JP7294206B2 - Holding devices and machine tools - Google Patents

Description

The present technology relates to a holding device and a machine tool that hold a rotating work.

2. Description of the Related Art Conventionally, there is a machine tool that performs turning work, and the machine tool is equipped with a steady rest device that holds down the center of rotation of a rotating work. The anti-vibration device suppresses the radial movement of the rotating work and improves the machining accuracy (see Patent Document 1, for example).

Japanese Patent No. 6145396

The anti-vibration device has a moving mechanism that moves closer to or away from the center of rotation of the workpiece. Chips are generated during machining of workpieces. Chips may enter gaps in the moving mechanism, causing malfunctions in the moving mechanism.

The present disclosure has been made in view of such circumstances, and an object of the present disclosure is to provide a holding device for holding a workpiece and a machine tool that can suppress the occurrence of defects due to chips.

A holding device according to an embodiment of the present disclosure is a holding device that holds a work supported by a support device that is swingable about a first axis and rotatable about a second axis perpendicular to the first axis, wherein the The apparatus includes a holding section that faces the support device and holds the center of rotation of the workpiece, a moving mechanism that moves the holding section in a direction in which the holding section and the supporting device face each other, and a cover that covers the moving mechanism.

In the present disclosure, the moving mechanism is covered with a cover to prevent chips from entering.

In a holding device according to an embodiment of the present disclosure, the moving mechanism includes a track arranged inside the cover, a slider attached to the holding part and sliding on the track, and the holding part and a drive source coupled to.

In the present disclosure, the track, slider, and drive source are arranged inside the cover to prevent chips from entering gaps in the moving mechanism.

In a holding device according to an embodiment of the present disclosure, the holding portion and the supporting device face each other in a horizontal direction, and the track is arranged below the cover.

In the present disclosure, the track is arranged on the underside of the cover to prevent the moving mechanism from protruding upward.

In a holding device according to an embodiment of the present disclosure, a discharge port for discharging chips is formed between the cover and the track.

In the present disclosure, chips that have entered the cover are discharged from the discharge port.

In a holding device according to an embodiment of the present disclosure, a portion of the upper portion of the cover facing the support device is provided with an inclined surface that descends toward the support device.

In the present disclosure, the provision of the inclined surface prevents the cover from interfering with the spindle head.

In a holding device according to an embodiment of the present disclosure, the holding portion and the supporting device are horizontally opposed, the track is attached to the top of the cover, and the entire bottom surface of the cover is open.

In the present disclosure, since the entire lower surface of the cover is open, chips are less likely to accumulate inside the cover.

A machine tool according to an embodiment of the present disclosure includes a support device that supports a workpiece, is swingable about a first axis and rotatable about a second axis perpendicular to the first axis, and the aforementioned holding device. Prepare.

In the present disclosure, the moving mechanism is covered with a cover to prevent chips from entering.

In the holding device and the machine tool according to the embodiment of the present disclosure, the movement mechanism can be covered with a cover to prevent chips from entering and ensure smooth movement of the movement mechanism.

1 is a schematic perspective view of a machine tool according to Embodiment 1; FIG. It is a partially enlarged perspective view schematically showing a support device and a holding device. FIG. 4 is a partially enlarged perspective view schematically showing the configuration of the vicinity of the front surface of the support when the holding device is removed; Fig. 2 is a schematic perspective view of a holding device; It is a partially enlarged right side cross-sectional view schematically showing the configuration around the holding device. It is a schematic partial enlargement right side sectional view of a holding device. FIG. 4 is a schematic perspective view of the holding device in the retracted position with the cover removed; FIG. 4 is a schematic front view of the holding device in the retracted position with the cover removed; It is a schematic right side view of the holding device in the retracted position with the cover removed. FIG. 4 is a schematic rear view of the holding device in the retracted position with the cover removed; 4 is a schematic partial enlarged right side view of the moving plate and the holding portion; FIG. FIG. 4 is a schematic right side view of the holding device in the holding position with the cover removed; FIG. 11 is a schematic right side cross-sectional view of a holding device according to Embodiment 2;

(Embodiment 1)
The present invention will be described below with reference to drawings showing a machine tool according to Embodiment 1. FIG. In the following description, up, down, front, back, left, and right in the drawings are used. FIG. 1 is a perspective view schematically showing a machine tool. In FIG. 1, illustration of a tool magazine for storing replacement tools is omitted.

