JPH1034410A - Main spindle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a high speed rotation and super high speed rotation and also strengthen the clamp force of a tool by reducing the imbalance amount at the spindle rotation time in a main spindle device providing a tool clump/ unclamp mechanism for ATC. SOLUTION: A cylindrical part 22a is installed on the tip part of a spindle 22 and a release rod 41 is inserted and stored along the diametral direction of the spindle 22 therein and engaged screwingly to the outer periphery of the release rod 41 and a cone 42 for holder tightening/releasing telescoped along the axial direction of the release rod 41 is arranged and by connecting the cone 42 for holder tightening/releasing with a tool clamp shaft 44 through a change mechanism, a clamp/unclamp mechanism is installed on the tip part of the spindle 22 and the imbalance amount at the rotation time of the spindle 22 is reduced and also the strong clamp force of the tool 30 is ensured by the operation of a tightening wedge force by the cone 42 for holder tightening/ releasing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle device such as a machining center. The present invention relates to an enabled spindle device.

[0002]

2. Description of the Related Art For example, as a spindle device installed in a machining center or the like, as shown in FIG.
A spindle 3 is rotatably supported via a bearing 2 therein. A tool 4 is mounted on a tip portion of the spindle 3, and the spindle 3 is rotated at a high speed to cut a workpiece (not shown). .

A clamping / unclamping mechanism for clamping and unclamping the tool 4 includes a disc spring 5 and an ejector rod 6 inside a cylindrical spindle 3.
In the clamped state of the tool 4 shown in FIG. 5, the ejector rod 6 is pulled in the direction of the arrow in FIG. The tool 4 is clamped by the spring force of the disc spring 5 in order to pull the holder portion 4a of 4 in the direction of the arrow in a clamped state.

When the tool is changed by the ATC mechanism, the ejector rod 6 is pushed in the direction opposite to the arrow shown in the figure by pressing the rear end portion of the ejector rod 6 against the spring force of the disc spring 5 by a pressing means such as a cylinder. Then, the drawbar portion 7 of the ejector rod 6 expands outward, the clamped state of the holder portion 4a of the tool 4 is released and becomes the unclamped state, and the tool 4 is pulled out.
After being stored in the empty tool pot, a new tool is mounted on the tip of the spindle 3.

When a new tool 4 is mounted, the drawer 7 of the ejector rod 6 shrinks the holder 4a of the tool 4 in the radial direction, thereby securely holding the tool 4.

[0006]

As described above, in the conventional clamp / unclamp mechanism of the spindle device, the disc spring 5 is built in the spindle 3 and the ejector rod 6 is opposed to the spring force of the disc spring 5. The actual situation is that the chuck is opened by pressing the tool and the tool 4 is attached and detached.
The spindle 3 has a sleeve shape over its entire length, and a disc spring 5, an ejector rod 6, and the like are internally provided inside the sleeve.
When the spindle 3 rotates, the spindle 3 becomes unbalanced, and the spindle 3 is likely to generate vibration and heat.
High-speed rotation of 0 rpm or more was impossible.

The present invention has been made in view of such circumstances, and provides a clamp / unclamp mechanism at the tip of a spindle to reduce the amount of unbalance during rotation of the spindle and to enhance the holding force of the tool. An object of the present invention is to provide a spindle device capable of high-speed rotation and ultra-high-speed rotation.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a spindle rotatably supported in a casing via a bearing, and a clamp / unclamp mechanism installed at the tip of the spindle. A spindle device having a clamp / unclamping device installed on the side of the tip (tool side) of the spindle and a spindle having a mechanism for clamping / unclamping a tool by the clamp / unclamping device. It is characterized by the following.

The spindle device is applied to a high-speed machining unit such as a machining center and a flexible transfer machine, an ultra-high-speed machining unit, and the like.

The main spindle device is rotatably supported in the casing via upper and lower bearings, and is configured to be able to rotate at a high speed of 50,000 rpm or more by a high frequency motor.

