JPH10263908A - Chuck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chuck which facilitates elastic deformation to a contracting direction in diameter of a chuck tube over almost whole length of the chuck tube without requiring a large clamping force, expands its effective holding length without enlarging the length of the chuck tube, and also prevents oscillation in processing. SOLUTION: This chuck is provided with a holder body 10 consisting of a shank part 101, a flange 102 formed on large diameter side of the shank part 101, and a chuck tube 103 installed from the terminal side of the opposite shank side of the flange 102, a clamp tube 50 which is connected so that it may allow the rotation with the peripheral of the chuck tube 103 and axial movement of the chuck tube, and many needle rollers 40 which re mounted over whole circumference between the chuck tube 103 and the clamp tube 50. The chuck contracts the chuck tube in diameter or restores it by spiral revolution while rotating needle rollers by the rotation of the clamp tube 50. The chuck supports and fixes the annular body 105 of different member in concentric with support surface 102a on the support surface 102a in the opposite shank side of the flange 102, and forms an annular groove 104 with a depth equivalent to the annular of the ring body 105.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck for gripping a cutting tool such as a drill, and more particularly, to rotating a tightening cylinder fitted to the outer periphery of a chuck cylinder of a holder body via a needle roller in a tightening direction. The present invention also relates to a chuck for reducing the diameter of a chuck cylinder and holding a target tool tightly.

[0002]

2. Description of the Related Art A conventional chuck will be described with reference to FIGS. FIG. 8 is a cross-sectional view of the chuck for holding a tool, and FIG. 9 is a perspective view of each of the constituent members in an exploded view of the chuck for holding a tool. 8 and 9, the chuck for holding a tool has a holder body 1. The holder body 1 includes a taper shank 1A inserted into a spindle of a machine tool (not shown) and a taper shank 1A. 1A, a gripping flange 1B formed at the large-diameter end portion, and a tapered shank portion 1B from the end surface of the flange 1B on the side opposite to the tapered shank portion.
And a chuck cylinder 1C having a tapered surface 1Ca whose outer peripheral surface is formed with a tapered surface 1Ca whose diameter decreases as going from the flange 1B to the tip end in a direction opposite to that of the tapered shank portion 1A. .

[0003] Reference numeral 2 denotes a roller holding cylinder which is loosely fitted on the outer periphery of the chuck cylinder 1C. The diameter of the roller holding cylinder 2 becomes smaller toward the tip at a taper angle substantially similar to that of the tapered surface 1Ca of the chuck cylinder 1C. It is formed from a cylindrical body. Further, the roller holding cylinder 2 is held by a stop ring 3 provided on the outer periphery of the distal end portion of the chuck cylinder 1C so as not to fall off from the chuck cylinder 1C. A large number of needle rollers 4 fitted in the roller holding cylinder 2 at a predetermined angle in the circumferential direction with respect to the axis of the roller holding cylinder 2 are fitted.
Are arranged in several steps over the entire surface. Further, each needle roller 4 is formed to have a diameter larger than the thickness dimension of the roller holding cylinder 2, so that each needle roller 4 projecting toward the inner peripheral surface side of the roller holding cylinder 2 is attached to the tapered surface 1Ca of the chuck cylinder 1C. The needle rollers 4 projecting toward the outer peripheral surface of the roller holding cylinder 2 are brought into contact with the inner peripheral surface of a tightening cylinder 5 described later. The fastening cylinder 5 is the chuck cylinder 1
C is reduced in diameter to hold a target tool tightly, and is fitted to the outer periphery of the chuck cylinder 1C via a needle roller 4 held by a roller holding cylinder 2. This tightening cylinder 5
Is formed as a tapered cylindrical surface whose diameter decreases from the end facing the flange 1B to the tip. Further, a retaining ring 6 serving as a seal is mounted on the inner end surface of the fastening cylinder 5 on the flange 1B side. The retaining ring 6 serving also as a seal comes into contact with the outer peripheral surface of the chuck cylinder 1C to provide a sealing function. Further, by contacting the end surface of the roller holding cylinder 2, the fastening cylinder 5 is prevented from falling off from the chuck cylinder 1 </ b> C.

