JPH0663209U - Tool chuck - Google Patents

Abstract

(57) [Summary] [Purpose] As a needle roll lock type tool chuck in which a seal ring and a locking ring are fitted in an annular groove formed on the outer circumference on the tip side of the chuck cylinder, it is possible to use centrifugal force during cutting. (EN) Provided is one which can prevent the locking ring from coming off and can sufficiently cope with cutting processing by recent ultra-high speed rotation. A tool chuck for tightening and fixing a tool 5 inserted into a tool holding hole 1b of the chuck cylinder 1 by tightening a tightening cylinder 1 which is externally fitted to the outer circumference of the chuck cylinder 1 via a needle roller 6. In the annular groove 1a formed on the outer periphery on the tip side of the chuck cylinder 1, a seal ring 3a made of an elastic material for sealing between the chuck cylinder 1 and the tightening cylinder 2 when the tool 5 is tightened and fixed, This seal ring 3
A ring-shaped locking ring 4a, which is arranged closer to the tip of the chuck cylinder 1 than a, is fitted, and an annular flange for preventing the locking ring 4a from coming off is provided on the inner periphery of the tip of the tightening cylinder 2. Part 1
1 is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a needle roll lock type tool chuck in which a tool inserted into a tool holding hole of a chuck cylinder is tightened and fixed by tightening a tightening cylinder externally fitted to a tapered outer circumference through a needle roller.

[0002]

[Prior art]

 In this type of tool chuck, the shank part of the cutting tool is inserted into the chuck cylinder of the chuck body directly or through a straight collet, and the loose outer taper taper outer periphery of the chuck cylinder is externally fitted through a needle roller. By tightening the attached cylinder, the diameter of the chuck cylinder or the chuck cylinder and the collet are reduced with the spiral revolution of the needle roller, and the tool is clamped and fixed. However, in cutting with such a tool chuck, fine chips and cutting oil easily enter between the chuck cylinder and the clamping cylinder, and this intrusion reduces chucking accuracy and gripping force, resulting in If the tool is dropped, the life of the chuck will be shortened, and the tool may come off, resulting in damage to the work piece or a serious accident.

Therefore, conventionally, as shown in FIG. 6, annular grooves 1a and 2a are formed in the outer circumference on the tip end side of the chuck cylinder 1 and the inner circumference on the rear end side of the tightening cylinder 2, and these annular holes 1a are formed. , 2a are respectively fitted with seal rings 3a, 3b made of an elastic material such as rubber and open or closed annular metal locking rings (snap rings) 4a, 4b arranged on the outer side thereof, and chucks are attached. When the cutting tool 5 fitted in the tool holding hole 1b of the cylinder 1 is clamped by tightening the cylinder 2, the needle roller 6 between the chuck cylinder 1 and the clamp cylinder 2 is loaded. The annular space 7 is sealed by the seal rings 3a and 3b on both front and rear sides to prevent invasion of cutting chips and cutting oil into the annular space 7 during cutting, and the seal rings 3a and 3b are provided with needles. Stopping the roller 6 ... Therefore, a structure that is designed to have a function is often used. 6a is a cylindrical retainer holding the needle rollers 6 ..., 8a and 8b are washers arranged on both sides for maintaining the shape of the seal rings 3a and 3b.

[0004]

[Problems to be solved by the device]

 In recent years, however, the speed of machining centers has increased, and in addition to machines with spindle speeds of 10,000 to 20,000 rpm during cutting, machines with the same speed of 40,000 to 50,000 rpm have also appeared. is doing. However, at such a high speed rotation, in the tool chuck using the conventional seal rings 3a and 3b, as shown in FIG. 7, the locking ring 4a on the tip side of the chuck cylinder 1 is subjected to centrifugal force during machining. The diameter is expanded and easily disengaged from the annular groove 1a, and it pops out as shown by the phantom line in the figure, and it may get caught in the cutting site when entangled with the cutting edge of the tool, resulting in poor cutting or uncutability. There is a problem that the fitted state of the ring 3a becomes unstable and the original sealing effect cannot be exhibited.

In view of the above situation, the present invention has a needle roll lock system in which a seal ring 3a and a locking ring 4a are fitted in an annular groove 1a formed on the outer circumference of the chuck cylinder 1 on the tip side. It is an object of the present invention to provide a tool chuck that can prevent the locking ring 4a from being pulled out due to centrifugal force during cutting and can sufficiently cope with cutting processing by ultra-high speed rotation in recent years.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, claim 1 of the present invention provides a tool for a chuck cylinder 1 by tightening a tightening cylinder 1 fitted around a tapered outer circumference of a chuck cylinder 1 via needle rollers 6 ... In a tool chuck for tightening and fixing the tool 5 inserted in the holding hole 1b, the tool cylinder 5 is clamped in the annular groove 1a formed on the outer periphery of the chuck cylinder 1 at the tip end side when the tool 5 is clamped and fixed. A seal ring 3a made of an elastic material that seals between the tightening cylinder 2 and an open ring-shaped locking ring 4a arranged closer to the tip of the chuck cylinder 1 than the seal ring 3a are fitted and A configuration is adopted in which a projecting edge portion 11, 12, 12a, 12b for preventing the locking ring 4a from coming off is provided on the inner periphery on the tip end side of the tightening cylinder 2.