Next, the clamp / unclamp mechanism according to the present invention is installed only at the tip end of the spindle, without having a coned disc spring and an ejector rod installed over the entire length of the spindle as in the prior art.

That is, the tip of the spindle is
The clamp / unclamp mechanism, which is formed in a cylindrical portion, is provided in the cylindrical portion of the spindle along a radial direction of the spindle. A holder tightening / releasing cone that expands and contracts in the axial direction of the release rod with the rotation of the shaft, a conversion mechanism that converts the expansion / contraction operation of the holder tightening / release cone into an axial movement of the spindle, and the shaft A tool clamp shaft for clamping / unclamping the tool by the movement in the direction.

As a means for driving the release rod, a screw driver is provided at a position coinciding with the axis of the release rod so as to be able to advance and retreat with respect to the release rod. And the screw driver is forwardly connected to the release rod side, and the screw driver is operated to rotate in the forward direction or the reverse direction by the torque motor.

Next, since the direction of the screw of the holder tightening / releasing cone which is screw-engaged with the outer periphery of the releasing rod is opposite to the center of the releasing rod, the holder is tightened / released by the forward rotation of the releasing rod. The cone for contraction contracts in the axial direction of the release rod. Conversely, when the release rod is rotated in the reverse direction, the cone for tightening / releasing the holder extends in the axial direction of the release rod.

That is, the relationship between the tapered surfaces provided at both ends of the holder tightening / release cone and the inclined surface provided at the inner periphery of the through hole of the spindle indicates that when the tool is clamped, the holder tightening / release cone can be used. Extending outward, the taper surface of the holder tightening / releasing cone slides on the inclined surface of the spindle, and as the holder tightening / releasing cone rises, the tool clamps together with the plate connected to the cone When the shaft is raised, the tool holder is clamped by the drawbar at the tip of the tool clamp shaft.

At this time, a strong tightening force is secured between the tapered surface of the holder tightening / releasing cone and the inclined surface of the spindle.

Next, when changing the tool, the holder tightening / releasing cone shrinks along the axial direction of the release rod, and at this time, the pressing pin set above the holder tightening / releasing cone is pressed by the holder pin. The cam surface of the attachment / release cone abuts and the holder tightening / release cone is pressed toward the tool by the pressing pin, which also pushes the tool clamp shaft toward the tool and opens the drawbar of the tool clamp shaft. The chucking state of the tool is released.

As is apparent from the above configuration, when the tool is replaced, the holder tightening / releasing cone is contracted by rotating the release rod in the forward direction, and the holder tightening / releasing cone and the pressing cone are released by the pressing pin. The tool clamp shaft is pushed out to the tool side, the drawbar at the tip of the tool clamp shaft expands, and the clamped state of the tool is released.

After the tool is replaced, the holder of the new tool is positioned on the drawbar at the tip of the tool clamp shaft, and then the release rod is rotated in the opposite direction to remove the holder tightening / release cone. It expands so that it may expand toward one.

At this time, the tapered surfaces at both ends of the holder tightening / releasing cone slide along the inclined surface of the spindle, and the holder tightening / releasing cone and the tool clamp shaft move in the direction of pulling in the tool. And firmly clamp the tool holder.

As described above, the clamp / unclamp mechanism according to the present invention does not have a structure in which a coned disc spring and an ejector rod are installed along the entire length inside the spindle as in the prior art. /
Since the unclamping mechanism is provided, the amount of unbalance during rotation of the spindle is small, and the tool can be firmly held even by a short taper holder type tool by the tightening wedge force.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a spindle device according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a side view showing a spindle device installed in an ultra-high-speed machining unit, FIG. 2 is a sectional view showing the configuration of the spindle device, FIG. 3 is a sectional view taken along the line III-III in FIG. 2, and FIG. It is sectional drawing which shows the unclamping state of the tool in the spindle device which concerns on invention.

