JP4316354B2 - Spindle unit - Google Patents

Description

  The present invention relates to a spindle unit that chucks a tool at the tip of a spindle.

Conventionally, this type of spindle unit is configured such that the spindle end of various machine tools can be replaced as a unit, or mounted on the tip of a processing robot to perform various types of processing such as grinding, polishing, lapping, burring, etc. It is often used for taking out work.
An example of this will be described with reference to FIG.
This device is generally called a grinder, and is a precision rotary tool device that grips the tool T and rotates the tool by an electric motor or air drive to grind, polish, lap and deburr the workpiece. is there.

  This device has a main shaft end structure in which a tool T is gripped inside a collet main shaft 2 mounted in a housing 1, and a collar 3 slides in an axial direction by the force of an internal disc spring 4, and a sleeve 6, the outer diameter portion of the collet main shaft 2 is drawn inward (left side in the drawing), whereby the outer shape of the tool T is firmly held by the tapered collet portion 7 on the tip side of the collet main shaft 2.

  A screw 9 is formed on the rear end portion of the housing 1 as an attachment structure to the main shaft end 8 portion. The housing 1 is screwed onto the main shaft end 8 and is not shown in detail. However, the rear end portion of the collet main shaft 2 that is rotatably arranged inside is also rotatable inside the main shaft end. It arrange | positions and it is comprised so that a motor or an air drive device can be connected via a bearing.

The tool T is removed by pushing the collar 3 back to the tool T side. For removal of the tool T, there are a method using the illustrated eccentric cam 5, a method using direct air drive, etc., which are not shown.
JP-A-5-69202

  However, since the conventional apparatus relies on the force of the disc spring 4 for the gripping force of the tool T, a gripping force sufficient for holding the tool cannot be obtained. Further, since the gripping force is weak, the rotational accuracy is inferior to the hand-tightened collet when rotating at high speed. Further, the tool change requires the operator to loosen and tighten the tool T by manual operation, and the tool cannot be changed automatically. Furthermore, when the tool T is replaced, it is necessary to clean the inner surface (tool mounting surface) of the taper collet portion 7 (for example, removal of attached dust). However, there is a problem that this operation cannot be easily performed. there were.

A spindle unit of a machine tool in which a tool clamp shaft and a motor shaft are divided is known (see, for example, Patent Document 1). This spindle unit is designed to be able to cope with diversification of tools by exchanging various attachment main bodies with respect to the main body, and has an effect of increasing the processing range and processing capability.
However, in patent document 1, it was not able to respond | correspond enough when the magnitude | size (diameter) of the tool with which a front-end | tip part is mounted | worn changes.

  The present invention has been made to solve such a conventional problem, and its object is to provide a structure in which the operation at the time of tool replacement can be performed under automatic operation or manual operation, and at the time of replacement. An object of the present invention is to provide a spindle unit that can also clean the inner surface of a collet.

  According to the first aspect of the present invention, there is provided a collet insertion hole on one end side, a rotation main shaft rotatably held in the housing, a collet inserted into the collet mounting hole, and a front end of the housing on one end side of the rotation main shaft. A tool holder portion for fixing the tool by pushing the collet in the radial direction, an automatic locking means for the rotary main shaft arranged on the rear end side of the housing, and an axis of the rotary shaft A spindle unit characterized by comprising a manual locking means for a rotating main shaft disposed on the rear end side of the housing so as to face the automatic locking means for the rotating main shaft.

In the invention according to claim 2, the automatic locking means for the rotation main shaft includes a pneumatic cylinder and a sleeve provided on the rotation main shaft, and the rotation main shaft is fixed in the rotation direction by locking the piston of the pneumatic cylinder to the sleeve. The spindle unit according to claim 1, wherein:
In the invention according to claim 3, the rotation main shaft is provided with a fine hole communicating with the collet insertion hole in the axial length direction, and a hole communicating with the fine hole is provided through the other end side in the radial direction. 3. The spindle unit according to claim 2, wherein the air pressure flowing into the housing from the side of the pneumatic cylinder is guided to the collet insertion hole in the tool holder main body through the hole when the air cylinder is locked.

  The invention according to claim 4 is the spindle unit according to claim 1, characterized in that the tool holder is provided with an automatic tightening / loosening operation section on the outer periphery for communicating with the automatic tightening / loosening operation means of the collet. .

According to the present invention, since the tool holder, the automatic locking means and the manual locking means for the rotating spindle are provided together, workability is improved by setting and preparing a predetermined tool in advance, which can contribute to rationalization.
Further, according to the present invention, since the cleaning air is supplied from the automatic locking means side to the collet insertion hole, it is only necessary to form the communication hole in the rotating spindle without providing any special air supply means. Well, since it can be performed by utilizing a part of the air used for the automatic locking means, the collet insertion hole can be reliably cleaned at a low cost.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front sectional view of a spindle unit 10 according to an embodiment of the present invention.
The spindle unit 10 according to this embodiment has a rotating spindle 12 mounted in a housing 11 via bearings 18 and 19 so as to be rotatable. The rotary main shaft 12 includes a tapered collet insertion hole 12 a on one end side, and the outer side thereof is fixed to the housing 11 by a fastening member 17. ing. The rotary spindle 12 has a tool holder portion H at the front end portion, and a connecting portion J with a rotation driving means (not shown) of the motor at the rear end portion.

