JP2000263361A - Tool holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool holder which can be held to the spindle of a machine tool strongly and cut precisely, even if a draw in force is small. SOLUTION: In a tool holder interposing an elastic member 7 between the rear end of a flange 4 provided on the front side of the shuck 3 of a holder main body 2 and the front end of a taper cone inserted in the shunk 3 and supporting the rear end surface of the cone 8 to the shunk 3 by a stopper member 9, the outer periphery of the cone 8 whose rear side is a small diameter is made to the angle same as the taper of the inner periphery surface 21a of the taper hole 21 of a spindle 20 and the rear side is made to be a small diameter with the angle mutually equal to the taper of the inner periphery surface of the cone 8 and the outer periphery surface of the shunk 3 and the angle more gentle than the outer periphery taper of the cone 8 and the diameter of the cone 8 is expanded by the draw in of the holder main body 2 and its outer periphery surface can be held to the inner periphery surface of the taper hole 21 strongly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool holder detachably mounted on a spindle of a machine tool.

[0002]

The conventional tool holder is
By forming the shank portion into a taper with a small outside diameter on the rear side, forming a tapered hole with a small inside diameter on the rear side at the front end of the spindle of the machine tool, and pulling in the shank portion of the tool holder to the rear side by a retracting member, The tool holder is mounted on a spindle. However, a gap is provided between a 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 is formed only by the tapered outer peripheral surface of the shank portion and the tapered hole inner peripheral surface of the spindle. Since the portion was restrained, the shank portion 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, the front end surface of the spindle is pressed by pressing the rear end surface of the flange portion provided on the front side of the shank portion of the tool holder, by applying the restriction by the outer peripheral surface having the taper and the inner peripheral surface of the tapered hole, thereby restricting the operation. Some tried to increase the power.
However, in order to achieve the above-described configuration, manufacturing tolerances must be severe, resulting in high costs,
If the spindle has been used for a long period of time, the tapered hole needs to be polished again, and the polished hole expands the tapered hole, resulting in only the restriction by the flange of the tool holder and the end face of the spindle. However, the tapered portion does not contact, and the tool oscillates and cannot be used. When the spindle is rotated at a high speed, the front end of the spindle expands due to the centrifugal force due to the tapered hole, the restraining force due to the tapered hole decreases, the tool held by the tool holder vibrates, and the processing accuracy decreases.

Therefore, a straight is provided on a shank portion of a holder body of a tool holder having a flange portion, a taper cone is fitted therein, and a disc spring is interposed between a rear end surface of the cone and a front end surface of the shank portion. By applying a preload to the taper cone, the outer peripheral surface of the taper cone having a small outer diameter on the rear side is pressed against the inner peripheral surface of the taper hole having a small outer diameter on the rear side of the spindle, and the holder body is drawn into the rear side of the spindle. Although some results can be obtained and the manufacture is relatively easy, there is a case where the taper cone is not sufficiently restrained by the inner peripheral surface of the tapered hole unless the retraction force of the holder body is increased. In addition, a large-diameter end portion and a small-diameter end portion are formed in a two-stage straight portion on the outer periphery of the shank portion of the holder body, and the straight small-diameter end portion is formed on the inner periphery of the taper cone so as to correspond to the end portion. Although there is a diameter end portion, there is a problem that since the inner peripheral surface of the tapered cone is straight, a sufficient effect cannot be obtained unless the holder main body is pulled in with a strong pulling force.

[0004] The present invention solves the above-mentioned problems,
Even if the pulling force of the holder body is relatively small, the outer peripheral surface of the shank portion of the holder body and the inner peripheral surface of the tapered cone that is closely fitted to the shank portion have the inner peripheral surface of the tapered hole of the spindle and the outer periphery of the tapered cone each having a small diameter on the rear side. By forming a taper with a smaller angle than the taper angle of the surface, the outer peripheral surface of the shank has a locking function by a so-called wedge effect on the tapered cone, and the lining force of the outer peripheral surface of the tapered cone against the inner peripheral surface of the tapered hole of the spindle Acts as a result
An object of the present invention is to provide a tool holder that can hold a tool holder mounted in a tapered hole of a spindle with a large restraining force and can withstand high-speed rotation and low-speed heavy cutting.

[0005]

According to a first aspect of the present invention, there is provided a tool holder removably fitted in a tapered hole of a spindle of a machine tool having a tapered hole having a small outer diameter on the rear side. A flange part with a large outer diameter is provided on the front side of the shank part provided in the part, an elastic member is interposed between the rear end of the flange part and the front end of the tapered cone fitted in the shank part, and the rear side has a small outer diameter. In a tool holder in which the rear end surface of the tapered cone is supported by a stopper member provided in the shank portion, the outer peripheral surface of the tapered cone is formed at an angle equal to the inner peripheral surface of the tapered hole of the spindle, and the inner peripheral surface of the tapered cone is formed. The outer peripheral surface of the shank portion and the rear side have a smaller diameter, and a taper having a smaller angle than the outer peripheral surface of the tapered cone is formed at least partially in the front-rear direction. Than it is.

According to a second aspect of the present invention, there is provided a tool holder as set forth in the first aspect, wherein a loose taper having a smaller diameter on the rear side is formed on the entire inner peripheral surface of the tapered cone and substantially the entire outer peripheral surface of the shank portion. It is.

According to a third aspect of the present invention, the outer peripheral surface of the front side of the shank portion of the holder body and the inner peripheral surface of the front side of the tapered cone are each formed with a loose taper having a smaller diameter on the rear side and an equal angle to each other. The front part of the taper cone is fitted to the part, a gap is provided between the middle part of the shank part and the middle part of the taper cone, and the straight part is provided on the outer peripheral surface of the rear part of the shank part and the inner peripheral surface of the rear part of the taper cone. The tool holder according to claim 1, wherein a rear side portion of the tapered cone is fitted to a rear side portion of the shank portion.

According to a fourth aspect of the present invention, the slit is formed by inclining with respect to the axial direction over the entire length of the tapered cone, and the slit is filled with an elastic material such as a fluorine-based rubber and bonded. It is a tool holder described in one of the above.

According to a fifth aspect of the present invention, a front slit and a rear slit are provided in the taper cone in a circumferential direction from a front end and a rear end of the taper cone, and are inclined in the axial direction at an equal angle to each other. The tool holder according to any one of claims 1 to 3, wherein the slit is filled with an elastic body such as a fluorine-based rubber and bonded.

According to a sixth aspect of the present invention, an annular recess is formed in contact with the outer periphery of the front end of the shank portion and opened to the rear, and at least a part of the elastic member is accommodated in the annular recess to support the front end face of the tapered cone. The tool holder according to any one of claims 1 to 5, wherein the elastic member is configured by stacking a plurality of disc springs and washers on at least one of a front side and a rear side thereof.

According to a seventh aspect of the present invention, at least one of a washer, a spring washer, and a nut screw-fitted to the inner periphery of the rear end of the shank portion is provided at the rear end of the tapered cone. It is a tool holder as described in any one of 1-6.

According to the invention of claim 8, a pair of arc-shaped shim plates are detachably fixed to the rear end surface of the annular concave portion formed in the flange portion by screwing or the like, and the shim plate is attached to the spindle. The tool holder according to any one of claims 1 to 7, wherein the tool holder is in contact with a front end surface.

According to a ninth aspect of the present invention, there is provided the tool holder according to any one of the first to eighth aspects, wherein each member constituting the tool holder, such as the holder main body and the tapered cone, is subjected to a rust prevention treatment.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

As shown in FIGS. 1 and 2, the tool holder 1 of the first embodiment has a shank 3
The shank 3 is provided with a large-diameter flange 4 on the front end side, and a front end 6 is formed in a series on the front end side of the flange 4.

The rear end face 4a of the flange portion 4 is formed at right angles to the axial direction from the outer peripheral side toward the center side, and an arm (not shown) of an automatic tool changer is disengaged from the outer peripheral surface of the flange portion 4. A trapezoidal groove 4b is formed so as to engage as much as possible, an annular concave portion 4c is formed in the rear end surface 4a of the flange portion 4, and an elastic member 7 described later is fitted in the annular concave portion 4c. In addition, 4
e and 4e are key grooves.

A front end surface of the shank portion 3 abuts on an elastic member 7 and a taper cone 8 forming a taper shank is slidably fitted in a radial direction and an axial direction. A stopper member 9 for adjusting the preload, which will be described later, is fitted to the shank portion 3, and a pull stud 10 for supporting the rear end surface of the stopper member 9 is screwed and fixed to the rear end portion of the shank portion 3. The taper cone 8 is pressed against the elastic member 7 to compress the elastic member 7 to provide a preload.