According to a second aspect of the present invention, as the annular projecting edge portions 11, 12, 12a, 12b of the first aspect, the engagement on the chuck cylinder 1 side when the inner peripheral surface is in the tightened state of the tightening cylinder 2 is described. The stopper ring 4a is opposed to the outer peripheral surface of the stopper ring 4a, and the contact between the opposed surfaces prevents the lock ring 4a from being detached from the annular groove 1a due to the increased diameter.

Further, a third aspect of the present invention is from an open annular ring or a closed annular ring 11 in which the projecting edge portion of the first or second aspect is fitted in an annular groove 2b provided in the inner periphery of the tightening cylinder 2. According to a fourth aspect of the present invention, similarly, the projecting edge portion is a projecting edge portion 12 integrally formed on an inner circumference of the tightening tube 2, and the fifth aspect is similarly such that the projecting edge portion is within a tip of the tightening tube. A structure comprising an annular ring 12a screwed into the peripheral surface, or claim 6 is such that the projecting edge portion is radially press-fitted or screwed into the tip portion of the tightening cylinder, and the tip portion is from the inner peripheral surface of the tip of the tightening cylinder. Each of them adopts a configuration including a protruding protrusion 12b.

[0009]

[Action]

 Since the protrusions 11, 12, 12a, 12b are provided on the inner circumference of the tip end side of the tightening tube 2, the tool ring is rotated at high speed during cutting, so that the seal ring 3a is formed in the annular groove 1a on the tip end side of the chuck tube 1. Even if the fitted locking ring 4a is expanded in diameter by centrifugal force caused by high speed rotation of the tool chuck during cutting, the protruding edges 11, 12, 12a, 12b cause the locking ring 4a to move to the outside. Jumping out is blocked.

Therefore, the protruding edge portions 11, 12, 12a, 12b are more than the locking ring 4a fitted in the annular groove 3a on the tip side of the chuck cylinder 1 in the tightened state of the tightening cylinder. The locking ring 4a is located outside and only prevents the locking ring 4a from protruding to the outside. Further, as in claim 2, the inner peripheral surface faces the outer peripheral surface of the locking ring 4a in the same tightened state. The contact between the facing surfaces may be set so as to prevent the locking ring 4a from being separated from the annular groove 1a due to the increased diameter.

Incidentally, such a projecting edge portion includes an open ring-shaped or closed ring-shaped locking ring 11 fitted in an annular groove 2b provided in the inner circumference of the tightening cylinder 2 as claimed in claim 3. And a projecting edge portion 12 integrally formed on the inner circumference of the tightening cylinder 2 of claim 4, wherein the projecting edge portion comprises an annular ring 12a screwed onto the inner circumferential surface of the tip of the tightening tube. The structure according to claim 5, or the structure according to claim 6, wherein the projecting edge portion is radially press-fitted or screwed into the distal end portion of the tightening cylinder, and the distal end portion is a projection 12b protruding from the inner peripheral surface of the distal end of the tightening cylinder. Either of them can be adopted.

[0012]

【Example】

 1 to 3 show a needle roller lock type tool chuck according to a first embodiment of the present invention. FIGS. 1 and 2 show a state before tool tightening, and FIG. 3 shows a state after tool tightening. is there. In these figures, 10 is a chuck body, which constitutes a chuck cylinder 1 whose front side has a tapered outer surface with a loose outer circumference, and whose rear side is a tapered taper shank detachably attached to a spindle such as a machining center. The outer peripheral portion of the central portion 9 is provided with a chuck positioning collar 10a for gripping the manipulator. Reference numeral 2 denotes a tightening cylinder having an inner circumference that forms a taper surface corresponding to the outer circumference of the chuck cylinder 1, and is fitted to the outside of the chuck cylinder 1 via a large number of needle rollers 6 held by a retainer 6a. There is.

The needle rollers 6 are arranged such that the roller axis is slightly inclined with respect to the generatrix of the tapered surface of the chuck cylinder 1 in the rotating direction of the tightening cylinder 2, and the chuck roller 1 is rotated in accordance with the rotating operation of the tightening cylinder 2. The screw cylinder 1 revolves in a spiral shape, so that the tightening cylinder 2 axially moves with respect to the chuck cylinder 1. The shank portion of the cutting tool 5 is fitted into the tool holding hole 1b, and the tightening cylinder 2 is rotated in the tightening direction to reduce the diameter of the chuck cylinder 1 and prevent axial movement and relative rotation. Is gripped by.