In FIG. 1, a spindle device 20 which moves up and down a predetermined stroke in the Z-axis direction indicated by an arrow in the figure is arranged for a work (not shown) installed on a work jig board 11 of the ultra-high-speed machining unit 10. I have.

As shown in FIGS. 2 and 3, the spindle device 20 includes a casing 21 in which a spindle 22 is rotatably supported via upper and lower bearings 23. It is configured to be capable of ultra-high speed rotation.

Reference numeral 25 in the drawing denotes a fixed point stop magnet sensor.

By the way, the spindle device 20 according to the present invention comprises:
A clamp / unclamp mechanism for the tool 30 is provided at the tip of the spindle 22 to reduce the amount of unbalance that causes vibration and heat generation when the spindle 22 rotates.
By increasing the holding force of the tool 30, the tool 30 of the short taper holder type can be rotated at an ultra-high speed, and the machining accuracy by the ultra-high speed rotation is improved.

That is, for this purpose, the spindle device 20 according to the present invention comprises a clamp / unclamp mechanism 40 for clamping / unclamping the tool 30 to the tip of the spindle 22, and a clamp / unclamp mechanism for driving the clamp / unclamp mechanism 40. A feature of the present invention is that, by installing the clamping device 50 and using a tightening wedge force for firmly holding the tool as compared with the spring force of a conventional disc spring, a strong tool can be held. .

FIGS. 2 and 3 show a state where the tool 30 is clamped, and FIG. 4 shows a state where the tool 30 is unclamped.

Next, a specific configuration of the clamp / unclamp device 40 of the spindle device 20 according to the present invention will be described.

The spindle 22 has a solid structure, and only a tip portion is formed in a cylindrical shape. A release rod 41 is inserted through the cylindrical portion 22a so as to be rotatable in the forward and reverse directions around the axis in the radial direction. A holder tightening / releasing cone 42 that is screwed into the outer circumference of the release rod 41 is fitted therein.

More specifically, since the release rod 41 is formed with a screw thread such that the screw direction is opposite to the right and left from the center, the holder is tightened by the forward rotation and the reverse rotation of the release rod 41, respectively. The release cone 42 contracts or extends along the axial direction of the release rod 41.

At the lower part of the holder tightening / releasing cone 42, a connecting plate 43 which moves up and down as the cone 42 moves up and down is installed, and a tool clamp shaft 44 is supported by the connecting plate 43. The holder 31 of the tool 30 is clamped by a draw bar 45 at the lower end of the tool clamp shaft 44.

Next, the conversion mechanism for converting the expanding and contracting operations of the holder tightening / releasing cone 42 into the vertical movement of the tool clamp shaft 44 is configured as follows.

That is, when the tool 30 is in the clamped state, as shown in FIG. 2, the holder tightening / releasing cone 42 is expanded and extended outward, and the holder tightening / releasing cone 42 is The tapered surfaces 42a at both ends are inclined surfaces 2 on the inner periphery of the through hole 26 provided in the cylindrical portion 22a of the spindle.
7, and the holder tightening / releasing cone 42 expands outward due to the rotation of the release rod 41, and the holder tightening / releasing operation is performed along the inclined surface 27 of the spindle 22.
A tool clamp shaft 44 in which the tapered surface 42 a of the releasing cone 42 slides upward and is connected via the connecting plate 43.
Is pulled upward, and a strong tightening wedge force is exerted by the inclined surface 27 and the tapered surface 42 a, so that the holder portion 31 of the tool 30 is firmly pulled up by the draw bar 45 of the tool clamp shaft 44.

On the other hand, when the tool 30 is exchanged, when the holder tightening / releasing cone 42 contracts toward the center, the holder cams 42b provided on the holder tightening / releasing cone 42 face the inclined cam surface 42b. A pressing pin 47 fixed to a plate 46 located on the upper side of the tightening / releasing cone 42 pushes down the holder tightening / releasing cone 42 downward, thereby moving the connecting plate 43 and the tool clamp shaft 44 downward. And the draw bar 45 at the lower end of the tool clamp shaft 44 expands to release the clamped state of the holder portion 31 to make the tool 30 replaceable.