The machine tool has a rectangular base 1 extending back and forth. A support device 3 for supporting a work is provided on the front side of the upper portion of the base 1 . The support device 3 includes a table 3a, an A-axis motor 3b, a C-axis motor 3c, and two support plates 3d. The two support plates 3d are arranged on the left and right sides of the base 1. As shown in FIG. The base 3a is arranged between two support plates 3d and connected to the support plates 3d so as to be rotatable about the A axis. The A axis extends in the horizontal direction. By driving the A-axis motor 3b, the table 3a rotates around the A-axis.

The table 3a has a support surface 3e for supporting the work, and a C-axis motor 3c is provided on the opposite side of the support surface 3e. The support surface 3e is parallel to the A axis. The C-axis extends in a direction perpendicular to the support surface 3e. By driving the C-axis motor 3c, the support surface 3e rotates around the C-axis.

A support base 2 is provided on the rear side of the upper part of the base 1 to support a vertical column 4, which will be described later. A Y-axis direction moving mechanism 10 that moves in the front-rear direction is provided on the upper part of the support base 2 . The Y-axis movement mechanism 10 includes two tracks 11 extending back and forth, a Y-axis screw shaft 12 , a Y-axis motor 13 , and bearings 14 .

The tracks 11 are provided on the left and right sides of the upper part of the support base 2, respectively. The Y-axis screw shaft 12 extends back and forth and is provided between the two tracks 11 . Bearings 14 are provided at the front end portion and midway portion of the Y-axis screw shaft 12, respectively. Illustration of the bearing provided in the middle is omitted. The Y-axis motor 13 is connected to the rear end of the Y-axis screw shaft 12 .

A nut (not shown) is screwed onto the Y-axis screw shaft 12 . A plurality of sliders 15 are slidably provided on each track 11 . A moving plate 16 is connected to the top of the nut and slider 15 . The moving plate 16 extends horizontally. The rotation of the Y-axis motor 13 causes the Y-axis screw shaft 12 to rotate, the nut to move in the front-rear direction, and the moving plate 16 to move in the front-rear direction.

An X-axis direction moving mechanism 20 is provided on the upper surface of the moving plate 16 to move in the horizontal direction. The moving plate 16 constitutes a support. The X-axis movement mechanism 20 includes two tracks 21 extending left and right, an X-axis screw shaft 22, and an X-axis motor (not shown).

Tracks 21 are provided on the front and back of the upper surface of the moving plate 16, respectively. The X-axis screw shaft 22 extends left and right and is provided between the two tracks 21 . Bearings 24 support the left end portion and the middle portion of the X-axis screw shaft 22 . A bearing 24 is fixed to the moving plate 16 .

A nut (not shown) is connected to the X-axis screw shaft 22 . A plurality of sliders 26 are slidably provided on each track 21 . The pillar 4 is connected to the upper part of the nut and slider 26 . The standing pillar 4 has a columnar shape. The rotation of the X-axis motor 23 causes the X-axis screw shaft 22 to rotate, the nut to move in the left-right direction, and the vertical column 4 to move in the left-right direction.

A Z-axis direction moving mechanism 30 that moves vertically is provided on the front surface of the vertical column 4 . The Z-axis movement mechanism 30 includes two vertically extending tracks 31 , a Z-axis screw shaft 32 , a Z-axis motor 33 and bearings 34 .

Tracks 31 are provided on the left and right sides of the front surface of the vertical column 4 . The Z-axis screw shaft 32 extends vertically and is provided between the two tracks 31 . Bearings 34 are provided at the lower end and midway of the Z-axis screw shaft 32, respectively. Illustration of the bearing provided in the middle is omitted. The Z-axis motor 33 is connected to the upper end of the Z-axis screw shaft 32 .

A nut (not shown) is screwed onto the Z-axis screw shaft 32 . A plurality of sliders 35 are slidably provided on each track 31 . The spindle head 5 is connected to the front portion of the nut and slider 35 . The rotation of the Z-axis motor 33 causes the Z-axis screw shaft 32 to rotate, the nut to move vertically, and the spindle head 5 to move vertically.

A vertically extending spindle 5 a is provided in the spindle head 5 . The main shaft 5a rotates about its axis. A spindle motor 6 is provided at the upper end of the spindle head 5 . A tool is mounted on the lower end of the spindle 5a. The rotation of the spindle motor 6 causes the spindle 5a to rotate and the tool to rotate. The rotated tool processes the workpiece supported by the support device 3 .

The machine tool includes a tool changer (not shown) for changing tools. The tool changing device changes a tool stored in a tool magazine (not shown) and a tool mounted on the spindle 5a.

FIG. 2 is a partially enlarged perspective view schematically showing the support device 3 and the holding device 50. FIG. In FIG. 2, the supporting surface 3e of the supporting device 3 faces rearward, and the holding portion 58 of the holding device 50 is in the holding position as will be described later. The support surface 3e supports the workpiece W. As shown in FIG. The workpiece W is elongated and arranged at right angles to the support surface 3e. A funnel-shaped concave portion Wa is formed in the tip surface of the work W (see FIG. 6). A holding device 50 for holding the work W is provided on the front surface 2a of the support table 2 (see FIG. 3). The holding device 50 faces the support surface 3e in the front-rear direction.

FIG. 3 is a partially enlarged perspective view schematically showing the configuration around the front surface 2a of the support base 2 when the holding device 50 is removed. The support base 2 has a front surface 2a, and the front surface 2a and the support device 3 are spaced apart in the longitudinal direction. The front surface 2a is formed with a concave portion 2b recessed toward the rear side. The upper and front sides of the recess 2b are open and the recess 2b comprises a lower surface 2c, a rear surface 2d, a left surface 2e and a right surface. Two mounting members 2f are provided on the rear surface 2d with a space left and right. Each mounting member 2f has a plate shape and extends vertically. One surface of each mounting member 2f constitutes a front surface, and two internal threads 2g are vertically arranged side by side at the upper end of the front surface of each mounting member 2f.

4 is a schematic perspective view of the holding device 50, FIG. 5 is a partially enlarged right side sectional view schematically showing the configuration around the holding device 50, and FIG. 6 is a partially enlarged right side sectional view of the holding device 50. is. The holding device 50 comprises a cover 51 . 4-6, the holding portion 58 is in the holding position, as will be described later. The cover 51 has a box shape with an open bottom side and a rear side. The cover 51 has a front surface 51a, a right surface 51c and a left surface 51h. The front surface 51a, the right surface 51c and the left surface 51h are rectangular. The right surface 51c and the left surface 51h are opposed and parallel. The right edge and left edge of the front surface 51a continue at right angles to the front edges of the right surface 51c and left surface 51h, respectively. A through hole 51b is formed through the front surface 51a in the front-rear direction.

A triangular front upper surface 51f is provided on the upper edge of the front surface 51a. Three sides of the front upper surface 51f constitute a lower edge, a right edge and a left edge, respectively. The lower edge of the front upper surface 51f continues to the upper edge of the front surface 51a. The front upper surface 51f is inclined so as to fall rearward. That is, it inclines so that it may descend as it goes to the front side. Since the front upper surface 51f is inclined, it is possible to prevent the spindle head 5 from interfering with the front upper surface 51f. The front upper surface 51f constitutes an inclined surface.

A trapezoidal right upper surface 51e is provided at the upper edge of the right surface 51c. The upper right surface 51e includes a top edge, a bottom edge, a leading edge and a trailing edge. The top and bottom edges are parallel and the top edge is shorter than the bottom edge. As shown in FIG. 5, the front and rear positions of the rear ends of the upper and lower edges are the same. The rear edge of the upper right surface 51e continues perpendicularly to the right ends of the upper and lower edges. The front edge of the upper right surface 51e continues to the front ends of the upper and lower edges. The front edge of the upper right surface 51e slopes down toward the front and continues to the right edge of the front upper surface 51f. The upper right surface 51e is inclined so as to fall to the left. That is, it inclines so that it may descend as it goes to the right side.

A trapezoidal upper left surface 51g is provided at the upper edge of the left surface 51h. The left upper surface 51g has a top edge, a bottom edge, a leading edge and a trailing edge. The top and bottom edges are parallel and the top edge is shorter than the bottom edge. As shown in FIG. 6, the front and rear positions of the rear ends of the upper and lower edges are the same. The rear edge of the left upper surface 51g continues perpendicularly to the right ends of the upper and lower edges. The front edge of the left upper surface 51g continues to the front ends of the upper edge and the lower edge. A front edge portion of the left upper surface 51g is inclined downward toward the front side and continues to a left edge portion of the front upper surface 51f. 51 g of left upper surfaces incline so that it may fall rightward. That is, it inclines so that it may descend|fall as it goes to the left side. Since the upper right surface 51e and the upper left surface 51g are inclined, chips accumulated on the upper right surface 51e and the upper left surface 51g can slide off.

7 is a schematic perspective view of the holding device 50 at the retracted position without the cover 51, FIG. 8 is a schematic front view of the holding device 50 at the retracted position without the cover 51, and FIG. FIG. 10 is a schematic right side view of the holding device 50 in the retracted position, FIG. 10 is a schematic rear view of the holding device 50 in the retracted position with the cover 51 removed, and FIG. It is an enlarged right side view.

The holding device 50 includes a bottom plate 52 that is rectangular in plan view. The bottom plate 52 extends in the front-rear direction. A track 53 extending in the front-rear direction is provided in the center of the bottom plate 52 in the left-right direction. A moving plate 57 is positioned above the track 53 and connected to the track 53 via a slider 54 . The slider 54 and the moving plate 57 move forward and backward along the track 53 .

The moving plate 57 is L-shaped when viewed from the side, and includes a front plate 57a which is rectangular when viewed from the front and a lower plate 57b which is rectangular when viewed from the top. The front plate 57a projects upward at right angles from the front edge of the lower plate 57b. The lower surface of the lower plate 57b is connected to the slider 54. As shown in FIG.

As shown in FIGS. 7 to 9 and 11, a holding portion 58 for holding the tip surface of the work W is fixed to the front surface of the front plate 57a. The retaining portion 58 includes a cylindrical portion 58a, a conical portion 58b and a flange 58c. A conical portion 58b is coaxially provided on one end face of the cylindrical portion 58a. The tip of the conical portion 58b faces the opposite side of the columnar portion 58a in the axial direction. An annular flange 58c is formed around the other end surface of the cylindrical portion 58a.

As shown in FIG. 11, the flange 58c is formed with four through holes 58d penetrating back and forth. The four through holes 58d are arranged at equal intervals in the circumferential direction. Four screw holes 57c are formed in the front plate 57a. The positions of the four screw holes 57c correspond to the positions of the four through holes 58d. The flange 58c is attached to the front surface of the front plate 57a so that each through hole 58d is positioned in front of each screw hole 57c. Four bolts 58e are inserted from the front in each through hole 58d and connect to each threaded hole 57c. The diameter of the through hole 58d is larger than the diameter of the shaft of the bolt 58e and smaller than the diameter of the head of the bolt 58e.

A rear plate 55 perpendicular to the bottom plate 52 is provided at the rear edge of the bottom plate 52 . The rear plate 55 has a rectangular shape when viewed from the rear and extends in the vertical direction. The lower edge of the rear plate 55 connects to the rear edge of the bottom plate 52 . As shown in FIGS. 7, 8 and 10, two insertion holes 55a penetrating in the front-rear direction are formed on the upper right side of the rear plate 55 and arranged vertically. Two insertion holes 55a penetrating in the front-rear direction are formed on the upper left side of the rear plate 55 and arranged vertically. The positions of the four insertion holes 55a correspond to the positions of the four female screws 2g.

A cylinder 56 is provided on the front surface of the rear plate 55 . The cylinder 56 is arranged between the rear plate 55 and the front plate 57a in the front-rear direction. The axial direction of the cylinder 56 is the front-rear direction, and a piston 56b (see FIG. 6) is provided in a cylinder chamber inside the cylinder 56. As shown in FIG. The piston 56b divides the cylinder chamber into front and rear. Compressed air is supplied to one of the divided chambers and exhausted from the other chamber to move the piston 56b back and forth.

A rod 56a protrudes forward from the piston 56b. The rod 56 a protrudes forward from the cylinder 56 . The tip of the rod 56a is connected to the front plate 57a. By driving the cylinder 56, the piston 56b and the rod 56a move back and forth, and the moving plate 57 and the holding portion 58 also move back and forth. The cylinder 56, rod 56a and piston 56b constitute a drive source. Incidentally, instead of the cylinder 56, rod 56a and piston 56b, a ball screw mechanism, a linear motor drive mechanism, or the like may be used as the drive source.

FIG. 12 is a schematic right side view of the holding device 50 in the holding position with the cover 51 removed. The holding portion 58 moves between a retracted position on the rear side and a holding position on the front side. As shown in FIG. 9, when the workpiece W is short or rotation around the C-axis is not required, and the workpiece W need not be held by the holder 58, the holder 58 is at the retracted position. On the other hand, as shown in FIGS. 2, 4 to 6, and 12, when the workpiece W is long and the support device 3 rotates around the C axis, the holding portion 58 moves from the retracted position to the holding position, The tip of the work W is held.

The cover 51 covers the bottom plate 52, track 53, slider 54, rear plate 55, cylinder 56, rod 56a, moving plate 57, holding portion 58 and the like. The track 53, the slider 54, the cylinder 56, the rod 56a, and the moving plate 57 constitute a moving mechanism, and the bottom plate 52 and rear plate 55 also function as a cover for covering the moving mechanism. As shown in FIG. 6, a gap is formed between the front edge of the bottom plate 52a and the front surface 51a in the front-rear direction. This gap forms the outlet 59 . In other words, a discharge port 59 is formed between the track 53 and the front surface 51a.

As shown in FIGS. 2, 4 and 5, the holding portion 58 is inserted into the through hole 51b of the front surface 51a. By driving the cylinder 56, the holding portion 58 moves back and forth through the through hole 51b. As shown in FIG. 6, when moving forward, the conical portion 58b of the holding portion 58 is inserted into the concave portion Wa of the work W to hold the work W thereon. When chips enter the cover 51 , the chips are discharged from the discharge port 59 . Since the discharge port 59 is arranged on the front side of the track 53 , chips accumulated around the track 53 are easily discharged from the discharge port 59 when the moving plate 57 moves forward.

The attachment of the holding device 50 to the support base 2 is performed as follows. A rear plate 55 is placed on the lower surface 2c so that each insertion hole 55a is positioned in front of each internal thread 2g, and a bolt is inserted into the insertion hole 55a and connected to the internal thread 2g. The retaining device 50 is attached to the support base 2 by coupling the bolt to the internal thread 2g.

Positioning of the holding portion 58 with respect to the work W is performed as follows. The workpiece W is a workpiece for testing. The holding portion 58 is positioned so that the tip of the conical portion 58b is inserted into the recess Wa of the work W. As shown in FIG. After positioning, the bolt 58e is inserted into the through hole 58d and connected to the screw hole 57c. As described above, the diameter of the through hole 58d is larger than the diameter of the shaft of the bolt 58e, so the position of the holding portion 58 can be adjusted vertically or horizontally within the range of the difference between the two diameters. can.

In the holding device 50 and the machine tool according to Embodiment 1, the movement mechanism is covered with the cover 51 to prevent chips from entering. A track 53, a slider 54, a cylinder 56, a rod 56a and a piston 56b are arranged inside the cover 51 to prevent chips from entering gaps of the moving mechanism.

Since the track 53 is arranged under the cover 51, the moving mechanism is prevented from protruding upward. Therefore, interference with the spindle head 5 can be easily prevented. Moreover, by providing the discharge port 59, chips that have entered the cover 51 can be discharged. Further, since the front upper surface 51f is inclined, it is possible to prevent the cover 51 from interfering with the spindle head 5. FIG.

(Embodiment 2)
The present invention will be described below based on the drawings showing a machine tool according to Embodiment 2. FIG. Among the configurations according to the second embodiment, the configurations similar to those of the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted. FIG. 13 is a schematic right side sectional view of the holding device 50A.

The holding device 50A comprises an upper plate 52A and a moving plate 57A. A track 53 is provided on the upper plate 52A. The moving plate 57A has a top plate 57B, and a front plate 57a extends downward from the front edge of the top plate 57B. A holding portion 58 is provided on the front surface of the front plate 57a.

The holding device 50A comprises a cover 51A. The cover 51A is U-shaped in plan view and has a front surface, a left surface and a right surface. The cover 51A covers the front side, left side and right side of the upper plate 52A, the track 53, the slider 54, the rear plate 55, the cylinder 56, the rod 56a, the moving plate 57A and the holding portion 58. The entire bottom surface of the cover 51A is open. The upper plate 52A and the rear plate 55 also function as a cover that covers the track 53, the slider 54, the cylinder 56, the rod 56a and the moving plate 57A, that is, the moving mechanism.

In the second embodiment, since the track 53 is provided on the upper plate 52A, chips do not accumulate around the track 53. FIG. In addition, since the entire lower surface of the cover 51A is open, even if chips enter the cover 51A, they will fall off.

The embodiments disclosed this time should be considered as examples in all respects and not restrictive. The technical features described in each embodiment can be combined with each other, and the scope of the present invention is intended to include all modifications within the scope of the claims and the scope of equivalents to the scope of the claims. be done.

3 support device 50 holding device 51 cover 51f front upper surface (inclined surface)
53 track 54 slider 56 cylinder (driving source)
56b piston (driving source)
56a rod (driving source)
58 holding part 59 outlet W workpiece

Claims (9)

It has a support surface that is swingable about a first axis and rotatable about a second axis perpendicular to said first axis, and is arranged apart in a predetermined direction from a swing/rotation device that supports a workpiece on said support surface. in a holding device comprising :
a holding portion for holding the center of rotation of the work when the axial direction of the second shaft is along the predetermined direction and the work supported on the support surface faces each other;
a moving mechanism for moving the holding portion in the predetermined direction;
and a cover that covers the moving mechanism ,
The moving mechanism is
a track disposed inside the cover;
a slider attached to the holding part and sliding on the track;
a driving source connected to the holding portion;
with
the holding part and the swinging and rotating device face each other in the horizontal direction,
the track is disposed on the lower portion of the cover;
A holding device in which a discharge port for discharging chips is formed between the cover and the raceway . It has a support surface that is swingable about a first axis and rotatable about a second axis perpendicular to said first axis, and is arranged apart in a predetermined direction from a swing/rotation device that supports a workpiece on said support surface. in a holding device comprising:
a holding portion for holding the center of rotation of the work when the axial direction of the second shaft is along the predetermined direction and the work supported on the support surface faces each other;
a moving mechanism for moving the holding portion in the predetermined direction;
a cover that covers the moving mechanism;
with
The moving mechanism is
a track disposed inside the cover;
a slider attached to the holding part and sliding on the track;
a driving source connected to the holding portion;
with
the holding part and the swinging and rotating device face each other in the horizontal direction,
the track is disposed on the lower portion of the cover;
A portion of the upper portion of the cover facing the rocking and rotating device is provided with an inclined surface that descends toward the rocking and rotating device.
holding device. It has a support surface that is swingable about a first axis and rotatable about a second axis perpendicular to said first axis, and is arranged apart in a predetermined direction from a swing/rotation device that supports a workpiece on said support surface. in a holding device comprising:
a holding portion for holding the center of rotation of the work when the axial direction of the second shaft is along the predetermined direction and the work supported on the support surface faces each other;
a moving mechanism for moving the holding portion in the predetermined direction;
a cover that covers the moving mechanism;
with
The moving mechanism is
a track disposed inside the cover;
a slider attached to the holding part and sliding on the track;
a driving source connected to the holding portion;
with
the holding part and the swinging and rotating device face each other in the horizontal direction,
said track is attached to the top of said cover,
The entire bottom surface of the cover is open
holding device. It has a support surface that is swingable about a first axis and rotatable about a second axis that is perpendicular to the first axis, and is arranged apart in a predetermined direction from a swing/rotation device that supports a work on the support surface. in a holding device comprising:
a holding portion for holding the center of rotation of the work when the axial direction of the second shaft is along the predetermined direction and the work supported on the support surface faces each other;
a moving mechanism for moving the holding portion in the predetermined direction;
a cover that covers the moving mechanism;
with
The moving mechanism is
a track disposed inside the cover;
a moving part having one surface and the other surface that intersects with the one surface;
a slider attached to one surface of the moving part and sliding on the track;
a driving source connected to the moving part;
with
The holding part is attached to the other surface of the moving part,
A through hole into which the holding portion is inserted is formed in a portion of the cover that faces the other surface of the moving portion.
holding device. the holding part and the swinging and rotating device face each other in the horizontal direction,
5. A retaining device as claimed in claim 3 or 4, wherein the track is arranged under the cover. The holding device according to claim 5 , wherein a discharge port for discharging chips is formed between the cover and the track. 7. The holding device according to claim 5 , wherein a portion of the upper portion of the cover facing the oscillating and rotating device is provided with an inclined surface that descends toward the oscillating and rotating device. the holding part and the swinging and rotating device face each other in the horizontal direction,
said track is attached to the top of said cover,
5. A holding device according to claim 1, 2 or 4, wherein the entire underside of the cover is open. an oscillating and rotating device that supports a workpiece and is oscillatable about a first axis and rotatable about a second axis perpendicular to the first axis;
A machine tool comprising a holding device according to any one of claims 1 to 8 .

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