JP6732608B2 - Machine Tools - Google Patents

Description

The present invention relates to a machine tool, and more particularly to a machine tool for performing high precision cutting under high rotation.

Conventionally, in a machine tool such as a machining center, various cutting tools are attached to the tip of a spindle supported by a spindle head, and the spindle is rotated to perform cutting of a work.
Various cutting tools are selected according to the processing content of the workpiece. A common holder such as the BT standard is used to mount various shaped tools on the tip of the same spindle.

In recent years, in order to meet the demand for high-speed and high-accuracy rotation of the spindle, a machine tool that mounts a tool on the spindle without using a holder has been used.
For example, in some machine tools, an air bearing (aerostatic bearing) is used to support the spindle, and a high rotation speed of tens to hundreds of thousands of revolutions per minute is achieved (see Patent Document 1). ..
In the high-speed rotation type machine tool as described above, the structure in which the tool is mounted via the holder becomes inconvenient. For example, when the accuracy of the shaft core is not sufficient when fixing the tool to the holder, the runout at the time of high-speed rotation becomes large, which is not suitable for rotational support by the air bearing. Further, it is difficult to reduce the size mechanically by using the holder, which makes it unsuitable for high-precision machining of a fine shape in which a high-speed rotation type machine tool is often used.

From such a background, in a machine tool that uses an air bearing for supporting the spindle, a machine tool that can directly fix the tool to the spindle and has a simple structure of the spindle has been required.
In response to such a demand, the inventors of the present application have, as a result of diligent research, developed a technology that satisfies the above-mentioned demand, and have applied for a patent thereof (see Patent Document 2).

Patent Document 2 is a machine tool having a spindle rotatably supported by a spindle head, a chuck device installed at the tip of the spindle, and a tool chucked by the chuck device. The chuck device is a tool. A cylindrical collet member into which a collet member can be inserted, a chuck hole that is opened in the end face of the main shaft and can accommodate the collet member, and a chuck hole that is formed between the outer circumference of the collet member and the inner circumference of the chuck hole. A diaphragm mechanism having a tapered surface that is close to the central axis of the main shaft from the opening toward the rear side, and a retracting mechanism that retracts the collet member from the opening of the chuck hole toward the rear side are provided.

In such machine tools, the collet member, chuck hole, drawing mechanism, and retracting mechanism allow the tool to be clamped by tightening it from the entire circumference while pulling it in the axial direction of the spindle, and fixing the tool directly to the spindle. Since there is no mechanism for projecting to the tip side of the shaft, the structure of the main shaft portion can be simplified.

Japanese Patent Laid-Open No. 09-257037 JP, 2016-107362, A

By the way, in a general machine tool that does not use an air bearing for supporting the main spindle, a tool movement is controlled not only by three XYZ axes but also by four to six axes including ABC axes around each axis. Machines are in use.
However, in a machine tool that uses an air bearing for supporting the spindle, only the XYZ three-axis control is performed, and the spindle is arranged exclusively in the vertical direction (Z-axis direction).
Therefore, there has been a demand for a machine tool in which the main shaft is supported by an air bearing and the axial direction of the main shaft can be changed.

An object of the present invention is to provide a machine tool in which a main shaft is supported by an air bearing and the axial direction of the main shaft can be changed.

According to the present invention, in a machine tool that uses an air bearing for supporting the spindle, miniaturization of the structure around the spindle head is required in order to perform high-precision and minute machining, and an additional mechanism is added to the spindle head support structure. It was difficult to install, and for this reason the rotation mechanism of the ABC shaft could not be applied, and it was found that it is possible to add the rotation mechanism of the ABC shaft if the support structure for the spindle head is prevented from increasing in size. Based on.

A machine tool according to the present invention includes a spindle on which a tool is mounted, a spindle head having an air bearing that rotatably supports the spindle and a motor that drives the spindle to rotate, a table on which a work is fixed, and a table on which the workpiece is fixed. And a support structure that supports the spindle head so as to be movable relative to each other, and the support structure translates the spindle head along at least one of an X axis, a Y axis, and a Z axis that are orthogonal to each other. A rotary mechanism that rotates the spindle head about at least one of the X axis, the Y axis, and the Z axis, and the rotation axis of the rotary mechanism is the spindle. It is characterized in that it is arranged so as to pass through a region of a predetermined radius from the center of gravity of the head.

