WO2017154145A1

WO2017154145A1 - Chuck for tools

Info

Publication number: WO2017154145A1
Application number: PCT/JP2016/057428
Authority: WO
Inventors: 仲谷穣治; 駿河宏和; 矢内正隆; 緒方達也
Original assignee: ＢｉｇＤａｉｓｈｏｗａ株式会社
Priority date: 2016-03-09
Filing date: 2016-03-09
Publication date: 2017-09-14
Also published as: TW201731613A

Abstract

A chuck for tools is provided with: a chuck body having at the front end thereof either a cylinder section into which a tool is inserted along an axis or a cylinder section into which a collet is inserted, the collet allowing a tool to be inserted therein along an axis, the chuck also having a male thread at the rear end thereof; a cylindrical pressing member engaging with the outer surface of the cylinder section; a nut having a female thread which engages with the male thread and coming in contact with the pressing member so as to be rotatable relative to the pressing member; and a rotation prevention mechanism comprising a protrusion provided to one of the cylinder section and the pressing member, the rotation prevention mechanism also comprising a recess provided in the other and extending in the direction of the axis. The chuck for tools is configured so that, during the mounting of the pressing member and the nut to the chuck body, the female thread and the male thread engage with each other after the protrusion and the recess engage with each other.

Description

Tool chuck

For tools that apply gripping force from the outer periphery of the shank by rotating the nut and moving the pressure member engaged with the nut in the axial direction to grip the shank of the tool inserted into the chuck body Related to chuck.

In recent years, the maximum number of revolutions of the tool spindle has increased due to the evolution of machine tools. For this reason, there is an increasing demand for small-diameter high-precision chucks that can withstand precision machining at ultra-high speed rotation, particularly in die machining and micromachining.

For example, in the conventional collet chuck in which the nut is rotated and the collet is pushed in, friction occurs with the collet when the nut is tightened, so that the collet is pushed in a distorted state by being twisted in the rotation direction of the nut. As a result, the collet shaft core is disengaged from the chuck body shaft core, and the gripping accuracy of the tool is lowered.

Also, the nut and collet are worn by friction, and the contact state of the nut with the collet becomes inappropriate and the gripping accuracy is lowered.

As a technique for solving this problem, for example, there is a technique disclosed in Patent Document 1.
In this technique, the key member embedded in the pressure member is engaged with the key groove provided in the chuck main body, so that the pressure member and the chuck main body cannot be rotated relative to each other. Thereby, when a nut is rotated, a pressurizing member does not rotate together, but a collet can be drawn straight along the axial direction.

Japanese Utility Model Publication No. 53-011779

However, the above conventional tool chuck has a problem that it is difficult to match the relative phase along the rotation direction of the key member and the key groove when the pressure member and the nut are attached to the chuck body.

In other words, when attaching the pressure member to the chuck body, the pressure member with the nut inserted is brought close to the chuck body, and the female threaded part of the nut is screwed into the male threaded part of the chuck body. In addition, the operator cannot visually recognize the key member and the key groove. Therefore, the operator cannot confirm whether the positional relationship between the key member and the key groove is appropriate or not after the nut is screwed to the chuck body to some extent. On the other hand, if the nut and the chuck body are screwed together, the key member and the key groove cannot be moved greatly along the direction of the axis, and the engagement state between the key member and the key groove cannot be moved by hand. It was difficult to confirm with. Thus, the conventional tool chuck has room for improvement in order to improve the work efficiency of the tool change.

Therefore, it is desired to provide a tool chuck with improved tool runout accuracy and superior tool replacement workability compared to conventional products.