  The tool holder portion H includes a collet 13 having a tapered outer periphery inserted into a tapered collet insertion hole 12a of the rotary spindle 12, a first nut member 14 for tightening a collet screwed to the end of the rotary spindle 12, and a collet. It consists of a second nut member 15 for tightening. The first nut member 14 for collet tightening includes a locking portion 14 a that engages with an end portion 13 a of the collet 13. The collet tightening second nut member 15 is integrally formed on the outer side of the collet tightening first nut member 14, and a gear 15a is formed on the outer periphery thereof. The tool holder portion H engages an automatic attaching / detaching means (not shown) and rotates the tool holder portion H, whereby the collet 13 is moved to the rear end side of the rotary spindle 12 via the collet tightening first nut member 14. The collet is tightened by reducing the diameter of the collet 13 while being screwed and fixing the tool 16 inserted into the collet 13 or by rotating the gear 15a in reverse to loosen the first nut member 14 for collet tightening. The tool 16 can be attached and detached by releasing the tightening force applied to the tool 16 by the collet 13 via the first nut member 14.

  On the rear end side of the rotary main shaft 12, a sleeve 20 having engagement holes 20a and 20b drilled in two places on the outer periphery is fixed integrally. In one engagement hole 20a, the tip of the piston rod 24 of the piston 23 of the pneumatic cylinder 21 fixed to the housing 11 is arranged to be engageable. In the other engagement hole 20b, the distal end of the plunger 30a of the manual lock device 30 formed on the outer peripheral portion of the rotary main shaft 12 which is 180 ° away from the mounting position of the pneumatic cylinder 21 is disposed so as to be engageable.

The rotation main shaft 2 is provided at the rear end portion of the sleeve 20 through a hole 12c passing through the axis in the direction perpendicular to the axis. The hole 12c and the bottom of the collet insertion hole 12a are communicated with each other by a hole 12b formed in the axial length direction.
Next, the locking device for the rotating spindle 12 will be described.
In the present embodiment, the automatic locking device for the rotating spindle 12 is constituted by the pneumatic cylinder 21. The pneumatic cylinder 21 includes a cylinder body 22 that is fixed to the opening 11a of the housing 11, a piston 23 that moves in the cylinder body 22, a piston rod 24 that is connected to the piston 23 and moves in the hole 25 of the cylinder body 22, A spring 27 disposed between the step portion 26 of the hole portion 25 and the piston 23, a narrow passage 28 formed in the hole portion 25 between the step portion 26 and the opening 11a of the housing 11, and an air pressure supply side of the piston 23 And a hole 29 communicating with the.

  For example, when a tool change command signal is input to a control device (not shown), the pneumatic cylinder 21 switches the control valve and supplies air pressure to the pneumatic cylinder 21. Then, the piston 23 moves forward, the tip end portion of the piston rod 24 engages with the engagement hole 20a of the sleeve 20 integrated with the rotation main shaft 12, and the rotation main shaft 12 is fixed in the rotation direction. Then, an exchange mechanism (not shown) is operated to reversely loosen the first nut member 14 for collet tightening, and the tool 16 is exchanged. When the tool 16 is replaced, the collet tightening first nut member 14 is rotated and tightened in the reverse direction, and then the air pressure that has been pushing the piston 23 is released and exhausted. The piston 23 returns upward in the figure by the force of the spring 27, and the lock of the rotary main shaft 12 is released.

  On the other hand, the manual lock device 30 is normally in an unlocked state, and is used for maintenance, for example. For example, when the operation is performed by manually locking the rotary spindle 12, the pusher 31 is pushed in to engage the plunger 30 a with the engagement hole 20 b of the sleeve 20. In this state, if the hand is released, it will return to its original position. Therefore, it is desirable that the lock mechanism is formed in a keyhole type so as to hold the engagement position by, for example, pushing and turning.

Next, the operation of the spindle unit 10 according to this embodiment configured as described above will be described.
First, as shown in FIG. 1, a predetermined tool 16 is attached to a collet 13 inserted into a tapered collet insertion hole 12 a of the rotary spindle 12 via a tool holder portion H. The tool holder portion H engages and rotates the gear 15a with automatic attaching / detaching means (not shown) while screwing the collet 13 to the rear end side of the rotary spindle 12 via the first nut member 14 for collet tightening. The diameter of the collet 13 is reduced in the radial direction, and the tool 16 inserted in the collet 13 is fixed.

Thereby, the use according to the objective of the tool 16 is attained.
Next, when a tool change command signal is input to a control device (not shown), the control valve is switched and air pressure is supplied to the pneumatic cylinder 21. Then, the piston 23 moves forward, the tip end portion of the piston rod 24 engages with the engagement hole 20a of the sleeve 20 integrated with the rotation main shaft 12, and the rotation main shaft 12 is fixed in the rotation direction.