In the conventional chuck configured as described above, when gripping the tool 7, the shank 7 of the tool 7 is used.
A spring collet 8 is fitted into A, and the shank 7A of the tool 7 is inserted into the cylindrical hole of the chuck cylinder 1C together with the spring collet 8. When the tightening cylinder 5 is rotated clockwise in this state, each of the needle rollers 4 in contact with the tapered cylindrical surface of the tightening cylinder 5 rotates in a direction perpendicular to its own axis while rotating around the outer circumference of the chuck cylinder 1C. Because the surface revolves spirally, the roller holding cylinder 2 moves while rotating with the revolving of the needle roller 4 from the tip side of the chuck cylinder 1C toward the flange 1B, and at the same time, the tightening cylinder 5 also moves the flange 1B.
Move in the direction of. As a result, the distance between the tapered cylindrical surface of the tightening cylinder 5 and the outer peripheral taper surface of the chuck cylinder 1C decreases, and the tightening cylinder 5 moves the chuck cylinder 1C from the outer circumference to the inner circumferential direction via each needle roller 4. Apply pressure from the entire circumference to reduce the diameter. As a result, the shank of the tool 7 inserted into the cylindrical hole of the chuck cylinder 1C is tightened via the spring collet 8 and gripped. When the tightening cylinder 5 in the tightened state is rotated in the counterclockwise direction opposite to the above, the roller holding cylinder 2 moves to the distal end side of the chuck cylinder 1C and the tightening cylinder 5 also moves in the same direction. For this reason, the chuck cylinder 1C whose diameter has been reduced is restored to the original diameter, and the tool 7
As a result, the tool 7 can be pulled out or replaced.

[0005]

The chuck cylinder 1C in the conventional chuck as described above has a structure extending from the end surface of the flange 1B on the side opposite to the taper shank portion in the direction opposite to the taper shank portion 1A. So the flange 1
The elastic deformation rigidity in the radial direction of the region 1Ca adjacent to the base of the chuck cylinder 1C connected to B is considerably higher than the elastic deformation rigidity in the radial direction of the other region other than the region 1Ca. I have. For this reason, even if the chuck cylinder 1C is rotated in the tightening direction to reduce the diameter of the chuck cylinder 1C, the diameter reduction rate of the region 1Ca is extremely lower than the diameter reduction ratio of the other regions. This will be described with reference to FIG.

FIG. 2A is a graph showing the change in the inner diameter of the chuck cylinder and its reduced diameter when the chuck cylinder is tightened, and FIG. 2B shows a conventional chuck cylinder 1C. FIG. 2B is a graph showing the change in the reduced inner diameter at each of points P1 to P12 from the opening end of the chuck cylinder 1C to the flange 1B by tightening the conventional chuck cylinder 1C shown in FIG. A curve 62 of FIG. As is apparent from the curve 62, the change ratio of the reduced diameter inside diameter in the range of the points P2 to P9 is relatively large and stable, but the area portion 1 corresponding to the range of the points P10 to P12.
The rate of change of the reduced diameter inner diameter in Ca decreases extremely,
The rate of change increases as the distance to the flange 1B increases.

The reason for this is that points P10 to P12
Since the elastic deformation rigidity in the diameter reducing direction of the region portion 1Ca corresponding to the range becomes larger as approaching the flange 1B, the portion of the tightening cylinder 5 facing the region portion 1Ca is elastically deformed in the radially increasing direction. Because. As a result, the area part 1
The gripping force of Ca decreases, so that the shank of the tool 7 inserted into the chuck cylinder 1C cannot be gripped with a uniform gripping force over the entire length, and the chuck cylinder 1C effectively grips the tool. The length L1 becomes shorter. In particular, when heavy cutting is performed with a tool gripped in a state where the effective gripping length L1 is short as described above, the tool generates a swinging motion with the tip end side of the chuck cylinder 1C as a fulcrum. Friction occurs between the outer peripheral surface of the tool shank corresponding to the low-force area portion 1Ca and the inner surface of the chuck cylinder 1C, and there is a problem that the outer peripheral surface of the tool shank and the inner surface of the chuck cylinder 1C are damaged. .

If the tightening cylinder 5 is tightened until the end surface of the tightening cylinder 5 on the flange 1B side contacts the flange 1B of the holder body 1, the rate of change of the reduced diameter inner diameter in the region 1Ca can be increased to some extent. On the other hand, a large tightening force is required for the tightening cylinder 5 and the region portion 1Ca
In the worst case, the load on the needle roller corresponding to the above becomes excessive, and in the worst case, the surface of the needle roller, the outer peripheral surface of the chuck cylinder, and the inner peripheral surface of the tightening cylinder are damaged, and the gripping force of the tool is There was a problem that caused trouble. Further, if the effective gripping length L1 of the chuck cylinder 1C with respect to the tool is sufficiently ensured, the chuck cylinder 1C becomes longer, the tool length L2 of the holder body 1 becomes longer, and the chuck becomes larger and heavier. there were. The present invention has been made in view of the above circumstances, and it is possible to easily elastically deform the chuck cylinder in the diameter reducing direction over substantially the entire length of the chuck cylinder, and reduce the effective gripping length without elongating the chuck cylinder. It is an object of the present invention to provide a chuck that can be enlarged, and vibration of a cutting edge of a tool such as an end mill is absorbed by a chuck body to perform quiet cutting.