The characteristic configuration of the tool chuck according to the present invention has a cylindrical portion at the tip of which a cylindrical portion into which a tool is inserted along the axis or a collet into which a tool is inserted along the axis is inserted. A chuck body having a male screw at the rear portion, a cylindrical pressure member that engages with the outer surface of the cylindrical portion, or that engages with the outer surface of the cylindrical portion and houses the collet; A nut having a mating female screw, the pressure member being mounted so as to be relatively rotatable, a convex portion provided on one of the cylindrical portion and the pressure member, and the shaft provided on the other An anti-rotation mechanism comprising a recess extending in the direction of the core, and when the pressing member and the nut are attached to the chuck body, the female screw and the male are engaged after the protrusion and the recess are engaged. The screw is configured to engage with the screw.

In the case of the tool chuck having this configuration, the concave portion engages with the convex portion before the male screw and the female screw are engaged with each other at an initial stage in which the concave portion is brought close to the convex portion. Therefore, the operator can clearly feel the engagement between the concave portion and the convex portion by quickly moving the pressing member along the circumferential direction while approaching the chuck body. Therefore, at the stage where the female screw of the nut is screwed with the male screw of the chuck body, the convex portion and the concave portion are in a state of being securely engaged. In this way, with the tool chuck having this configuration, the tool gripping operation can be performed quickly and reliably.

In the chuck for a tool according to the present invention, a widened portion can be formed at the opening end of the concave portion.

In this configuration, when the pressure member is engaged with the chuck body, the engagement range of the concave portion with respect to the convex portion is widened. Therefore, it becomes easy to find an appropriate posture when the pressure member is moved in the circumferential direction to find the engagement position between the two. Therefore, the tool gripping operation becomes even quicker.

In the tool chuck according to the present invention, the first ball that is rotatably held by the cylindrical portion or the pressure member can be used as the convex portion.

The formation of the convex portion is ensured by using the first ball as the convex portion as in this configuration. For example, when forming a convex part on the surface of a cylinder part, the direction which attaches the 1st ball | bowl prepared separately stabilizes the shape of a convex part rather than forming a convex part integral with a cylinder part. Further, by appropriately selecting the material of the first ball, it is possible to improve the friction resistance and extend the life of the apparatus. Furthermore, it is also possible to hold | maintain a 1st ball | bowl so that rotation is possible, and in that case, the frictional force at the time of pushing a pressurization member into a chuck | zipper main body falls more, and the holding | grip operation | work becomes smooth.

In the tool chuck according to the present invention, a plurality of rolling members are brought into contact with the pressure member and the nut in an annular space formed in the circumferential direction with respect to the shaft core by the pressure member and the nut. A second ball may be provided, the annular space may be formed among the pressure member and the nut, and a contact surface with the second ball may be configured to be perpendicular to the direction of the axis.

回転 By using a plurality of second balls as in this configuration, the rotational resistance between the pressure member and the nut is greatly reduced. Therefore, the pressing member does not rotate or tilt based on the rotation of the nut, and the pulling posture of the pressing member becomes extremely stable.

Further, since the contact surface of the pressure member and the contact surface of the nut are in perpendicular contact with the second ball, when the nut is rotated, only the axial force is applied to the pressure member. Acts, and the pressure member can be pulled straight along the axis. As a result, a part of the pressure member is prevented from being irregularly deformed. Furthermore, since the axial center of the pressing member does not tilt and a part of the pressing member does not contact the cylindrical portion of the chuck body, the tool can be gripped with high accuracy.

More preferably, a slight gap should be provided in the radial direction of the second ball. If there is a machining error in the female screw of the nut or the male screw of the chuck body, and the female screw is screwed into the male screw, the shaft core formed by these will be the inner surface of the chuck body and the pressure member. May be misaligned with the axis formed between the two. In that case, the specific position of the inner surface of the pressurizing member is pressed against the surface of the cylindrical portion as the female screw and the male screw are screwed together, and the axis of the gripped tool may be displaced. However, by providing a slight gap in the radial direction of the second ball, a biased contact between the pressure member and the cylindrical portion does not occur, and the axis of the tool can be properly maintained.

