JP2010214568A - Unclamping device, main spindle device and machining center - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily replace a tool holder by canceling a close contact state of the tool holder contacting with a tapered hole of a spindle and the tapered hole. <P>SOLUTION: If a plunger pin 216 is pressed when unclamping, a draw bar 20 is moved downward by a booster mechanism with a tapered face 212B and a ball 222, the tool holder 40 is pressed out and the close contact state of a tapered face 31 and a tapered face 44 of the tool holder 40 is canceled. In a temporary holding mechanism 100, as the ball 104 is returned to a groove 102 by a temporary holding spring 112, the draw bar 20 is moved upward, the tool holder 40 is returned upward and the tapered face 44 contacts with the tapered face 31 at the side of the spindle 30 again and is returned to an original position. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an unclamping device, a spindle device, and a machining center, for example, an unclamping device, a spindle device, and a machining center suitable for exchanging a tool holder in an ATC (automatic tool changer) of a machining center. It is about.

  A taper hole is provided at the tip of the spindle device or spindle mechanism of the automatic tool changer of the machining center, and a tool holder having the same taper shape is inserted into this to be clamped (fixed). . A large number of disc springs are provided in the main shaft, and the pull stud at the rear end of the tool holder is gripped by the collet on the main shaft side by the bending thereof. For example, a hydraulic cylinder is provided at the rear end portion of the spindle device, and the collet is opened and closed by pushing a draw bar penetrating the inside of the spindle device by the piston.

  For example, Patent Document 1 below discloses an automatic tool holding device including a booster mechanism that transmits a spring force of a spring placed in a main shaft to a pull-in bar that pulls a pull stud. In Patent Document 2 below, in order to enable tool change in a short time, a clamp spring is provided around the draw bar in addition to the disc spring, and when the draw bar retracting bias by the disc spring is released, the draw spring is moved by the clamp spring. A tool clamping device is disclosed in which a tool is prevented from falling off by being pulled and biased with a weak force.

Japanese Utility Model Publication No. 2-104906 JP 2003-231008 A

  By the way, in the state which processed by clamping a tool, it will be in the state which the taper surface by the side of a tool holder, and the taper surface by the side of a spindle end contact tightly. For this reason, at the time of unclamping, the tool holder cannot be unclamped by opening the collet unless the draw bar is pushed with a considerable force by the piston of the hydraulic cylinder. In addition, there is also a disadvantage that the tool holder cannot be replaced at a high speed in order to release the close contact state of the tapered portion.

  The present invention focuses on the above points, and an object of the present invention is to provide a clamp mechanism that can unclamp the taper surface by satisfactorily releasing the close state of the clamp target. Another object is to release the tool holder in close contact with the taper hole of the spindle and the taper hole to facilitate replacement of the tool holder, particularly in the spindle device of the ATC. Still another object is to speed up the tool changing operation by temporarily holding the tool holder in an unclamped state.

  An unclamping device according to the present invention includes a clamping object having a tapered surface, a spindle having a tapered surface that contacts the tapered surface at the time of clamping, and a gripper that moves within the spindle and grips the clamping object. A draw bar provided with means, a knock mechanism for releasing the joining state between the tapered surface of the clamp object and the tapered surface of the spindle during unclamping, and returning the position of the clamp object displaced by the knock mechanism to the original position A temporary holding mechanism for holding is provided.

  In the spindle device of the present invention, a tapered surface whose diameter increases toward one end portion of the hollow spindle rotatably supported in the housing is formed. A spindle device in which the spindle and the tool holder rotate integrally by bringing the tapered surface of the tool holder into close contact with the surface, provided at the tip of a draw bar that can move the hollow portion of the spindle in its axial direction, Grasping means for detachably gripping the pull stud of the tool holder, provided in a hollow portion on the other end side of the spindle, the tool holder in a clamped state is pushed out to the tip side via the draw bar, and the tool A knock mechanism for releasing the joining state between the taper surface of the holder and the taper surface on the spindle side, and a tool holder pushed out by the knock mechanism, Tapered surface is characterized by comprising a temporary holding mechanism, back to the original position in contact with the spindle side of the tapered surface of the.