In the present invention, as the moving mechanism, an existing X-axis driving mechanism, Y-axis driving mechanism, or Z-axis driving mechanism can be used. The machine tool may be configured such that a table and a column are installed on a base, a saddle is supported on a crossbar of the column, and a spindle head is supported by the saddle. In such a machine tool, the mechanism for moving the column or table with respect to the base is an X-axis drive mechanism, the mechanism for moving the saddle with respect to the crossbar is a Y-axis drive mechanism, and the spindle head is moved up and down with respect to the saddle. The mechanism for making it can be a Z-axis drive mechanism.
In the present invention, the rotating mechanism includes an A-axis drive mechanism that rotates the spindle head about the X axis, a B-axis drive mechanism that rotates the spindle head about the Y axis, and a spindle head about the Z axis. Any of the C-axis drive mechanisms that rotate and a combination thereof can be used. Each of the A-axis to C-axis drive mechanisms can be interposed in a part of the X-axis to Z-axis drive mechanisms described above. For example, the A-axis drive mechanism can be interposed in the portion supporting the spindle head on the saddle via the Z-axis drive mechanism, and the spindle can be rotated about the X-axis with respect to the saddle. At this time, in the present invention, the rotation axis of the A-axis drive mechanism is installed so as to pass through the center of gravity of the spindle head or within a predetermined radius.
In the present invention, the area of a predetermined radius from the center of gravity of the spindle head through which the rotation axis of the rotation mechanism passes is preferably within a range of a radius of 10 mm from the center of gravity of the spindle head.

In the present invention, the rotation axis of the rotation mechanism passes through a region having a predetermined radius from the center of gravity of the spindle head. Therefore, even if the spindle head is rotated by the rotating mechanism, the center of gravity of the spindle head is not displaced or is slightly displaced due to the rotation.
Therefore, it is not necessary to reinforce the supporting structure of the spindle head in order to cope with the variation of the position of the center of gravity of the spindle head due to the rotation, and the moment of inertia is minimized, so that the driving performance of the rotating mechanism is also minimized. As a result, according to the present invention, even if the rotating mechanism is added, it is possible to avoid an increase in the supporting structure of the spindle head, and to add the rotating mechanism for the ABC axis in addition to the XYZ three-axis control. Is possible.
As a result, it is possible to realize a machine tool in which the main shaft is supported by the air bearing and the axial direction of the main shaft can be changed.

In the machine tool of the present invention, an air pipe for supplying air to the air bearing is connected to the spindle head, and an end portion of the air pipe connected to the spindle head has a continuous direction axis line of the spindle head. It is preferable that it is arranged in a region parallel to the rotation axis and having a predetermined radius from the rotation axis.

In the present invention, since the continuous direction axis line of the end portion of the air pipe connected to the spindle head is along the rotation axis line of the spindle head, even if the spindle head rotates, the displacement of the air pipe is slightly reduced and eliminated. You can
Here, when the position of the air pipe changes greatly with the rotation of the spindle head, it is necessary to secure a space around the spindle head according to the displacement of the air pipe in order to avoid interference with peripheral devices. is there. Securing such a space runs counter to the demand for downsizing around the spindle head, which may impede the addition of the rotating mechanism.
On the other hand, in the present invention, since the displacement of the air pipe due to the rotation is small and can be eliminated, it is not necessary to secure an extra space around the spindle head, and it is possible to easily add the rotation mechanism.
Although the air pipe may be twisted due to the rotation of the spindle head, use a flexible material for the air pipe or use a relatively rotatable coupler or the like at the end or the middle of the air pipe. Then, the twist should be eliminated.

In the machine tool of the present invention, it is preferable that the spindle head has a cover surrounding a mechanical portion of the spindle head including the air bearing, and the air pipe is housed inside the cover.

In the present invention, the cover encloses the mechanical portion of the spindle head including the air bearing so that these can be shielded from the outside for protection. Further, since the air pipe is housed in the cover, it is possible to prevent interference between the air pipe and peripheral devices.
In the present invention, as a premise, since the displacement of the air pipe can be minimized even if the spindle head rotates, the cover can be easily accommodated in the cover and the size of the cover for accommodating the air pipe can be minimized. Can be

In the machine tool of the present invention, it is preferable that the rotation axis of the rotation mechanism is arranged so as to pass through the motor.
In the present invention, since the rotation axis of the rotation mechanism passes through the motor, it is possible to prevent a reaction force around the rotation axis from occurring even if there is a change in cutting load or a change in rotation reaction force, and high machining accuracy is achieved. Can be secured.