[0009]

According to a first aspect of the present invention, there is provided a shank portion to be inserted into a spindle of a machine tool, a gripping flange formed at one end of the shank portion, and a flange on an opposite side of the shank portion of the flange. A holder body having a chuck cylinder extending from the end surface in a direction opposite to the shank portion so as to coincide with the axis of the shank portion and having a tapered surface formed on the outer peripheral surface with a diameter decreasing from the flange toward the tip end; A clamping cylinder rotatably engaged with the outer periphery of the chuck cylinder and movably engaged in the axial direction of the chuck cylinder, and having a tapered surface on an inner peripheral surface whose diameter decreases from the flange toward the tip end; A number of needle rollers which are disposed over the entire circumference between the outer peripheral surface of the cylinder and the inner peripheral surface of the tightening cylinder and are inclined at an appropriate angle in the circumferential direction with respect to the axis of the chuck cylinder and the tightening cylinder. Prepared, front In the chuck in which the needle roller is rotated by the rotation of the tightening cylinder and revolved in a spiral while the diameter of the chuck cylinder is reduced or restored, an annular body of another member is provided on the support surface of the flange opposite to the shank portion with the support surface. It is concentrically supported and fixed to the flange, and an annular groove having a thickness equivalent to the thickness of the annular body is formed along the circumferential direction of the chuck cylinder.

According to a second aspect of the present invention, in the chuck according to the first aspect, the annular body is supported and fixed to a flat support surface orthogonal to the axial direction of the flange by a plurality of screws.

According to a third aspect of the present invention, in the chuck according to the first aspect, the annular body is fitted and fixed in a projecting portion projecting from a support surface of the flange.

According to a fourth aspect of the present invention, in the chuck according to any one of the first to third aspects, the inside of the wall constituting the chuck cylinder extends in the axial direction of the chuck cylinder over substantially the entire length of the wall. A plurality of holes are formed at predetermined intervals in the circumferential direction of the chuck cylinder.

According to a fifth aspect of the present invention, in the chuck according to any one of the first to third aspects, the inside of the wall constituting the chuck cylinder extends in substantially the entire length of the wall in the axial direction of the chuck cylinder. A plurality of holes are formed at predetermined intervals in the circumferential direction of the chuck cylinder.

According to a sixth aspect of the present invention, in the chuck according to any one of the first to third aspects, the chuck extends in the axial direction of the chuck cylinder over substantially the entire length of the wall constituting the chuck cylinder. A plurality of holes are formed at predetermined intervals in the circumferential direction of the chuck cylinder, and a plurality of slits are formed in the inner wall surface of the chuck cylinder corresponding to the holes and communicate with the inside of the chuck cylinder from the holes. It is characterized by.

According to a seventh aspect of the present invention, in the chuck according to any one of the first to sixth aspects, an inner peripheral portion of an elastic metal annular side plate is fixed to an outer peripheral surface of a distal end portion of the chuck cylinder, An outer peripheral end portion of the annular side plate is pressed and engaged with an inner peripheral surface of the tightening cylinder.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a chuck showing a first embodiment according to the present invention. In FIG.
The chuck for holding a tool has a holder body 10, which is provided with a tapered shank portion 101 inserted into a spindle of a machine tool (not shown) and a large-diameter end portion of the tapered shank portion 101. Gripping flange 1 formed on
02, the flange 102 extends from the support surface 102a of the flange 102 on the side opposite to the taper shank portion in the direction opposite to the taper shank portion 101 so as to coincide with the axis of the taper shank portion 101, and goes from the flange 102 to the tip on the outer peripheral surface Cylinder 1 having a tapered surface 103a whose diameter becomes smaller in accordance with
03. Further, the support surface 102a of the flange 102 on the side opposite to the taper shank portion is a flat surface orthogonal to the axial direction of the flange 102, and the support surface 102 is provided with a ring member 105 made of die steel, hardened steel, or the like as a separate member. 10
2a, and a required number of through-holes 105a are provided at equal intervals in the circumferential direction of the annular body 105. A frusto-conical counterbore is formed on the anti-taper shank side of the through-hole 105a. Screw hole 10 facing hole 105a
2b is formed at a predetermined length in the axial direction of the flange 102 from the support surface 102a. And the through hole 105
a into the screw holes 102b
The annular body 105 is fixed to the support surface 102a of the flange 102, and an annular groove 104 having a predetermined depth (about 3 to 5 mm) is formed between the inner peripheral surface of the annular body 105 and the chuck cylinder 103. The length of the chuck cylinder 103 is formed along the circumferential direction of the flange 103 by the annular groove 104 without changing the tool length L3 of the holder body 10.
The structure is extended to the 02 side. Thus, the elastic deformation of the area of the chuck cylinder 103 close to the flange 102 in the diameter reducing direction is made substantially the same as the elastic deformation of the other area of the chuck cylinder 103 in the diameter reducing direction. It is a characteristic part of. The countersunk head of the screw 106 is accommodated in the counterbore of the through hole 105a so as not to protrude outside the annular body 105.