  According to one of the main forms, the knock mechanism includes a booster cam provided around the drawbar, first and second balls provided between the drawbar and the booster cam, A first booster mechanism configured by a first recess provided on the outside of the draw bar, the first ball, and a first tapered surface provided on the inside of the booster cam, and operating during clamping; A second booster configured by a second recess provided outside the draw bar, the second ball, and a second tapered surface provided inside the booster cam and operating during unclamping Including a mechanism.

  One of the other forms is that the temporary holding mechanism is urged from the spindle side to the draw bar side from the first and second grooves formed on the outer peripheral surface on the tip end side of the draw bar. In the clamped state, the elastic means is fitted in the first groove, and the draw bar moved by the operation of the first booster mechanism is returned to its original position. In the unclamped state, the elastic means is fitted into the second groove to temporarily hold the draw bar.

  A machining center according to the present invention includes any one of the main spindle devices.

  According to the present invention, at the time of unclamping, the joining state of the taper surface of the clamp object and the taper surface on the spindle side is released, and the position of the clamp object displaced by this release is restored and temporarily held. Therefore, it is possible to perform unclamping by satisfactorily releasing the close state of the clamp target on the tapered surface.

It is a figure which shows the unclamp state of Example 1 of this invention, (A) is a figure which shows the whole, (B) is an enlarged view of a knock mechanism, (C) is an enlarged view of a temporary holding mechanism. It is a figure which shows the operation | movement at the time of the clamp of the said Example 1. FIG. It is a figure which shows the operation | movement at the time of the clamp of the said Example 1. FIG. (A) is an overall view, (B) is an enlarged view of a knock mechanism, and (C) is an enlarged view of a temporary holding mechanism. It is a figure which shows the operation | movement at the time of the unclamp of the said Example 1. FIG. (A) is a diagram showing the whole, and (B) is an enlarged view of the knock mechanism. It is a figure which shows the operation | movement at the time of the unclamp of the said Example 1. FIG. It is a figure which shows Example 2 of this invention, (A) is the figure at the time of a clamp, (B) is a figure which shows the state at the time of an unclamp, (C) is a figure which shows a mode that the ball press was seen from the side surface.

  Hereinafter, the best mode for carrying out the present invention will be described in detail based on examples. For convenience of explanation, the lower part of the figure is expressed as “front side” or “lower side”, and the upper part of the figure is expressed as “rear side” or “upper side”. In addition, all drawings are exaggerated for easy understanding of the present invention.

  First, the configuration of the spindle device of the present embodiment will be described with reference to FIG. In the figure, the spindle device 10 is constructed around a draw bar 20, is rotatably supported by a housing (not shown), and penetrates through a spindle 30. A collet 22 for rotatably holding the pullstat 42 of the tool holder 40 is provided at the tip of the draw bar 20. A clamp spring 50 is provided in a space 32 between the approximate center portion of the draw bar 20 and the spindle 30. A temporary holding mechanism 100 is provided on the leading end side of the draw bar 20 and in the vicinity of the collet 22, and a knock mechanism 200 is provided on the rear end side of the draw bar 20. A tapered surface 31 whose diameter increases toward the distal end is formed inside the distal end of the spindle 30, and a tapered surface 44 that abuts on the tapered surface 31 is formed on the outer surface of the tool holder 40. That is, the rotation of the spindle 30 is transmitted to the tool holder 40 via the tapered surfaces 31 and 44, and a tool (not shown) attached to the tool holder 40 is rotated.

  As shown in FIG. 1C, the temporary holding mechanism 100 includes a plurality of grooves 102 and 104 formed on the side surface of the draw bar 20 at equal intervals, a ball 110 fitted in these, and the ball 110 on the draw bar 20 side. It is comprised centering on the temporary holding spring 112 pressed on. That is, the balls 110 and the temporary holding springs 112 are respectively housed in a plurality of holes 34 formed radially at equal intervals in the radial direction of the spindle 30 (a direction perpendicular to the longitudinal direction). A spring retainer 114 is provided.

