JP2000061715A - Tool clamping and unclamping device for main spindle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize clamping/unclamping a tool, tool replacement, and machining in a high speed in all by driving a draw bar in a high speed. SOLUTION: An axial directional clutch mechanism 70 for transmitting forward driving force to a draw bar device by a lever device 39, preventing the transmission of the driving force to a second draw bar driving means 62, and transmitting the forward driving force to the draw bar device by an actuator 30 to the draw bar device, is provided between a first and second draw bar driving means 61 and 62 by axis feeding and oil pressure respectively and the draw bar device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool clamp / unclamp device for a spindle in a machine tool such as a machining center, which clamps / unclamps the tool when the tool is attached / detached to / from the spindle.

[0002]

2. Description of the Related Art Conventionally, the spindle of a machining center or the like has been
A collet device for mounting a tool on the spindle is provided, and the collet device is driven by a draw bar. As for the drawbar driving means for driving the drawbar, there is known a mechanical type that drives the drawbar by axial feed (for example, using a cam lever) when driving the head stock and the like. It is said that the drawbar can be driven at a higher speed than the type in which the drawbar is driven by utilizing hydraulic pressure or air pressure.

[0003]

By the way, in a machining center or the like having a mechanical type drawbar driving means for driving a drawbar by axial feed, a tool mounted on the spindle is manually replaced or removed without automatic tool replacement. As a drawbar driving means in the case of doing, a second drawbar driving means is provided separately from the drawbar driving means. Usually, this second drawbar drive means is adapted to drive the drawbar in a direction parallel to the central axis of the main shaft by means of a hydraulic (or pneumatic) actuator. Therefore, when the draw bar is driven by the mechanical type draw bar driving means during automatic tool change, the second draw bar driving means is also forcibly driven by the mechanical type draw bar driving means along with the operation of the draw bar. As a result, relative movement of the cylinder and the piston occurs in the second drawbar drive means. When the relative movement of the cylinder and the piston occurs in this way, resistance due to the pressure oil (air) in the cylinder occurs, and as a result, high speed driving of the drawbar is impeded.

In view of the above circumstances, the present invention can drive a draw bar at high speed in a machine tool, thereby realizing high-speed clamping / unclamping of a tool, and thus high-speed tool exchange, and high-speed machining. An object of the present invention is to provide a tool clamping / unclamping device for a spindle, which can be used.

[0005]

That is, the first invention of the present invention has a frame (5) in which a headstock (7) is attached to the frame (5) via an axial feed drive mechanism (9). The headstock (7) is provided with a main shaft (12) and a predetermined central axis (CT1).
Is provided so as to be rotatable about an axis, and the main shaft (1
A collet device (17) that can clamp and unclamp the tool (50) at the tip portion (12a) of the spindle (12) is provided in 2), and in the spindle (12),
The collet device (17) is clamped and driven by a reciprocating movement in the first and second directions in the central axis direction with respect to the main shaft (12), and by a moving operation in the first direction. Drawbar device (1) connected to the collet device (17) in such a manner that the collet device (17) can be unclamped by a moving operation in the direction.
8) is provided, and the first drawbar drive means (61) and the second drawbar drive means (62) are provided so that the drawbar device (18) can be moved and driven in the second direction. The means (61) includes an engaging means (46) provided on the frame (5) and an axial direction of the headstock (7) with respect to the frame (5) via the axial feed drive mechanism (9). A lever means (39) which engages with the engaging means (46) to move the drawbar device (18) in the second direction when the drawbar device is moved to a predetermined position (TCP). The second drawbar driving means (62) has an actuator (30) provided on the headstock (7) by a fluid pressure, and drives the actuator (30) to drive the drawbar device (18). Second In a tool clamping / unclamping device (60) for a spindle (12) in a machine tool (1) that is driven to move in a direction, the first drawbar drive means (61) and the second drawbar drive Drive means in the second direction for the drawbar device (18) by means of the lever means (39) is transmitted to the drawbar device (18) between the means (62) and the drawbar device (18), and The drive force is prevented from being transmitted to the second drawbar driving means (62), and the drawbar device (1) by the actuator (30) is prevented.
8) is provided with an axial clutch mechanism (70) for transmitting the driving force in the second direction to the drawbar device (18).

A second aspect of the present invention is the tool clamping / unclamping apparatus according to the first aspect, wherein the axial clutch mechanism (70) is the drawbar device (1).
8) a sleeve (21) inserted into the outer peripheral side of the drawbar device (18) so as to be able to be pressed in the second direction, and
The drawbar device (1) is attached to the actuator (30).
8) has a contact engagement means (22, 26) which is provided so as to be freely engageable in the second direction, and the sleeve (21) is moved by the lever means (39) to the first position. It was engaged with the lever means (39) in such a manner that it could be pressed and driven in the direction of 2.

A third aspect of the present invention is the tool clamp / unclamp apparatus according to the second aspect, wherein the abutting engagement means (22, 26) is the actuator (3).
0), a first abutment engaging portion (22) provided so as to be abuttably engageable with the sleeve (21) in a second direction, and the sleeve (21) with the drawbar device ( 1
8) has a second abutment engaging portion (26) provided so as to be abuttably engageable in the second direction.