In the machine tool of the present invention, it is preferable that at least two air bearings are arranged in an axial direction of the main shaft, and the motor is installed between the two air bearings.
In the present invention, since the motor is sandwiched between the pair of air bearings along the axial direction of the main shaft, the runout of the main shaft can be effectively suppressed.

According to the present invention, it is possible to provide a machine tool in which a spindle is supported by an air bearing and the axial direction of the spindle can be changed.

A perspective view showing the whole machine tool of one embodiment of the present invention. The perspective view which shows the Z-axis moving mechanism of the said embodiment. The side view which shows the A-axis moving mechanism of the said embodiment. Sectional drawing which shows the internal structure of the spindle head of the said embodiment. The expanded sectional view which shows the spindle chuck part of the said embodiment. The side view which shows the air piping of the said embodiment. The perspective view which shows the spindle head which mounted the spindle cover of the said embodiment. The perspective view which shows the spindle head which mounted the piping cover of the said embodiment. The expanded perspective view which shows the drawing-out state of the air piping of the said embodiment.

An embodiment of the present invention will be described below with reference to the drawings.
〔overall structure〕
In FIG. 1, the machine tool 1 of the present embodiment performs high-precision cutting of a work 3 by rotating a tool 2 such as a straight shank at high speed.

The machine tool 1 is capable of relatively moving the spindle 11 on which the tool 2 is mounted, the spindle head 10 that rotatably supports the spindle 11, the table 21 to which the work 3 is fixed, and the spindle head 10 with respect to the table 21. And a support structure 20 for supporting.

The machine tool 1 has a bed 22 installed on the foundation floor surface, and the table 21 and the support structure 20 described above are installed on the upper surface of the bed 22.
The support structure 20 has a gate-shaped column 23 installed so as to straddle both sides of the bed 22. A crossbar 24 is installed on the column 23, and a saddle 25 is installed on the crossbar 24. A lifting guide 26 is installed on the saddle 25, and a lifting member 27 is supported on the lifting guide 26.

The spindle head 10 is supported by the lifting member 27. The spindle 11 extends downward from the spindle head 10, and the tool 2 at the tip can cut the work 3 on the table 21.
In order to cut an arbitrary three-dimensional shape on the work 3 using the tool 2, the spindle 11 and the tool 2 can be moved three-dimensionally relative to the work.
In order to perform such a three-dimensional movement, the support structure 20 is provided with XYZ triaxial movement mechanisms (31 to 33).

Further, in this embodiment, an A-axis moving mechanism 34 that rotates the spindle head 10 around the A-axis, that is, the X-axis is installed.
The bed 22 may be provided with a C-axis moving mechanism 35 that rotates the table 21 around the C-axis, that is, the Z-axis.

The X-axis moving mechanism 31 is installed between the table 21 and the bed 22 and can move the table 21 in the X-axis direction with respect to the bed 22.
The Y-axis moving mechanism 32 is installed between the crossbar 24 and the saddle 25, and can move the crossbar 24 in the Y-axis direction with respect to the saddle 25.
The Z-axis moving mechanism 33 is installed between the elevating guide 26 and the elevating member 27, and is capable of moving (elevating) the spindle head 10 in the Z-axis direction with respect to the saddle 25.
The A-axis moving mechanism 34 is installed below the elevating member 27, and is capable of rotating the main spindle head 10 around the X axis with respect to the elevating member 27 (A-axis movement).

In the present embodiment, the spindle head 10, the Z-axis moving mechanism 33, and the A-axis moving mechanism 34 are provided with a cover 40 that covers them.
The cover 40 includes a head cover 41 that covers the Z-axis movement mechanism 33, a piping cover 42 and a spindle cover 43 that cover the spindle head 10, and an A-axis cover 44 that covers the A-axis movement mechanism 34. These will be described in detail later.

As shown in FIG. 2, the Z-axis moving mechanism 33 has a pair of rails 261 formed on the elevating guide 26, and the elevating member 27 can be moved up and down along the rails 261. A drive mechanism 331 such as a ball screw is installed between the pair of rails 261, and the elevating member 27 can be moved up and down (moved in the Z axis) with respect to the elevating guide 26.

As shown in FIG. 3, the A-axis moving mechanism 34 rotates the rotating shaft member 341 connected to the spindle head 10, the bearing 342 rotatably supporting the rotating shaft member 341, and the rotating shaft member 341. A driving motor 343 and an encoder 344 for detecting the angular position of the rotary shaft member 341 are provided. The bearing 342, the motor 343, and the encoder 344 are fixed to the lower surface side of the elevating member 27 and are covered with the A-axis cover 44.

The A-axis moving mechanism 34 uses the bearing 342 and the motor 343 to rotate the spindle head 10 supported by the rotating shaft member 341 around the rotating axis AA in the X-axis direction, and refers to the encoder 344 to set an arbitrary angle. Can be stopped in position.
Therefore, the A-axis moving mechanism 34 can adjust the orientation of the main shaft 11 to any orientation in the A-axis direction (around the X-axis).

In the present embodiment, in the connection position of the rotary shaft member 341 with respect to the spindle head 10, the rotary axis line AA passes through the center of gravity G of the spindle head 10 (the center of gravity position when the standard tool 2 is mounted on the spindle 11). Is set.
Here, the position where the rotation axis AA passes may be within a range of a predetermined radius (for example, 10 mm) from the center of gravity G of the spindle head 10.

[Spindle head 10]
In FIG. 4, the spindle head 10 has a substantially cylindrical case 101 having a side surface to which a rotary shaft member 341 is connected. Inside the case 101, an air bearing 12 that rotatably supports the main shaft 11 around a central axis C, an air supply path 13 that supplies pressurized air to the air bearing 12, and a main shaft 11 that rotates around the central axis C. A driving spindle motor 14 is installed.

The main spindle 11 has a main spindle body 111, and a core hole of the main spindle body 111 is formed along the central axis C of the main spindle 11 so as to penetrate the main spindle body 111.
A chuck device 15 (described later) for mounting the tool 2 is provided at the tip of the main shaft 11.
The spindle head 10 includes a push cylinder 16 on the base end side (the side opposite to the tip of the spindle 11 on which the tool 2 is mounted). A push rod 161 is connected to the push cylinder 16, the push rod 161 is inserted through the center hole 112 of the main shaft 11, and its tip reaches the chuck device 15.

[Chuck device 15]
As shown in FIG. 5, the chuck device 15 has a sleeve member 151 fixed to the tip of the main shaft 11. A chuck hole 152 is formed in the sleeve member 151 from the front end side toward the base end side. A collet member 153 is housed in the chuck hole 152.
The collet member 153 has a tubular shape, and the tool 2 can be inserted from the tip side. In the collet member 153, a plurality of slits 154 are formed from the tip side to an intermediate position. By the slit 154, the tip end side (the portion into which the tool 2 is inserted) of the collet member 153 can be elastically deformed to be expanded or reduced in diameter.

The outer peripheral surface of the collet member 153 on the front end side is formed so that the outer diameter gradually increases toward the front end, thereby forming an outer conical surface 159 that expands in diameter toward the front end.
On the tip end side of the sleeve member 151, the inner peripheral surface of the chuck hole 152 is formed such that the inner diameter thereof gradually increases toward the tip, thereby forming an inner conical surface 150 that expands in diameter toward the tip.
The outer conical surface 159 and the inner conical surface 150 can be brought into close contact with each other by inserting the collet member 153 into the chuck hole 152. Then, when the collet member 153 is pushed further into the chuck hole 152 from the close contact state, the outer conical surface 159 is narrowed by the inner conical surface 150, and the tip side of the collet member 153 is deformed so as to be reduced in diameter. It

A diaphragm mechanism 155 is formed by the outer conical surface 159 and the inner conical surface 150, and the diameter of the tip side of the collet member 153 is reduced by the diaphragm mechanism 155 to straighten the tool 2 inserted from the tip of the collet member 153. The shank part can be tightened and fixed.
The base end side of the collet member 153 described above is exposed from the sleeve member 151, and the collet nut 156 is screwed to the end portion. A large number of disc springs 157 are inserted in a laminated state in the portion of the collet member 153 exposed from the sleeve member 151.
These disc springs 157 are sandwiched between the sleeve member 151 and the collet nut 156, and the elastic repulsive force urges the collet nut 156 and the collet member 153 toward the base end side with respect to the sleeve member 151. ..

A retracting mechanism 158 is formed by the disc spring 157 and the collet nut 156. The retracting mechanism 158 always retracts the collet member 153 toward the inner side of the chuck hole 152, and the tip of the collet member 153 is constantly reduced in diameter. Maintained at.
Therefore, when the straight shank portion of the tool 2 is inserted from the tip of the collet member 153, the retracting mechanism 158 maintains the tightened and fixed state of the tool 2.

Returning to FIG. 4, the chuck device 15 is inserted into the center hole 112 from the tip end side of the main spindle body 111, and the flange portion of the sleeve member 151 is fixed to the end surface of the main spindle body 111. On the base end side of the chuck device 15, the end of the collet member 153 is arranged to face the tip of the push rod 161 at a slight interval.

In the chuck device 15, by pushing the push rod 161 forward by the push cylinder 16, the collet member 153 is pushed by the push rod 161, and the collet member 153 moves to the tip side against the pulling force of the pulling mechanism 158. To do. By such movement, the outer conical surface 159 of the collet member 153 separates from the inner conical surface 150 of the chuck hole 152, and the diaphragm mechanism 155 releases the restriction on the tip side of the collet member 153. As a result, the fastening and fixing of the tool 2 on the tip side of the collet member 153 is released, and the tool 2 can be extracted from the chuck device 15.

As described above, in the chuck device 15, the push cylinder 16 advances the push rod 161 toward the tip side to release the tightening and fixing of the tool 2, and the push rod 161 is returned to the retracting mechanism 158 and the drawing mechanism 155. Are re-enabled and the tool 2 can be clamped and fixed.

[Air piping 17]
In FIG. 4, in order to continuously supply the air used in the air bearing 12 described above to the air supply path 13 and to appropriately supply the control air to the push cylinder 16 described above, the spindle head 10 is provided. Is connected to a plurality of air pipes 17.
The air pipe 17 is connected to the side surface of the case 101. A circular frame-shaped pipe guide 18 that surrounds the air pipe 17 is installed on the side surface of the case 101, and the air pipe 17 is protected so that the connecting portion of the air pipe 17 is not unduly bent and deformed. There is.

In the present embodiment, the position where the air pipe 17 is connected to the spindle head 10 is on an extension line of the rotation axis line AA of the A-axis moving mechanism 34, and the air pipe 17 is connected to the spindle head 10. The continuous direction of is the direction along the rotation axis AA.
The rotation axis AA passes through the region of the spindle head 10 in which the spindle motor 14 is formed (between the pair of air bearings 12 arranged with the spindle motor 14 in between), and as described above, The center of gravity G of 10 is also arranged on this rotation axis AA.

As shown in FIG. 6, one end of the air pipe 17 is connected to the spindle head 10, is drawn out along the rotation axis AA, is then bent upward, and is passed through the inside of the cover 40 so that the elevating member 27 of the elevating member 27. The pipe receiving member 271 is pulled up.
As shown in FIG. 2, the pipe receiving member 271 is drawn out to the saddle 25 through the side surface of the elevating guide 26. The air pipe 17 reaches the saddle 25 along the pipe receiving member 271 and is connected to an external air supply source.

In the present embodiment, the air pipe 17 is made of a flexible material, or a relatively rotatable coupler or the like is used at an end portion or an intermediate portion of the air pipe 17, so that the spindle head 10 can be rotated. It is configured so that the air pipe 17 is not twisted.

[Cover 40]
As described above, the spindle head 10, the Z-axis moving mechanism 33, and the A-axis moving mechanism 34 are provided with the cover 40 that covers them.
As shown in FIGS. 1 and 6, the cover 40 includes a head cover 41, a piping cover 42, a main shaft cover 43, and an A shaft cover 44.
A plurality of air pipes 17 for supplying air to the air bearing 12 and the push cylinder 16 are drawn out through the inside of the cover 40 (spindle cover 43, pipe cover 42 or head cover 41).

As shown in FIGS. 6 and 7, the A-axis cover 44 is arranged so as to surround the A-axis moving mechanism 34, and is fixed to the lower surface side of the elevating member 27. A rotating shaft member 341 projects from the A-axis cover 44 along the rotating shaft line AA, and the rotating shaft member 341 supports the spindle head 10.

As shown in FIGS. 6 and 7, the main spindle cover 43 is arranged so as to surround the main spindle head 10, is fixed to the main spindle head 10, and is rotatable with the main spindle head 10 about a rotation axis AA.
An opening 431 is formed on the lower surface side of the spindle cover 43, and the tip of the spindle 11 and the tool 2 are exposed from the opening 431.
A piping opening 432 is formed on the surface of the spindle cover 43, and the piping guide 18 and the air piping 17 of the spindle head 10 are inserted through the piping opening 432.

As shown in FIGS. 6, 8 and 9, the pipe cover 42 has a base fixed to the elevating member 27 and a portion extending downward from the base so as to cover the surface of the spindle cover 43.
A piping opening 421 is formed on a surface of the piping cover 42 that faces the spindle cover 43. The piping opening 421 has a position and size corresponding to the piping opening 432 of the main shaft cover 43, and the air piping 17 drawn out from the piping opening 432 is drawn upward through the inside of the piping cover 42.
The upper surface side of the piping cover 42 is an opening 422, and the air piping 17 guided from the piping opening 432 to the inside of the piping cover 42 is sent upward through the opening 422.

As shown in FIGS. 6 and 8, the head cover 41 is arranged so as to collectively surround the elevating guide 26, the elevating member 27, and the Z-axis moving mechanism 33, and is fixed to the elevating guide 26.
An opening 411 is formed on the lower surface side of the head cover 41, and part of the A-axis moving mechanism 34 and the spindle head 10 supported by the elevating member 27 can be accommodated inside the head cover 41 through the opening 411.
When the Z-axis moving mechanism 33 is lowered, the A-axis moving mechanism 34 and the spindle head 10 are largely exposed from the head cover 41. When the Z-axis moving mechanism 33 is raised, most of the A-axis moving mechanism 34 and the spindle head 10 are housed inside the head cover 41.
Inside the opening 411 of the head cover 41, a cavity 412 of a sufficient size is secured so as not to interfere with the rotation of the spindle head 10 even when the spindle head 10 is maximally raised.

[Effects of this embodiment]
According to this embodiment described above, the following effects can be obtained.
In the present embodiment, the rotation axis AA of the A-axis moving mechanism 34, which is a rotation mechanism, passes through the center of gravity G of the spindle head 10 (a region within a radius 10 mm from the center of gravity G). Therefore, even if the spindle head 10 is rotated by the A-axis moving mechanism 34, the center of gravity G of the spindle head 10 is not displaced or is slightly displaced with respect to the foundation of the machine tool 1 in accordance with the rotation.

Therefore, it is not necessary to reinforce the support structure (support structure 20) of the spindle head 10 in order to cope with the variation of the position of the center of gravity of the spindle head 10 due to the rotation, and the moment of inertia is minimized, so that the A-axis moving mechanism 34. Drive performance is minimal.
As a result, according to the present embodiment, even if the A-axis moving mechanism 34 is added to the XYZ three-axis movement, it is possible to avoid increasing the size of the support structure 20 of the spindle head 10.
As a result, it is possible to realize the machine tool 1 in which the main shaft 11 is supported by the air bearings 12 and the direction of the central axis C of the main shaft 11 can be changed.

In the present embodiment, since the continuous axis line of the end portion of the air pipe 17 connected to the spindle head 10 is along the rotation axis line AA of the spindle head 10, the air pipe 17 is rotated even if the spindle head 10 is rotated. The displacement can be reduced or eliminated.
Here, in the case where the position of the air pipe 17 greatly changes with the rotation of the spindle head 10, a space corresponding to the displacement of the air pipe 17 is provided around the spindle head 10 in order to avoid interference with peripheral devices. It is necessary to secure it. Securing such a space runs counter to the demand for downsizing around the spindle head 10 and hinders the addition of the A-axis moving mechanism 34.
On the other hand, in the present embodiment, since the displacement of the air pipe 17 due to the rotation of the spindle head 10 is small and can be eliminated, it is not necessary to secure an extra space around the spindle head 10 and the A-axis moving mechanism 34 is not required. It can be easily added.

In the present embodiment, since the cover 40 is provided to surround each part of the spindle head 10, the Z-axis moving mechanism 33, and the A-axis moving mechanism 34, these can be shielded from the outside for protection. Further, since the air pipe 17 is housed in the cover, it is possible to prevent interference between the air pipe 17 and peripheral devices.
Further, in the present embodiment, as described above, the air pipe 17 is arranged along the rotation axis AA, and the displacement of the air pipe 17 due to the rotation of the spindle head 10 is minimized. Is easily accommodated, and the size of the cover 40 for accommodating the air pipe 17 can be minimized.

Further, in the present embodiment, the cover 40 is configured by the head cover 41, the pipe cover 42, the main shaft cover 43, and the A shaft cover 44.
That is, since the Z-axis moving mechanism 33 is covered with the head cover 41, the A-axis moving mechanism 34 is covered with the A-axis cover 44, and the main spindle head 10 is covered with the main spindle cover 43, the operations of the relative moving parts are not hindered. ..
Furthermore, by using the pipe cover 42, it is possible to secure a route suitable for routing the air pipe 17 from the spindle cover 43 to the head cover 41.

In this embodiment, the rotation axis AA of the A-axis moving mechanism 34, which is a rotation mechanism, is arranged so as to pass through the spindle motor 14 of the spindle head 10. Therefore, in the spindle motor 14 of the spindle head 10, even if there is a variation in the cutting load or a variation in the rotational reaction force, it is possible to prevent the reaction force around the rotation axis line AA from being generated, and to secure high processing accuracy. You can

In this embodiment, in the spindle head 10, two air bearings 12 are arranged with the spindle motor 14 interposed therebetween. Therefore, the spindle motor 14 is sandwiched between the pair of air bearings 12 along the axial direction of the spindle 11, so that the swing of the spindle 11 can be effectively suppressed.

In this embodiment, the tool 2 and the spindle 11 can be directly fixed by the chuck device 15 installed at the tip of the spindle 11.
In particular, since the tool 2 is clamped and fixed by the collet member 153, the tool 2 can be reliably fixed even if the shank portion is straight.
When the collet member 153 is clamped, the retracting mechanism 158 retracts the collet member 153 along the central axis C of the main shaft 11 and the squeezing mechanism 155 tightens the tool 2. Therefore, unlike the tightening of the collet member 153 by the rotary type outer cylinder, the collet member 153 is not deformed in the rotation direction or biased in the axial direction, and can be fixed with high accuracy.
On the other hand, the push cylinder 16 pulls the collet member 153 toward the tip end side of the main shaft 11 against the pulling force of the pulling mechanism 158, and releases the collet member 153 from the drawing by the drawing mechanism 155. The tool can be removed from the spindle 11 by releasing the clamp of the tool.

[Other Embodiments]
The present invention is not limited to the above-described embodiments, and modifications and the like within a range in which the object of the present invention can be achieved are included in the present invention.
Although the A-axis moving mechanism 34 is provided as the turning mechanism in the above-described embodiment, a B-axis moving mechanism for turning the spindle head 10 around the B-axis, that is, the Y-axis may be provided instead. Alternatively, the A-axis moving mechanism 34 and the B-axis moving mechanism may be installed together under the elevating member 27. However, as described above, when the C-axis moving mechanism 35 is provided on the table 21, either the A-axis moving mechanism 34 or the B-axis moving mechanism is sufficient.

The cover 40 of the above-described embodiment is not limited to the configuration including the head cover 41, the piping cover 42, the main shaft cover 43, and the A-axis cover 44, and other auxiliary covers may be added, and the head cover 41 and the piping cover 42 may be added. Modifications such as integrating and are possible.
On the other hand, each part, especially the head cover 41 having a large size, may be assembled from a plurality of members.
As the material of each part constituting the cover 40, for example, synthetic resin, fiber-reinforced material, metal and other materials may be appropriately selected.

In the chuck device 15 of the above-described embodiment, when releasing the clamp of the tool 2, another mechanism for releasing the retracting force of the retracting mechanism 158 may be used, or the collet member 153 may be resisted against the retracting force of the retracting mechanism 158. Another drive mechanism for moving can be used. For example, the collet member 153 can be driven by supplying pressurized air through a coolant hole that is passed through the center hole 112 of the main shaft 11.
It should be noted that if the cutting waste adheres to the inner surface of the collet member 153, the mounting accuracy of the tool 2 may be reduced. Therefore, prior to mounting the tool 2, the inner surface of the collet member 153 may be sprayed with pressurized air to remove cutting chips.

The diaphragm mechanism 155 is not limited to the conical surface, and a plurality of protrusions that are evenly arranged in the circumferential direction and extend in the central axis C direction of the main shaft 11 are formed on the outer peripheral surface of the collet member 153 or the inner side surface of the chuck hole 152. The surface may be an inclined surface closer to the central axis C toward the inner side of the chuck hole 152, and these inclined surfaces may be a diaphragm mechanism.
In the retracting mechanism 158, the retractable elastic member is not limited to the plurality of disc springs 157, but may be a coil spring or other elastic member, or a material that compresses volume.

INDUSTRIAL APPLICABILITY The present invention can be used as a machine tool for performing high precision cutting under high rotation.

1... Machine tool, 2... Tool, 3... Work, 10... Spindle head, 11... Spindle, 12... Air bearing, 13... Air supply path, 14... Spindle motor, 15... Chuck device, 16... Push cylinder, 17... Air piping, 18... Piping guide, 20... Support structure, 21... Table, 22... Bed, 23... Column, 24... Crossbar, 25... Saddle, 26... Lift guide, 27... Lift member, 31... X-axis moving mechanism , 32... Y-axis moving mechanism, 33... Z-axis moving mechanism, 34... A-axis moving mechanism (rotating mechanism), 35... C-axis moving mechanism, 40... Cover, 41... Head cover, 42... Piping cover, 43... Spindle Cover, 44... A-axis cover, 101... Case, 111... Main shaft body, 112... Center hole, 150... Inner conical surface, 151... Sleeve member, 152... Chuck hole, 153... Collet member, 154... Slot, 155... Throttle mechanism, 156... Collet nut, 157... Disc spring, 158... Retraction mechanism, 159... Outer conical surface, 161... Push rod, 261... Rail, 271... Pipe receiving member, 331... Drive mechanism, 341... Rotating shaft member , 342... Bearings, 343... Motor, 344... Encoder, 411, 422, 431... Opening, 412... Cavity, 421, 432... Piping opening, AA... Rotation axis, C... Central axis, G... Center of gravity.

Claims (4)

A spindle on which a tool is mounted, an air bearing for rotatably supporting the spindle, and a spindle head having a motor for rotationally driving the spindle, a table on which a work is fixed, and the spindle head relative to the table. A support structure that movably supports, a cover that surrounds a mechanical portion of the spindle head that includes the air bearing, and an air pipe that is housed inside the cover and supplies air to the air bearing ,
The support structure moves a Z-axis moving mechanism that raises and lowers a lifting member that supports the spindle head along a Z-axis lifting guide, and a saddle that supports the Z-axis moving mechanism in the X-axis direction and the Y-axis direction. At least one of an X-axis moving mechanism and a Y-axis moving mechanism , and a rotating mechanism for rotating the spindle head around the X-axis,
The rotation axis of the rotation mechanism is arranged so as to pass through a region of a predetermined radius from the center of gravity of the spindle head ,
The cover is arranged so as to surround the spindle head and is fixed to the spindle head, and a base is fixed to the elevating member, and a portion extending downward from the base covers the surface of the spindle cover. And a head cover fixed to the elevating guide and arranged to collectively surround the elevating member and the Z-axis moving mechanism,
One end of the air pipe is connected to the spindle head, is drawn out along the rotation axis of the rotation mechanism, is then bent upward, and passes through the inside of the cover to the pipe receiving member of the elevating member. It is pulled up and pulled out to the saddle through the side surface of the lifting guide,
The machine tool , wherein the pipe receiving member is formed in a bifurcated shape that extends to both sides of the elevating member and reaches the saddle . The machine tool according to claim 1,
The end portion of the air pipe connected to the spindle head is arranged in a region in which a continuous direction axis line is parallel to the rotation axis line of the spindle head and has a predetermined radius from the rotation axis line. Machine Tools. In the machine tool according to claim 1 or 2 ,
A machine tool, wherein a rotation axis of the rotation mechanism is arranged so as to pass through the motor. The machine tool according to any one of claims 1 to 3 ,
At least two air bearings are arranged in the axial direction of the main shaft,
The machine tool, wherein the motor is installed between the two air bearings.

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