  In the unclamped state, the ball 110 fits in the groove 104 as shown in the figure, and in the clamped state, the ball 110 fits in the groove 102 as shown in FIG. It comes to include. That is, when the draw bar 20 moves up and down between the unclamped state and the clamped state, the ball 110 is urged by the temporary holding spring 112, so that it protrudes from the hole 34 along the shape of the grooves 102 and 104. Withdraw. Since the ball 110 rotates outside the draw bar 20 with the rotation of the spindle 30, the grooves 102 and 104 are formed over the entire outer periphery of the draw bar 20.

  On the other hand, the knock mechanism 200 has a configuration shown in FIG. 1B, and a booster cam 210 is provided outside the draw bar 20. In other words, the ball presser 230 holding the balls 220 and 222 rotatably and the booster cam 210 are sandwiched between the draw bar 20 and the apparatus main body (housing) 36 connected to the spindle 30. . The ball presser 230 is fixed to the apparatus main body 36. A plurality of sets of balls 220 and 222 are provided at equal intervals on the outer peripheral side of the draw bar 20. Concave portions 202 and 204 are formed on the outer peripheral surface of the draw bar 20, and concave portions 212 and 214 are formed on the inner peripheral side of the booster cam 210.

  The recess 202 on the draw bar 20 side is for constituting a boosting mechanism via the ball 220 at the time of clamping, and the recess 204 retracts the ball 220 at the time of clamping and the boosting mechanism via the ball 222 at the time of unclamping. It is for comprising. On the other hand, the recess 212 on the boost cam 210 side is for retracting the ball 220 during unclamping, and for constructing a booster mechanism via the ball 220 during clamping, and the recess 214 is configured so that the ball 222 is retracted during unclamping. It is for comprising a booster mechanism via.

  The front end (lower end in the figure) of the boost cam 210 is in contact with the clamp spring 50 described above, and a plurality of plunger pins 216 are provided at the rear end (upper end in the figure). These plunger pins 216 can be pushed down by hydraulic means (not shown). Note that the booster cam 210 and the balls 220 and 222 do not rotate outside the draw bar 20. Accordingly, the recesses 202, 204, 212, and 214 need not be provided on the entire outer periphery of the draw bar 20, and may be provided corresponding to the positions of the balls 220 and 222.

  Next, the operation at the time of clamping will be described with reference to FIGS. First, the tool holder 40 is pushed into the tip end side of the spindle 30 in the state shown in FIG. 1A in which the plunger pin 216 is pushed by hydraulic means. Then, the pull-stat 42 at the rear end of the tool holder 40 comes into contact with the collet 22 at the front end of the draw bar 20 and becomes as shown in FIG. When the tool holder 40 is further pushed in, the tapered surface 44 comes into contact with the tapered surface 31 on the spindle 30 side, the draw bar 20 rises, and the collet 22 holds the pull stat 42.

  At this time, in the temporary holding mechanism 100, the ball 110 moves from the groove 104 of the draw bar 20 to the groove 102. On the other hand, in the knock mechanism 200, the lower ball 220 fits into the recess 202 of the draw bar 20. Note that the upper ball 222 fitted in the recess 214 of the booster cam 210 only slides in the recess 204 on the draw bar 20 side. As a result, the state of FIG. 2A becomes as shown in FIG.

  In this state, when the pressing of the plunger pin 216 by the hydraulic means is released, the clamp spring 50 expands and the booster cam 210 rises. Then, the tapered surface 212 </ b> A below the recess 212 of the boost cam 210 pushes up the ball 220. That is, the ball 220 and the tapered surface 212A constitute a boosting mechanism, whereby the draw bar 20 is firmly fixed, and as a result, the clamp of the pull-stat 42 of the tool holder 40 by the collet 22 on the tip side is firmly fixed. Will be done. FIG. 3A shows the state of this clamped state. Also, an enlarged view of the knock mechanism 200 is shown in FIG. 5B, and an enlarged view of the temporary holding mechanism 100 is shown in FIG.

  Next, the operation at the time of unclamping will be described with reference to FIGS. When the plunger pin 216 is pushed by the hydraulic means from the clamped state shown in FIG. 3, the booster cam 210 is lowered and the tapered surface 212 </ b> B on the upper side of the concave portion 212 hits the ball 222 as shown in FIG. FIG. 4B shows the state in an enlarged manner.