As described above, the holder tightening / releasing cone 42 is contracted or extended along the axial direction of the release rod 41 by the forward rotation and the reverse rotation of the release rod 41, respectively. The tool 30 is operated to take a state of clamping and unclamping of the tool 30, respectively.
That is, as the clamp / unclamp device 50,
This embodiment is configured as follows.

That is, as shown in FIG. 3, a screw driver 51 which can move forward and backward with respect to the release rod 41 so as to be connectable to the release rod 41 is supported via a bearing 52 so as to be rotatable forward and backward. The screw driver 51 expands and contracts the piston rod 54 of the connecting cylinder 53, thereby connecting or releasing the connection to the release rod 41.

The forward and reverse rotation of the screw driver 50 is as follows.
This is performed by a torque motor 55,
The timing pulleys 56 and 57 are provided on the rotary shaft 55a and the screw driver 51, respectively, and the toothed belt 58 is wound around the timing pulleys 56 and 57.

Next, an exchange operation of the tool 30 in the spindle device 20 according to the present invention will be described.

First, when the tool 30 shown in FIG. 2 is clamped, the spindle 22 is stopped at a fixed position by the magnet sensor 25, and the axes of the release rod 41 and the screw driver 50 are aligned.

Then, after the connecting cylinder 53 contracts and the tip of the screw driver 51 is connected to the release rod 41, the torque motor 55 rotates in the forward direction, and passes through the timing pulleys 56 and 57 and the toothed belt 58. The rotation of the torque motor 55 is transmitted to the rotation of the screw driver 51 to rotate the release rod 41 in the forward direction.

When the release rod 41 rotates in the forward direction, the holder tightening / release cone 42 contracts along the axial direction of the release rod 41 depending on the direction of the thread on the outer peripheral surface of the release rod 41.

Further, as the holder tightening / releasing cone 42 contracts, a pressing pin 47 provided on the upper side of the holder tightening / releasing cone 42 causes the holder tightening / releasing cone 4 to move.
2, the release rod 41 and the holder tightening / release cone 42 are pressed downward in the drawing, that is, toward the tool 30 by the cam mechanism. The tool clamp shaft 44 also moves down to the unclamped state of the tool 30 shown in FIG.

When the tool 30 is in the unclamped state, the draw bar 4 at the lower end of the tool clamp shaft 44 is closed.
5 is opened outward, and the holder portion 31 of the tool 30 is opened.
Since the tool 30 is not grasped, the tool 30 is removed by an arm (not shown), and the tool 30 is also housed in an empty tool pot (not shown). Then, the holder of the new tool 30 is inserted into the draw bar 45 at the lower end of the tool clamp shaft 44. A new tool 30 is mounted.

At this time, although the axes of the release rod 41 and the screw driver 51 do not coincide with each other, the screw driver 5
Since one end is tapered, the connection between the two is maintained.

On the other hand, when the installation of the new tool 30 is completed, the torque motor 55 rotates in the reverse direction, and the screw driver 51 also rotates in the reverse direction through the timing pulleys 56 and 57 and the toothed belt 58. Release rod 41
Performs reverse rotation.

With the rotation of the release rod 41 in the reverse direction, the holder tightening / release cone 42 expands along the axial direction of the release rod 41, and is provided at both ends of the holder tightening / release cone 42. The tapered surface 42a rises on the inclined surface 27 provided on the inner peripheral surface of the through hole 26 of the cylindrical portion 22a of the spindle 22 to the state shown in FIG.

Accordingly, the connecting plate 43 and the tool clamp shaft 44 are also raised, and the draw bar 45 of the tool clamp shaft 44 clamps the holder 31 of the tool 30 and the taper surface of the holder tightening / releasing cone 42. 4
A tool wedge force acts between the tool 2a and the inclined surface 27 of the spindle 22 to apply the tool clamp shaft 44 to the holder 3 of the tool 30.
1 can be pulled firmly and the tool 30 can be brought into a clamped state with a strong holding force.