FIG. 3 is a side cross-sectional view showing an initial fastening state of the tool chuck according to the first embodiment. Sectional side view which shows the state of completion of fastening of the chuck | zipper for tools which concerns on 1st Embodiment Explanatory drawing which shows the structure of a rotation prevention mechanism. Explanatory drawing which shows the other structure of a rotation prevention mechanism. The perspective view which shows the structure of the pressure member of another shape. The cross-sectional view of the pressure member of another shape. VII-VII sectional view taken on the line of FIG. Explanatory drawing which shows the latching structure of a pressurization member and a nut. The sectional side view which shows other structure of a rotation stopping mechanism. The sectional side view which shows the initial stage state of the fastening of the chuck | zipper for tools which concerns on 2nd Embodiment. The sectional side view which shows the completion state of the fastening of the chuck | zipper for tools which concerns on 2nd Embodiment.

Hereinafter, preferred embodiments of a tool chuck according to the present invention will be described with reference to the drawings.
In addition, embodiment described below is the illustration for demonstrating this invention, and this invention is not limited only to these embodiment. Therefore, the present invention can be implemented in various forms without departing from the gist thereof.

[First Embodiment]
(Overview)
The tool chuck according to the first embodiment will be described with reference to FIGS. The tool chuck has a chuck body 1 that holds a tool 2 inserted along an axis X. A cylindrical portion 11 into which the tool 2 is inserted is formed at the distal end of the chuck body 1, and a male screw 12 is formed at the proximal end portion of the cylindrical portion 11. A cylindrical pressure member 3 is provided on the outer surface of the cylindrical portion 11 so as to be engaged with the cylindrical portion 11 so as not to be relatively rotatable around the axis X and movable along the axis X.

A nut 4 for pulling the pressure member 3 toward the base end side of the chuck body 1 is provided on the outer peripheral side of the pressure member 3. The nut 4 has a female screw 41 that is screwed into the male screw 12 of the chuck body 1. The nut 4 and the pressure member 3 are provided with a contact surface capable of transmitting a tensile force along the direction of the axis X, and the rotation of the nut 4 causes the pressure member 3 to move toward the proximal end side of the chuck body 1. You can pull in.

A rotation preventing mechanism 5 that engages with each other is formed on each of the cylindrical portion 11 and the pressure member 3 of the chuck body 1. For example, as shown in FIGS. 1 to 3, the anti-rotation mechanism 5 is formed of a convex portion 51 provided on the outer peripheral surface of the cylindrical portion 11 and a concave portion 52 provided on the inner surface of the pressure member 3.

(Non-rotating mechanism)
A first cylindrical surface 13 having the same radius with the axis X as the center is formed on the base end side of the outer surface of the cylindrical portion 11. Further, a tapered cone-shaped pressed surface 14 is formed on the tip side adjacent to the first cylindrical surface 13. On the other hand, a second cylindrical surface 31 is formed on the inner peripheral surface of the pressure member 3 so as to face the first cylindrical surface 13 on the proximal end side, and the cylindrical portion 11 is brought into contact with the pressurized surface 14 on the distal end side. A tapered conical pressure surface 32 for reducing the diameter is formed.

The anti-rotation mechanism 5 in the present embodiment uses the first ball 51a as the convex portion 51 in the cylindrical portion 11 as shown in FIGS. The 1st ball | bowl 51a is hold | maintained at the hole 15 formed in the 1st cylindrical surface 13 of the cylinder part 11, for example. The first ball 51a may be either rotatable relative to the hole 15 or not. However, if it is rotatable, the frictional force when moving the pressure member 3 to the proximal end side of the chuck body 1 is reduced, and the gripping operation of the tool 2 becomes smooth. Further, the durability of the detent mechanism 5 can be enhanced by using a member having high hardness as the first ball 51a.

The second cylindrical surface 31 has a recess 52 that engages with the first ball 51a. The concave portion 52 is a linear groove portion that opens at the proximal end side of the pressure member 3 and is formed in parallel with the axis X. The cross-sectional shape of the recess 52 can be configured to be, for example, a semicircle so as to follow the outline of the first ball 51a. As a result, the play in the circumferential direction is unlikely to occur when engaging with the first ball 51 a, and the pressure member 3 can be drawn straight along the axis X with respect to the chuck body 1.