As shown in FIG. 3, the diameter of the tapered cone 8 is reduced from the front side to the rear side, and the entire outer peripheral surface is formed to have a taper α of 1/10 taper. Is formed in a taper β which is smaller than the outer peripheral surface such as a 1/50 taper.

As shown in FIGS. 3 and 4, the taper cone 8 is provided with a slit 8a which is provided with a gentle inclination with respect to the axial direction and is cut off over its entire length at one location in the circumferential direction.
The slit 8a is filled with an elastic body 8b such as a fluorine-based rubber to be elastically deformable in the radial direction. The elastic body 8b is filled in the slit 8a so as not to protrude from the inner and outer peripheral surfaces of the tapered cone 8, and the slit 8a
Is fixed to the opposing surface with an adhesive so as to have a dustproof function.

The elastic member 7 is formed by stacking a plurality of annular disc springs 7a made of an elastic metal plate such as a steel plate and a thin plate 7b made of an annular metal plate. It is housed in the recess 4 c and is interposed between the bottom of the recess 4 c and the front end face of the tapered cone 8.
The stopper member 9 is configured such that an elastic ring 9a and a washer 9b are overlapped, and these are supported on the rear end face of the tapered cone 8 by a large-diameter support portion 10b of a pull stud 10.

Further, on the outer peripheral surface of the portion of the shank portion 3 where the taper cone 8 is fitted, a lubricant enclosing groove 3a is formed in a circumferentially continuous mountain shape, and a lubricant such as grease is filled in the enclosing groove 3. The shank 3 and the tapered cone 8 can be smoothly moved relative to each other over a long period of time.

A tapered hole 11 for holding a collet and a tapered hole 11 are provided between the axially intermediate portion and the front end of the holder body 2.
And a straight hole 12 extending to the rear end side of the bolt hole. A bolt support portion 14 having a small-diameter bolt insertion hole 13 formed in the rear end side of the straight hole 12 is annularly projected toward the center side. A rear end hole 15 is formed on the rear end side of the holder main body 2 so as to open to the rear end surface, and a female screw portion 15a is formed at an appropriate position in the axial direction of the rear end hole 15 to form the holes 11, 12, 1
Reference numerals 3 and 15 are provided in a series and concentrically with the axis of the holder body 2.

The pull stud 10 has a front end male thread portion 1.
0a is fastened to the female thread portion 15a of the rear end hole 15, the large-diameter support portion 10b is brought into contact with the rear end surface of the shank portion 3, and the engaging portion 10c is projected to the rear end side of the large-diameter support portion 10b, A through-hole 10d is formed in the center, and a flat notch 10e facing the large-diameter support 10b. In addition,
10f is a seal member fitted and disposed above the front end male thread portion 10a.

The tapered hole 11 and the straight hole 12 of the holder body 2 have a tapered portion 16a on the front end side and a straight rear end portion 1 formed on the tapered collet 16 in series.
6b is inserted. In the tapered portion 16a of the tapered collet 16, a taper equal to the tapered hole 11 is formed on the outer peripheral surface, and cut portions 16c are formed at three positions in the circumferential direction at equal intervals, and at the center in the circumferential direction between the cut portions 16c. The cutting fluid supply groove 16d is formed on the inner peripheral surface, and a female screw hole 16e penetrating the center portion is formed at the rear end 16b of the tapered collet 16. In addition, the cutting part 16c
Is formed over the entire length of the tapered portion 16a, and the cutting fluid supply groove 16d extends from the front end to the rear end 16
It is elongated to b.

The pull bolt 17 is inserted into the rear end hole 15 from the rear end side of the holder body 2, and the leg 17 a of the pull bolt 17 is inserted.
Through the bolt insertion hole 13 from the rear end side, and insert the rear end 1 of the collet 16 into the male thread 17b formed in the leg 17a.
6b is screwed into the screw hole 16e.
The pulling bolt 17 has an engaging recess 17d having a regular hexagonal cross section in the head 17c, and a small diameter cutting fluid passage hole 17e extending from the bottom of the engaging recess 17d to the tip of the leg 17a. It is formed to penetrate the shaft center. Also,
The head 17c is supported on the rear end face of the bolt support 14 of the holder body 2 via a washer 18 fitted to the leg 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. 2, reference numeral 20 denotes a spindle of a machine tool. A tapered hole 21 is formed at the front end of the spindle 20. The tapered hole 21 is opened at the front end of the spindle 20, and The inner peripheral surface 21a is formed in a 1/10 taper having a small diameter on the rear end side. Then, a retracting member 22 is attached to the rear end side of the tapered hole 21 of the spindle 20.
Is provided. Further, metal members such as the holder body 2, the taper cone 8, and the taper collet 16 are each subjected to a rust prevention treatment so that rust does not occur on the metal members due to a 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 to make the flange. The engaging portion 10c of the pull stud 10 provided on the tool holder 1 is engaged with the front end of the retracting member 22 provided in the spindle 20 of the machine tool, and the pull stud 10 is , The outer peripheral surface of the tapered 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 into the rear side of the spindle 20, the shank portion 3 of the holder body 2 fixed to the pull stud 10 and the tapered cone 8 fitted into the shank portion 3 are pulled back, and the outer peripheral surface of the shank portion 3 5 and the inner peripheral surface of the tapered cone 8 are formed with a loose taper such as a 1/50 taper that is equal to each other and has a small diameter on the rear side.
, The wedge effect acts and the inner peripheral surface of the tapered cone expands, and the lining force acts as indicated by the arrow N.

The inner peripheral surface 21a of the tapered hole 21 of the spindle 20 and the outer peripheral surface of the tapered cone 8 are equal to each other.
Since the rear side of the / 10 taper is formed with a taper having a small diameter, the tapered hole 21 is formed in the outer peripheral surface of the tapered cone 8.
The tightening force M of the inner peripheral surface 21a acts to reduce the diameter of the taper cone 8, but the lining force as indicated by the arrow N of the taper cone 8 acts to strongly restrain both members.
This is possible even if the pulling force of the vehicle is relatively weak. It is already known that the smaller the taper angle, the higher the coupling rigidity.

FIG. 6 is an explanatory view showing a state of a drawing force of the tool holder 1 of the present invention and a conventional standard type tool holder, in which the holder main body 2 is drawn into the tapered hole 21 of the spindle 20 by a draw bar. . For example, when the set value of the retraction force of the holder main body 2 is set to 900 kg, when the tool holder 1 is mounted on the tapered hole 21 of the spindle 20, the retraction member 22 connected to the draw bar (not shown) is retracted. The instantaneous retraction force of the provided compressed disk spring (not shown) or the like is called a hammering effect, and varies depending on the retraction force set value and retraction speed. 8 times 1200
Retracting force of about kg is reached.

However, in the conventional standard type tool holder, since the inner peripheral surface of the taper cone and the outer peripheral surface of the shank are straight in the front-rear direction, the retracting force immediately returns to the retracting force set value of 900 kg indicated by the dotted line, The cutting operation is performed in this state.

On the other hand, the tool holder 1 according to the present invention
According to this, 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 pull stud 10
Part 3 of the holder body 2 fixed to the
The tapered cone 8 fitted into the tapered cone is drawn rearward, and the outer peripheral surface of the shank portion 3 and the inner peripheral surface of the tapered cone 8 have a loose taper such as a 1/50 taper equal to each other and having a small diameter on the rear side. As a result of the retraction of the portion 3, the outer peripheral surface of the shank portion 3 exhibits a locking function by a so-called wedge effect on the tapered cone 8, and the lining force of the outer peripheral surface of the tapered cone 8 acts on the inner peripheral surface 21 a of the tapered hole 21 of the spindle 20. The restraint can be performed in a state where the pulling force of 1200 kg, which is the instantaneous reaching point of the pulling force, is maintained. Therefore, the tool holder 1 attached to the tapered hole 21a of the spindle 20 can be held in close contact 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 restraint is possible while maintaining the retraction force, which is the instantaneous end point of the retraction force, is a problem when applied to a retraction means of a spindle which is used for 4 to 5 years and has a reduced retraction force. Of course, the effect of improving the retraction force can be exerted. Note that the automatic tool changer appropriately removes the arm from the trapezoidal groove 4b and returns the arm to the position before the operation.

After performing the above-described processing, the tool holder 1
In order to perform the automatic tool change, the arm of the automatic tool changer is engaged with the trapezoidal groove 4b to hold the flange portion 4 and the tool holder 1 is pulled out to the tip end side of the spindle 20.