  In this state, when the plunger pin 216 is further pushed, the tapered surface 212B pushes the ball 222 toward the draw bar 20, and as a result, the draw bar 20 is displaced downward. For this reason, the tool holder 40 is slightly pushed out at the front end side of the draw bar 20. That is, the tool holder 40 is pushed out by the boosting mechanism by the tapered surface 212B and the ball 222, and the state is as shown in FIG.

  By the way, when the tool is attached in a clamped state of the tool holder 40 and some work is performed on the workpiece, the tool holder 40 is pressed against the spindle 30 and the tapered surfaces 31 and 44 are in close contact with each other. According to the present embodiment, the close contact between the tapered surfaces 31 and 44 is satisfactorily released by the operation of the booster mechanism shown in FIG.

  Next, in the state of FIG. 5A, the ball 110 of the temporary holding mechanism 100 comes up from the groove 102, but tries to return to the groove 102 by the temporary holding spring 112. For this reason, the draw bar 20 moves upward, as shown in FIG. As a result, the tool holder 40 also returns upward, and the tapered surface 44 comes into contact with the tapered surface 31 on the spindle 30 side again. That is, the tool holder 40 once comes away from the spindle 30 and then comes into contact with the spindle 30 again, and assumes its original position.

  Next, the tool holder 40 is pulled downward by means not shown. Since the tool holder 40 is in its original position by the operation shown in FIG. 5B, the positioning when performing the pulling work may be the same as the conventional one. When the tool holder 40 is pulled down, the draw bar 20 moves downward, and the state shown in FIG. 2 (A) is further changed to the state shown in FIG. 1, and the tool holder 40 is completely pulled out. At this time, in the knock mechanism 200, the ball 222 is fitted into the recess 214.

  As described above, according to the present embodiment, at the time of unclamping, the tool holder 40 is once separated from the spindle 30 by the knock mechanism 200, and then the tool holder 40 is returned to the original position by the temporary holding mechanism 100. For this reason, the tool holder 40 can be satisfactorily pulled out from the spindle device 10 without any special positioning operation, and the tool holder 40 can be easily replaced in a short time.

  Next, Embodiment 2 of the present invention will be described with reference to FIG. This example is another configuration example of the knock mechanism, and has a structure in which the apparatus main body 36 in the above-described embodiment is omitted. In FIG. 6, (A) shows a clamped state, and (B) shows an unclamped state. In these drawings, a clamp spring 504 is provided below the draw bar 500 between the draw bar 500 and the spindle 502, as in the above-described embodiment. The collet on the front end side of the draw bar 500 and the temporary holding mechanism are the same as in the above-described embodiment. A booster cam 510 is provided on the outer peripheral side of the draw bar 500, and balls 520 and 522 are provided between the boost cam 510 and the drawbar 500. A plurality of sets of balls 520 and 522 are provided at equal intervals on the outer peripheral side of the draw bar 500.

  The balls 520 and 522 are rotatably held by a ball presser 524, and the ball presser 524 is fixed to the spindle 502 side. On the other hand, the booster cam 510 is fixedly supported on the draw bar 500 by a fixing pin 506 that passes through the ball presser 524. FIG. 6C shows a state in which the ball presser 524 is viewed from the side. The fixing pin 506 passes through the long hole 526 formed in the ball presser 524, and the fixing pin 506 is long. The structure can move in the hole 526.

  On the outer peripheral surface of the draw bar 500 and the inner peripheral surface of the booster cam 510, a concave portion and a tapered surface for forming the above-described booster mechanism are formed. First, the concave portion 530 on the outer peripheral surface of the draw bar 500, the tapered surface 532 on the inner peripheral surface of the boost cam 510, and the ball 520 constitute a boost mechanism at the time of clamping. The concave portion 540 on the outer peripheral surface of the draw bar 500, the tapered surface 542 on the inner peripheral surface of the boost cam 510, and the ball 522 constitute a boost mechanism during unclamping. According to the present embodiment, the same effects as those of the above-described embodiment can be obtained with a simple configuration.

