holes 11, 12, 13, 15 are provided in series with the axis of the holder body 2.

The pull stud 10 has a front end male screw portion 10a fastened to a female screw portion 15a of a rear end portion hole 15, a large diameter support portion 10b is brought into contact with a rear end surface of the shank portion 3, and a rear end side of the large diameter support portion 10b. The engaging portion 10c is protruded, a through hole 10d is formed in the center portion, and the flat support 10b is formed in the large-diameter support portion 10b.
Reference numeral 10f denotes a seal member fitted and disposed above the front end male screw portion 10a.

In the tapered hole 11 and the straight hole 12 of the holder main body 2, a tapered portion 16a on the front end side and a straight rear end portion 16b formed in series on the tapered collet 16 are fitted. The said tapered portion 16a of the tapered collet 16, a tapered equal taper hole 11 on the outer circumferential surface, further forming a cut-split portion 16c at equal intervals in the circumferential direction of the three of the tapered portion 16a, adjacent cut-split section the inner peripheral surface of the tapered bore 11 located between 16c Yes forms shape cutting fluid supply grooves 16d, the rear end 16b of the tapered collet 16, internally threaded hole 16e penetrating the axial center portion is formed It is.
The slit portion 16c is formed over the entire length of the taper portion 16a, and the cutting fluid supply groove 16d is elongated from the front end to the rear end portion 16b of the taper collet 16.

A pulling bolt 17 is inserted into the rear end hole 15 from the rear end side of the holder body 2, and a leg portion 17 a of the pulling bolt 17 is inserted into the bolt insertion hole 13 from the rear end side to form a male screw portion 17 b formed on the leg portion 17 a. Are screwed into female screw holes 16e formed in the rear end portion 16b of the collet 16. The pull bolt 17 is formed with an engagement recess 17d having a regular hexagonal cross section in the head portion 17c, and a small diameter cutting fluid passage hole 17e extending from the bottom of the engagement recess 17d to the tip of the leg 17a. It is formed so as to penetrate the shaft center. The head portion 17c is supported on the rear end surface of the bolt support portion 14 of the holder body 2 through a washer 18 fitted to the leg portion 17a.
Reference numeral 19 denotes a tool such as an end mill or a drill in which the shank 19a is fitted to the taper collet 16.

In FIG. 1, reference numeral 20 denotes a spindle of a machine tool. A tapered hole 21 is formed at the front end portion of the spindle 20. The tapered hole 21 opens at the front end of the spindle 20, and the inner peripheral surface of the tapered hole 21. 21a is formed in a 7/24 taper having a small diameter on the rear end side. A pull-in member 22 is provided on the rear end side of the tapered hole 21 of the spindle 20.
Further, the metal members such as the holder main body 2, the taper cone 8 and the taper collet 16 are each subjected to rust prevention treatment so that the metal members are not rusted by cutting fluid or the like.

  In order to use the tool holder 1 of the first embodiment configured as described above, the arm of the automatic tool changer is engaged with the trapezoidal groove 4b provided in the flange portion 4 of the tool holder 1, and the flange portion 4 is moved. Gripping and engaging the engaging portion 10c of the pull stud 10 provided in the tool holder 1 with the front end portion of the drawing member 22 provided in the spindle 20 of the machine tool, and pulling the pull stud 10 to the rear side of the spindle 20. Thus, the outer peripheral surface of the taper cone 8 of the tool holder 1 is brought into close contact with the inner peripheral surface of the spindle 20. When the pull stud 10 is pulled to the rear side of the spindle 20, the shank portion 3 of the holder main body 2 fixed to the pull stud 10 and the tapered cone 8 fitted to the shank portion 3 are drawn to the rear side, and the outer peripheral surface of the shank portion 3. And a taper cone 8 having a small taper on the rear side, such as a 1/50 taper, which is equal to each other, a wedge effect is exerted on the taper cone 8 by drawing in the shank portion 3, and the inner circumference of the taper cone. The surface expands and the lining force works.