The fourth invention of the present invention is the second or third invention.
Tool clamping / unclamping device according to the invention, wherein said lever means (39) and said sleeve (21)
And are engaged via two cam mechanisms (28, 28), each cam mechanism (28) being provided on one of the lever means (39) and the sleeve (21). A cam (42) and a cam groove (27) provided on the other side in a form in which the cam (42) is engaged, and each of the cam mechanisms (28) includes the central shaft (CT1).
Are arranged symmetrically around.

The numbers in parentheses are for convenience of showing the corresponding elements in the drawings, and the present description is not limited to the description in the drawings.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall perspective view showing a machining center adopting an example of a tool clamping / unclamping device according to the present invention, FIG. 2 is a side sectional view showing a headstock and a main shaft, etc. in FIG. 1, and FIG. 2 is an enlarged view of the vicinity of the tool clamp / unclamp device, FIG. 4 is a sectional view taken along line X1-Y1 of FIG. 2, FIG. 5 is a side view of the vicinity of the cam member, and FIG. 6 is a drawbar. FIG. 3 is a diagram showing the vicinity of a tool clamp / unclamp device in a state where is positioned at an unclamp position.

The machining center 1 has a base 2 as shown in FIG. 1, on which a table 3 on which a work can be placed via a pallet or the like is provided. It is provided so as to be movable and driven in the direction (directions of arrows A and B in the figure). Further, a tower-shaped column 5 is movably driven in a predetermined Z-axis direction (direction of arrows E and F in the drawing) which is a horizontal direction perpendicular to the X-axis direction on the base 2, and accordingly, the table 3 is provided. It is provided so that it can approach and retreat. In the column 5, rails 6 and 6 extending in a predetermined Y-axis direction (directions of arrows C and D in the drawing), which is a vertical direction perpendicular to the X-axis direction and the Z-axis direction, are provided at positions facing the table 3 side. Further, a headstock 7 is provided on the column 5 via these rails 6, 6 so as to be movable in the Y-axis direction. The column 5 is provided with a Y-axis driving device 9 such as a ball screw device, and the Y-axis driving device 9 allows the head stock 7 to move freely in the Y-axis direction via the rails 6 and 6. Has become.

The headstock 7 is substantially cylindrical as shown in FIGS. 1 and 2 (for simplification, most of the headstock 7 except the spindle holder 10 is omitted in FIG. 2). Has a main spindle holder 10 in which the installation space 11 is in the Z axis direction (arrows E, F).
Direction), and is formed so as to open to the outside in the direction of arrow E in FIG. The spindle holder 10 is provided with a basically cylindrical spindle 12 extending in the Z-axis direction, which is housed in the installation space 11, via a plurality of bearing devices 13. Therefore, the spindle 12 is , Spindle holder 1
0, the central axis CT1 of the main shaft 12 parallel to the Z-axis direction
The shaft is rotatable in the directions of arrows P and Q in FIG. Further, a motor unit 15 is provided in the installation space 11 between the spindle holder 10 and the spindle 12, and the spindle unit 12 is operated by operating the motor unit 15.
Is driven to rotate about the central axis CT1 with respect to the spindle holder 10 in the directions of arrows P and Q in the drawing.

The front end 12a of the main shaft 12 (the end of the main shaft 12 on the arrow E side) is exposed in the direction of the arrow E from the installation space 11 to the outside of the main shaft holder 10, and the front end 12a is exposed.
A taper-shaped tool mounting hole 16 having a shape that is opened forward (in the direction of arrow E in the figure) is formed in a. For convenience of description, in FIG. 2, the center axis C is shown with respect to the inside of the tool mounting hole 16, the collet device 17 and the drawbar device 18 described later, and the like.
A boundary between the one-dot chain lines in FIG. 2 showing T1 indicates a state where the tool is not mounted on the upper side of the paper and a state when the tool is completed on the lower side of the paper. Further, the tool 50 (a known tool with a pull stud) mounted on the main shaft 12 has a tool main body 51 and a rear end side (arrow F side) of the tool main body 51 as shown in FIGS. The shank 52 is provided with a basically cone-shaped shank 52, and the shank 52 has a pull stud 52a on its rear end side. Therefore, in the portion of the tool mounting state shown in FIG. 2, the tool 50 is mounted such that the shank 52 side of the tool 50 is inserted into the tool mounting hole 16.

Further, the collet device 1 is arranged in the main shaft 12 so as to be adjacent to the rear end side (arrow F side) of the tool mounting hole 16.
7 is provided, and this collet device 17 is of a type (a known type) for clamping and unclamping a tool via a pull stud. That is, the collet device 17 clamps the pull stud 52a of the tool 50 that has been delivered in the form of being inserted into the tool mounting hole 16 and retracts the pull stud 52a rearward (direction of arrow F) to pull the tool 50.
Can be clamped and mounted, and the tool 50 can be unclamped by pushing out the clamped pull stud 52a in the forward direction (direction of arrow E). The collet device 17 is not limited to the type in which a tool is clamped / unclamped via the pull stud as shown in FIG. 2, and is driven by the movement of a draw bar such as a draw bar 19 described later in the Z-axis direction. Any type may be used as long as it is one. For example, a collet device of a type (known type) that clamps / unclamps the tool by engaging / disengaging the spherical engagement member with the engagement groove on the shank side of the tool can be adopted.