Reference numeral 20 denotes a roller holding cylinder which is loosely fitted on the outer periphery of the chuck cylinder 103. The diameter of the roller holding cylinder 20 decreases toward the tip thereof at a taper angle substantially similar to that of the tapered surface 103a of the chuck cylinder 103. It is formed from a cylindrical body. Further, the roller holding cylinder 20 is provided with the chuck cylinder 1
A stop ring 30 provided on the outer periphery of the distal end portion 03 holds the chuck tube 103 from falling off the chuck cylinder 103.
Also, a large number of needle rollers 40 fitted in the roller holding cylinder 20 at a predetermined angle in the circumferential direction with respect to the axis of the roller holding cylinder 20 are arranged in the circumferential direction similarly to the case shown in FIG. The needle rollers 40 are provided in a plurality of stages in the longitudinal direction of the chuck cylinder 20, for example, three stages, one stage less than the case shown in FIG. Further, each of the needle rollers 40 is formed to have a diameter larger than the thickness dimension of the roller holding cylinder 20, so that each of the needle rollers 40 projecting toward the inner peripheral surface side of the roller holding cylinder 20 is tapered on the outer periphery of the chuck cylinder 103. , And each needle roller 40 projecting toward the outer peripheral surface of the roller holding cylinder 20 is brought into contact with an inner peripheral surface of a tightening cylinder 50 described later.

The tightening cylinder 50 is for reducing the diameter of the chuck cylinder 103 to grip a target tool tightly. The tightening cylinder 50 is connected to the outer periphery of the chuck cylinder 103 via the needle roller 40 held by the roller holding cylinder 20. Mated. The inner peripheral surface of the tightening cylinder 50 is formed as a tapered cylindrical surface whose diameter decreases from the end facing the annular body 105 toward the tip. Further, a retaining ring 67 also serving as a seal is attached to the inner end surface of the tightening cylinder 50 on the annular body 105 side, and the retaining ring 67 also serves as a seal by contacting the outer peripheral surface of the chuck cylinder 103. It exerts its function and abuts against the end face of the roller holding cylinder 20 to make the tightening cylinder 5
0 is prevented from falling out of the chuck cylinder 103.

In the chuck according to the first embodiment configured as described above, when gripping the tool 7, the spring collet 8 is fitted to the shank 7A of the tool 7,
The shank 7A of the tool 7 together with the spring collet 8 is inserted into the cylindrical hole of the chuck cylinder 103. When the tightening cylinder 50 is rotated clockwise in this state, each of the needle rollers 40 abutting on the tapered cylindrical surface of the tightening cylinder 50 rotates while rotating in a direction perpendicular to its own axis.
Of the roller holding cylinder 2 in order to revolve spirally around the outer peripheral surface of
Numeral 0 moves from the tip end side of the chuck cylinder 103 to the direction of the flange 102 while rotating along with the revolution of the needle roller 40, and at the same time, the tightening cylinder 50 also moves toward the flange 102. This reduces the distance between the tapered cylindrical surface of the tightening cylinder 50 and the outer peripheral tapered surface of the chuck cylinder 103,
The tightening cylinder 50 reduces the diameter of the chuck cylinder 103 by strongly pressing the chuck cylinder 103 from the outer periphery to the inner periphery through the needle rollers 40 from the entire peripheral surface. As a result, the shank of the tool 7 inserted into the cylindrical hole of the chuck cylinder 103 becomes the spring collet 8
Is clamped and gripped. When the tightening cylinder 50 in the tightened state is rotated in the counterclockwise direction opposite to the above, the roller holding cylinder 20 moves to the tip end side of the chuck cylinder 103 and the tightening cylinder 50 also moves in the same direction.
Therefore, the reduced diameter of the chuck cylinder 103 is restored to the original diameter, and the gripping force on the tool 7 is released. As a result, the tool 7 can be removed or replaced.

Next, a description will be given, with reference to FIG. 2, of a chuck cylinder of the chuck according to the first embodiment and a change in the diameter of the reduced inner diameter at the time of fastening. FIG. 2A is a graph showing a change in the inner diameter of the chuck cylinder and the diameter of the reduced diameter when the chuck cylinder is tightened. FIG. 2C shows the chuck cylinder 103 according to the first embodiment. As shown in FIG. 2C, the length of the chuck cylinder 103 is determined by the annular groove 104.
Since the holder body 10 has a structure extended to the flange 102 side without increasing the tool length L4, the chuck cylinder 103 is tightened by the tightening cylinder 50 to
3A is a graph showing the change in the diameter of the reduced diameter at each of points P1 to P12 from the open end of No. 3 to the distal end surface of the annular body 105 fixed to the support surface 102a of the flange 102.
The result shown by the curve 61 of FIG. As is apparent from this curve 61, the rate of change of the reduced diameter inside diameter from the point P2 to the point P11 is relatively large and stable. That is, the effective gripping length L4 of the chuck cylinder 103 that can effectively and strongly exert the gripping force on the shank of the tool 7
2C is enlarged from the base of the chuck cylinder 103 connected to the support surface 102a of the flange 102 to the vicinity of the opening end, as shown in FIG.
The effective holding length L1 of C can be greatly increased.