It is preferable to provide at least one set of the first ball 51a and the recess 52 along the circumferential direction. If only one set is provided, the structure of the detent mechanism 5 is the simplest. However, in the case of only one set, when the pressure member 3 is pulled along the cylindrical portion 11, the distribution of the contact friction between the two is not uniform along the circumferential direction, and the axis X of the pressure member 3 is There is a possibility of misalignment with respect to the axis X of the chuck body 1. Therefore, it is preferable to form a plurality of pairs of the first balls 51a and the recesses 52 and arrange them at equal intervals along the circumferential direction in order to further stabilize the posture of the pressure member 3.

As shown in FIG. 3, a widened portion 53 whose width increases toward the end is formed at the proximal end of the recess 52. This facilitates the engaging operation when engaging the recess 52 with the first ball 51a. FIG. 3 shows an example in which the widened portion 53 is provided only on one side in the circumferential direction. Usually, the screw part formed in the pressurizing member 3 or the nut 4 described later is screwed in by clockwise rotation. Therefore, the concave portion 52 is configured to be easily engaged with the first ball 51a when the pressurizing member 3 is brought close to the cylindrical portion 11 of the chuck body 1 while being rotated clockwise.

In addition, as shown in FIG. 4, you may provide the wide part 53 in the both sides of the circumferential direction. With this configuration, since the engagement range of the recess 52 with respect to the first ball 51a is widened, the recess 52 can be quickly and easily moved with respect to the first ball 51a even if the pressing member 3 is rotated in any direction. Can be engaged.

Further, the pressure member 3 may have the shape shown in FIGS. In the pressure member 3, three widened portions 53 are formed on the second cylindrical surface 31 at intervals of 120 degrees along the radially outward direction and the circumferential direction. Between each widened portion 53, three stoppers 53a projecting radially inward are formed. A concave portion 52 is formed from the widened portion 53 along the axis X at one peripheral end in the same direction of each widened portion 53. The inner surface of the recess 52 is smoothly connected to one wall surface of the stopper 53a. When the pressing member 3 has three recesses 52, the cylindrical portion 11 of the chuck body 1 holds the three first balls 51a at intervals of 120 degrees along the circumferential direction.

If the widened portion 53 has such a shape, the engagement of the pressure member 3 with the cylindrical portion 11 is further facilitated. Specifically, when the nut 4 having the pressurizing member 3 is engaged with the cylindrical portion 11 of the chuck body 1, the first ball 51a enters the widened portion 53 except for the portion where the stopper 53a is formed, and the widened width is increased. It contacts the bottom surface 53b of the portion 53. When the nut 4 (pressure member 3) is rotated in this state, the first ball 51a contacts the wall surface of the stopper 53a. Since the recess 53 is formed on the wall surface of the stopper 53a that is brought into contact with the nut 4 by rotating it clockwise, the first ball 51a is recessed when the nut 4 is further pushed into the chuck body 1 side. 52. That is, the stopper 53a serves as a guide for engaging the first ball 51a with the recess 52. Even if the nut 4 is rotated counterclockwise and brought into contact with the wall surface of the stopper 53a, the concave portion 52 is not formed there, so that the nut 4 cannot be pushed further.

If the pressurizing member 3 has such a shape, the pressurizing member 3 can be easily and reliably engaged with the cylindrical portion 11 even in a situation where the concave portion 52 cannot be visually recognized. The number of stoppers 53a and first balls 51a is not limited to three. Although it may be more or less than three sets, it is preferable that a plurality of them are arranged at equal intervals in the circumferential direction.

As the convex part 51, it can replace with the 1st ball | bowl 51a and can take various structures. For example, various shapes such as a cube, a rectangular parallelepiped, and a hemisphere can be formed integrally or separately from the first cylindrical surface 13.