Further, a draw bar device 18 is provided in the main shaft 12 so as to be adjacently connected to the rear end side (arrow F side) of the collet device 17. The drawbar device 18 has a cylindrical bar-shaped drawbar 19 that extends in the Z-axis direction (arrow E and F directions) in the main shaft 12, and the collet device 17 is moved by the movement of the drawbar 19 in the Z-axis direction. It is driven. Further, the drawbar device 18 has a plurality of disc springs 20 arranged in the extending direction of the drawbar 19 in a form provided in the main shaft 12, and the disc springs 20 allow the drawbar 1 to be arranged in the main shaft 12.
9 is biased in the direction of arrow F. For example, in the diagram (upper side of the drawing) showing the state when the tool is not attached in FIG. 2, the position of the draw bar 19 is the standby position PT0. Also, FIG.
Showing the state in which the tool 50 has been installed (bottom side of the page)
Then, the drawbar 19 is at the mounting completion position PT1 which is moved slightly forward (direction of arrow E) from the standby position PT0, and the drawbar 19 is pressed backward (direction of arrow F) by the disc spring 20. The clamping and mounting of the tool 50 via the collet device 17 is maintained. That is, the collet device 17 that clamps the tool 50 is pressed rearward (in the direction of arrow F) via the draw bar 19, and thus the shank 52 of the tool 50 is pressed.
Is pressed rearward (in the direction of arrow F) so as to be in close contact with the inner wall of the tool mounting hole 16.

The rear end side of the drawbar 19 (the arrow F side in the figure)
Protrudes to the outside of the main shaft 12 from the rear, and is pivotally supported by the rear end portion 10b of the main shaft holder 10 through the installation space 11 as shown in FIG. In addition, as shown in FIG. 3, a first sleeve 21 basically formed in a cylindrical shape is provided on the outer peripheral side of the drawbar 19 (at the drawbar 19 First sleeve 2
1 is rotatable but the first sleeve 21 is fixed in the rotational direction) and is slidable in the Z-axis direction (arrow E and F directions) with respect to the draw bar 19. It is provided. On the first sleeve 21, a bar pressing surface 22 facing forward in the Z-axis direction (arrow E direction) is annularly formed at a position adjacent to the draw bar 19 (a position near the inner circumference of the first sleeve 21). . On the other hand, a part of the above-mentioned draw bar 19 has a pressure receiving portion 19c with an expanded outer circumference.
Is formed in an annular shape, and the pressure receiving portion 19c and the bar pressing surface 22 of the first sleeve 21 described above are arranged to face each other in the Z-axis direction (arrows E and F directions). Further, a second sleeve 25, which is basically formed in a cylindrical shape, is inserted into the outer peripheral side of the first sleeve 21 in the first sleeve 21 and is in the Z-axis direction (arrow) with respect to the first sleeve 21. It is provided slidably in the E and F directions. On the second sleeve 25, a sleeve pressing surface 26 that faces the Z-axis front (direction of arrow E) is formed annularly at a position adjacent to the first sleeve 21 (a position near the inner circumference of the second sleeve 25). ing.
On the other hand, at the portion near the front end (closer to the end on the arrow E side) of the first sleeve 21 described above, the pressure receiving portion 2 is formed with the outer circumference expanded.
3 is formed in an annular shape, and the pressing receiving portion 23 and the sleeve pressing surface 26 of the second sleeve 25 described above are arranged to face each other in the Z-axis direction (arrow E and F directions).

By the way, as shown in FIGS. 2 and 3, a part of the spindle holder 10 serves as a sleeve enclosing portion 10a in which the outer periphery of the second sleeve 25 is basically abutted and enclosed. The second sleeve 25 includes the sleeve surrounding portion 10.
It is slidable in the Z-axis direction (directions of arrows E and F) with respect to a. The second sleeve 2 is attached to the sleeve surrounding portion 10a.
An annular groove-shaped cylinder 31 is formed at a position adjacent to 5 (a position closer to the inner circumference of the sleeve surrounding portion 10a). On the other hand, in a part of the second sleeve 25, a piston 32 is formed in an annular shape so that the outer circumference is expanded, and the piston 32 is arranged in the cylinder 31. The cylinder 31 is provided with pressure oil supply / discharge means (not shown), and the piston 32 can be pressed and driven via the pressure oil supplied / discharged by the pressure oil supply / discharge means. That is, the cylinder 31, the piston 32, and the second sleeve 25 (that is, the piston rod) constitute a hydraulic actuator 30. As another embodiment, an air pressure actuator or the like may be adopted instead of the hydraulic pressure actuator 30.