Therefore, according to the first embodiment of the present invention, the annular member 105, which is a separate member, is supported concentrically with the support surface 102a on the support surface 102a at the end of the flange 102 on the side opposite to the taper shank. And the annular body 105
An annular groove 104 having a depth equal to the thickness of the chuck body 103 is formed by the annular groove 104 so that the length of the chuck cylinder 103 can be increased without increasing the tool length L4 of the holder body 10.
Since the structure is extended to the side, the elastic deformation of the base region close to the flange 102 of the chuck cylinder 103 in the radial reduction direction is almost the same as the elastic deformation of the other region of the chuck cylinder 103 in the radial reduction direction. Can be. Along with this, the effective gripping length L3 of the chuck cylinder 103 capable of exerting an effective and strong gripping force on the shank of the tool 7 is increased from the base of the chuck cylinder 103 connected to the flange 102 to near the opening tip. At the same time, the connection base region of the chuck cylinder 103 with the flange 102 is also easily elastically deformed in the diameter reducing direction, and the flange 102 side end surface of the clamping cylinder 50 is
Until the flange 102 comes into contact with the flange 102, the tightening cylinder 50 can be easily tightened without requiring a large tightening force as in the related art, and the gripping force of the tool on the shank in the connection base region is sufficiently exhibited. be able to. In addition, since the gripping force of the tool on the shank in the connection base region between the chuck cylinder 103 and the flange 102 can be increased, even when heavy cutting is performed, the tool does not oscillate around the tip of the chuck cylinder 103 as a fulcrum. And the inner surface of the chuck tube 103 can be prevented from being damaged due to friction between the outer peripheral surface of the tool shank and the inner surface of the chuck cylinder 103 due to friction between the outer peripheral surface of the tool shank and the inner surface of the chuck cylinder 103.

Further, the effective holding length L4 of the chuck cylinder 103
And the tightening cylinder 50 can be tightened until the flange 102 side end surface of the tightening cylinder 50 comes into contact with the annular body 105 fixed to the support surface 102a of the flange 102 of the holder body 10. Therefore, the tool length L3 of the holder body 10 can be shortened, and the weight and size of the chuck can be reduced.

The depth of the annular groove 104 can be adjusted to about 3 to 5 mm by changing the thickness of the annular body 105, and the annular body 105 is formed as a separate member from the flange 102. When used in contact with the support surface 102a of the tool 102, vibrations generated during cutting by a cutting edge of a tool such as an end mill are absorbed by the chuck body 10 so that quiet cutting can be performed, and the chuck body 10 and the annular body 105 are made of different materials. It is preferable that the vibration can be sufficiently absorbed during cutting.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 (A) and 3 (B). In FIG.
The same components as those in FIG. 1 are denoted by the same reference numerals, and the description of the configurations will be omitted, and portions different from FIG. 1 will be mainly described. The second embodiment is characterized in that the chuck cylinder 10
3 is provided with an annular groove 104 for substantially increasing the length of the flange 10.
In addition to being formed by the annular body 105 fixed to the second support surface 102a, a plurality of grooves 60 extending in the axial direction of the chuck cylinder 103 are formed on the inner wall surface of the chuck cylinder 103 over the entire length of the inner wall surface. It is formed at equal intervals in the circumferential direction.

In the chuck according to the second embodiment,
The formation of the plurality of grooves 60 on the inner wall surface of the chuck cylinder 103 further facilitates the elastic deformation of the chuck cylinder 103 by the tightening cylinder 50 in the diameter reducing direction. Then, FIG. 2 (C)
Can be further increased in the range from the point P2 to the point P11, and the change ratio in the range can be made uniform from the curve 61 shown in FIG. Therefore, the elastic deformation of the chuck cylinder 103 in the diameter reducing direction can be easily performed over substantially the entire length of the chuck cylinder without requiring a large tightening force, and the effective gripping length can be increased without lengthening the chuck cylinder. In addition, the thickness of the fastening cylinder 50 can be reduced. In addition, by forming the groove 60 on the inner wall surface of the chuck cylinder 103, when the tool inserted into the chuck cylinder 103 is tightened, the oil adhering to the tool is easily released.

Next, a third embodiment of the present invention will be described with reference to FIGS. In FIG.
The same components as those in FIG. 1 are denoted by the same reference numerals, and the description of the configurations will be omitted, and portions different from FIG. 1 will be mainly described. The third embodiment is characterized in that the chuck cylinder 10
3 is provided with an annular groove 104 for substantially increasing the length of the flange 10.
In addition to being formed by the annular body 105 fixed to the second support surface 102a, a plurality of holes 70 extending in the axial direction of the chuck cylinder 103 are formed in the wall constituting the chuck cylinder 103 over substantially the entire length of the wall. It is formed at equal intervals in the circumferential direction of the cylinder 103.

