JP2583290Y2 - Chuck - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck for holding a rotary cutting tool such as a drill and an end mill, and more particularly to a holding cylinder for inserting a rotary cutting tool or an adapter for holding the rotary cutting tool and an outer peripheral surface thereof. The present invention relates to a roll-lock type chuck having a plurality of needle rollers interposed between a rotatable mounting cylinder.

[0002]

2. Description of the Related Art Conventionally, as a chuck for gripping a rotary cutting tool, a holding cylinder for directly or indirectly mounting a target tool, and a clamp rotatably mounted on the outer peripheral surface of the holding cylinder at a predetermined interval. A large number of needle rollers are arranged in a plurality of stages across the entire surface between the peripheral surfaces between the attachment cylinders and at axes forming an appropriate inclination angle with respect to the generatrix of the two cylinders, and the rotation of the tightening cylinders A roll-lock type chuck in which the holding cylinder is contracted and restored while the needle roller rotates and revolves in a spiral while rotating is already known (Japanese Utility Model Publication No. 41-23987).
As for this type of chuck, the applicant of the present application has previously made the apparatus smaller, facilitated the deformation of the holding cylinder, increased the gripping force, and prevented slippage due to improved oil drainage. For the purpose, a chuck with the following configuration (Jitsuhei 3-29501) is proposed.

That is, as shown in FIGS. 3, 4 and 5, 1
Reference numeral 0 denotes a holder main body that is attached to the main shaft 2 via a shank 15, and has a holding cylinder 11 integrally formed on the same axis at the tip end. The holding cylinder 11 is the target tool 1
Has a cylindrical inner peripheral surface 11b which is inserted and held directly or via an adapter (not shown) which holds the outer peripheral surface, and an outer peripheral surface 11a formed in a tapered shape tapering from the base. Around the inner peripheral surface 20a of the holding cylinder.
A tightening cylinder 20 formed on a tapered surface similar in shape to a is rotatably mounted at a predetermined interval. In the circumferential interval between the inner peripheral surface 20a of the tightening cylinder 20 and the outer peripheral surface 11a of the holding cylinder 11 of the holder body, a large number of needle rollers 30 rotatably held at predetermined positions by a roller cage 31 are provided. The needle rollers 30 are arranged in a plurality of steps over the entire circumference, and the arrangement direction of the needle rollers 30 has an inclination angle α with respect to the generatrix of the tightening cylinder 20 and the holding cylinder 11 as shown in FIG. Arranged along the axial direction, the holding cylinder 11 is contracted and restored while the needle roller 30 revolves in a spiral while rotating by rotation of the tightening cylinder 20. Reference numerals 13 and 22 denote retaining rings, which are provided on the peripheral surfaces of the holding cylinder 11 and the tightening cylinder 20, respectively.
To regulate the axial movement of the roller gauge 31. As shown in FIGS. 3 and 5, a seal ring 40 formed of an annular metallic ring is interposed between the retaining ring 13 and the roller gauge 31. The outer diameter of the seal ring 40 is
a is set slightly smaller than the distal end portion of a, and when the tightening cylinder 20 is operated and tightened to move in the axial direction, the inner diameter 2
0a so as to prevent external dust from entering the roller accommodating portion. (See FIG. 5) The inner diameter side of the ring 40 has a large gap with respect to the fitting groove of the holding cylinder 11, but is in contact with the retaining ring 13, so that processing and mounting can be performed without lowering the sealing performance. Is made easy.

As shown in FIG. 4, a slit-shaped through groove 12 ′ extending from the outer diameter to the inner diameter is formed on the peripheral surface of the holding cylinder 11 in a direction intersecting the axial direction of the needle roller 30 at a predetermined angle β. A plurality of needle rollers 30, which are formed and rolled directly on the outer peripheral surface of the holding cylinder 11, can be rolled without being hindered from rotating by the through groove 12 ', and the through groove 12' In the form of a closed slit that does not open to the front end surface of the holding cylinder 11, the predetermined angle β is 3 to 5 ° or more, and the slit width is 0.5 mm or less (1/1 of the diameter of the needle roller). 4 or less). With the above configuration, when gripping the target tool by operating the tightening cylinder,
The required deformation can be easily performed while maintaining the strength of the holding cylinder,
In addition, quick restoration is possible, and the oil is easily drained.