As shown in FIGS. 3 and 4, the outer peripheral portion of the first sleeve 21 faces the central axis CT1 at a position rearward of the pressure receiving portion 23 (on the side of arrow F) of the first sleeve 21. Two cam grooves 27, 27 having a width W1 are formed in a concave shape, and the cam grooves 27, 27 are formed on the central axis CT1.
And is formed symmetrically with respect to a plane HM1 (shown by the alternate long and short dash line in FIG. 4) which is perpendicular to the X axis. The portion of the first sleeve 21 in which the above-described cam grooves 27, 27 are formed is arranged so as to project from the second sleeve 25 to the outside rearward (arrow F side) as shown in FIG. The groove 27 is formed with a depth that does not reach the inner peripheral side of the first sleeve 21. Further, the spindle holder 10 has a structure shown in FIG.
Further, as shown in FIG. 4, a lever device 39 is provided, and the lever device 39 includes a lever 40 extending in a substantially vertical direction and a lever 40 in the X-axis direction via a pin 40a parallel to the X-axis direction in the spindle holder 10. A central axis CT2 parallel to the direction is pivotally attached in the directions of arrows R and S in the figure. The portion of the lever 40 below the pin 40a serves as support portions 41, 41, which are bifurcated into an inverted Y-shape and straddle the first sleeve 21 from above. , A cantilevered roller 42 at the forked position
Is supported. Each roller 42 is pivotally attached to each support portion 41 about a rotation axis CT3 parallel to the X-axis direction, and the rollers 42, 42 of the support portions 41, 41 are rotatable.
Are symmetrically formed and arranged about the plane HM1 as shown in FIG. Further, each roller 42 is inserted and arranged in each cam groove 27 of the first sleeve 21 described above. Each set of the cam groove 27 and the roller 42 is a cam mechanism 28, 28 that engages the lever device 39 and the first sleeve 21, respectively. They are arranged symmetrically around the central axis CT1. On the other hand, as shown in FIG. 5, a roller 45 (illustrated by a broken line) is supported in a cantilever manner near the tip of the lever 40 above the pin 40a, and the roller 45 extends in the X-axis direction. Central axis CT4 parallel to
Is pivotally attached to each lever 40 so as to be rotatable about its axis.

As shown in FIG. 2, a return spring 43 urges the lever 40 in the direction of arrow R in the drawing between a predetermined portion of the lever 40 above the pin 40a and the headstock 7. It is provided in the shape. On the other hand, in the column 5 above the head stock 7, as shown in FIG. 5, there is provided a substantially plate-shaped cam member 46 perpendicular to the X-axis direction (the cam member 46 appears in FIG. 1). Not), cam member 4
A cam groove 47 is formed on one plate surface side of 6 in such a manner as to be bent and extended in the vertical direction. The cam groove 47 opens to the outside below the cam member 46 via a roller receiving port 47a which is an opening. The lever device 39 and the cam member 46 described above constitute the first drawbar drive means 61 for driving the drawbar device 18 by utilizing the axial feed of the head stock 7, and the actuator 30 described above has a hydraulic pressure. Is the second drawbar driving means 62 for driving the drawbar device 18. The axial pressing mechanism 70 is formed by the sleeve pressing surface 26 formed on the first sleeve 21 and the second sleeve 25 described above.
The first and second drawbar driving means 61, 62, the axial clutch mechanism 70, the drawbar device 18, and the collet device 17 can clamp and unclamp the tool 50 with respect to the spindle 12. A tool clamp / unclamp device 60 is configured.

Since the machining center 1 and the like are constructed as described above, the machining of the workpiece by the machining center 1 is such that the table 3 is moved in the X-axis direction and the column 5 is moved in the Z-axis direction with respect to the base 2. At the same time, by moving and driving the head stock 7 in the Y-axis direction with respect to the column 5 via the Y-axis drive device 9, a work (not shown) installed on the table 3 and the head stock 7 are provided. A tool 50 mounted on the spindle 12 by rotating the spindle 12 in the directions of arrows P and Q in the drawing through the motor unit 15 while changing the relative positional relationship with the spindle 12 in a three-dimensional manner. Is rotated to cut the work. Further, usually, during such processing, tool exchange by automatic tool exchange is performed. Hereinafter, tool exchange by automatic tool exchange in the machining center 1 (or tool attachment to the spindle 12 with no tool attached)
The procedure will be described.

The tool 50 is attached to the spindle 12 before the tool change.
In the state where the tool is completely attached, the draw bar 19 is at the attachment completion position PT1 as shown on the lower side of the paper surface of FIG. 2, and the first sleeve 21 has its bar pressing surface 22 as shown in FIG. , The second sleeve 25, which is arranged close to the press receiving portion 19c of the draw bar 19.
Is arranged such that the sleeve pressing surface 26 is close to the pressing receiving portion 23 of the first sleeve 21. In this state, as shown in FIGS. 2 and 3, the actuator 30
In, the piston 32 formed on the second sleeve 25 is arranged at the rear end side (direction of arrow F) in the cylinder 31. When the spindle 12 is in a state where no tool is attached, the drawbar 19 is at the standby position PT0 as described above, but the position of the drawbar 19 is slightly different between the standby position PT0 and the attachment completion position PT1. Since it is only, drawbar 19, first sleeve 21,
The positional relationship between the second sleeves 25 and the actuator 3
The relative positional relationship between the cylinder 31 and the piston 32 at 0 is substantially the same as in the case where the tool mounting is completed.

Therefore, in order to replace the tool 50 of the spindle 12 described above (or to mount the tool on the spindle 12 in which the tool is not mounted), the headstock 7 is first moved to a predetermined tool replacement position TCP (this embodiment). Then, the headstock 7 is located at a position where the headstock 7 is moved upward in the Y-axis direction to the full extent with respect to the column 5.). Therefore, the headstock 7 is moved to the column 5 by the Y-axis drive device 9.
With respect to the Y-axis direction (upward in the direction of arrow C in the figure). As a result, the lever device 39 provided on the headstock 7 also moves upward in the column 5 in the Y-axis direction, so that the roller 45 of the lever device 39 also moves inside the column 5 in the Y-axis as shown by the alternate long and short dash line in FIG. Move upward in the direction. Further, by driving the head stock 7 to move upward, the roller 45 reaches the cam member 46 in the column 5 and is inserted into the cam groove 47 of the cam member 46 as shown by the chain double-dashed line in FIG. That is, when the roller 45 has not reached the cam member 46 (shown by the one-dot chain line in FIG. 5), the cam member 46 uses the return spring 43 to position the roller 45 and the roller receiving port 47 a of the cam groove 47. Are arranged so as to correspond to the Y-axis direction (directions of arrows C and D). Therefore, when the roller 45 moves upward and reaches the cam member 46, the roller 45 moves from the roller receiving port 47a. Cam groove 4
7 will be inserted upward (direction of arrow C).
Subsequently, the headstock 7 is driven to move upward. Since the roller 45 is inserted in the cam groove 47 at this time, the roller 45 moves upward along the cam groove 47. As shown in FIG. 5, since the cam groove 47 is formed so as to be substantially right above from the bottom to the top, the cam groove 47 is bent obliquely upward and to the right in the plane of FIG. The roller 45, which has moved substantially right above, moves diagonally upward (in the direction of arrow H in FIG. 5). Further, subsequently, the head stock 7 is moved upward to be positioned at a predetermined tool exchange position TCP. In this state, the position of the roller 45 that has moved along the cam groove 47 is more Z than the position before reaching the cam member 46 (illustrated by the one-dot chain line in FIG. 5), as shown by the broken line in FIG. It is positioned at a position moved by a distance L1 in the axial direction (direction of arrow F in the figure).

On the other hand, when the roller 45 moves in the direction of arrow H in FIG. 5 along the cam groove 47 as described above, the lever 40 is arranged with respect to the head stock 7 around the central axis CT2 of the pin 40a. It is driven to rotate in the arrow S direction. As a result, the rollers 42, 42 provided on the support portions 41, 41 of the lever 40 are driven forward in the Z-axis direction (arrow E direction) as shown in FIG. Since each roller 42 is inserted into the cam groove 27 of the first sleeve 21,
When the roller 42 is driven forward in the Z-axis direction, the roller 42 is inserted forward in the cam groove 27 (arrow E side).
The inner wall 27a is pressed forward in the Z-axis direction, thereby driving the first sleeve 21 forward in the Z-axis direction as shown in FIG. Since the cam mechanisms 28, 28 are symmetrically arranged about the central axis CT1, the first sleeve 21 is stably driven in a well-balanced manner. The first sleeve 21 is Z
The first sleeve 2 is driven by being driven forward in the axial direction.
The press receiving portion 19c of the draw bar 19 is pressed forward in the Z-axis direction on the bar pressing surface 22 of the first unit to move the draw bar 19 in the Z direction.
Drives axially forward. In this way, when the headstock 7 is positioned at the tool exchange position TCP (the state shown in FIG. 6), each roller 42 is moved to the state shown in FIG.
Since the state is moved forward by the distance L2 in the Z-axis direction than the state shown in FIG. 7, the draw bar 19 is also moved forward by the distance substantially equal to the distance L2 in the Z-axis direction and placed at the predetermined unclamp position PT2. When the draw bar 19 is arranged at the unclamp position PT2, the draw bar 19 drives the collet device 17, and the tool 50 clamped by the collet device 17 is unclamped and pushed forward (the collet device 17 is pressed). The operation mechanism and operation method are publicly known and will not be described).

As described above, the first drawbar driving means 6
When the draw bar 19 is driven forward in the Z-axis direction by 1, the pressing receiving portion 23 of the first sleeve 21 moves in the direction away from the sleeve pressing surface 26 of the second sleeve 25 in the arrow E direction. Second sleeve 25 in the direction
Is not driven movably, so that there is no movement of the piston 32 in the cylinder 31 of the actuator 30. That is,
When the drawbar 19 is driven by the first drawbar driving means 61, the movement of the actuator 30 of the second drawbar driving means 62 is prevented by the axial clutch mechanism 70, so that resistance due to pressure oil or the like in the cylinder 31 does not occur and the drawbar 19 moves. Driving can be performed quickly with a small force.

As described above, the headstock 7 is positioned at the tool exchange position TCP, and accordingly, the collet device 17 is driven through the draw bar 19 to unclamp the clamped tool 50 and push it forward. In this state, a known automatic tool changer (AT
(C device) removes the tool 50 from the spindle 12 and transfers another tool to the spindle 12 (when the spindle 12 is in a state where the tool is not installed, the tool 50 is not removed and the automatic tool changer is used). Only the delivery of tools). When the delivery of the tool is completed, the head stock 7 is moved and driven toward a predetermined standby position for performing the subsequent processing. Therefore, the head stock 7 is driven to move downward in the Y-axis direction with respect to the column 5. As a result, the lever device 39 provided on the headstock 7 also moves inside the column 5
Therefore, the roller 45 of the lever device 39 moves diagonally downward along the cam groove 47 of the cam member 46 and then moves downward in the Y-axis direction to move downward in the Y axis direction.
It moves from a to the outside of the cam groove 47. In this way, when the roller 45 is disengaged from the cam groove 47, the lever 40 is
As shown in FIG. 3, it is rotationally driven in the direction of arrow R (at this time, the lever 40 is rotated in the direction of arrow R by being pulled by the return spring 43 provided between the lever 40 and the headstock 7. The drive is reliable and quick).

As described above, when the lever 40 is rotationally driven in the direction of arrow R, the rollers 42, 42 provided on the supporting portions 41, 41 of the lever 40 are driven rearward in the Z-axis direction. Each roller 42 presses the rear (arrow F side) inner wall 27b in the cam groove 27 in which the roller 42 is inserted rearward in the Z-axis direction, thereby driving the first sleeve 21 rearward in the Z-axis direction. By driving the first sleeve 21 rearward in the Z-axis direction, the bar pressing surface 22 of the first sleeve 21 moves in the direction away from the press receiving portion 19c of the drawbar 19 rearward in the Z-axis direction. It is driven rearward in the Z-axis direction while being pressed by the disc spring 20. In this way, the draw bar 19 is again moved to the mounting completion position PT1 shown in FIGS. 2 and 3. In addition, the collet device 17 is driven by driving the draw bar 19 rearward in the Z-axis direction.
Was driven, the tool delivered to the collet device 17 was clamped, and the collet device 17 was pulled backward and the attachment to the spindle 12 was completed.

Even in the step of driving the drawbar 19 by the first drawbar driving means 61 to clamp and attach the delivered tool to the spindle 12, the first sleeve 21 and the second sleeve 25 interfere with each other in the Z-axis direction. I don't
The second sleeve 25 is not moved and driven in the Z-axis direction,
Therefore, the actuator 30 of the second drawbar driving means 62
There is no movement of the piston 32 in the cylinder 31 at. That is, since the actuator 30 does not move, resistance due to pressure oil or the like does not occur and the draw bar 19 can be driven quickly with a small force. The above is the description of the procedure of tool exchange (or tool attachment to the spindle 12 in which no tool is attached) by automatic tool exchange in the machining center 1.

By the way, the machining center 1 has a spindle 1
The tool 50 mounted on the No. 2 may be manually removed or replaced without using the automatic tool change. In this case, the headstock 7 is moved to the tool change position TC described above.
After stopping at a position other than P, the tool is replaced (or removed) as follows by using the second drawbar driving means 62. First, by driving the actuator 30, the piston 32 is moved forward in the Z-axis direction in the cylinder 31, and thus the second sleeve 25 is moved forward in the Z-axis direction with respect to the head stock 7.
Then, the first sleeve 21 is moved forward in the Z-axis direction such that the pressure receiving portion 23 is pushed forward in the Z-axis direction by the sleeve pressing surface 26 of the second sleeve 25. Therefore, the bar-pressing surface of the first sleeve 21 is driven. The draw receiving member 19c of the draw bar 19 is pressed forward by the Z-axis in the Z-axis direction to move the draw bar 19 forward in the Z-axis direction to the unclamp position PT2. As a result, the collet device 17 is driven to unclamp the clamped tool 50 and push it forward. In this state, the operator manually removes the unclamped tool 50, and instead, delivers another tool to the collet device 17 (or only removes the tool 50), and then the actuator 30 is removed. By driving, the piston 32 is moved rearward in the cylinder 31 in the Z-axis direction (direction of arrow F in the figure), and therefore the second sleeve 25 is moved rearward in the Z-axis direction with respect to the head stock 7. Then, the drawbar 1 is pressed backward by the disc spring 20 in the Z-axis direction.
9 is a form in which the first sleeve 1 is pushed back rearward in the Z-axis direction via the pressure receiving portion 19c, and is moved and driven rearward in the Z-axis direction along with the second sleeve 25, and the mounting completion position shown in FIGS. Return to PT1. In addition, as the draw bar 19 is moved rearward in the Z-axis direction to the mounting completion position PT1 in this way, the collet device 17 is moved.
It was driven in such a manner that the tool delivered to the spindle was clamped and the tool was pulled into the spindle mounting hole 16, so that the tool was completely mounted on the spindle 12. When the drawbar 19 is driven by the second drawbar driving means 62 as described above, the first sleeve 21 is moved and driven in the Z-axis direction, and therefore the first sleeve 21 and the cam mechanisms 28, 28 are engaged. The combined lever device 39 is also driven to rotate in the directions of the arrows R and S in the figure, but since the head stock 7 is arranged at a position other than the tool exchange position TCP described above, the lever is arranged in the column 5. There is nothing other than the return spring 43 that restrains the device 39, and there is no hindrance to the movement of the lever 40 and the like.

As described above, the machining center 1
Then, in the tool clamping / unclamping device 60 for clamping / unclamping a tool to / from the spindle 12, at the time of automatic tool replacement, the drawbar 19 is driven via the first drawbar driving means 61 by utilizing the axial feed of the headstock 7. The drawbar 19 is driven at high speed. Further, when the first drawbar driving means 61 is driven, the movement of the actuator 30 of the second drawbar driving means 62 is prevented by the axial clutch mechanism 70, so resistance due to pressure oil does not occur, and high speed driving of the drawbar 19 is hindered. There is no such thing. As a result, in the machining center 1, high-speed clamping / unclamping of tools, and thus high-speed tool exchange, can be realized, and high-speed machining can be realized.

In the above-mentioned embodiment, the tool clamping / unclamping device adopted in the machining center 1 has been described as an example, but the tool clamping / unclamping device of the spindle according to the present invention is adopted in a machine tool other than the machining center. Alternatively, for example, the tool may be adopted in an NC lathe of a type in which a tool is attached to and detached from a tool spindle by using an ATC device. Further, the axial clutch mechanism does not necessarily have to be configured to have the first sleeve 21. For example, the draw bar 19 and the lever device 39 may be directly engaged with each other, and the second sleeve 25 of the actuator 30 and the draw bar 19 may be directly engaged with each other. In the embodiment described above, in the cam mechanism 28, the cam groove 27 has the first sleeve 21.
On the side, the roller 42 is provided on the lever device 39 side, but it is also possible to provide the cam groove 27 on the lever device 39 side and the roller 42 on the first sleeve 21 side.

[0031]

As described above, the first aspect of the present invention has a frame such as a column 5 in which a headstock such as a headstock 7 is fed to the frame and a shaft feed such as a Y-axis driving device 9 is performed. The headstock is provided with a main shaft such as a main shaft 12 so as to be movable and driven in a predetermined axial direction via a drive mechanism so as to be rotatable about an axis about a predetermined central axis such as a central axis CT1. Provided inside the main shaft is a collet device such as a collet device 17 capable of clamping and unclamping a tool such as the tool 50 at the front end portion such as the front end portion 12a of the main shaft. The collet device is reciprocally movable in the first and second directions in the axial direction, and the collet device is clamp-driven by the moving operation in the first direction, and the collet device is moved by the moving operation in the second direction. In a form that can be unclamped drives, the drawbar is connected to the collet device 18
And the like, and a first drawbar drive means 6
A first drawbar driving means such as 1 and a second drawbar driving means such as a second drawbar driving means 62 are provided so that the drawbar device can be moved and driven in the second direction, and the first drawbar driving means includes: When the engaging means such as a cam member 46 provided on the frame and the head stock are axially moved and driven with respect to the frame via the axial feed drive mechanism to a predetermined position such as a tool exchange position TCP. To engage the engaging means with the second drawbar device.
Has a lever means such as a lever device 39 for moving and driving in the direction of, and the second drawbar drive means has an actuator such as an actuator 30 by fluid pressure provided in the head stock, and drives the actuator. Thus, in a tool clamp / unclamp device for a spindle in a machine tool configured to move and drive the drawbar device in a second direction, the first drawbar driving means, the second drawbar driving means, and the second drawbar driving means. Between the drawbar device and the lever means, the driving force to the drawbar device in the second direction is transmitted to the drawbar device, and the driving force is prevented from being transmitted to the second drawbar driving device. The drive force of the actuator in the second direction with respect to the drawbar device is applied to the drawbar device. It constituted by providing an axial clutch mechanism 70 such as an axial clutch mechanism for transmitting. Therefore, according to the tool clamp / unclamp device of the present invention, when the automatic tool is changed, the drawbar device is driven by the first drawbar driving means by utilizing the axial feed of the head stock through the axial feed drive mechanism. Not only is the drawbar device driven at high speed,
When the drawbar device is driven by the first drawbar driving means, transmission of the driving force to the second drawbar driving means is prevented by the axial clutch mechanism, and movement of the actuator is prevented, so that resistance due to fluid pressure is applied to the actuator. Does not occur and does not hinder high speed driving of the drawbar device. As a result, high-speed clamping / unclamping of the tool, and thus high-speed tool exchange, can be realized, and high-speed machining can be realized.

A second aspect of the present invention is the tool clamp / unclamp apparatus according to the first aspect, wherein the axial clutch mechanism is configured to be capable of pressing the drawbar device in a second direction. A sleeve pressing surface 22 and a sleeve pressing surface 2 provided on the sleeve such as the first sleeve 21 and the like inserted in the outer peripheral side of the actuator and the actuator so as to be abuttable and engageable with the drawbar device in the second direction.
6 has a contact engagement means such as 6, and the sleeve is engaged with the lever means in such a manner that it can be pressed and driven in the second direction by the lever means. By adopting a sleeve centered on the central axis as in the drawbar device, the axial clutch mechanism is convenient because its structure and arrangement with respect to the drawbar device are simple.

A third aspect of the present invention is the tool clamp / unclamp apparatus according to the second aspect, wherein the abutment engagement means abuts the actuator in the second direction with respect to the sleeve. A first contact engagement portion such as a bar pressing surface 22 that is provided so as to be engageable, and a sleeve pressing surface that is provided in the sleeve so as to come into contact with and engage with the draw bar device in a second direction. Since the second contact engaging portion such as 26 is provided, in addition to the effect according to the second invention, the contact engaging means provided in the actuator does not have to be provided in a position separate from the sleeve, and accordingly, the space is increased accordingly. Can be saved and the tool clamping / unclamping device can be made compact.

The fourth invention of the present invention is the second or third invention.
In the tool clamping / unclamping device according to the invention, the lever means and the second sleeve are provided with a cam mechanism 2
8 and the like via two cam mechanisms, and each cam mechanism is engaged with a cam such as a roller 42 provided on one of the lever means and the sleeve, and the cam. It is configured by a cam groove such as a cam groove 27 provided on the other side in a curved shape, and the cam mechanisms are symmetrically arranged about the central axis. Therefore, according to the second or third invention. In addition to the effect, the driving force transmitted to the sleeve via the two cam mechanisms is applied symmetrically around the central axis, so the sleeve is stably driven in a balanced manner, and the tool clamp / smooth operation is smooth. An unclamping device is realized.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing a machining center adopting an example of a tool clamping / unclamping device according to the present invention.

FIG. 2 is a side sectional view showing a headstock, a main shaft and the like in FIG.

FIG. 3 is an enlarged view of the vicinity of the tool clamp / unclamp device in FIG.

4 is a sectional view taken along line X1-Y1 of FIG.

FIG. 5 is a side view showing the vicinity of a cam member.

FIG. 6 is a diagram showing the vicinity of the tool clamp / unclamp device in a state where the draw bar is located at the unclamp position.

[Explanation of symbols]

1 ... Machine tool (machining center) 5 ... Frame (column) 7 ... Headstock 9 ... Shaft feed drive mechanism (Y-axis drive device) 12 ... Spindle 12a ... Tip (front end) 17 ... Collet Device 18 Drawbar device 21 Sleeve (first sleeve) 22 Abutment engagement means, first abutment engagement portion (bar pressing surface) 26 Abutment engagement means, second abutment means Contact engagement part (sleeve pressing surface) 27 ... Cam groove 28 ... Cam mechanism 30 ... Actuator 39 ... Lever means (lever device) 42 ... Cam (roller) 46 ... Engagement means (cam member) 50 …… Tool 60 …… Tool clamp / unclamp device 61 …… First drawbar driving means (first drawbar driving means) 62 …… Second drawbar driving means (second drawbar driving means) 70 …… Axial clutch mechanism T1 ...... central axis TCP ...... position (tool change position)

Claims (4)

[Claims] 1. A head stock is provided on the frame so as to be movable and driven in a predetermined axial direction via an axial feed drive mechanism, and a spindle is provided in the head stock around a predetermined central axis. Provided so as to be rotatably driven, a collet device capable of clamping and unclamping a tool at the tip of the spindle is provided in the spindle, and a collet device in the spindle in the central axis direction with respect to the spindle is provided. 1
And reciprocally movable in a second direction, and in a form capable of clamping and driving the collet device by a moving operation in a first direction and unclamping the collet device by a moving operation in a second direction, A drawbar device connected to the collet device is provided, first drawbar driving means and second drawbar driving means are provided so that the drawbar device can be moved and driven in a second direction, and the first drawbar driving means is Engaging means provided on the frame and engaging means with the engaging means when the head stock is axially moved to a predetermined position with respect to the frame through the axial feed drive mechanism. A lever means for moving and driving the drawbar device in a second direction, wherein the second drawbar driving means is a fluid provided on the headstock. A tool clamp / unclamp device for a spindle in a machine tool having an actuator according to claim 1, wherein the drawbar device is moved and driven in a second direction by driving the actuator. Means and the second drawbar driving means and the drawbar device, the driving force in the second direction for the drawbar device by the lever means is transmitted to the drawbar device, and the driving force is the second force. Of the main spindle tool clamp, which is configured to prevent transmission to the drawbar drive means of the main shaft and to transmit the driving force of the actuator in the second direction to the drawbar device to the drawbar device. Unclamping device. 2. The axial clutch mechanism includes a sleeve inserted into the outer peripheral side of the drawbar device so as to press the drawbar device in a second direction, and the actuator and the drawbar device with respect to the drawbar device. A contact engagement means provided so as to be capable of contact engagement in the second direction, and the sleeve engages with the lever means in a form that can be pressed and driven in the second direction by the lever means. The tool clamping / unclamping device for a spindle according to claim 1, characterized in that. 3. The abutment engagement means includes a first abutment engagement portion provided on the actuator so as to be abuttably engageable with the sleeve in a second direction, and the sleeve, The tool clamping / unclamping device for a spindle according to claim 2, further comprising a second abutment engaging portion which is abuttably engageable with the drawbar device in a second direction. 4. The lever means and the sleeve are engaged with each other via two cam mechanisms, and each of the cam mechanisms includes a cam provided on one of the lever means and the sleeve. 3. The cam mechanism is constituted by a cam groove provided on the other side in the engaged state, and the cam mechanisms are symmetrically arranged about the central axis. Alternatively, the tool clamping / unclamping device for the spindle as described in 3).