In the chuck according to the third embodiment,
By forming a plurality of holes 70 in the wall constituting the chuck cylinder 103, the clamping cylinder 50
Elastic deformation in the direction of diameter reduction is further facilitated. Then, the change rate of the reduced diameter inner diameter in the range from the point P2 to the point P11 shown in FIG. 2C is further increased, and the change rate in the range can be made uniform from the curve 61 shown in FIG. Therefore, the elastic deformation of the chuck cylinder 103 in the diameter reducing direction can be easily performed over substantially the entire length of the chuck cylinder 103 without requiring a large tightening force, and the effective gripping length can be increased without making the chuck cylinder long. With the tightening cylinder 50
Can be made thinner.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. 5 (A) and 5 (B). In FIG.
The same components as those in FIG. 1 are denoted by the same reference numerals, and the description of the configurations will be omitted, and portions different from FIG. 1 will be mainly described. The feature of the fourth embodiment is that the chuck cylinder 10
3 is provided with an annular groove 104 for substantially increasing the length of the flange 10.
In addition to being formed by the annular body 105 fixed to the second support surface 102a, a plurality of holes 70 extending in the axial direction of the chuck cylinder 103 are formed in the wall constituting the chuck cylinder 103 over substantially the entire length of the wall. The chuck cylinder 103 is formed at regular intervals in the circumferential direction of the cylinder 103, and on the inner wall surface of the chuck cylinder 103, the chuck cylinder 1
03, where a plurality of slits 80 communicating with the inside of the slit 03 are formed.

In the chuck according to the fourth embodiment,
A plurality of holes 70 are formed in the wall portion of the chuck cylinder 103, and a slit 80 communicating from the hole 70 to the inside of the chuck cylinder 103 is formed. The elastic deformation in the direction is further facilitated. Then, the points P2 to P11 shown in FIG.
Can be further increased, and the change rate in the range can be made more uniform than the curve 61 shown in FIG. Therefore, the chuck cylinder 103
Elastic deformation in the diameter reducing direction of the chuck tube 103 can be easily performed over substantially the entire length of the chuck tube 103 without requiring a large clamping force, and the effective gripping length can be increased without lengthening the chuck tube. 50 can be made thinner. Also,
By forming the slit 80, the chuck cylinder 103
It facilitates the escape of oil adhering to the tool when the tool inserted therein is tightened.

Next, a fifth embodiment of the present invention will be described with reference to FIGS. 6 (A) and 6 (B). In FIG.
The same components as those in FIG. 1 are denoted by the same reference numerals, and the description of the configurations will be omitted, and portions different from FIG. 1 will be mainly described. The feature of the fifth embodiment is that the chuck cylinder 10
3 is provided with an annular groove 104 for substantially increasing the length of the flange 10.
In addition to being formed by the annular body 105 fixed to the second support surface 102a, an annular step 90 that opens in the distal direction is formed on the outer peripheral surface of the distal end portion of the chuck cylinder 103, and is adjacent to the annular step 90. An annular groove 91 is formed, an inner peripheral portion of a resilient metal annular side plate 92 is engaged with the annular step portion 90, and a stop ring 93 is fitted into the annular groove 91, so that the annular side plate 92 is chucked. The annular side plate 92 is held so as not to fall off the cylinder 103, and the outer peripheral end of the annular side plate 92 is engaged with the inner peripheral surface of the tightening cylinder 50.

In the fifth embodiment configured as described above, when gripping the tool 7, the shank 7A of the tool 7 is inserted into the cylindrical hole of the chuck cylinder 103, and the tightening cylinder 5
Rotate 0 clockwise. Then, each of the needle rollers 40 in contact with the tapered cylindrical surface of the tightening cylinder 50 revolves spirally around the outer peripheral surface of the chuck cylinder 103 while rotating in a direction perpendicular to its own axis.
Moves while rotating with the revolution of the needle roller 40 in the direction of the flange 102 from the distal end side of the chuck cylinder 103,
At the same time, the tightening cylinder 50 also moves in the direction of the flange 102.
As a result, the tightening cylinder 50 grips the shank of the tool 7 by reducing the diameter of the chuck cylinder 103 from the outer circumference to the inner circumference via the respective needle rollers 40. On the other hand, the outer peripheral end of the annular side plate 92 is pressed against the inner peripheral surface of the distal end side taper of the tightening cylinder 50 and is pressed in the direction of the chuck cylinder 103 to reduce the diameter of the distal end of the chuck cylinder 103. As a result, a strong gripping force against the tool shank is exerted on the tip portion of the chuck cylinder 103 as well. Therefore, according to the fifth embodiment, a strong gripping force can be exerted on the tool shank from the flange connection base portion to the distal end portion of the chuck cylinder 103, and the gripping of the tool can be further reliably performed. .