Further, since the taper hole 21 inner peripheral surface 21a of the spindle 20 and the outer peripheral surface of the taper cone 8 are tapered so that the rear side of the 7/24 taper which is equal to each other has a small diameter, the taper hole is formed on the outer peripheral surface of the taper cone 8 21. The tightening force of the inner peripheral surface 21a works to reduce the diameter of the taper cone 8. However, the inner lining force of the taper cone 8 works and strongly restrains both, even if the pulling force of the tool holder 1 is relatively weak. It becomes possible.
It is already known that the coupling rigidity is improved as the taper angle is smaller.

  FIG. 5 is an explanatory view showing a state of a pulling force in which the holder main body 2 is pulled into the tapered hole 21 of the spindle 20 by a draw bar in the tool holder 1 of the present invention and a conventional standard type tool holder.

For example, when the set value of the pull-in force of the holder body 2 is set to 900 kg, when the tool holder 1 is mounted in the tapered hole 21 of the spindle 20, the pull-in member 22 connected to the draw bar (not shown) is pulled in. The instantaneous pulling force of a compression spring (not shown) or the like provided is called a hammering effect and varies depending on the pulling force set value and the pulling speed, but is instantaneously 1.3 to 1. It reaches 8 times the pulling force of about 1200kg.
However, in the conventional standard type tool holder, the inner peripheral surface of the taper cone and the outer peripheral surface of the shank portion are straight in the front-rear direction, and immediately return to the pulling force of 900 kg, which is the pulling force setting value indicated by the dotted line. Cutting work is performed.

  On the other hand, according to the tool holder 1 of the present invention, when the draw bar pulls the pull stud 10 to the rear side of the spindle 20 when the tool holder 1 is mounted in the tapered hole 21 of the spindle 20, the tool holder 1 is fixed to the pull stud 10. The holder cone 2 has a shank portion 3 and a tapered cone 8 fitted to the shank portion 3 that is retracted to the rear side, and the rear side such as a 1/50 taper that is equal to the outer circumferential surface of the shank portion 3 and the inner circumferential surface of the tapered cone 8 has a small diameter. Since the shank portion 3 is pulled in, the outer peripheral surface of the shank portion 3 has a locking function by a so-called wedge effect with respect to the tapered cone 8 and the tapered cone 21 has an inner peripheral surface 21a of the tapered hole 21 of the spindle 20. As a result of the lining force on the outer peripheral surface of 8, the pulling force of 1200 kg, which is the instantaneous reaching point of the pulling force, is obtained. It is possible to restraint while maintaining the only force.

  Therefore, the tool holder 1 mounted in the tapered hole 21a of the spindle 20 can be held tightly with a large restraining force, and the tool holder 1 that can withstand high speed rotation and low speed heavy cutting can be provided.

The fact that the pull-in force, which is the instantaneous reaching point of the pull-in force, can be restrained is that the pull-in force is applied to a pull-in means of a spindle for 4 to 5 years in which the pull-in force decreases. Needless to say, the effect of improving the resistance can be exhibited.
The automatic tool changer removes the arm from the trapezoidal groove 4b in a timely manner and returns it to the position before the operation.

  To perform automatic tool change of the tool holder 1 after performing the above-described processing, the arm of the automatic tool changer is engaged with the trapezoidal groove 4b, the flange portion 4 is gripped, and the tool is placed on the tip side of the spindle 20. Pull the holder 1 out.