The taper cone 8 provided on the tool holder 1 of the first embodiment is a pull stud in which the rear end face of the taper cone 8 fitted to the shank 3 of the holder body 2 is screwed to the rear end of the shank 3. The large-diameter support portion 10b is brought into contact with the rear end surface of the shank portion 3 and pushed toward the front end side. The elastic member 7 is fitted into the annular concave portion 4b formed on the rear end surface 4a of the flange portion 4, and the front end surface of the tapered cone 8 is Since it is pressed against the flange portion 4 via the elastic member 7, the tapered cone 8
Can be moved in the axial direction of the shank portion 3, and the taper cone 8 is provided with a notch 8a over the entire length in the circumferential direction.
Since the slit 8a is filled with the elastic body 8b, the taper cone 8 can be expanded and reduced in diameter, and the taper cone 8 can be fitted into the taper hole 21 of the spindle 20 by being in close contact therewith. The rear end face 4a of the spindle 20 can be securely brought into close contact with the front end face 20a of the spindle 20.

In the first embodiment, in order to replace the tool 19 whose blade portion has been worn or missing due to use, the tool holder 1 is detached from the machine tool and carried to a tool changing work place.
The front end of the cross-section regular hexagonal operation rod, which is formed by fixing the flange portion 4 of the holder main body 2 with a vice fixed to a vise table and bending the pull stud 10 into an L shape from the rear end side,
It is inserted into the through hole 10d of the pull stud 10 to engage with the engaging recess 17d provided on the head 17c of the pull bolt 17.

Then, the operation rod is rotated in the loosening direction outside the pull stud 10, and the pull bolt 17 is rotated in the same direction, whereby the head 17c is brought into contact with the front end of the pull stud 10, and further loosened. By rotating in the female direction, the collet 16 is pushed out toward the front end side of the holder main body 2 by screw fitting between the external thread 17b of the pull bolt 17 and the female screw hole 16e of the taper collet 16, and the collet 16 Tapered hole 11 at front end of holder body 2
Loosen the tightening.

Thus, the tapered portion 1 of the collet 16
Since the tightening of the shank 19a of the tool 19 by 6a is also loosened, the tool 19 can be pulled out from the collet 16 and the shank 19a of a usable tool 19 such as a new tool can be fitted to the tapered portion 16a of the collet 16. afterwards,
Contrary to the operation described above, the pulling bolt 1 is
7, the taper portion 16a of the collet 16 is fastened to the peripheral surface of the taper hole 11 of the holder body 2 by rotating the holder 7 in the tightening direction and pulling it toward the rear end side of the holder body 2.
The tool shank is held and fixed to the front end of the holder main body 2 through the above, and then the operating rod is pulled out to the rear end of the tool holder 1 and the flange 4 is removed from the vice,
The tool holder 1 can be reused.

Further, the tool holder 1 is mounted on the spindle 20, the tool 19 is advanced while rotating the spindle 20, and a cutting fluid is supplied from the center of the spindle 20 when machining the workpiece. Remove the solution from the pull stud 10
Through the through hole 10d, the rear end hole 15 of the holder body 2, the engaging recess 17d of the pull bolt 17, and the rear end 16b of the taper collet 16, and the cutting fluid supply groove 16 of the collet 16
Through d, the collet 16 can be jetted from the front end along the outer peripheral surface of the tool 19 to cool the blade portion of the tool 19 and the processed portion of the workpiece by the blade portion.

In the first embodiment of the present invention, the flange portion is formed integrally with the holder body, or the whole or the front end portion is formed as a separate member, and this member is fitted to the outer periphery of the holder body by shrink fitting or the like. It is configured by fixing. In the first embodiment of the present invention, the inner peripheral surface of the tapered hole and the outer peripheral surface of the tapered cone provided at the front end of the spindle are formed into a tight taper such as a 7/24 taper having a small diameter on the rear side. The inner peripheral surface and the outer peripheral surface of the shank portion of the holder main body may be formed in a loose taper such as 1/50 having a small diameter on the rear side.

As shown in FIG. 7, the tool holder 1 of the second embodiment is provided with a shank 3 at the rear end of the holder body 2 and a large-diameter flange 4 at the front end of the shank 3. is there. An annular recess 4 is provided on the rear end surface 4a of the flange portion 4.
c, an elastic member 7 is fitted in the annular concave portion 4c, a taper cone 8 is rotatably fitted on the outer periphery of the shank portion 3, and a stopper member 9 for adjusting the preload is provided at the rear end of the shank portion 3. .

The tapered cone 8 is formed such that the entire outer peripheral surface is formed into a tight taper of 7/24 taper, and the front side 8g of the inner peripheral surface is formed to have a taper of 1/10 to 1/100, preferably 1/50. The intermediate portion 8h connected to the front side portion 8g is slightly protruded toward the center via a step, and a straight portion 8i is formed after the intermediate portion 8h.

The shank portion 3 is a front side portion 3c of the outer peripheral surface.
Is equal to 1/10 to 1 which is equal to the front side portion 8g of the tapered cone 8.
/ 100 taper, preferably 1/50 taper, the intermediate portion 3d connected to the front side portion 3c has a slightly smaller outer diameter, the straight cylindrical straight portion 3e connected to the intermediate portion 3d, and the rear straight portion. A rear end 3f having an equal outer diameter connected to 3e is provided.

The tapered cone 8 is fitted to the shank 3, the front side 8 g of the tapered cone 8 is fitted to the front side 3 c of the shank 3, and the gap between the intermediate part 8 h of the tapered cone 8 and the intermediate part 3 d of the shank 3 is formed. A gap a in the radial direction and a gap b in the front-rear direction are formed in the taper cone 8, and the straight portion 8i of the tapered cone 8 is fitted to the straight portion 3f of the shank portion 3.

The stopper member 9 is provided with a washer 9 at the rear end 3f of the shank 3 projecting from the rear end surface of the tapered cone 8.
b, the nut 9c is screwed into the rear end 3f and tightened, and the washer 9b is pressed against the rear end face of the tapered cone 8.

On the outer peripheral surface of the front side portion 3c and the straight portion 3e of the shank portion 3, a lubricating groove 3a and a lubricating groove 3g are formed in a mountain shape continuous in the circumferential direction, respectively. Lubricant such as grease is put in 3a and 3g. At the front end of the spindle 20 of the machine tool, there is formed a tapered hole 21 opening to the front end face, and a 7/24 taper tight taper having a small diameter on the rear side is formed on the inner peripheral surface 21a of the tapered hole 21.

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 effect of the tool holder according to the second embodiment are the same as those of the tool holder according to the first embodiment. However, according to the second embodiment, the front side 8g of the tapered cone 8 and the front side 3c of the shank 3 are not used. Has a tapered mating,
The length of the cutting process at the portion where the taper is formed is short, so that the process can be easily performed. In addition, the straight portion 8i provided on the rear side of the taper cone 8 and the rear straight portion 3e provided on the shank portion 3
Are fitted, the taper cone 8 can be supported by the shank portion 3 at the front and rear two places, and vibration during use can be reduced, and the machining accuracy of the workpiece by the tool can be improved.

The tool holder of the second embodiment can use the tapered cone 8 of the modified example shown in FIG. 8, and the front cut 8c and the rear cut 8d are connected to the tapered cone 8 shown in FIG.
Are formed in the range from the front end and the rear end to the middle part in the front-rear direction, the front cut 8c and the rear cut 8d are inclined at the same angle with respect to the axial direction, and the front and rear cuts 8c and 8d are formed. The gaps are filled with elastic bodies 8e and 8f, such as fluorine rubber, respectively, and the slits 8c and 8d are formed.
Is fixed to the opposing surface with an adhesive so as to have a dust-proof function, and since the slits 8c and 8d are short, they can be easily processed, and the aging of the elastic bodies 8e and 8f is slow and long-term use is possible. I have to. The taper of the inner and outer peripheral surfaces of the tapered cone 8 is the same as that of the tapered cone shown in FIG.

As shown in FIG. 9, the tool holder 1 of the third embodiment has two flat arc-shaped shim plates 24, 24 on the rear end face 4a of the flange portion 4 of the holder body 2, and has a The shims 24, 24 are provided with holes 24a, 24a, and countersunk screws 25, 25 are fitted into the holes 24a, 24a. It is fixed detachably, and the shim plates 24, 24
The rear surface of the machine tool is brought into close contact with the front end surface 20a of the spindle 20 of the machine tool.

The configuration of the tool holder according to the third embodiment other than that described above is the same as that of the tool holder according to the second embodiment. The use and effect of the tool holder according to the third embodiment are the same as those of the tool holder according to the second embodiment.
When the shim plates 24, 24 are damaged due to wear or the like due to multiple attachment / detachment of the tool holder 1, the shim plates 24, 24 are replaced with new ones. In the case where is damaged, a shim plate having a required thickness may be supported on the rear end face after cutting the rear end portion of the flange portion 4 and fixed by flathead screws. It is preferable that a plurality of shims having different thicknesses are prepared, and a shim having an appropriate thickness is used.