In addition, this invention is not limited to the Example mentioned above, A various change can be added in the range which does not deviate from the summary of this invention. For example, the following are also included.
(1) The shapes and dimensions shown in the above embodiments are merely examples, and the design can be changed so as to obtain the same effect. For example, instead of the ball 110 and the temporary holding spring 112 of the temporary holding mechanism 100 shown in the embodiment, a coil spring that expands and contracts in the radial direction is used. The booster mechanism and the tool holder pull-stat, collet, etc. may have a known structure that exhibits the same action.
(2) Various known members may be applied to each member. For example, in the above embodiment, the clamp spring 50 is used, but a disc spring may be used.
(3) In the above embodiment, the present invention is applied to an ATC spindle device, but can be applied to various clamping mechanisms. Therefore, the object to be clamped is not limited to the tool holder.

  According to the present invention, when the object is unclamped, the object is once pushed out, and then the position is returned and temporarily held, which is suitable for applications such as an ATC spindle device.

10: Spindle device 20: Draw bar 22: Collet 30: Spindle 31, 44: Tapered surface 32: Space 34: Hole 36: Device main body (housing)
40: Tool holder 42: Pull stat 44: Tapered surface 50: Clamp spring 100: Temporary holding mechanism 102, 104: Groove 110: Ball 112: Temporary holding spring 114: Spring presser 200: Knock mechanism 202, 204: Recess 210: Boosting force Cam 212, 214: Concave 212A, 212B: Tapered surface 214: Concave 216: Plunger pin 220: Ball 222: Ball 230: Ball presser 500: Draw bar 502: Spindle 504: Clamp spring 506: Fixing pin 510: Booster cam 520, 522: Ball 524: Ball presser 526: Long hole 530: Concave portion 532: Tapered surface 540: Concave portion 542: Tapered surface

Claims (5)

Clamping object with tapered surface,
A spindle with a tapered surface formed at the tip that contacts the tapered surface during clamping,
A draw bar provided with gripping means for moving within the spindle and gripping the clamping object;
A knock mechanism for releasing the joined state between the tapered surface of the object to be clamped and the tapered surface of the spindle during unclamping;
A temporary holding mechanism for returning and holding the position of the clamp object displaced by the knock mechanism;
An unclamping device comprising: A tapered surface having a diameter increasing toward the one end is formed on one end of the hollow spindle rotatably supported in the housing, and the tapered surface of the tool holder is formed on the tapered surface. Is a spindle device in which the spindle and the tool holder rotate integrally,
A gripping means provided at the tip of a draw bar which is movable in the axial direction of the hollow portion of the spindle, and detachably grips the pull stud of the tool holder;
It is provided in a hollow portion on the other end side of the spindle, and a tool holder in a clamped state is pushed out to the front end side via the draw bar to join the tapered surface of the tool holder and the tapered surface on the spindle side. Knock mechanism to release the state,
A temporary holding mechanism for returning the tool holder pushed out by the knock mechanism to the original position where the tapered surface is in contact with the tapered surface on the spindle side;
A spindle apparatus characterized by comprising: The knock mechanism is
A boost cam provided around the draw bar;
First and second balls provided between the draw bar and the boost cam;
A first booster mechanism configured by a first recess provided outside the draw bar, the first ball, and a first tapered surface provided inside the booster cam and operating at the time of clamping. ,
A second booster configured by a second recess provided outside the draw bar, the second ball, and a second tapered surface provided inside the booster cam and operating during unclamping mechanism,
The spindle apparatus according to claim 2, comprising: The temporary holding mechanism is
First and second grooves formed on the outer peripheral surface of the draw bar at the front end side;
An elastic means that is biased from the spindle side to the draw bar side and is radially expandable;
With
In the clamped state, the elastic means is fitted in the first groove, the draw bar moved by the operation of the first booster mechanism is returned to the original position and temporarily held,
4. The spindle device according to claim 2, wherein, in the unclamped state, the elastic means temporarily fits the draw bar by being fitted into the second groove. 5.   A machining center comprising the spindle device according to any one of claims 2 to 4.

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