The taper cone 8 provided in the tool holder 1 of the first embodiment is a large pull stud 10 in which the rear end surface of the taper cone 8 fitted to the shank portion 3 of the holder body 2 is screwed to the rear end portion of the shank portion 3. The diameter support portion 10b is brought into contact with the rear end surface of the shank portion 3 and pushed to the front end side, the elastic member 7 is fitted into the annular recess 4b formed in the rear end surface 4a of the flange portion 4, and the front end surface of the taper cone 8 is fixed to the elastic member 7 , The taper cone 8 can move in the axial direction of the shank portion 3.
Further, it provided in one place cut-split 8a entire length circumferential direction of the taper cone 8, the inner surface of the front side and the rear side portion of the tapered cone are formed along the wide recess 8j than the respective cut-split 8a to cut-split 8a At the same time, the plate-like portion 30b of the elastic body 30 disposed along the cut 8a is inserted and filled into the cut 8a , and the retaining portion 30a of the elastic body 30 is engaged with the recess 8j. The elastic body 30 filled in the 8 cuts 8a is securely held, so that it can be prevented from protruding due to leakage of cutting fluid and the like, and the diameter can be expanded and reduced. The taper cone 8 is brought into close contact with the taper hole 21 of the spindle 20. Thus, the rear end surface 4a of the flange portion 4 can be securely brought into close contact with the front end surface 20a of the spindle 20.

  In the first embodiment, in order to replace the tool 19 whose blade portion is worn or missing due to use, the tool holder 1 is removed from the machine tool and carried to the tool replacement work place, and the flange portion 4 of the holder body 2 is moved to the vise. The front end portion of the operation bar having a regular hexagonal cross section, which is fixed by a vise fixed to the front end and bent in an L shape from the rear end side of the pull stud 10, is inserted into the through hole 10 d of the pull stud 10 and pulled down. 17 is engaged with an engagement recess 17d provided on the head 17c.

  Then, by rotating the operating rod outside the pull stud 10 in the loosening direction and rotating the pull bolt 17 in the same direction, the head 17c is brought into contact with the front end of the pull stud 10, and further in the loosening direction. By rotating, the collet 16 is pushed out to the front end side of the holder main body 2 by screw fitting of the male screw 17b of the pulling bolt 17 and the female screw hole 16e of the taper collet 16, and the holder main body 2 with respect to the tapered portion 16a of the collet 16 is pushed. The tightening by the tapered hole 11 at the front end is loosened.

  Accordingly, the tightening of the shank 19a of the tool 19 by the tapered portion 16a of the collet 16 is also loosened, so that the tool 19 is pulled out from the collet 16 and the shank 19a of the usable tool 19 such as a new tool is fitted into the tapered portion 16a of the collet 16. Can do. Then, contrary to the above-described operation, the pulling bolt 17 is rotated in the tightening direction by the operating rod and pulled to the rear end side of the holder body 2, so that the tapered portion 16 a of the collet 16 is rotated around the taper hole 11 of the holder body 2. The tool shank is held and fixed to the front end portion of the holder body 2 via the collet 16, and then the operating rod is pulled out to the rear end side of the tool holder 1 to remove the flange portion 4 from the vise. Thus, the tool holder 1 can be reused.

Further, when the tool holder 1 is mounted on the spindle 20, the tool 19 is advanced while rotating the spindle 20, and machining is performed on the workpiece, the cutting fluid is supplied from the center of the spindle 20, Through the through hole 10 d of the pull stud 10, the rear end hole 15 of the holder body 2, the engaging recess 17 d of the pulling bolt 17, the rear end part 16 b of the taper collet 16, and through the cutting fluid supply groove 16 d of the collet 16, the collet. It is also possible to jet the tool 19 along the outer peripheral surface of the tool 19 from the front end of the tool 16 and cool the work part of the work piece by the blade part and the blade part of the tool 19.
Further, a notch step portion 8k is provided on the outer peripheral surface of the rear end portion of the taper cone 8, and the step portion 9a formed on the inner peripheral surface of the front end side of the stopper member 9 is engaged with the step portion 8k. since it is, achieving the sealing effect by the shank portion 3 is engaged the two step portions 8k, 9a even in a state in which the taper cone 8 is clamped to the spindle 20 is moved to the rear end diameter In addition, when the pull stud 10 is removed from the rear end side of the shank portion 3 when not in use, the taper cone 8 fitted to the shank portion 3 can be prevented from falling off the shank portion 3 , and the taper cone 8 There is no such thing as falling apart from the shank part 3 .