An annular groove 1a is formed on the outer periphery of the tip end side of the chuck cylinder 1, and in the annular hole 1a, a seal ring 3a made of an elastic material such as rubber and a metal for holding a shape sandwiching the seal ring 3a from both sides are formed. The washer 8a, 8a, and an open annular metal locking ring (snap ring) 4a, which is arranged on the outer side thereof, that is, near the tip of the chuck cylinder 1, are fitted. An annular groove 2a is also formed on the inner periphery of the rear end side of the tightening cylinder 2, and a seal ring 3b, washers 8b, 8b and a locking ring 4b are similarly fitted in the annular groove 2a. Here, both seal rings 3a, 3b have a radial width larger than that of the adjacent washers 8a, 8a, and tighten the tool 5 fitted in the tool holding hole 1b of the chuck cylinder 1. Tightening operation of the cylinder 2. The former 3a and the latter 3b come into close contact with the inner circumference of the tightening cylinder 2 and the outer circumference of the chuck cylinder 1, respectively, and thus the needle roller 6 between the chuck cylinder 1 and the tightening cylinder 2 is tightened. The annular space 7 loaded with ... Is sealed on both front and rear sides to prevent invasion of cutting chips and cutting oil into the annular space 7 during cutting, and also has a function of preventing the needle rollers 6 from coming off.

Therefore, in the tool chuck of the first embodiment, the annular groove 2a is formed on the inner periphery on the tip side of the tightening cylinder 2, and the open annular metal locking ring ( When the tool 5 is tightened and fixed by the tightening operation of the tightening tube 2, as shown in FIG. The inner peripheral surface is set to face the outer peripheral surface of the locking ring 4a on the chuck cylinder 1 side. Therefore, when the tool chuck rotates at a high speed during cutting, the locking ring 4a on the chuck cylinder 1 side tends to expand due to the centrifugal force, but when the diameter has expanded to a certain extent, the locking ring on the clamping cylinder 2 side expands. Since it abuts against No. 11 and further expansion is prevented, it cannot be separated from the annular groove 1a. Therefore, for example, even in high-speed cutting where the spindle speed during cutting is 40,000 to 50,000 rpm, the sealing effect of the seal ring 3a is sufficiently exerted, and cutting chips and cutting oil are prevented from entering the annular space 7. Prevents high precision machining.

FIGS. 4 and 5 show a needle roller lock type tool chuck according to a second embodiment of the present invention. FIG. 4 shows a state before tool tightening, and FIG. 5 shows a state after tool tightening. . In the tool chuck of the second embodiment, instead of the locking ring 11 provided on the inner circumference on the front end side of the tightening cylinder 2 in the first embodiment, the tool chuck is provided on the inner circumference on the front end side of the tightening cylinder 2 itself. The annular projecting edge portion 12 is integrally formed. As a result, when the tool 5 is tightened and fixed by the tightening operation of the tightening cylinder 2, the inner circumferential surface of the annular projecting edge portion 12 of the locking ring 4a on the chuck cylinder 1 side is, as shown in FIG. It is set to face the outer peripheral surface.

Therefore, also in the second embodiment, when the tool chuck rotates at high speed during cutting, the clamping cylinder 2 is expanded at a stage where the engagement ring 4a on the chuck cylinder 1 side is expanded to some extent by the centrifugal force. Since it cannot come off from the annular groove 1a because it abuts against the annular protruding edge portion 12 on the side and further expansion is prevented, the sealing effect of the seal ring 3a is sufficiently exerted as in the first embodiment. Intrusion of cutting chips and cutting oil into the annular space 7 is prevented, and highly accurate machining can be performed.

In the above embodiment, the metal washers 8a, 8a for retaining the shape are arranged on both sides of the seal ring 3a. However, these washers 8a, 8a have a large axial thickness of the seal ring 3a and are sufficient. It is not necessary when it has self-shape retention. Further, in the above-mentioned embodiment, the annular groove 2a is also provided on the rear end side of the tightening cylinder 2 and the seal ring 3b and the snap ring 4b are fitted therein. As means for sealing the space 7 on the rear side, a thick and large-diameter seal ring made of an elastic material such as rubber is fitted to the base of the chuck cylinder 1, or the rear end surface or the chuck of the tightening cylinder 2 is fitted. A seal ring is attached to the peripheral side surface of the collar portion 10a of the main body 10 to seal between the rear end surface of the clamping cylinder 2 and the collar portion 10a of the chuck body 10 in the tightened state of the clamping cylinder 2. A configuration can also be adopted.