Next, a sixth embodiment of the present invention will be described with reference to FIG. 7, the same components as those of FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.
We will focus on the differences. The feature of the sixth embodiment is that a substantially annular groove 104 for enlarging the length of the chuck cylinder 103 is formed by projecting a cylindrical projection 102c on the distal end side of the outer peripheral portion of the flange 102. Is fixed to the inner peripheral surface of the cylindrical protrusion 102c by shrink fitting or the like so that the annular body 105 made of a separate member, such as die steel or hardened steel, comes into contact with the support surface 102a of the flange 102. The narrow annular groove 104 is formed between the inner peripheral surface of the annular body 105 and the chuck cylinder 103.

The chuck according to the sixth embodiment has the same effects as the chuck according to the first embodiment.
Any one of the groove 60, the hole 70, the hole 70 and the slit 80 formed in the chuck cylinder 103 of the chuck according to the second to fourth embodiments can be selectively applied, or the fifth embodiment can be applied. Chuck cylinder 10 of such a chuck
The annular side plate 92 can be applied as in the case of the distal end portion of the third embodiment, and therefore, the effect of any of the above configurations in the second to fifth embodiments can be obtained. In the chuck according to the sixth embodiment, it is preferable that the material of the chuck body 10 and that of the annular body 105 are different from each other as in the first embodiment, and further, as in the first embodiment. The screw 106 and the like can be omitted.

In the above embodiment, the case where the shank of the tool 7 is inserted into the chuck cylinder 103 via the spring collet and gripped is described. However, the present invention is not limited to this, and the shank 7A of the tool 7 is not limited to this. The chuck tube 1 directly
It is also possible to use a method in which the device is inserted into the device 03 and gripped. Further, the shank portion 101 of the holder body 10 is not limited to a tapered one,
It can also be applied to a holder body with a straight shank configuration.

[0035]

As described above, according to the first aspect of the present invention, the annular body of another member is supported concentrically with the support surface on the support surface of the holder body on the side opposite the shank portion of the flange. An annular groove fixed to a flange and having a depth equivalent to the thickness of the annular body is formed along the circumferential direction of the chuck cylinder 103,
The annular groove allows the length of the chuck cylinder to be extended to the flange side without increasing the tool length of the holder body, so that the base region near the flange of the chuck cylinder can be elastically deformed in the diameter-reducing direction. It can be made almost the same as the elastic deformation of the other area of the chuck cylinder in the diameter reducing direction.

Thus, the effective gripping length can be increased without lengthening the chuck cylinder, and the chuck cylinder can be easily elastically deformed in the diameter reducing direction. The tightening cylinder can be easily tightened until the flange-side end surface contacts the annular body fixed to the support surface of the flange. Further, since the gripping force on the tool shank in the connection base region of the chuck cylinder can be increased, even when heavy cutting is performed, the tool can be prevented from oscillating around the tip end of the chuck cylinder. Also,
By increasing the effective gripping length of the chuck cylinder and tightening the clamp cylinder until the flange-side end surface of the clamp cylinder comes into contact with the annular body fixed to the support surface of the flange of the holder body, the length of the chuck cylinder can be reduced. Therefore, the tool length of the holder body can be shortened, and the weight and size of the chuck can be reduced. In this case, the annular body of another member is fixed to the support surface, and the annular body is interposed between the holder main body and the tightening cylinder. Help.

According to the second aspect of the present invention, since the annular body is supported and fixed to the flat support surface of the flange of the holder body by the plurality of screws, the annular grooves having different depths can be easily formed by changing the thickness of the annular body. Is obtained.

According to the third aspect of the present invention, since the annular body is fixed by shrink fitting or the like in the projecting portion projecting from the support surface of the holder body, it is resistant to swaying such as left and right orthogonal to the axial direction.

According to the fourth or sixth aspect of the present invention, in addition to the annular groove for increasing the length of the chuck cylinder, a plurality of grooves are formed on the inner wall surface of the chuck cylinder. The elastic deformation in the diameter reducing direction is further facilitated, the effective gripping length can be increased without lengthening the chuck cylinder, and the thickness of the tightening cylinder can be reduced. By forming the groove in the inner wall surface of the chuck cylinder, when the tool inserted into the chuck cylinder is tightened, oil adhering to the tool can be easily released.

According to the fifth aspect of the present invention, in addition to the annular groove for enlarging the length of the chuck cylinder, a plurality of holes are formed in the wall constituting the chuck cylinder, so that the chuck cylinder is formed by the tightening cylinder. Elastic deformation in the diameter-reducing direction is further facilitated, the rate of change in the elastic deformation of the diameter-reduced inner diameter can be made uniform over substantially the entire length of the chuck cylinder, and the tightening cylinder can be made thinner.