[0005]

However, in the above configuration, since the closing slit, which is the through-groove, partially divides the holding cylinder in the circumferential direction, each of the cut ends is divided into the base and the tip of the holding cylinder. Although it becomes a doubly supported elastic body with both ends as the ends, the contraction restoration of the holding cylinder will be easily achieved,
The inner diameter of the holding cylinder becomes drum-shaped (middle height), and when the cutting tool or the like is held, the tool is likely to fall down, and the runout accuracy of the tool becomes unstable. Further, in side surface processing in which a tipping moment is applied to a blade during cutting, the blade has a defect such that the blade is easily inclined and the perpendicularity of a processing side surface is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and enables the holding cylinder to be contracted when the target tool is gripped without causing extreme partial deformation, and the tip to be added to the cutting tool at the time of cutting. It is an object of the present invention to provide a stable chuck having high holding performance that can withstand a moment.

[0007]

According to the present invention, in order to attain the above technical object, when only a plurality of continuous closing slits as through grooves are provided in the holding cylinder as described above, the interposition of the slits is effective. The holding cylinder is divided in the circumferential direction, and each of the divided cylinders becomes a doubly supported elastic body having both ends at the base and the tip of the holding cylinder. Although a low rotational power required for the rotation is obtained, a defect that the runout accuracy becomes unstable due to the occurrence of the tool falling due to the drum-like deformation of the inner surface of the holding cylinder is incorporated.
On the other hand, when the continuous closing slit is divided in the longitudinal direction as an intermittent closing slit as a solution to this, when the holding cylinder is contracted, the deformed shape at the time of contraction becomes substantially cylindrical, and the portion parallel to the axis is formed. It has been confirmed by experiments that the cutting tool can be held stably by using the characteristics of the intermittent closing slit, and the cutting tool can be prevented from falling down during side cutting. In order to make use of the characteristics of the continuous closing slit and the intermittent closing slit to compensate for the above-described disadvantages, the arrangement is characterized in that they are appropriately arranged in the circumferential direction so that they are alternately located.

[0008]

According to the above technical means, the through groove is configured such that the continuous closing slit and the intermittent closing slit are alternately arranged in the circumferential direction of the holding cylinder. Characteristics that cause the cylinder to shrink,
The latter has the characteristic of maintaining the deformed shape of the holding cylinder in a substantially cylindrical shape when the holding cylinder is contracted, and the holding cylinder can be contracted and restored when the target tool is gripped by the appropriate rotation of the tightening cylinder. At the same time, it is possible to prevent a drum-shaped (middle and high) deformation at the time of the contraction, and it is possible to secure a stable holding ability that can sufficiently cope with a tipping moment with respect to the blade. In addition, in the present technical means, the improvement of running out of oil on the inner surface of the holding cylinder, the prevention of a decrease in gripping force, and since the cutting tool and the shank are not held on the entire inner surface of the holding cylinder, the gripping force is not dispersed and the axial direction is not increased. It is needless to say that slipping of the cutting tool can be prevented by locally concentrating the gripping force.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only. 1 and 2 show an embodiment according to the present invention, in which a holding cylinder is provided with three sets of through-grooves including a continuous closing slit and an intermittent two-step closing slit. FIG. 1 is a plan view of a relevant part showing a relational position between a holding cylinder busbar, a through groove, and a needle roller axis, and FIG. 2 is a view along AA in FIG. Note that the same reference numerals are used for the same parts as in the conventional structure.

As shown in FIG. 1, a holding cylinder 11 of a holder body 10 for holding a target tool is provided with a through groove 12 extending from an outer peripheral surface 11a of the holding cylinder 11 to an inner peripheral surface 11b. Is extended from the vicinity of the base of the holding cylinder 11 by a predetermined angle with respect to the generatrix to extend substantially on a straight line, and the continuous closing slit 12 is stopped at a position near the tip.
S and two intermittent two-stage closing slits 12W having their dividing positions in the center in the longitudinal direction, and three sets are alternately arranged in the circumferential direction at intervals of 60 degrees. The angle between the slits 12S and 12W and the generatrix of the holding cylinder is set to, for example, 10 °, and the slit width is considerably smaller than the diameter (2 mm) of the needle roller 30, for example, 0.2 mm.
Set to ± 0.05. The angle α between the axis required for the spiral revolution of the needle roller 30 in FIG. 1 and the busbar of the holding cylinder is 1 to 2 °, and in this case, the value of β is 11 to 12 °.

According to the above configuration, the direction of the through groove 12 and the axial direction of the needle roller 30 correspond to the aforementioned positional relationship (β =
11 to 12 °) and the slit width is set to be considerably narrower than the diameter of the needle roller 30 (0.2 mm ± 0.05). Even if it rolls directly on the outer peripheral surface 11a of 11, smooth rolling is possible without dropping into the slits 12S and 12W constituting the through groove 12 and without hindering the operation. In addition, through grooves 12 composed of the continuous closing slits and the intermittent two-step closing slits are arranged at equal intervals of 360 degrees in the circumferential direction of the holding cylinder.
Since the 2S and 12W are alternately provided with a positional shift of 60 degrees, the continuous closing slit 12S causes a large contraction of the holding cylinder caused by a small rotating force of the clamping cylinder at the time of gripping the tool. It is possible to have both the characteristic and the characteristic of maintaining the deformed shape of the holding cylinder in a substantially cylindrical shape when the holding cylinder is contracted by the intermittent two-stage closing slit 12W, so that the holding cylinder can be appropriately contracted and restored when the target tool is gripped. This can be achieved by the rotating power of the tightening cylinder, and can prevent a drum-shaped (middle and high) deformation at the time of the contraction, and can secure a stable holding ability that can sufficiently cope with the overturning moment with respect to the blade.

The slits 12S and 12W forming the through groove 12 are processed by laser processing or the like while rotating the holding cylinder 11 in accordance with their inclination (β-α) with respect to the generatrix. As shown in FIG. 2, the slit is formed toward the axis of the holding cylinder at any position of the slit, which is desirable from the viewpoint of expecting uniform deformation of the holding cylinder itself and from the viewpoint of processing. Further, in the above-mentioned processing method, since the shape of each slit of the through groove 12 forms a slight helical curve, the operation of the needle roller 30 is more smoothly performed without any hindrance as compared with the linear slit. Movement becomes possible. Further, as another embodiment, the cross-sectional shape of each slit forming the through-groove 12 provided in the holding cylinder is set such that the width on the outer diameter side of the holding cylinder is smaller than the width on the inner diameter side, and the holding cylinder is easily deformed. It may be shaped.

[0013]

According to the present invention as described above, the following effects can be obtained. Since the through-groove provided in the holding cylinder is configured by alternately equidistant arrangement of the continuous closing slit and the intermittent multi-stage closing slit, the former has a large holding cylinder corresponding to a small turning force of the tightening cylinder when gripping the tool. It is possible to have both the shrinkage characteristic and the characteristic of maintaining the deformed shape of the holding cylinder in a substantially cylindrical shape when the holding cylinder shrinks, and the shrinkage of the holding cylinder when gripping the target tool causes extreme partial deformation. It is possible to obtain a stable chuck with high holding performance that can withstand the overturning moment applied to the blade during cutting.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part showing a positional relationship among a holding cylinder busbar, a through groove, and a needle roller axis of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a partially cutaway view showing a configuration of a conventional chuck.

FIG. 4 is a main part plan view showing a positional relationship among a holding cylinder bus bar, a through groove, and a needle roller axis of FIG. 3;

5 is a cross-sectional view of a main part of the distal end portion of FIG. 3 after tightening of a tightening cylinder.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Holding cylinder, 12 ... Through-groove 12S ... Continuous closing slit, 12W ... Intermittent closing slit 20 ... Tightening cylinder, 30 ... Needle roller

Claims (2)

(57) [Scope of request for utility model registration] 1. A holding cylinder on which a target tool is directly or indirectly mounted, a clamping cylinder rotatably mounted on an outer peripheral surface of the holding cylinder at a predetermined interval, and an interposition between the peripheral surfaces of the two cylindrical bodies. A plurality of needle rollers mounted thereon, wherein the needle rollers are deflected by a predetermined angle with respect to both cylindrical body buses, and are arranged in a plurality of steps over the entire circumference between the two cylindrical body peripheral surfaces, and the holding cylinder outer peripheral surface. A plurality of sets of through-grooves extending from the outer diameter to the inner diameter are formed on the upper side at a predetermined angle to intersect with the axial direction of the needle roller, and the needle roller rotates while revolving in a spiral while rotating the tightening cylinder. In a chuck configured to perform contraction and restoration of the holding cylinder, the through-groove is formed by a continuous closing slit that is divided into slits without opening to the tip of the holding cylinder and an intermittent multi-stage closing slit that is divided into a plurality of pieces in the longitudinal direction. Comprising Chuck, characterized in that are arranged alternately slit in the circumferential direction. 2. The chuck according to claim 1, wherein the intermittent multi-step closing slit is an intermittent two-step slit having a dividing position provided in the middle of the longitudinal direction.