  In the invention of the first embodiment, since the front side portion 8g of the tapered cone 8 and the front side portion 3c of the shank portion 3 are fitted with a taper, the length of the cutting process of the portion forming the taper is short, Since the straight portion provided on the rear side portion 8i of the taper cone 8 and the rear straight portion 3e of the shank portion 3 are fitted, the taper cone 8 is attached to the shank portion 3 at the front and rear two locations. It can be supported, and vibration during operation can be reduced, so that the processing accuracy of the workpiece by the tool can be improved.

As shown in FIG. 6, the tool holder 1 according to the second embodiment includes a pair of shim plates 24, 24 having two arcs in plan view on the rear end surface 4 a of the flange portion 4 of the holder body 2. Female screw holes 4d and 4d formed in advance in the flange portion 4 by fitting countersunk screws 25 and 25 into holes 24a and 24a provided in the shim plates 24 and 24, respectively. The back surfaces of the shim plates 24, 24 are in close contact with the front end surface 20a of the spindle 20 of the machine tool.
The configuration of the tool holder of the second embodiment other than that described above is the same as that of the tool holder of the first embodiment.

  The use and effects of the tool holder of the second example are the same as those of the tool holder of the first embodiment. In the second example, the shim plate 24 is attached to the spindle 20 by attaching and detaching the tool holder 1 many times. When the rear end face 4a of the flange portion 4 to which the shim plates 24, 24 are not attached is damaged due to attachment / detachment of the tool holder 1 a number of times, the flange portion 4 After cutting the rear end portion, a shim plate having a required thickness may be supported on the rear end surface and fixed with a countersunk screw. Note that it is preferable to prepare a plurality of shim plates having different thicknesses and use a shim plate having an appropriate thickness.

1 is an enlarged longitudinal sectional view showing a tool holder according to a first embodiment of the present invention. The expansion perspective view of the taper cone of the tool holder shown in FIG. FIG. 3 is an enlarged longitudinal sectional view of the tapered cone shown in FIG. 2, (A) is a sectional view taken along 3A-3A, (B) is a sectional view taken along 3B-3B, and (C) is a sectional view taken through 3C-3C. FIG. 2 shows an elastic member filled in the taper cone of the tool holder shown in FIG. 1, wherein (A) is a front view, (B) is a side view, (C) is a bottom view, and (D) is 4D-4D. End view along the line. Explanatory drawing which showed the drawing force in the operation state in the tool holder of this invention and the conventional standard type tool holder. Longitudinal explanatory drawing showing a tool holder according to a second embodiment of the present invention. Schematic which shows the combined state of the conventional spindle and tool holder.

DESCRIPTION OF SYMBOLS 1 Tool holder 2 Holder main body 3 Shank part 3a Lubricant enclosure groove 3c Front end part of shank part outer peripheral surface 3d Middle part 3e Straight part 3f Rear end part 4 Flange part 4a Rear end face 4b Trapezoid groove 4c Annular recessed part 4d Female screw hole 6 Front end part 7 Elastic member 8 Tapered cone 8a Cutting 8b Recessed part 8g Front side part 8h Intermediate part 8i Rear side part (straight part)
8j Concave portion 8k Stepped portion 9 Stopper member 9a Stepped portion 10 Pull stud 10a Front end male screw portion 10b Large diameter support portion 10c Engagement portion 10d Through hole 10e Flat cutout portion 10f Seal member 11 Taper hole 12 Straight hole 13 Bolt insertion hole 14 Bolt support Part 15 Rear end hole 15a Female thread part 16 Tapered collet 16a Front end side taper part 16b Rear end part 16c Split part 16d Cutting fluid supply groove 16e Female thread hole 17 Pull bolt 17a Leg part 17b Male thread part 17c Head part 17d Engaging recess 17e Cutting fluid passage hole 18 Washer 19 Tool 19a Tool shank 20 Spindle 20a Front end surface 21 Tapered hole 21a Inner peripheral surface of taper hole 22 Pull-in member 24, 24 Shim plate 25, 25 Countersunk screw 30 Elastic member 30a Retaining portion 30b Plate shape Part