The tool holder of each of the above embodiments is not limited to use mounted on a spindle of a vertical machine tool, but can be used even if mounted on a spindle of a horizontal machine tool. The taper cone of the tool holder of each of the above embodiments need not form a split.

[0051]

As described above, the first aspect of the present invention is a tool holder removably fitted in a tapered hole of a spindle of a machine tool having a tapered hole having a small outside diameter on the rear side. A large outer diameter flange is provided on the front side of the shank provided on the rear side, and an elastic member is interposed between the rear end of the flange and the front end of the tapered cone fitted on the shank, and the rear side is small. In a tool holder in which a tapered cone having an outer diameter is supported by a stopper member provided at a rear end surface of the tapered cone in a shank portion, an outer peripheral surface of the tapered cone is formed at an angle equal to an inner peripheral surface of a tapered hole of the spindle. The peripheral surface and the outer peripheral surface of the shank portion have a smaller diameter on the rear side and are equal to each other. As a result, the holder body is retracted to the rear side by the retracting member provided in the spindle, so that the outer peripheral surface of the shank portion and the inner peripheral surface of the taper cone are equal to each other, and the taper cone is enlarged by the taper in which the rear side has a smaller diameter. The outer peripheral surface is pressed 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 tapered cone is brought into close contact with the inner peripheral surface of the tapered hole, and the taper cone is sufficiently restrained. The tool can be held firmly, and heavy cutting can be performed with a tool mounted on the tool holder by driving the spindle, and high-precision cutting can be performed. Also, the outer peripheral surface of the shank portion has a locking function by a so-called wedge effect on 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. The tool can be restrained while maintaining the pull-in force, and the tool holder attached to the tapered hole of the spindle is held tightly with a large restraining force to provide excellent damping effect and can withstand high-speed rotation and low-speed heavy cutting. It can be.

According to the second aspect of the present invention, the tapered cone having a small diameter on the rear side is formed on the entire inner peripheral surface of the tapered cone and almost the entire outer peripheral surface of the shank portion. Use the whole effectively 1
It is preferable to use a spindle having a / 10 taper hole.

According to a third aspect of the present invention, in the tool holder according to the first aspect, a loose taper is formed only on an outer peripheral surface of a front side portion of a shank portion and an inner peripheral surface of a taper cone, and an area for taper processing is reduced. Since the rear side of the outer surface of the shank and the inner surface of the taper cone was straight, and the taper cone was fitted to the shank,
Although machining is easy, vibration during machining is small and high-precision cutting can be performed. This is preferable for use in a spindle having a 7/24 tapered hole.

According to the fourth and fifth aspects of the present invention, in the tool holder according to any one of the first to third aspects, the taper cone is provided with a slit, and the slit is filled with an elastic material such as a fluorine-based rubber and bonded. Therefore, it has a dustproof function.

According to a sixth aspect of the present invention, in the tool holder according to any one of the first to fifth aspects, since a plurality of disc springs and washers are stacked on at least one of the front side and the rear side, the taper cone is formed. Can be biased to the rear,
By changing the number and thickness of the washers, the position of the taper cone in the front-rear direction and the like can be adjusted.

According to a seventh aspect of the present invention, in the tool holder according to any one of the first to sixth aspects, at least one of a washer, a spring washer, and a nut which is screw-fitted to the inner periphery of the rear end of the shank portion. Since the rear end of the tapered cone is provided to support the rear end of the tapered cone, different pull studs can be used.

According to an eighth aspect of the present invention, in the tool holder according to any one of the first to seventh aspects, a pair of arc-shaped shim plates are detachably fixed to the rear end face of the flange portion, and the front end of the spindle is provided. The holder body can be used effectively for a long period of time, and by using a shim plate of the required thickness, the difference between the gap between the spindle end face of the machine tool and the rear end face of the tool holder flange Can be absorbed.

According to a ninth aspect of the present invention, in the tool holder according to any one of the first to eighth aspects, the members constituting the tool holder, such as the holder main body and the tapered cone, are subjected to rust prevention treatment. Tapered cones can be used for a long time.

[Brief description of the drawings]

FIG. 1 is an exploded side view showing a tool holder according to a first embodiment of the present invention.

FIG. 2 is an explanatory longitudinal sectional view of the tool holder shown in FIG. 1;

FIG. 3 is an enlarged vertical sectional view of a taper cone of the tool holder shown in FIG.

FIG. 4 is a front view of a taper cone of the tool holder shown in FIG. 1;

FIG. 5 is an operation explanatory view of the tool holder shown in FIG. 1;

FIG. 6 is an explanatory view showing an operating state of a drawing force in the tool holder of the present invention and a conventional standard type tool holder.

FIG. 7 is an explanatory longitudinal sectional view showing a tool holder according to a second embodiment of the present invention.

FIG. 8 is a front view of a taper cone of the tool holder shown in FIG. 7;

FIG. 9 is a longitudinal sectional view of a main part showing a tool holder according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tool holder 2 Holder main body 3 Shank part 3a Lubricant sealing groove 3c Front end of shank outer peripheral surface 3d Intermediate part 3e Straight part 3f Rear end 4 Flange 4a Rear end 4b Trapezoidal groove 4c Annular recess 4d Female screw hole 6 Front Part 7 Elastic member 7a Disc spring 8 Taper cone 8a Split 8b Elastic body 8c Front split 8d Rear split 8e, 8f Elastic body 8g Front side 8h Intermediate part 8i Straight part 9 Stopper member 9a Elastic ring 9b Washer 10 Front pull stud 10 Pull stud Part 10b Large diameter support part 10c Engagement part 10d Through hole 10e Flat notch part 10f Seal member 11 Tapered hole 12 Straight hole 13 Bolt insertion hole 14 Bolt support part 15 Rear end hole 15a Female thread part 16 Taper collet 16a Front end side Tapered part 16b Rear end part 16c Slot 16d Cutting fluid supply groove 16e Female thread hole 17 Pull bolt 17a Leg 17b Male thread 17c Head 17d Engaging recess 17e Cutting fluid passage hole 18 Washer 19 Tool 19a Tool shank 20 Spindle 20a Front end face 21 Tapered hole 21a Inner peripheral surface of tapered hole 22 Retraction member 24, 24 Shim plate 25, 25 Countersunk screw

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[Procedure amendment]

[Submission date] March 28, 2000 (2003.
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Tool holder

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool holder detachably mounted on a spindle of a machine tool.

[0002]

The conventional tool holder is
The shank portion is formed on a tapered surface having a smaller outer diameter as going rearward, and the shank portion is inserted into a tapered hole of a spindle of a machine tool, and the shank portion is pulled rearward by a pull-in member, thereby obtaining the tool holder. Is mounted on the spindle. However, since a gap is formed between the flange provided on the front side of the shank of the tool holder and the front end face of the spindle, the tool holder is not tightly fitted only with the tapered shank in the tapered hole of the spindle. , The shank portion could not be held with a large force, and chattering occurred in high-speed rotation or low-speed heavy cutting, and satisfactory cutting could not be performed. Therefore, the end face restraint obtained by pressing the rear end face of the flange portion provided on the front end side of the shank portion of the tool holder against the front end face of the spindle, the outer peripheral surface of the tapered shank portion, and the inner peripheral surface of the tapered hole. In addition to the above-mentioned restraint, a large restraining force is obtained. But,
In order to achieve the above configuration, the manufacturing tolerance of the tool holder must be severe, which increases the cost.In addition, if the spindle is used for a long period of time, the tapered hole needs to be polished again. In the re-ground, the tapered hole expands, so the restraining force by the outer peripheral surface of the shank portion and the inner peripheral surface of the tapered hole is reduced, and only the restraint by the flange portion of the tool holder and the end surface of the spindle is performed. There is no contact, and the tool shakes and cannot be used. When the spindle is rotated at a high speed, the front end of the spindle expands due to the centrifugal force due to the tapered hole, the restraining force due to the tapered hole decreases, the tool held by the tool holder vibrates, and the processing accuracy decreases.

Therefore, a straight is provided on a shank portion of a holder body of a tool holder having a flange portion, a taper cone is fitted therein, and an elastic member is interposed between a front end surface of the taper cone and the flange portion to preload the taper cone. By pressing the outer peripheral surface of the taper cone, which becomes smaller in diameter toward the rear, against the inner peripheral surface of the tapered hole of the spindle, and further pulling the holder body to the rear of the spindle, it is possible to obtain a certain result, and it is possible to manufacture the device. Some are relatively easy. However, unless the retraction force of the holder body is increased, the taper cone cannot be sufficiently restrained by the inner peripheral surface of the tapered hole. In addition, a large-diameter end portion and a small-diameter end portion are formed in a two-stage straight portion on the outer periphery of the shank portion of the holder body, and the straight small-diameter end portion is formed on the inner periphery of the taper cone so as to correspond to the end portion. Although there is a diameter end portion, there is a problem that since the inner peripheral surface of the tapered cone is straight, a sufficient effect cannot be obtained unless the holder main body is pulled in with a strong pulling force.

[0004] The present invention solves the above-mentioned problems,
Even if the retraction force of the holder body is relatively small, the inner peripheral surface of the shank portion of the holder body and the inner peripheral surface of the tapered cone that is closely fitted to the shank portion, the inner peripheral surface of the taper hole of the spindle having a smaller diameter toward the rear, and By forming a taper surface with a smaller angle than the taper angle of the taper cone outer peripheral surface, the shank outer peripheral surface exerts a locking function by the so-called wedge effect on the taper cone, and the taper cone outer peripheral surface to the spindle taper hole inner peripheral surface The object of the present invention is to provide a tool holder that can hold a tool holder mounted in a tapered hole of a spindle with a large restraining force as a result of the lining force of the tool and can withstand high-speed rotation and low-speed heavy cutting.

[0005]

According to a first aspect of the present invention, there is provided a taper cone which is fitted in a taper hole formed in a spindle of a machine tool so as to have a smaller diameter as going from the front end of the spindle to the rear. A holder body having a shank portion fitted so as to be relatively movable in the axial direction, a flange portion provided integrally with the holder body and in contact with a front end surface of the spindle, and a front end surface of the flange portion and the tapered cone. An elastic member provided therebetween,
In a tool holder having a stopper member that is in contact with a rear end surface of the tapered cone and that can apply a preload to the elastic member by being able to tighten a pull stud screwed to a rear end of the shank portion, the outer peripheral surface of the tapered cone is The taper surface of the spindle is formed to have a taper surface having the same angle as the inner circumferential surface, and the inner diameter of the taper cone and at least a part of the outer circumferential surface of the shank portion fitted to the inner circumferential surface become smaller as going rearward. The tapered surfaces are formed to be equal to each other, and the tapered surface is formed at an angle smaller than the taper angle of the outer peripheral surface of the tapered cone.

According to a second aspect of the present invention, there is provided the tool holder according to the first aspect, wherein the tapered surface having a small angle is formed on the entire inner peripheral surface of the taper cone and the entire outer peripheral surface of the shank portion.

According to a third aspect of the present invention, the tapered surface having a small angle is formed on an outer peripheral surface on a front end side of the shank portion and an inner peripheral surface on a front end side of the tapered cone, respectively, and the rear end portion of the shank portion is provided. The outer peripheral surface and the inner peripheral surface on the rear end side of the tapered cone are formed into a straight surface that closely fits slidably in the axial direction, and the shank portion that is located between the tapered surface with a gentle angle and the straight surface. The tool holder according to claim 1, wherein a gap is provided between the intermediate portion and the intermediate portion of the tapered cone.

According to a fourth aspect of the present invention, the tapered cone is formed with a slit which is inclined with respect to the axial direction over the entire length of the tapered cone, and the slit is filled with an elastic material such as a fluorine-based rubber and bonded. 2 is a tool holder described in FIG.

According to a fifth aspect of the present invention, a front cutout which is inclined with respect to the axial direction is provided at a portion of the taper cone facing the tapered surface having a small angle, and an axial direction is provided at a portion of the taper cone facing the straight surface. 4. The tool holder according to claim 3, wherein a rear slit is provided which is inclined with respect to the first and second slits, and the both slits are filled with an elastic material such as fluorine rubber and bonded.

According to a sixth aspect of the present invention, an annular concave portion for accommodating the elastic member is formed at a position of the flange portion facing the front end surface of the tapered cone, and the elastic member includes a plurality of disc springs laminated to each other. The tool holder according to claim 1, further comprising a washer stacked on at least one of the laminated disc springs.

According to a seventh aspect of the present invention, the stopper member comprises:
The tool holder according to claim 1, wherein the tool holder is configured by stacking an elastic ring and a washer.

The invention according to claim 8 is such that a pair of arc-shaped shim plates are detachably provided at the flange portion facing the front end surface of the spindle, and the shim plate is brought into contact with the front end surface of the spindle. The tool holder according to any one of claims 1 to 7, wherein:

According to a ninth aspect of the present invention, there is provided the tool holder according to any one of the first to eighth aspects, wherein each member constituting the tool holder, such as the holder main body and the tapered cone, is subjected to a rust prevention treatment.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A tool holder 1 according to a first embodiment comprises:
As shown in FIGS. 1 and 2, a holder main body 2 is provided. The holder main body 2 has a shank portion 3 on a rear end side and a large outer diameter flange portion 4 on a front end side of the shank portion 3. A front end 6 for holding a tool is provided at the front end of the flange 4.
Are integrally formed.

The rear end face 4a of the flange portion 4 is formed at right angles to the axial direction from the outer peripheral side toward the center side, and an arm (not shown) of an automatic tool changing device is engaged and disengaged from the outer peripheral surface of the flange portion 4. A trapezoidal groove 4b is formed so as to engage as much as possible, an annular recess 4c is formed in the rear end face 4a of the flange portion 4, and an elastic member 7 described later is housed in the annular recess 4c. 4e, 4e are key grooves.

A tapered cone 8 having a front end surface abutting against an elastic member 7 to form a tapered shank is fitted on the outer periphery of the shank portion 3 so as to be reduced in diameter and slidable in the axial direction.
A stopper member 9 for preload adjustment, which will be described later, is in contact with the rear end of the tapered cone 8, and a pull stud 10 that supports the rear end surface of the stopper member 9 is screwed to the rear end of the shank portion 3. By tightening the pull stud 10, the taper cone 8 is pressed against the elastic member 7 via the stopper member 9, and the elastic member 7 is compressed to apply a preload.

As shown in FIG. 3, the tapered cone 8 is configured to have a smaller diameter from the front end to the rear end, and the entire outer peripheral surface has a taper angle of 1/10 taper. The inner peripheral surface has a 1/50 taper surface, and is formed at a taper angle β that is smaller than the outer peripheral surface.

As shown in FIGS. 3 and 4, the tapered cone 8 has a slit 8a that is gently inclined with respect to the axial direction.
Is formed over the entire length of the tapered cone 8, and the slit 8a is filled with an elastic body 8b such as a fluorine-based rubber to be elastically deformable in the radial direction. The elastic body 8b is filled in the slit 8a so as not to protrude from the inner and outer peripheral surfaces of the tapered cone 8, and has a dustproof function by being fixed to an opposing surface of the slit 8a with an adhesive.

The elastic member 7 is formed by stacking a plurality of annular disc springs 7a made of an elastic metal plate such as a steel plate and a thin plate (washer) 7b made of an annular metal plate or the like. The upper layer portion is housed in the annular concave portion 4c so as to protrude from the annular concave portion 4c.
It is interposed between the bottom of the annular recess 4 c and the front end face of the tapered cone 8. The stopper member 9 includes an elastic ring 9a.
And the washer 9b are overlapped, and these are supported on the rear end face of the tapered cone 8 by the large-diameter support portion 10b of the pull stud 10.

Further, on the outer peripheral surface of the portion of the shank portion 3 where the taper cone 8 is fitted, a mountain-shaped lubricant enclosing groove 3a which is continuous in the circumferential direction is formed, and a lubricant such as grease is filled in the enclosing groove 3. The shank 3 and the tapered cone 8 can be smoothly moved relative to each other over a long period of time.

A tapered hole 11 for holding the collet and a straight hole 12 extending to the rear end side of the tapered hole 11 are formed coaxially between the axially intermediate portion of the holder body 2 and the front end thereof. A bolt support portion 14 is formed by forming a small-diameter bolt insertion hole 13 at the rear end side of the bolt 12, and a rear end hole opening at the rear end surface of the holder body 2 at the rear end side of the bolt insertion hole 13. 15 is formed, and a female screw portion 15 a is formed at an appropriate position in the axial direction of the rear end hole 15. The holes 11, 12, 13, and 15 are provided in a series concentrically with the axis of the holder body 2.

The front end thread portion 10 of the pull stud 10
a is screwed into the female screw portion 15a of the rear end hole 15, and the pull stud 10 is tightened until the large diameter support portion 10b comes into contact with the rear end surface of the shank portion 3, thereby stopping the stopper member 9. The taper cone 8 is pressed against the elastic member 9 via the elastic member 9 so that a predetermined preload can be applied to the taper cone 8. An engaging portion 10c is provided on the rear end side of the large-diameter support portion 10b, and a through hole 10d is formed in the center of the pull stud 10.
0b is formed with opposing flat notches 10e. Reference numeral 10f denotes a seal member fitted and disposed above the front end male thread portion 10a.