(Pressure member retraction mechanism)
As shown in FIGS. 1 and 2, a nut 4 is disposed on the outer peripheral portion of the pressurizing member 3, and the pressurizing member 3 is proximal to the chuck main body 1 by screwing the nut 4 with respect to the chuck main body 1. Be drawn into. As a result, the pressing surface 32 of the pressing member 3 presses the pressed surface 14 of the cylindrical portion 11 toward the axis X, the cylindrical portion 11 is reduced in diameter, and the shank portion 21 of the tool 2 is gripped. Although illustration is omitted, the cylindrical portion 11 may or may not be provided with at least one slit along the axis X for easy diameter reduction.

A third cylindrical surface 33 is formed on the outer peripheral surface of the tip of the pressure member 3, and a fourth cylindrical surface 42 formed on the inner periphery of the front end of the nut 4 faces the third cylindrical surface 33. The fourth cylindrical surface 42 rotates while being guided by the third cylindrical surface 33. Further, the fourth cylindrical surface 42 increases the diameter of the pressure member 3 when the pressure member 3 attempts to expand the diameter by receiving the reaction force from the cylindrical portion 11 as the pressure member 3 is retracted. It also has a restraining function.

A pressure member retracting mechanism 6 is provided between the pressure member 3 and the nut 4. As shown in FIGS. 1 and 2, a second ball 62 is provided in an annular space 61 formed between the pressure member 3 and the nut 4. That is, the annular space 61 includes a part of the third cylindrical surface 33, the first vertical surface 34 projecting from the third cylindrical surface 33 in the direction perpendicular to the axis X, and the base of the fourth cylindrical surface 42. A second vertical surface 43 provided perpendicularly to the axial center X from the end of the end side in the radial direction, and a fifth cylindrical surface 44 provided proximally from the second vertical surface 43 along the axial core X. Is formed with a part of. The rotational resistance between the pressure member 3 and the nut 4 is reduced by arranging the plurality of second balls 62 in the annular space 61. Thereby, the rotation of the pressure member 3 when the nut 4 is rotated is prevented, and the pressure member 3 can be pulled in an appropriate posture.

The throwing of the second ball 62 into the annular space 61 is performed, for example, from a throwing hole 45 formed through the wall of the nut 4. For example, the insertion hole 45 may be provided in only one place in the circumferential direction, and after the necessary amount of the second balls 62 has been inserted, the insertion hole 45 may be sealed with a cap screw-like plug member 63 or the like.

Even if the charging hole 45 is not used, a plurality of balls are temporarily fixed to the second vertical surface 43 of the nut 4 with grease or the like before the pressure member 3 and the nut 4 are combined. The second ball 62 can also be disposed by inserting the member 3. In this case, the structure of the rotation prevention mechanism 5 becomes simpler.

The pressure member 3 and the nut 4 are integrally assembled by a retaining ring 64 fixed to the inner peripheral surface of the nut 4, for example. The retaining ring 64 is, for example, a C-shaped metal ring, and is fitted in a mounting groove 46 provided in the fifth cylindrical surface 44 of the nut 4 along the circumferential direction.

1 and 2, the first vertical surface 34 of the pressure member 3 and the second vertical surface 43 of the nut 4 that are in contact with the second ball 62 are perpendicular to the axis X. Therefore, when the nut 4 is rotated, only the force along the axis X acts on the pressure member 3, and the pressure member 3 can be pulled straight along the axis X. Further, since the pressing member 3 has the first vertical surface 34, the pressing member 3 is not irregularly expanded or contracted by a force acting on the first vertical surface 34. Therefore, the axis X of the pressing member 3 does not tilt, and a specific portion of the pressing member 3 does not interfere with the cylindrical portion 11 of the chuck body 1. Therefore, the gripping accuracy of the tool 2 is extremely high.

As shown in FIG. 8, the second ball 62 abuts against the pressing member 3 only at the first vertical surface 34, and abuts against the nut 4 only at the second vertical surface 43. That is, the cross-sectional shape of the annular space 61 is wide in the radial direction so that the second ball 62 does not contact the pressing member 3 and the nut 4 in the radial direction. Thereby, when the nut 4 is screwed, the second ball 62 does not exert a force in the radial direction, and the posture of the pressing member 3 is more appropriately maintained.

Further, if a slight gap is provided in the radial direction of the second ball 62, if there is a processing error in the female screw 41 of the nut 4 or the male screw 12 of the chuck body 1, the female screw 41 is connected to the male screw 12. When screwed together, the shaft core formed by these may be displaced from the shaft core formed between the cylindrical portion 11 of the chuck body 1 and the inner surface of the pressing member 3. In that case, the specific position of the inner surface of the pressure member 3 is pressed against the surface of the cylindrical portion 11 as the female screw 41 and the male screw 12 are screwed together, and the axis of the gripped tool 2 may be displaced. However, by providing a slight gap in the radial direction of the second ball 62, an uneven contact between the pressing member 3 and the cylindrical portion 11 does not occur, and the axial center of the tool 2 is appropriately maintained. Can do.

Between the outer peripheral surface of the pressure member 3 and the inner peripheral surface of the nut 4, for example, two

seal members

71 and 72 are provided as shown in FIGS. 1 and 2. Thereby, a slight gap existing between the pressurizing member 3 and the nut 4 is filled, and both of them can be held concentrically to maintain a rotational balance.

Although not shown, when the cutting fluid or the like is sprayed onto the tip of the tool 2 using the space between the pressure member 3 and the nut 4, the sealing

members

71 and 72 seal the cutting fluid. There is also an effect.

(Pressure member and nut installation procedure)
The detent mechanism 5 between the pressure member 3 and the cylindrical portion 11 cannot be visually recognized from the outside. Therefore, if the nut 4 and the chuck body 1 are first screwed together and the anti-rotation mechanism 5 is engaged later, when the nut 4 is tightened, the positions of the concave portion 52 and the convex portion 51 are determined. Inappropriate causes such as the pressure member 3 being bitten or the rotation prevention mechanism 5 being damaged. When engaging the concave portion 52 with the convex portion 51, it is easy to operate by pressing the pressing member 3 to the back side while quickly moving the concave portion 52 in the circumferential direction with respect to the convex portion 51. However, if the nut 4 has already been screwed into the chuck body 1, even if only the pressure member 3 can be turned left and right, the pressure member 3 can be moved greatly along the axis X direction. Can not. Therefore, the operator cannot clearly feel the engagement state between the convex portion 51 and the concave portion 52.

In this respect, with the tool chuck of the present embodiment, the engagement between the concave portion 52 and the convex portion 51 can be easily confirmed. That is, the widened portion 53 of the concave portion 52 is engaged with the first ball 51a at the initial stage where the concave portion 52 as shown in FIG. On the other hand, the base end side end portion of the female screw 41 provided at the base end portion of the nut 4 is not yet screwed into the male screw 12 of the chuck body 1. Therefore, the pressure member 3 can be moved to the back side of the chuck body 1 while quickly moving the pressure member 3 along the circumferential direction, and the operator can engage the recess 52 with the first ball 51a. I can feel it clearly. Therefore, when the nut 4 is screwed into the chuck body 1, the recess 52 and the first ball 51a are securely engaged. In this way, with the tool chuck having this configuration, the gripping operation of the tool 2 can be performed quickly and reliably.

As the anti-rotation mechanism 5, as shown in FIG. 9, a positioning pin 51b as a convex portion 51 and a positioning hole 54 as a concave portion may be used. FIG. 9 shows a state in which the rotation prevention mechanism 5 is engaged and the male screw 12 and the female screw 41 are not yet engaged. The positioning pin 51b is embedded and fixed in the back end portion of the pressure member 3, and protrudes in the back side along the direction of the axis X.

On the other hand, a positioning hole 54 for determining a relative rotational phase between the chuck body 1 and the pressing member 3 is formed at the proximal end portion of the chuck body 1 by the positioning pin 51b. A chamfered portion 55 that facilitates insertion of the positioning pin 51b may be provided at the opening end of the positioning hole 54. Further, if the chamfering process is also performed on the tip corner portion of the positioning pin 51b, the engagement with the positioning hole 54 becomes easier.

In addition, it is good to provide at least one set of such positioning pins 51b and positioning holes 54 along the circumferential direction. However, when a plurality of sets are provided along the circumferential direction, the sliding resistance of the pressing member 3 with respect to the chuck body 1 is dispersed in the circumferential direction, and the pressing posture of the pressing member 3 is further stabilized.

[Second Embodiment]
As shown in FIGS. 10 and 11, the tool chuck according to the second embodiment may have a collet 8 that holds the shank portion 21 of the tool 2 inside the chuck body 1. The collet 8 is made of an elastically deformable metal material or the like, and grips / releases the shank portion 21 of the tool 2 by expansion / contraction of the outer diameter.

A proximal end tapered surface 81 is formed on the outer peripheral surface of the collet 8 on the proximal end side. The proximal end side tapered surface 81 is provided with a plurality of slits 82 extending in the direction of the axis X along the circumferential direction. An annular distal groove 83 is formed on the distal outer peripheral surface adjacent to the proximal taper surface 81. The tip groove portion 83 is engaged with an annular tip convex portion 35 formed on the inner peripheral surface of the tip portion of the pressure member 3. When the pressurizing member 3 is pulled back by the nut 4, the tip convex portion 35 pushes the tip groove portion 83 to the back side and pushes the collet 8 to the back side. Thereby, the diameter of the collet 8 is reduced and the shank portion 21 of the tool 2 is gripped. On the contrary, when removing the tool 2, the nut 4 is rotated in the reverse direction so that the tip convex portion 35 of the pressurizing member 3 pushes the tip groove portion 83 toward the tip side.

Unlike the first embodiment described above, the entire outer surface of the cylindrical portion 11 of the chuck body 1 is formed into a cylindrical surface. However, the said cylindrical surface has the small diameter small diameter cylindrical surface 16 provided in the front end side, and the large diameter large diameter cylindrical surface 17 provided in the base end side adjacent to this. A two-stage cylindrical surface, that is, a small-diameter cylindrical inner surface 36 and a large-diameter cylindrical inner surface 37 are also formed on the inner surface of one pressure member 3.

FIG. 10 shows a state in which the nut 4 and the pressure member 3 are brought close to the cylindrical portion 11 of the chuck body 1. A recess 52 formed in the small-diameter cylindrical inner surface 36 of the pressing member 3 is engaged with the first ball 51a. At this time, the cylindrical portion 11 and the pressure member 3 are such that the small-diameter cylindrical surface 16 of the cylindrical portion 11 and the small-diameter cylindrical inner surface 36 of the pressure member 3 serve as a guide portion for mutual alignment. From this state, as shown in FIG. 11, when the nut 4 is screwed relative to the chuck body 1, the large-diameter cylindrical inner surface 37 formed on the proximal end side of the pressurizing member 3 becomes the large-diameter cylindrical surface 17 of the cylindrical portion 11. In this case, the guiding relationship between the pressure member 3 and the cylindrical portion 11 is generated.

Thus, only the small-diameter cylindrical surface 16 becomes the guide surface in the initial stage of the gripping operation of the tool 2 because the frictional force generated between the cylindrical portion 11 and the pressurizing member 3 is reduced and the rotational force of the nut 4 is reduced. Is to keep the value small. Further, in the initial fastening state of the tool 2, a strong contact force is not yet generated between the proximal-side tapered surface 81 of the collet 8 and the tapered inner surface 18 of the cylindrical portion 11, and the cylindrical portion 11 is separated from the collet 8. There is little tendency to expand due to the repulsive force. Therefore, at the initial stage of fastening, there is no particular inconvenience that only the small diameter cylindrical surface 16 and the small diameter cylindrical inner surface 36 abut.

However, as shown in FIG. 11, when the collet 8 is pushed to the far side of the cylindrical portion 11 and the grip is completed, a strong repulsive force acts on the cylindrical portion 11 from the collet 8, and the cylindrical portion 11 expands in diameter. The trend increases. Therefore, by making the large-diameter cylindrical inner surface 37 of the pressurizing member 3 face the large-diameter cylindrical surface 17 of the cylindrical portion 11, the diameter of the cylindrical portion 11 is reliably prevented and the gripping force of the collet 8 is exerted strongly. I am doing so.

Two

seal members

71 and 72 are provided between the pressurizing member 3 and the nut 4, and one seal member 73 is provided between the pressurizing member 3 and the cylindrical portion 11. By disposing these seal members 71 to 73, the gap size between the members is averaged, and the centering of each member is appropriately performed. Although not shown, when the cutting fluid is sprayed onto the tip of the tool 2 using the space between the nut 4 and the cylinder portion 11, each of the seal members 71 to 73 also exhibits a liquid leakage preventing effect. To do.

In addition, about the structure which is the other structure of the said 2nd Embodiment and is common in 1st Embodiment, the same function effect demonstrated in the column of 1st Embodiment is exhibited.

[Other Embodiments]
As the anti-rotation mechanism 5 constituted by the pressure member 3 and the chuck body 1, a convex portion 51 such as a first ball 51 a is provided on the inner peripheral surface of the pressure member 3, and the concave portion 52 is formed on the cylindrical portion of the chuck body 1. 11 may be provided on the surface. Or the structure which provides a pin and a hole in each end surface of the cylinder part 11 and the pressurization member 3 may be sufficient.

In the annular space 61 formed by the pressure member 3 and the nut 4, for example, a resin ring having a low frictional resistance may be provided instead of the second ball 62. Alternatively, nothing may be provided. In short, any configuration may be used as long as the pressure member 3 is not misaligned when the nut 4 pulls in the pressure member 3.

The tool chuck according to the present invention can be widely applied to a tool that grips a shank portion of a tool from the outer periphery by rotating a nut and moving a pressing member engaged with the nut in the axial direction. .

DESCRIPTION OF SYMBOLS 1 Chuck main body 11 Cylinder part 12 Male screw 2 Tool 3 Pressurizing member 4 Nut 41 Female screw 5 Non-rotating mechanism 51 Protruding part 51a First ball 52 Concave part 53 Widening part 61 Annulus 62

Claims

A chuck body having a cylindrical portion into which a tool is inserted along the axial center, or a cylindrical portion into which a collet into which a tool is inserted along the axial center is inserted, and a male screw at the rear;
A cylindrical pressure member that engages with the outer surface of the cylindrical part, or engages with the outer surface of the cylindrical part and houses the collet;
A nut having a female screw threadedly engaged with the male screw, and the pressure member being rotatably mounted therein;
A convex portion provided on any one of the cylindrical portion and the pressure member, and a detent mechanism comprising a concave portion provided on either side and extending in the direction of the axis,
A tool chuck configured such that, when the pressing member and the nut are attached to the chuck body, the female screw and the male screw are screwed together after the convex portion and the concave portion are engaged.
The tool chuck according to claim 1, wherein a widened portion is formed at an opening end of the concave portion.
The tool chuck according to claim 1 or 2, wherein the convex portion is a first ball that is rotatably held by the cylindrical portion or the pressure member.
A plurality of second balls that roll in contact with the pressure member and the nut are provided in an annular space formed in the circumferential direction with respect to the shaft core by the pressure member and the nut,
The said pressurization member and the said nut form the said annular space, and the contact surface with respect to a said 2nd ball | bowl is perpendicular | vertical with respect to the direction of the said axial center. Tool chuck.