Claims (6)

A taper cone fitted to a taper hole formed on the spindle of a machine tool so as to have a smaller diameter as it goes rearward from the front end of the spindle;
A holder main body having a shank portion fitted to the taper cone so as to be relatively movable in the axial direction;
A flange portion provided integrally with the holder main body and in contact with the front end surface of the spindle;
An elastic member provided between the flange portion and the front end surface of the tapered cone;
A stopper member that is brought into contact with the rear end surface of the tapered cone, and that pre-loads the elastic member by screwing and tightening the rear end of the shank portion;
An outer peripheral surface of the tapered cone is formed into a tapered surface having an angle equal to an inner peripheral surface of the tapered hole of the spindle, and at least a part of the outer peripheral surface of the shank portion that is fitted to the inner peripheral surface of the tapered cone and the inner peripheral surface. Is formed into a tapered surface having a smaller diameter as it goes rearward, and the tapered surface has a gentler angle than the angle of the outer peripheral surface of the tapered cone,
Penetrating in the thickness direction of the taper cone to the tapered cone, and the cut-split inclined against the axial direction of the taper cone formed over the entire length of the taper cone,
A wide recess from the cut-split to the inner surface of the front side of the taper cone and formed along the longitudinal direction of the cut-split,
Forming a recess wider than the slit on the inner surface of the rear side portion of the tapered cone along the longitudinal direction of the slit;
An elastic body formed like fluorine-based rubber having a cut-split inserted filled the plate-like portion disposed along said cut-split,
Forming a retaining portion that engages with each recess at the end of the plate-like portion facing the inner surface of the tapered cone over the entire length of the plate-like portion,
Further, a step portion is formed on the outer peripheral surface of the rear end portion of the taper cone with which the stopper member abuts, and a step portion engaging with the step portion of the taper cone is formed on the front end side inner peripheral surface of the stopper member. A tool holder characterized in that the step portions engage with each other when the stopper member is screwed and tightened to the rear end of the portion . Forming front carboxymethyl Yanku portion of the outer peripheral surface and the rear on the inner peripheral surface of the front portion of the taper cone of the front portion of the loose tapered from each other equal angles whose diameter respectively, the front side of the taper cone on the front side of the shank portion part Mate, a gap is provided between the intermediate portion outer peripheral surface and the intermediate inner peripheral surface of the taper cone of the shank portion, a side portion within the circumferential plane of the side outer peripheral surface and the tapered cone after said shank portion the straight portion respectively, the tool holder according to claim 1, characterized in that fitted to the rear side of the taper cone to the rear side of the shank portion. An annular recess formed on the rear end surface of the flange portion facing the front end face of the shank portion, the elastic member in the annular recess is accommodated, it abuts against the front end surface of the taper cone the elastic member, the tool holder of claim 1 elastic member is characterized by being composed of a plurality of disc springs and these plates the front side and the rear side of at least one the superimposed washer spring.   The tool holder according to any one of claims 1 to 3, wherein the stopper member is a nut that is screwed into a screw formed at a rear end portion of the shank portion. A pair of shim plates having a circular arc shape in plan view are detachably fixed to the rear end surface of the flange portion located on the outer peripheral side of the annular recess, and the shim plates are in contact with the front end surface of the spindle. The tool holder according to any one of claims 1 to 4. The holder body, the tool holder according to any one of claims 1 to 5, characterized in that subjected to rust-preventive treatment to the members constituting the tool holder, such as the taper cone.