The tapered hole 11 and the straight hole 12 of the holder body 2 have a tapered portion 16a on the front end side formed in a tapered collet 16 and a straight rear end portion 1a.
6b is inserted. In the tapered portion 16a of the tapered collet 16, a taper equal to the tapered hole 11 is formed on the outer peripheral surface, and cut portions 16c are formed at three positions in the circumferential direction at equal intervals, and at the center in the circumferential direction between the cut portions 16c. The cutting fluid supply groove 16d is formed through the inner periphery of the tapered collet 16, and a female screw hole 16e is formed in the rear end 16b of the tapered collet 16 so as to penetrate the center. The cut portion 16c is formed over the entire length of the tapered portion 16a, and the cutting fluid supply groove 16d is formed to be elongated from the front end of the tapered collet 16 to the rear end 16b.

A pull bolt 17 is inserted into the rear end hole 15 from the rear end side of the holder body 2, and the leg 17 a of the pull bolt 17 is inserted into the bolt insertion hole 13 from the rear end side.
A male thread portion 17b formed in 7a is screwed into a screw hole 16e to be formed in a rear end portion 16b of the collet 16. The pull bolt 17 is provided with an engaging recess 1 having a regular hexagonal cross section.
7d with a head 17c
a small diameter cutting fluid passage hole 1 from the bottom of d to the tip of the leg 17a
7 e is formed so as to penetrate the axis of the pull bolt 17. The head 17c is configured to be engaged with the rear end surface of the bolt support portion 14 of the holder body 2 via 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. 2, reference numeral 20 denotes a spindle of a machine tool. The spindle 20 is formed with a tapered hole 21 having a smaller diameter as it goes backward from the front end face. It has a taper angle exhibiting a 1/10 taper surface. And the spindle 20
A pull-in member 22 is provided on the rear end side of the tapered hole 21. Further, metal members such as the holder body 2, the taper cone 8, and the taper collet 16 are each subjected to a rust prevention treatment so that rust does not occur on the metal members due to a cutting fluid or the like.

When the tool holder 1 according to the first embodiment having the above-described configuration is mounted on the spindle 20 of a machine tool, the flange 4 of the tool holder 1 is gripped by the arm of the automatic tool changer, and the tapered cone. The shank part 3 including the taper hole 8 in the spindle 20 of the machine tool
Insert inside. Thereafter, the engaging portion 10 c of the pull stud 10 is engaged with the front end of the pull-in member 22, and the pull stud 10 is pulled into the rear side of the spindle 20. Thereby, the outer peripheral surface of the tapered cone 8 of the tool holder 1 is brought into close contact with the inner peripheral surface of the spindle 20. And pull stud 1
0 is retracted to the rear of the spindle 20,
The shank portion 3 of the holder body 2 fixed to the pull stud 10 and the tapered cone 8 fitted to the shank portion 3 are pulled backward. At this time, since the outer peripheral surface of the shank portion 3 and the inner peripheral surface of the taper cone 8 are formed with a taper such as 1/50 taper, which is equal to each other, the diameter gradually decreases toward the rear.
On the other hand, as shown by an arrow K in FIG. 5, the wedge effect works, and the inner peripheral surface of the tapered cone expands, and a lining force acts as shown by an arrow N.

The inner peripheral surface 21a of the tapered hole 21 of the spindle 20 and the outer peripheral surface of the tapered cone 8 are equal to each other.
The taper whose diameter becomes smaller as it goes to the rear of the / 10 taper
As a result, the tightening force M of the inner peripheral surface 21 a of the tapered hole 21 acts on the outer peripheral surface of the tapered cone 8 to reduce the diameter of the tapered cone 8. In addition, it is possible to strongly restrain both of them even if the pulling force of the tool holder 1 is relatively weak.
It is already known that the smaller the taper angle, the higher the coupling rigidity.

FIG. 6 is an explanatory view showing a state of a drawing force of the tool holder 1 of the present invention and a conventional standard type tool holder, in which the holder main body 2 is drawn into the tapered hole 21 of the spindle 20 by a draw bar. . For example, when the set value of the retraction force of the holder main body 2 is set to 900 kg, when the tool holder 1 is mounted on the tapered hole 21 of the spindle 20, the retraction member 22 connected to the draw bar (not shown) is retracted. The instantaneous retraction force (called a hammering effect, which varies depending on the retraction force set value and retraction speed) of the installed compressed disk spring (not shown) or the like is instantaneously 1.3 to 1.3. 8 times 120
Retract force of about 0kg is reached.

However, in the conventional standard type tool holder, since the inner peripheral surface of the tapered cone and the outer peripheral surface of the shank portion are respectively straight in the front-rear direction, the retracting force immediately returns to the retracting force set value of 900 kg, which is indicated by the dotted line, and The cutting operation is performed in this state.

On the other hand, the tool holder 1 according to the present invention
According to this, when the tool holder 1 is mounted in the tapered hole 21 of the spindle 20, the draw bar pulls the pull stud 10 to the rear of the spindle 20, whereby the shank portion 3 of the holder main body 2 fixed to the pull stud 10 and the shank When the tapered cone 8 fitted in the portion 3 is pulled rearward, a loose taper such as a 1/50 taper, which is equal to the outer peripheral surface of the shank portion 3 and the inner peripheral surface of the tapered cone 8, becomes smaller in diameter as it goes rearward. As a result, the outer peripheral surface of the shank portion 3 exhibits a locking function by a so-called wedge effect on the tapered cone 8 due to the retraction of the shank portion 3, and the lining force of the outer peripheral surface of the tapered cone 8 against the inner peripheral surface 21 a of the tapered hole 21 of the spindle 20. Acts, as a result, the instantaneous reaching point of the retraction force is 1200 kg.
Can be restrained in a state where the pulling force is maintained. Therefore, the tool holder 1 mounted in the tapered hole 21a of the spindle 20 can be closely held with a large restraining force, and can withstand high-speed rotation and low-speed heavy cutting.
Can be provided.

The fact that the restraint can be performed while maintaining the retraction force, which is the instantaneous point of the retraction force, can be achieved when applied to the retraction means of a spindle used for 4 to 5 years in which the retraction force decreases. Of course, the effect of improving the retraction force can be exerted. Note that the automatic tool changer appropriately removes the arm from the trapezoidal groove 4b and returns the arm to the position before the operation.

When performing the above-mentioned automatic tool change of the tool holder 1, the arm of the automatic tool changer is engaged with the trapezoidal groove 4b to grip the flange portion 4. Pull out the tool holder 1.

In the tool holder 1 according to the first embodiment, since the elastic member 7 is interposed between the front end surface of the tapered cone 8 and the rear end surface 4a of the flange portion 4 facing the tapered cone 8, the tapered cone 8 Can be moved in the axial direction of the shank portion 3, and the taper cone 8 is formed with a cut 8a extending over the entire length, and the cut 8a is filled with an elastic body 8b, so that the taper cone 8 can be expanded and reduced in diameter. The taper cone 8 is fitted into the taper hole 21 of the spindle 20 in close contact with the
The rear end face 4a of the spindle 20 can be securely brought into close contact with the front end face 20a of the spindle 20.

In the first embodiment, in order to replace the tool 19 whose blade part has been worn or missing due to use, the tool holder 1 is detached from the machine tool, carried to a tool changing work place, and the holder body 2 The flange portion 4 is fixed to a vise table by a vice or the like, and the front end of the cross-section regular hexagonal operation rod bent in an L shape from the rear end side of the pull stud 10 is inserted into the through hole of the pull stud 10. 10d is inserted into the engaging recess 17d provided on the head 17c of the pull bolt 17.

Then, the operation rod is rotated in the direction of loosening from the outside of the pull stud 10, and the pull bolt 17 is rotated in the same direction, so that the head 17c of the pull stud 10 is rotated.
And the pull bolt 17 is further rotated in the loosening direction in this state, so that the male screw 17b of the pull bolt 17 and the female screw hole 16e of the tapered collet 16 are threadedly engaged with each other. Is pushed out to the front end side of the holder main body 2, and the tightening of the tapered portion 16 a of the collet 16 by the tapered hole 11 at the front end of the holder main body 2 is loosened.

Thus, the tapered portion 1 of the collet 16
Since the tightening of the shank 19a of the tool 19 by 6a is also loosened, the tool 19 can be pulled out from the collet 16 and the shank 19a of a usable tool 19 such as a new tool can be fitted to the tapered portion 16a of the collet 16. afterwards,
Contrary to the operation described above, the pulling bolt 1 is
7, the taper portion 16a of the collet 16 is tightened at the peripheral surface of the tapered hole 11 of the holder body 2 by rotating the tool 7 in the tightening direction and retracting the holder body 2, and the shank of the tool is inserted through the collet 16 into the holder body 2. The tool holder 1 can be reused by gripping it at the front end 6 and then pulling out the operating rod to the rear end side of the tool holder 1 and removing the flange 4 from the vice.