When the clamping state of the tool 30 is completed, the connecting cylinder 53 is extended to release the release rod 41.
The screw driver 51 in the connected state is retracted and retracted to a position where the rotation of the spindle 22 is not hindered.

As described above, the spindle device 20 according to the present invention
Is provided with a clamp / unclamp mechanism 40 for automatically clamping / unclamping the tool 30 at the distal end of the spindle 22, and a sleeve-like spring and an eject rod are provided inside the spindle in the form of a sleeve over the entire length of the spindle as in the prior art. Since it is not a configuration in which the spindle is mounted, the amount of unbalance during rotation of the spindle can be controlled to be small, and
Ultra high-speed rotation of 0 rpm or more can be realized.

Further, the tightening wedge force between the tapered surface 42a and the inclined surface 27 is applied not only to the holder portion (tool chuck portion) 31, but also to the tip end surface 22b of the spindle 22 and the tool 30.
There is an advantage in that it can be used for rotating a short taper holder type tool at a high speed, and that a wide range of tools can be rotated at a very high speed.

[0053]

As described above, the spindle device according to the present invention has the following special effects.

(1) Since the spindle device according to the present invention has a structure in which the clamp / unclamp mechanism is installed at the tip of the spindle, the spindle is not formed in a sleeve shape over the entire length as in the prior art. The disc spring and the ejector rod are installed along the entire length of the spindle, and the ejector rod driving means is not provided at the rear end of the spindle. Rotation becomes possible, and there is an effect that processing accuracy can be improved.

(2) In the spindle device according to the present invention, a clamp / unclamp mechanism is provided at the tip of the spindle, and the clamp / unclamp mechanism controls the extension / contraction operation of the holder tightening / releasing cone via a conversion mechanism. It converts the operation into clamping and unclamping operations of the tool clamp shaft. When the tool is clamped, the tightening wedge force of the holder tightening / releasing cone acts on the inclined surface of the spindle. The tool clamping force can be strengthened, which is also advantageous for high-speed rotation and ultra-high-speed rotation, and the tool holding force is strengthened, so that short taper holder type tools can be held firmly.
This has the effect that a wide range of tools can be automatically changed.

[Brief description of the drawings]

FIG. 1, showing an embodiment of the present invention, is a partially broken side view showing a spindle device of an ultrahigh-speed machining unit.

FIG. 2, showing an embodiment of the present invention, is a cross-sectional view illustrating a configuration of a spindle device.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a cross-sectional view showing an unclamped state of a tool in the spindle device showing one embodiment of the present invention.

FIG. 5 is a sectional view showing a configuration of a conventional spindle device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Ultra-high-speed processing unit 20 Spindle device 22 Spindle 30 Tool 40 Clamp / Unclamp mechanism 41 Release rod 42 Holder tightening / release cone 42a Tapered surface 42b Cam surface 44 Tool clamp shaft 47 Press pin 50 Clamp / unclamp device 51 Screw Driver 53 Connecting cylinder 55 Torque motor

Claims (2)

[Claims] 1. A spindle device provided with a tool clamping / unclamping device for ATC, wherein a clamp / tool installed on a side of a tip (tool side) of the spindle.
A spindle device comprising: an unclamping device; and a spindle having a mechanism for clamping / unclamping a tool by the clamping / unclamping device. 2. A tip part of the spindle is formed in a cylindrical part, and the clamp / unclamp mechanism includes a release rod housed in the cylindrical part of the spindle along a radial direction of the spindle, A holder tightening / releasing cone that is screw-engaged with the outer circumference of the release rod and expands / contracts in the axial direction of the release rod with the rotation of the release rod; A conversion mechanism that converts the movement into a direction, and the movement in the axial direction,
The spindle device according to claim 1, further comprising a tool clamp shaft for clamping / unclamping the tool.