Then, an exchange mechanism (not shown) is operated to reversely rotate the gear 15 a of the tool holder portion H to loosen the first nut member 14 for collet tightening, and to collet 13 via the first nut member 14 for collet tightening. The clamping force applied to the tool 16 is released, the tool 16 is removed, and the tool 16 is replaced.
During this time, the pneumatic cylinder 21 has a hole 29 communicating with the opposite chamber from the supply side to the piston 23 of the cylinder body 22 fixed to the housing 11, and a narrow passage 28 is formed in the hole 25. The hole 12c communicates with the piston rod 24 through the outer clearance of the sleeve 20 from the clearance with the piston rod 24. Accordingly, air from the pneumatic cylinder 21 side is ejected from the hole 12c to the collet mounting hole 12a side through the fine holes 12b, and the tapered collet insertion hole 12a of the rotary spindle 12 can be cleaned.

When the replacement is completed, the pneumatic cylinder 21 releases the air pressure that was pushing the piston 23 and exhausts it, and the piston 23 returns upward in the drawing by the force of the built-in spring 27 to unlock the rotary spindle 12. To do.
On the other hand, when the manual locking device 30 is operated, for example, during maintenance, the plunger 30a is manually engaged with the engagement hole 20b of the sleeve 20 by manually pushing the pusher 31 of the rotary spindle 12.

  As described above, according to this embodiment, the tool 16 can be gripped by the tool holder portion H regardless of the diameter and size of the tool 16 and is an automatic locking means for the rotary spindle 12 even during automatic operation. By operating the pneumatic cylinder 21, the rotary spindle 12 can be locked. In addition, at that time, the collet insertion hole 12a for gripping the tool 16 can be cleaned using the air pressure supplied from the pneumatic cylinder 21. Further, the rotary main shaft 12 can be locked by operating the manual lock device 30.

In the spindle unit 10 according to the present embodiment, the tightening nut constituting the tool holder portion H is composed of the first nut member 14 for collet tightening and the second nut member 15 for collet tightening. This may be integrated.
In the above embodiment, the gear 15a is provided on the outer peripheral portion of the collet tightening second nut member 15 for transmitting power. However, the present invention is not limited to this, and for example, the timing belt pulley of FIG. 2 (b), a round belt pulley in FIG. 2 (c), a urethane rubber pulley in FIG. 2 (d), and the like.

  In the above-described embodiment, the sleeve 20 provided on the rear end side of the rotary spindle 12 has been described in the case where the engagement holes 20a and 20b are drilled in two places on the outer periphery. However, the present invention is not limited to this. As shown in FIG. 3, engagement holes 35a and 35b may be drilled at eight locations on the outer periphery. In this case, each of the engagement holes 20a and 20b is provided with a spare, and even if each of the engagement holes 20a and 20b is worn, by using the spare engagement holes 20a and 20b, respectively, Exchange time can be delayed.

It is a front view sectional view of the spindle unit concerning one embodiment of the present invention. It is a figure which shows the modification of the shape of the outer peripheral part of the collet nut part of the spindle unit shown in FIG. It is a figure which shows the modification of the sleeve of the spindle unit shown in FIG. It is a figure which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Spindle unit 11 Housing 18, 19 Bearing 12 Rotating spindle 12a Collet insertion hole H Tool holder part J Connection part 13 Collet 14 Collet tightening first nut member 15 Collet tightening second nut member 16 Tool 20 Sleeve 20a, 20b Engagement Hole 21 Pneumatic cylinder (automatic locking means)
22 Cylinder body 23 Piston 24 Piston rod 25 Hole 26 Step 27 Spring 28 Narrow passage 30 Manual lock device 30a Plunger 31 Press

Claims (4)

A rotating spindle that has a collet insertion hole on one end and is rotatably held in the housing;
A collet inserted into the collet mounting hole;
A tool holder portion for rotatably attaching to the front end of the housing on one end side of the rotating spindle, and pressing the collet in the radial direction to fix the tool;
An automatic locking means for the rotating spindle disposed on the rear end side of the housing;
A spindle unit comprising: a manual locking means for the rotating main shaft disposed on a rear end side of the housing so as to face an automatic locking means for the rotating main shaft via an axis of the rotating shaft.   The automatic locking means for the rotating spindle includes a pneumatic cylinder and a sleeve provided on the rotating spindle, and the piston of the pneumatic cylinder is locked to the sleeve to fix the rotating spindle in the rotation direction. The spindle unit according to claim 1.   The rotation main shaft is provided with a fine hole communicating with the collet insertion hole in the axial length direction, and a hole communicating with the fine hole is provided in the radial direction on the other end side, and when the rotation main shaft is locked, 3. The spindle unit according to claim 2, wherein air pressure flowing into the housing from the pneumatic cylinder side is guided from the hole to the collet insertion hole in the tool holder main body through the hole.   2. The spindle unit according to claim 1, wherein the tool holder is provided with an automatic tightening / loosening operation portion on an outer periphery thereof to communicate with the automatic tightening / loosening operation means of the collet.

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