Further, the tool holder 1 is mounted on the spindle 20, the tool 19 is advanced while rotating the spindle 20, and a cutting fluid is supplied from the center of the spindle 20 when machining the workpiece. Remove the solution from the pull stud 10
Through the through hole 10d, the rear end hole 15 of the holder body 2, the engaging recess 17d of the pull bolt 17, and the rear end 16b of the taper collet 16, and the cutting fluid supply groove 16 of the collet 16
Through d, the collet 16 can be jetted from the front end along the outer peripheral surface of the tool 19 to cool the blade portion of the tool 19 and the processed portion of the workpiece by the blade portion.

In the tool holder according to the first embodiment, the flange portion may be formed integrally with the holder body, or may be formed as a separate member except for the entire or front end portion, and this member may be formed by shrink fitting or the like. It is configured by fitting and fixing to the outer periphery. Further, in the tool holder according to the first embodiment, the inner peripheral surface of the tapered hole and the outer peripheral surface of the tapered cone provided at the front end of the spindle have a tight taper surface such as a 7/24 taper whose diameter decreases toward the rear. And the inner peripheral surface of the taper cone and the outer peripheral surface of the shank portion of the holder main body may be formed in a taper such as 1/50 which becomes smaller as going backward.

As shown in FIG. 7, the tool holder 1 according to the second embodiment of the present invention is provided with a shank portion 3 longer than that shown in FIG. A flange portion 4 having a larger diameter than the shank portion 3 is provided at the front end side of 3. An annular concave portion 4c is formed in the rear end surface 4a of the flange portion 4, an elastic member 7 is fitted into the annular concave portion 4c, and a taper cone 8 having a length corresponding to the length of the shank portion 3 is provided on the outer periphery of the shank portion 3. A stopper member 9 for adjusting the preload is provided at the rear end of the shank 3 so as to be rotatable and slidable in the axial direction.

The entire outer peripheral surface of the tapered cone 8 is
A 7/24 taper is formed on a tight taper surface, and a front end 8g side of the inner peripheral surface is formed as a 1/10 to 1/100 taper, preferably a 1/50 taper loose taper surface, and a front end 8g is formed. The inner peripheral surface of the intermediate portion 8h is formed in the same shape as the tapered surface of the outer peripheral surface of the tapered cone 8, and a straight surface is formed on the inner peripheral surface of the rear end portion connected to the intermediate portion 8h. A straight portion 8i is formed.

The outer peripheral surface of the front end 3c of the shank 3 is equal to 1/10 of the front end 8g of the tapered cone 8.
The outer peripheral surface of the intermediate portion 3d connected to the front end portion 3c is formed to have a small outer diameter that does not contact the inner peripheral surface of the tapered cone 8, A straight portion 3e having the same straight surface as the straight portion 8i of the tapered cone 8 is formed on an outer peripheral surface of a rear end portion connected to the intermediate portion 3d, and a rear end portion 3f having an equal outer diameter connected to the straight portion 3e is formed. Is provided.

When the tapered cone 8 is fitted to the shank 3, the front end 8g of the tapered cone 8 and the front end 3c of the shank 3 are closely fitted, and the intermediate portion 8h of the tapered cone 8 and the intermediate portion of the shank 3 are tightly fitted. A gap a in the radial direction and a gap b in the front-rear direction are formed between the straight portion 3d and the straight portion 8i of the tapered cone 8 and the straight portion 3f of the shank portion 3 are closely fitted.

The stopper member 9 includes a washer 9b engaged with a rear end 3f of the shank portion 3 protruding from the rear end surface of the tapered cone 8, and a nut 9 screwed to the rear end 3f.
The washer 9b is pressed against the rear end face of the tapered cone 8 by screwing and tightening the nut 9c to the rear end 3f.

On the outer peripheral surfaces of the front end portion 3c and the straight portion 3e of the shank portion 3, a lubricating groove 3a and a lubricating groove 3g which are continuous in the circumferential direction are formed, respectively. Lubricant such as grease is put in 3a and 3g. At the front end of the spindle 20 of the machine tool, a tapered hole 21 opening at the front end face is formed, and the inner peripheral surface 21a of the tapered hole 21 is reduced in diameter on the rear side.
A tight taper is formed.

The configuration of the tool holder according to the second embodiment other than that described above is the same as that of the tool holder according to the first embodiment. The use and effect of the tool holder in the second embodiment are the same as those of the tool holder in the first embodiment. However, in the second embodiment, the length of the shank 3 is increased, and The present invention is applied to the case where the tapered cone 8 is made longer and the front end portion 8g of the tapered cone 8 and the front end portion 3c of the shank portion 3 are tightly fitted by a tapered surface. The length of the cutting process of the portion forming the groove is short, the process can be easily performed, and the straight portion 8i provided at the rear end portion of the tapered cone 8 and the straight portion 3e provided at the rear end portion of the shank portion 3 are dense. Since the fitting is performed, the tapered cone 8 can be supported by the shank portion 3 at the front and rear two places, and the vibration during use can be reduced, and the machining accuracy of the work by the tool can be improved.

FIG. 8 shows a modification of the tapered cone 8 of the tool holder according to the second embodiment. The tapered cone 8 has a front end 8g which is inclined with respect to the axial direction at a position facing the loosely tapered surface. A front notch 8c extending from the front end of the tapered cone 8 to the middle portion is provided, and extends from the rear end of the tapered cone 8 to the middle portion at a position opposed to the straight portion 8i of the tapered cone 8 with respect to the axial direction. A rear split 8d is provided, and both split splits 8c and 8 are provided.
d is filled with elastic bodies 8e and 8f such as fluorine-based rubber, respectively, and fixed to the opposing surfaces of the slits 8c and 8d with an adhesive so that a dust-proof function can be exhibited, and the slits 8c and 8d are short. Therefore, these processes are facilitated, and the elastic bodies 8e and 8f are slowly deteriorated, and can be used for a long time. The taper of the inner and outer peripheral surfaces of the tapered cone 8 is the same as that of the tapered cone shown in FIG.

FIG. 9 shows a third embodiment of the present invention. The tool holder 1 in this embodiment is similar to that of FIG.
As shown in FIG. 2, two flat arc-shaped shim plates 24, 24 are concentric with the flange portion 3 on the rear end surface 4a of the flange portion 4 of the holder body 2 facing the end surface 20a of the spindle 20, and are arranged in the circumferential direction. This shim plate 24,
24 are provided with a plurality of holes 24a,
The shim plates 24, 24 are removably fixed by inserting 25 and screwing into female screw holes 4d, 4d formed in advance on the flange portion 4, respectively.
The rear surface of the machine tool is brought into close contact with the front end surface 20a of the spindle 20 of the machine tool.

The configuration of the tool holder according to the third embodiment other than that described above is the same as that of the tool holder according to the second embodiment. The use and effect of the tool holder according to the third embodiment are the same as those of the tool holder according to the second embodiment. However, in the third embodiment, the tool holder 1 is rotated multiple times with respect to the spindle 20. When the shim plates 24, 24 are damaged by wear or the like due to attachment / detachment, the shim plates 24, 24 are replaced with new ones.
When the rear end surface 4a is damaged, a shim plate having a required thickness may be supported on the rear end surface after cutting the rear end portion of the flange portion 4 and fixed by flathead screws. It is preferable that a plurality of shims having different thicknesses are prepared, and a shim having an appropriate thickness is used.

The tool holder of each of the above embodiments is not limited to use mounted on a spindle of a vertical machine tool, but can be used even if mounted on a spindle of a horizontal machine tool. The taper cone of the tool holder of each of the above embodiments need not form a split.

[0050]

As described above, according to the first aspect of the present invention, the taper cone fitted into the taper hole formed in the spindle of the machine tool so as to have a smaller diameter as going from the front end to the rear of the spindle. A holder 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 body and abutting on a front end surface of the spindle; An elastic member provided between the front end surfaces of the tapered cones, and a stopper member which abuts on the rear end surface of the tapered cones and which can apply a preload to the elastic members by tightening a pull stud screwed to the rear end of the shank portion. Wherein the outer peripheral surface of the tapered cone has an angle equal to the inner peripheral surface of the tapered hole of the spindle. And forming at least a part of the inner peripheral surface of the tapered cone and the outer peripheral surface of the shank portion fitted to the inner peripheral surface into tapered surfaces having a smaller diameter as going backward, and forming the tapered surface into the same shape. Because the angle is less than the taper angle of the outer peripheral surface of the taper cone,
By retracting the holder body by the retracting member provided in the spindle, the outer peripheral surface of the shank portion exhibits a locking function by a so-called wedge effect with respect to the tapered cone, and the outer peripheral surface of the tapered cone with respect to the inner peripheral surface of the tapered hole of the spindle. As a result of the lining force of the surface acting, it is possible to restrain the tool holder mounted on the tapered hole of the spindle with a large restraining force, with the restraint being possible while maintaining the pulling force which is the instantaneous point of the pulling force. With this, the damping effect is excellent, and it is possible to sufficiently endure high-speed rotation and low-speed heavy cutting. In addition, by forming the tapered surfaces having the same angle smaller than the taper angle of the outer peripheral surface of the tapered cone on the outer peripheral surface of the shank portion and the inner peripheral surface of the tapered cone, even if the pulling force of the holder body is weak, the outer peripheral surface of the tapered cone is formed. Can be tightly held to the inner peripheral surface of the tapered hole, the taper cone can be sufficiently restrained and strongly held, and heavy cutting can be performed with a tool mounted on the tool holder by driving the spindle, and high-precision cutting can be performed.

According to the second aspect of the present invention, the tapered surfaces having the smaller diameter toward the rear and having the same angle are formed on the entire inner peripheral surface of the tapered cone and the entire outer peripheral surface of the shank portion. It is preferable to use the spindle in which a taper hole of 1/10 taper is formed by effectively using the entire inner peripheral surface of the taper cone.

According to the third aspect of the present invention, the tapered surface having a small angle is formed on the outer peripheral surface on the front end side of the shank portion and on the inner peripheral surface on the front end side of the tapered cone, respectively. The shank located between the tapered surface and the straight surface having a gentle angle, wherein the outer peripheral surface on the end side and the inner peripheral surface on the rear end side of the tapered cone are slidably fitted closely in the axial direction. By providing a gap between the middle part of the part and the middle part of the taper cone, even with a tool holder having a long shank part, the area for tapering can be reduced, and tapering can be easily performed. Vibration at the time is small, high-precision cutting can be performed, and it is preferable to use for a spindle having a tapered hole having a 7/24 taper.

According to the fourth and fifth aspects of the present invention, since the tapered cone is provided with a slit, and the slit is filled with an elastic material such as a fluorine-based rubber and adhered, a dustproof function can be exhibited.

According to the invention of claim 6, an annular recess is formed at the location of the flange portion facing the front end face of the tapered cone, and a plurality of disc springs laminated to each other in the annular recess and the laminated disc spring The elastic member consisting of a washer superimposed on at least one of the above is accommodated, so that the tapered cone can be biased to the rear side, and by changing the number and thickness of the washer, the longitudinal direction of the tapered cone can be changed. The position can be adjusted.

According to the seventh aspect of the present invention, by forming the stopper member by stacking an elastic ring and a washer,
Allows the use of different pull studs.

According to the eighth aspect of the present invention, a pair of arc-shaped shim plates are detachably provided at the flange portion facing the front end surface of the spindle, and the shim plate is brought into contact with the front end surface of the spindle. By making contact, the holder body can be used effectively for a long period of time, and by using a shim plate of the required thickness, the difference between the gap between the spindle end face of the machine tool and the rear end face of the tool holder flange can be reduced. Can be absorbed.

According to the ninth aspect of the present invention, the members constituting the tool holder, such as the holder main body and the depa cone, are subjected to rust prevention treatment, so that the holder main body and the depa cone can be used for a long period of time.

[Brief description of the drawings]

FIG. 1 is an exploded side view showing a tool holder according to a first embodiment of the present invention.

FIG. 2 is an explanatory longitudinal sectional view of the tool holder shown in FIG. 1;

FIG. 3 is an enlarged vertical sectional view of a taper cone of the tool holder shown in FIG.

FIG. 4 is a front view of a taper cone of the tool holder shown in FIG. 1;

FIG. 5 is an operation explanatory view of the tool holder shown in FIG. 1;

FIG. 6 is an explanatory view showing an operating state of a drawing force in the tool holder of the present invention and a conventional standard type tool holder.

FIG. 7 is an explanatory longitudinal sectional view showing a tool holder according to a second embodiment of the present invention.

FIG. 8 is a front view of a taper cone of the tool holder shown in FIG. 7;

FIG. 9 is a longitudinal sectional view of a main part showing a tool holder according to a third embodiment of the present invention.

[Description of Signs] 1 Tool holder 2 Holder body 3 Shank portion 3a Lubricant filling groove 3c Front end of outer peripheral surface of shank 3d Intermediate portion 3e Straight portion 3f Rear end 4 Flange 4a Rear end 4b Trapezoidal groove 4c Annular recess 4d Female thread hole 6 Front end 7 Elastic member 7a Belleville spring 8 Taper cone 8a Split 8b Elastic body 8c Front split 8d Rear split 8e, 8f Elastic body 8g Front side 8h Middle 8i Straight section 9 Stopper member 9a Elastic ring 9b Pull washer 10 Stud 10a Front end male thread part 10b Large diameter support part 10c Engagement part 10d Through hole 10e Flat notch part 10f Seal member 11 Tapered hole 12 Straight hole 13 Bolt insertion hole 14 Bolt support part 15 Rear end hole 15a Female thread part 16 Taper Collet 16a Tapered portion 16b on front end side Rear end part 16c Cut part 16d Cutting fluid supply groove 16e Female thread hole 17 Pull bolt 17a Leg 17b Male thread part 17c Head 17d Engagement concave part 17e Cutting fluid passage hole 18 Washer 19 Tool 19a Tool shank 20 Spindle 20a Front end face Reference Signs List 21 tapered hole 21a inner peripheral surface of tapered hole 22 lead-in member 24, 24 shim plate 25, 25 countersunk screw

Continued on the front page (72) Inventor Yusaku Yamamoto 1-6-153 Motomachi, Higashiosaka-shi, Osaka F-term in Niken Kozaku Co., Ltd. (reference) 3C016 AA02 FA03 FA36 3C032 AA01 AA18 BB16 3C046 KK02

Claims (9)

[Claims] 1. A tool holder removably fitted in a tapered hole of a spindle of a machine tool having a tapered hole having a small outer diameter on a rear side, wherein a large outside is provided on a front side of a shank provided on a rear side of the holder body. An elastic member is interposed between the rear end of the flange and the front end of the tapered cone fitted to the shank, and the rear end of the tapered cone with a small outside diameter is provided. In the tool holder supported by the stopper member provided in the portion, the outer peripheral surface of the tapered cone is formed at an angle equal to the inner peripheral surface of the tapered hole of the spindle, and the rear side is formed between the inner peripheral surface of the tapered cone and the outer peripheral surface of the shank portion. A tool holder, characterized in that tapers having smaller diameters and equal in angle to the outer peripheral surface of the tapered cone are formed at least partially in the front-rear direction. 2. A tool holder according to claim 1, wherein a loose taper having a smaller diameter on the rear side is formed on the entire inner peripheral surface of the tapered cone and substantially the entire outer peripheral surface of the shank portion. . 3. An outer peripheral surface of a front side portion of a shank portion of the holder body and an inner peripheral surface of a front side portion of the tapered cone are each formed with a taper having a small diameter on the rear side at an equal angle to each other, and a front side of the tapered cone is formed on a front side of the shank portion. Mating parts
A gap is provided between the middle part of the shank part and the middle part of the taper cone, and a straight part is provided on the outer peripheral surface of the rear part of the shank part and the inner peripheral surface of the rear part of the taper cone. The tool holder according to claim 1, wherein the side portions are fitted. 4. A slit is formed by inclining with respect to the axial direction over the entire length of the taper cone, and the slit is filled with an elastic body such as a fluorine-based rubber and adhered thereto. A tool holder according to one of the preceding claims. 5. A taper cone is provided with a front slit and a rear slit in a circumferential direction from a front end and a rear end of the taper cone, and is inclined in an axial direction at an equal angle to each other. The tool holder according to any one of claims 1 to 3, wherein the tool holder is filled with an elastic body and bonded. 6. An annular recess formed in contact with an outer periphery of a front end of a shank portion and opening rearward, at least a part of an elastic member is housed in the annular recess to support a front end surface of a tapered cone. The tool holder according to any one of claims 1 to 5, wherein a plurality of disc springs and washers are stacked on at least one of the front side and the rear side thereof. 7. The tapered cone according to claim 7, wherein at least one of a washer, a spring washer, and a nut screw-fitted to the inner periphery of the rear end of the shank portion is provided at the rear end of the tapered cone. The tool holder according to any one of 1 to 6. 8. A pair of arc-shaped shim plates are detachably fixed to a rear end surface on an outer peripheral side of an annular concave portion formed in a flange portion,
The tool holder according to any one of claims 1 to 7, wherein the shim plate is in contact with a front end surface of the spindle. 9. The tool holder according to claim 1, wherein each member constituting the tool holder, such as the holder body and the tapered cone, is subjected to a rust-preventive treatment.