Further, as shown in FIG. 6, the projecting edge portion may be one in which a female screw portion is provided on the inner peripheral surface of the front end portion of the tightening cylinder 2 and a ring 12a having a male screw portion corresponding to this is screwed in. Well, or as shown in (a) to (c) of FIG. 7, the projecting edge portion is a pin that is press-fitted or screwed into the distal end portion of the tightening cylinder 2 in the radial direction from the outer peripheral surface side to the inner peripheral surface side. Alternatively, as shown in FIG. 7C, the protrusions 12b may be provided at appropriate intervals in the circumferential direction, and the tips of these pins may protrude from the inner peripheral surface of the tightening cylinder 2.

[0020]

According to the invention of claim 1, a needle roll lock type tool chuck in which a seal ring and a locking ring are fitted in an annular groove formed on the outer periphery of the tip end side of the chuck cylinder. As a result, even when the spindle speed during cutting is extremely high, there is no risk of the locking ring popping out, the sealing effect of the seal ring is fully achieved, and the chuck cylinder and tightening cylinder are Between them, the invasion of cutting chips and cutting oil into the annular space loaded with the needle roller can be carried out, and thus high-precision machining can be performed safely and, for example, high-speed cutting such as the above rotation speed of 40,000 to 50,000 rpm. It is possible to provide something that can deal with the situation.

According to the invention of claim 2, as the tool chuck, the diameter of the locking ring is prevented from expanding to a certain extent or more due to a centrifugal force during cutting, so that the locking ring is formed from the annular groove. It is possible to provide a machine that can perform more highly accurate machining based on a more reliable sealing effect of the seal ring without detachment.

According to the inventions of claims 3 to 6, it is possible to provide a tool chuck which is structurally extremely simple and inexpensive to manufacture, and the existing tool chucks of this kind can be modified only slightly. As described above, there is an advantage that it can be converted to one that can support high-speed cutting.

[Brief description of drawings]

1 is a half sectional side view of a tool chuck according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a main part showing a state of the tool chuck before tightening the tools.

FIG. 3 is a vertical cross-sectional view of a main part showing a state after tightening the tool of the tool chuck.

FIG. 4 is a vertical cross-sectional view of a main part of the tool chuck of the second embodiment of the present invention before the tool is tightened.

FIG. 5 is a vertical cross-sectional view of a main part showing a state after tightening the tool of the tool chuck.

FIG. 6 is a vertical cross-sectional view of a main part showing another embodiment.

FIG. 7 is a vertical cross-sectional view of a main part showing a state of a conventional tool chuck before tool tightening.

FIG. 8 is a vertical cross-sectional view of a main part showing a state during processing of the conventional tool chuck.

[Explanation of symbols]

 1 Chuck Cylinder 1a Annular Groove 1b Tool Holding Hole 2 Tightening Cylinder 2b Annular Groove 3a Seal Ring 4a Locking Ring 5 Cutting Tool 6 Needle Roller 10 Chuck Body 11 Locking Ring (Projection Edge) 12 Projection Edge 12a Projection Edge 12b Edge

Claims (6)

[Scope of utility model registration request] 1. A tool chuck for tightening and fixing a tool fitted into a tool holding hole of the chuck cylinder by tightening a tightening cylinder externally fitted to the outer circumference of the chuck cylinder through a needle roller. A seal ring made of an elastic material for sealing between the chuck cylinder and the tightening cylinder at the time of tightening and fixing the tool in an annular groove formed on the outer periphery on the tip side of the cylinder, and a chuck more than the seal ring. A locking ring placed near the tip of the cylinder is fitted and
A tool chuck, characterized in that a projecting edge portion for preventing the locking ring from coming off is provided on the inner periphery of the front end side of the tightening cylinder. 2. The projecting edge portion has an inner peripheral surface facing the outer peripheral surface of the locking ring on the chuck cylinder side in the tightened state of the tightening cylinder, and the mutual contact of the facing surfaces causes the locking ring to move. 2. A member for preventing separation from an annular groove due to expansion of diameter.
Tool chuck described. 3. The tool chuck according to claim 1, wherein the projecting edge portion is an open ring-shaped ring or a closed ring-shaped ring fitted in an annular groove provided on the inner circumference of the tightening cylinder. 4. The tool chuck according to claim 1, wherein the projecting edge portion is integrally formed on the inner circumference of the tightening cylinder. 5. The tool chuck according to claim 1, wherein the projecting edge portion is an annular ring screwed into the inner peripheral surface of the tip of the tightening cylinder. 6. The projection edge portion according to claim 1, wherein the projection edge portion is a projection that is radially press-fitted or screwed into the tip end portion of the tightening cylinder and the tip end portion projects from the inner peripheral surface of the tip end of the tightening cylinder. Tool chuck.