According to the seventh aspect of the present invention, in addition to the annular groove for enlarging the length of the chuck cylinder, the inner peripheral portion of an elastic metal annular side plate is fixed to the outer peripheral surface of the distal end portion of the chuck cylinder. By pressing and engaging the outer peripheral end of the annular side plate with the inner peripheral surface of the tightening cylinder, a strong gripping force can be exerted on the tool shank from the flange connection base to the tip end of the chuck cylinder, The grip of the tool can be more reliably performed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a chuck according to a first embodiment of the present invention.

FIGS. 2A and 2B are explanatory views showing a chuck cylinder of a chuck according to an embodiment of the present invention and a conventional chuck, and a change in a reduced inner diameter when the chuck is tightened. FIG. FIG. 4B is a graph showing the change, FIG. 4B is an explanatory diagram of a conventional chuck tube, and FIG. 4C is an explanatory diagram of a chuck tube in the present invention.

FIG. 3 shows a second embodiment of the present invention,
(A) is a sectional view of the chuck, and (B) is a transverse sectional view of the chuck cylinder.

FIG. 4 shows a third embodiment of the present invention;
(A) is a sectional view of the chuck, and (B) is a transverse sectional view of the chuck cylinder.

FIG. 5 shows a fourth embodiment of the present invention;
(A) is a sectional view of the chuck, and (B) is a transverse sectional view of the chuck cylinder.

FIG. 6 shows a fifth embodiment of the present invention,
(A) is a cross-sectional view of the chuck, and (B) is an enlarged cross-sectional view of a main part.

FIG. 7 is a sectional view of a chuck showing a sixth embodiment according to the present invention.

FIG. 8 is a sectional view of a conventional chuck.

FIG. 9 is an exploded perspective view showing components of a conventional chuck.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Holder body 101 Taper shank part 102 Flange 102a Support surface 103 Chuck cylinder 104 Annular groove 105 Annular body 106 Screw 20 Roller holding cylinder 40 Needle roller 50 Tightening cylinder 60 Groove 70 Hole 80 Slit 92 Annular side plate

Claims (7)

[Claims] 1. A shank portion to be inserted into a spindle of a machine tool, a gripping flange formed at one end of the shank portion, and a shank in a direction opposite to the shank portion from an end surface of the flange opposite to the shank portion. A holder body extending along the axis of the part and having a chuck cylinder on the outer peripheral surface of which a tapered surface whose diameter decreases toward the tip from the flange is formed, and rotatable around the outer periphery of the chuck cylinder; A clamping cylinder which is movably engaged in the axial direction of the chuck cylinder and has a tapered surface on the inner peripheral surface whose diameter decreases as going from the flange to the tip, and an outer peripheral surface of the chuck cylinder and an inner surface of the clamping cylinder. A plurality of needle rollers disposed around the entire circumference between the peripheral surfaces and inclined at an appropriate angle in the circumferential direction with respect to the axes of the chuck cylinder and the tightening cylinder, and the needle roller is rotated by rotation of the tightening cylinder. In a chuck in which the chuck cylinder is reduced in diameter or restored by helically revolving while rotating the roller, the annular member of another member is supported concentrically with the support surface on the support surface of the flange on the side opposite to the shank portion, and the flange is formed. Wherein an annular groove having a thickness equal to the thickness of the annular body is formed along a circumferential direction of the chuck cylinder. 2. The chuck according to claim 1, wherein the annular body is supported and fixed on a flat support surface orthogonal to the axial direction of the flange by a plurality of screws. 3. The apparatus according to claim 1, wherein the annular body is fitted and fixed to a projecting member projecting from a support surface of the flange.
Chuck described. 4. A plurality of grooves extending in the axial direction of the chuck cylinder over the entire length of the inner wall surface of the chuck cylinder at predetermined intervals in a circumferential direction of the chuck cylinder. 4. The chuck according to any one of items 3 to 3. 5. A plurality of holes extending in the axial direction of the chuck cylinder over substantially the entire length of the wall constituting the chuck cylinder and formed at predetermined intervals in a circumferential direction of the chuck cylinder. The chuck according to claim 1. 6. A plurality of holes extending in the axial direction of the chuck cylinder over substantially the entire length of the wall constituting the chuck cylinder and formed at predetermined intervals in a circumferential direction of the chuck cylinder. The chuck according to any one of claims 1 to 3, wherein a plurality of slits are formed on the inner wall surface corresponding to each of the holes and communicate from the holes to the inside of the chuck cylinder. 7. An inner peripheral portion of a metal annular side plate having elasticity is fixed to an outer peripheral surface of a distal end portion of the chuck cylinder, and an outer peripheral end of the annular side plate is pressed and engaged with an inner peripheral surface of the tightening cylinder. The chuck according to any one of claims 1 to 6, wherein: