JPH0890318A - Collet chuck - Google Patents

Abstract

PURPOSE: To provide a collet chuck that is able to easily check the tightness of a collet from the outside, and to feed a tool with a coolant through a small diametral hole. CONSTITUTION: A pull stud 2 is clamped to a terminal part of a chuck body 1, while a collet 3 is taperingly fitted in a tip part of this body 1, installing a pull bolt 4, screwedly fitted in a terminal part of this collet 3, in an intermediate part of the body 1, and each of center holes 2r and 4c passing through in the axial direction is formed in the pull stud 2 and the pull bolt 4. A terminal part 7a of a wrench 7 inserted from the terminal part of the center hole 2e of the pull stud 2 is engaged with an engaging recess 4d of a head part 4b of the pull bolt 4, whereby this wrench 7 is rotated, the collet 3 is tightened or loosened, and when it is attached to a spindle of a collet chuck, a coolant is fed to the circumference of a tool 6 held on the collet 3 through the center holes 2e and 4c from the inside of the spindle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collet chuck for removably tightening various tools such as a drill, an end mill, a reamer and the like to be mounted on a spindle of a machine tool.

[0002]

2. Description of the Related Art Conventionally, as a collet chuck as described above, the tip of a pull stud is screwed and fixed to the distal end of a chuck body, and the collet is taper-fitted to the tip of the body. The pulling bolt provided inside is screwed into the end of the collet, the shank part of the tool is fitted to the collet, and the bolt is rotated from the outside to tighten and loosen the collet. On the other hand, there are those which fix and release and attach and detach the tool, and those which remove the pull stud and rotate the bolt.

[0003]

However, in the conventional collet chuck, the number of parts is large, and the attaching / detaching operation of the tool is troublesome, and a coolant flow hole is formed in the outer peripheral portion of the chuck body. Therefore, there is a problem that the diameter is increased. SUMMARY OF THE INVENTION It is an object of the present invention to solve all of the above-mentioned problems, to provide a collet chuck that has a small number of parts, can be easily attached and detached with a tool, and does not have a large diameter even when a coolant is circulated. I am trying.

[0004]

According to a first aspect of the present invention, there is provided a collet chuck, a chuck body, a pull stud having a tip end fixed to a distal end of the body, and a taper fitting to the tip end of the body. A collet for tightening the shank portion of the tool, and a pulling bolt in which the head located in the intermediate hole of the main body abuts the supporting surface formed on the main body from the distal end side and is screwed into the distal end portion of the collet. The pull stud and the pull bolt are each provided with a central hole penetrating in the axial direction, and the tip of the wrench inserted from the end of the central hole of the pull stud is engaged with the head of the pull bolt, and the pull bolt is pulled by the wrench. The collet is rotated to tighten and loosen it.

According to a second aspect of the present invention, in the collet chuck according to the first aspect, a tip cover having a tool insertion hole slightly larger than the outer diameter of the tool is detachably fixed to the tip cylindrical portion of the chuck body. It is a thing.

[0006]

In the collet chuck according to the first aspect of the present invention, the wrench is inserted into the center hole of the pull stud from the end side of the pull stud in a state where the wrench is removed from the spindle of the machine tool, and the end portion of the wrench is pulled by the head of the pull bolt. Part of the collet chuck, rotate the wrench by operating from outside the collet chuck, tighten and loosen the collet screwed with the pull bolt, fix and release the shank part of the tool fitted in the collet, and then remove the wrench. The tool can be easily attached to and detached from the chuck by pulling it out of the pull stud.

Further, with the tool mounted and the chuck mounted on the spindle, the coolant is supplied from the inside of the spindle so that the coolant flows through the central hole of the pull stud, the intermediate hole of the chuck body, and the central hole of the pull bolt. After that, it can be ejected outward from the tip of the tubular portion of the chuck body along the tool. Therefore, the entire collet chuck, such as the chuck body, can be made to have a small outer diameter, and it is not necessary to form a coolant flow hole in the outer peripheral portion of the body, so that the machining can be facilitated.

Further, the collet chuck according to the invention of claim 1 comprises a chuck body, a pull stud, a collet and a draw bolt as main parts, and when machining these parts, the draw bolt has a central hole and a tip of a wrench. Since it suffices to add processing to the engaging portion that engages with, the number of parts is small and processing is easy.

In the collet chuck according to the second aspect of the present invention, since the tip end cylindrical portion of the chuck body is provided with the tip cover having a tool insertion hole through which a tool can be inserted and extracted with almost no gap, the tip end cylindrical portion is provided. It is possible to easily eject the coolant sent to the nozzle from the insertion hole along the outer periphery of the tool and to prevent foreign matters such as dust from entering the distal end cylindrical portion by replacing the distal end cover.

It is preferable that the tip cover is screwed onto the inner peripheral surface of the portion of the tip tubular portion projecting from the tip of the collet because it can be mounted on the tip tubular portion without increasing the outer diameter.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment corresponding to the invention of claim 1. In FIG. 1, 1 is a chuck body, 2 is a pull stud, 3 is a collet, 4 is a draw bolt, and a collet chuck is constituted by using these as main components.

The chuck body 1 has a taper shank 1a formed at its distal end, a flange portion 1b for automatic tool exchange provided at an intermediate portion thereof, a V groove 1c formed on the outer peripheral surface of the flange portion 1b, and a flange portion 1b. A front end cylindrical portion 1d having a small outer diameter is formed so as to project therefrom. Further, the chuck body 1 has a series of female screw hole portions 1e, an intermediate hole portion 1f, a small diameter hole portion 1g and a taper hole portion 1h formed from the distal end to the front end, and the axial center of these hole portions is the main body 1 described above. Aligned with the axis of.

The tip portion 2a of the pull stud 2 is screwed into the female screw hole 1e of the chuck body 1 and tightened and fixed, and the operation portion 2b having a large outer diameter connected to the end side of the tip portion 2a is attached to the body 1. An engaging portion 2d having a large outer diameter to some extent is formed at the end portion of a small outer diameter protruding portion 2c which is brought into contact with the end surface of the operating portion 2b. Also, pull stud 2
A central hole 2e penetrating in the axial direction is formed in the.

The collet chuck 3 has a plurality of slits in the circumferential direction on the front end side from the distal end portion 3a, is supported by the peripheral surface of the tapered hole portion 1h of the chuck body 1, and is fitted in the tapered hole portion 1h so as to be movable in the axial direction. It is supported in common.

The pulling bolt 4 has a threaded portion 4a formed on the inner peripheral surface of the distal end portion 3a of the collet 3 and is screwed into the threaded portion. A head portion 4b connected to the distal end side of the threaded portion 4a has a small diameter hole portion. The supporting surface 1i consisting of a step at the end of 1g is supported from the end side of the main body 1. Further, the pulling bolt 4 has a central hole 4c penetrating in the axial direction, and the head portion 4b has a regular hexagonal engaging concave portion 4d opening to the end face. Then, each hole of the chuck body 1 and the center hole 2e of the pull stud 2 are
And the central hole 4c of the pull bolt 4 are formed so that their axes coincide with each other.

In FIG. 1, 5 is a spindle of a machine tool, a tapered hole 5a is formed at the tip, 6 is a tool such as a drill or an end mill, and the tool 6 has a straight shank portion 6a at the end. It is formed in the part. Reference numeral 7 is an L-shaped wrench 7 having a regular hexagonal cross section and bent at a right angle from a short grip portion 7b, and a tip end portion 7a thereof can be engaged with and disengaged from an engaging concave portion 4d provided on a head portion 4b of a pull bolt 4. Are formed so as to engage with. Reference numeral 8 denotes an O-ring for sealing which is arranged near the operating portion 2b of the tip portion 2a of the pull stud 2, is fitted to the outer periphery of the tip portion 2a, and is pressed against the inner peripheral surface of the end portion of the chuck body 1.

Next, the use of the collet chuck according to this embodiment will be described. With the collet chuck removed from the spindle 5 of the machine tool and the collet 3 loosened,
The straight shank portion 6a of the tool 6 is fitted into the collet 3. In this state, attach the wrench 7 to the center hole 2 of the pull stud 2.
The distal end portion 7a of the wrench 7 is engaged with the engaging recessed portion 4d formed in the head portion 4b of the pulling bolt 4, and the grip portion 7 of the wrench 7 located outside the collet chuck is inserted into the e.
By holding the b and rotating the wrench 7 in the forward direction to rotate the pulling bolt 4 in the forward direction, the collet 3 is pulled to the distal end side of the chuck body 1 and tightened, and the shank portion 6a of the tool 6 is tightened and fixed, and then the wrench. 7 is pulled out from the pull stud 2, and the attachment of the tool 6 to the collet chuck is completed.

The collet chuck with the tool 6 mounted thereon holds the taper shank 1a of the chuck body 1 in a tapered hole 5a formed in the spindle 5 of the machine tool by a conventionally known procedure, and holds it. Is processed. At the time of this processing, by supplying a liquid or gas coolant from the inside of the spindle 5, the coolant is passed through the center hole 2e of the pull stud 2, the intermediate hole portion 1f of the chuck body 1 and the center hole 4c of the pull bolt 4, By jetting from the tip of the center hole 4c to the outside of these tips through the slits of the collet 3, cooling and lubrication of the tool 6 and the machined portion of the workpiece by the tool 6 are performed. Therefore, it is not necessary to form a flow hole for supplying the coolant on the outer peripheral portion of the chuck body 1, and therefore the chuck body 1
Can have a small outer diameter.

When the blade portion of the tool 6 is worn or damaged by repeating the above-described processing, the spindle 5 removes the collet chuck together with the tool 6, and the tool 6 is removed from this chuck. To remove the tool 6, insert the wrench 7 into the center hole 2e of the pull stud 2,
By engaging the tip portion 7a of the wrench 7 with the engaging recess 4d of the pulling bolt 4 and rotating the wrench 7 in the reverse direction to rotate the pulling bolt 4 in the reverse direction, the collet 3 is pushed toward the tip side of the chuck body 1 and loosened. In this state, the tool 6 is pulled out to the tip side.

As described above, in the collet chuck of this embodiment, with the wrench 7 removed from the spindle 5, the wrench 7 is inserted into the center hole 2e of the pull stud 2, and the tip portion 7a of the wrench 7 is pulled to the head of the bolt 4. Since the collet 3 can be tightened and loosened by engaging the engaging recess 4d provided in the portion 4b and rotating the pulling bolt 4, this operation can be easily performed from outside the chuck without attaching or detaching the components of the collet chuck. it can.

Further, the collet chuck of this embodiment is
Since the chuck body 1, the pull stud 2, the collet 3 and the draw bolt 4 are main components, the number of components is small, and the circulation hole for supplying the coolant is provided in the chuck body 1.
Other than the holes such as the intermediate hole 1f, the chuck body 1 is not formed especially on the outer peripheral side of each hole.
Is also easy to process.

When assembling the collet chuck, the female screw hole portion 1 on the distal side of the small diameter hole portion 1g of the chuck body 1 is assembled.
e, the outer diameter of the intermediate hole portion 1f is larger than the outer diameter of the head portion 4b of the pulling bolt 4, and the pulling bolt 4 can be attached before the pull stud 2 is attached to the chuck body 1. Therefore, the assembly is troublesome. Nothing.

FIG. 2 shows a collet chuck according to a modification of the first embodiment of the present invention. In this modified example, as shown in FIG. 2, the taper shank 9 of the chuck body 1 projects a cylindrical portion 1j to the end side of the flange portion 1b of the chuck body 1, and the tapered cone 10 is fitted to the cylindrical portion 1j. Let
The tip end side of this is connected to the flange portion 1 via a plurality of disc springs 11.
1 is substantially the same as the embodiment shown in FIG. 1, except that the pull stud 2 is mounted on the cylindrical portion 1j by screwing the pull stud 2 onto the cylindrical portion 1j and the operating portion 2b of the pull stud 2 pushes the tapered cone 10 toward the flange portion 1b. With the same configuration, the same operation and effect can be obtained. In FIG. 2, the same symbols as those in FIG. 1 indicate corresponding parts.

3 and 4 show a second embodiment corresponding to the invention of claim 2. In FIGS. 3 and 4, reference numeral 12 is an example of an annular tip cover, and the tip cover 12 has a tool insertion hole 12a having a hole diameter slightly larger than the outer diameter of the tool 6 formed at the center thereof, and is opened in this hole 12a. The grooves 12b for ejecting the coolant of the book are formed at equal intervals in the circumferential direction, and male threads 12c are formed on the outer peripheral surface.

Also, the small-diameter tip cylindrical portion 1 of the chuck body 1
d is made longer than the tip cylindrical portion of the chuck body of the first embodiment so as to project from the tip of the collet 3, and a step 1k is formed in the projecting portion so that the tip side of the step 1k has a large inner diameter. , The external thread 12c of the tip cover 12 is screw-fitted to the internal thread of the portion having the large inner diameter and tightened, and the outer peripheral portion of the tip cover 12 is supported by the step 1k. The tip cover 12 is detachably fixed to the portion 1d. The configuration of the second embodiment other than that described above is the same as that of the first embodiment or a modification thereof.

Then, the collet chuck according to the second embodiment is mounted on a spindle of a machine tool, and a coolant such as cutting oil is supplied from the inside of the collet chuck to supply the coolant with the central hole of the pull stud and the intermediate hole of the chuck body. The coolant that has passed through the center hole of the pulling bolt and the collet 3 and is fed through the slit portion of the collet 3 is squeezed when passing through the recessed groove 12b provided in the tip cover 12, and the coolant is passed from the recessed groove 12b to the outer periphery of the tool 6, respectively. By jetting them together, cooling and lubrication of the tool 6 and the machined portion of the workpiece by the tool 6 are performed.

Another example of the tip cover 12 is shown in FIGS. 5 and 6, in which the tool insertion hole 12d is a tapered taper hole having a large diameter at the end and a small diameter at the tip. The coolant sent to the tip cylindrical portion 1d is squeezed when passing through the tool insertion hole 12d and jetted along the entire outer periphery of the tool 6, thereby cooling and lubricating the tool and the machined part of the workpiece.

FIG. 7 shows still another tip cover 12,
The tip cover 12 is a straight hole and has a tool insertion hole 1e having a diameter that allows the tool to be fitted with almost no gap, so that foreign matter such as dust or dust can be trapped when the coolant is not used. It is a dust cover that prevents it from getting inside and adhering to its inner peripheral surface or collet.

The tip cover 12 shown in FIGS. 5, 6 and 7 can be removably attached to the tip cylindrical portion 1d of the chuck body 1 like the tip cover 12 shown in FIGS. It is possible to select the three types of tip covers and attach them to the tip tubular portion 1d.

The number and shape of the concave grooves 12b of the tip cover 12 shown in FIGS. 3 and 4, and the tip cover 1 shown in FIGS.
The tapered shape of the second tool insertion hole 12d can be changed as appropriate.
5 to 7, the same reference numerals as those in Figs. 3 and 4 indicate corresponding parts.

Further, the tip cover may be detachably fitted and fixed to the outer peripheral surface of the tip cylindrical portion of the chuck body. In this case, the outer peripheral flange is integrally formed on the outer periphery of the cover portion having the tool insertion hole. The screw may be provided and formed on the inner peripheral surface of the outer peripheral flange by tightening the screw on the male screw formed on the outer peripheral surface of the distal end tubular portion. However, the tip cover 12 attached to the inner circumference of the tip cylindrical portion shown in FIGS. 3 to 7 is preferable because it does not increase the outer diameter of the tip portion of the collet chuck.

In the present invention, the engaging recess provided on the head of the pull bolt can be appropriately changed to, for example, a square shape, and the shape of the tip of the wrench can be changed to a square shape according to the engaging recess. An engaging projection is provided on the head of the pull bolt, and an engaging recess is formed on the tip of the wrench that engages with the engaging projection. If the pull bolt is rotated by the wrench from the end side of the pull stud and the collet can be tightened and loosened, the head of the pull bolt and the wrench can be changed appropriately, but the wrench engages with the head of the pull bolt. Providing the engaging recess is preferable because it is easy to manufacture and has good operability.

[0033]

As described above, in the collet chuck according to the first aspect of the present invention, the wrench is inserted from the distal end side of the pull stud into the center hole of the pull stud in a state of being removed from the spindle of the machine tool. Of the tool is fitted to the collet chuck, and the wrench is rotated by an operation from outside the collet chuck to tighten and loosen the collet in which the pull bolt is screwed. By fixing and releasing, and then pulling out the wrench from the pull stud, the tool can be easily attached to and detached from the chuck.

With the tool mounted and the chuck mounted on the spindle, the coolant is supplied from the inside of the spindle so that the coolant flows through the central hole of the pull stud, the intermediate hole of the chuck body, and the central hole of the pull bolt. After that, it can be ejected outward from the tip of the tubular portion of the chuck body along the tool. Therefore, the entire collet chuck, such as the chuck body, can be made to have a small outer diameter, and it is not necessary to form a coolant flow hole in the outer peripheral portion of the body, so that the machining can be facilitated.

Further, the collet chuck according to the invention of claim 1 comprises a chuck body, a pull stud, a collet and a draw bolt as main components, and when machining these parts, the pull bolt has a central hole and a tip of a wrench. Since it suffices to add processing to the engaging portion that engages with, the number of parts is small, processing is easy, and it can be provided at low cost.

In the collet chuck according to the second aspect of the present invention, since the tip end cylindrical portion of the chuck body is provided with the tip cover having a tool insertion hole through which a tool can be inserted and extracted with almost no gap, the tip end cylindrical portion is provided. It is possible to easily eject the coolant sent to the nozzle from the insertion hole along the outer periphery of the tool and to prevent foreign matters such as dust from entering the distal end cylindrical portion by replacing the distal end cover.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view of a collet chuck according to a first embodiment of the present invention.

FIG. 2 is a partially longitudinal front view of a collet chuck according to a modification of the first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a main part of a collet chuck according to a second embodiment of the present invention.

FIG. 4 is a front view of the tip cover of FIG.

FIG. 5 is a front view showing a modification of the tip cover.

6 is a cross-sectional explanatory view of the tip cover of FIG.

FIG. 7 is a front view showing another modification of the tip cover.

[Explanation of symbols]

 1 Chuck Body 1a Tapered Shank 1b Flange 1d Tip Cylindrical Part 1i Support Surface 2 Pull Stud 2e Center Hole 3 Collet 4 Pull Bolt 4b Head 4c Center Hole 4d Engagement Recess 5 Spindle 6 Tool 6a Shank Part 7 Wrench 7a Tip End Joint part 12 Tip cover 12a Tool insertion hole 12b Recessed groove 12d Tool insertion hole 12e Tool insertion hole

Claims (2)

[Claims] 1. A chuck body, a pull stud having a tip portion fixed to a distal end portion of the body, a collet for tapering the tip portion of the body to tighten a shank portion of a tool, and an intermediate hole portion of the body. A pulling bolt having a head located at the end contacting a supporting surface formed on the main body from the distal end side and screw-fitted to the end portion of the collet, and a center penetrating the pull stud and the pulling bolt in the axial direction. Each hole is formed, the tip of the wrench inserted from the end of the center hole of the pull stud is engaged with the head of the pull bolt, the pull bolt is rotated by the wrench, and the collet is tightened and loosened. Characteristic collet chuck. 2. The collet chuck according to claim 1, wherein a tip cover having a tool insertion hole slightly larger than the outer diameter of the tool is detachably fixed to the tip cylindrical portion of the chuck body.