JPH10151538A - Fastener for attachment for machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fastener for an attachment for a machine tool capable of easily and elastically clamp an attachment main body on a spindle head by clamping of a shank part installed on a spindle. SOLUTION: A disc spring 39 is interposed between a bevel gear 36 for rotation of a tool spindle axially supported in the center of an attachment main body 26 and a spline shaft 34 projected from a lower surface of a shank 30 of an attachment installed on a spindle 22 and inserted into the center of the bevel gear 36, this disc spring 39 is compressed at the time of pulling up the shank 30 by a collet 25, a coupling 29 of the attachment main body 26 is engaged by springing force of a spring, a clamp arm 83 is made free to oscillate, an upper end clamp click 83c is engaged with an upper surface of an inner peripheral collar 21a by a disc spring 85, and fixing of the shank to a spindle tapered hole and fixing of the attachment to a spindle head is carried out by one motion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an attachment to be attached to a spindle head of a machining center.

[0002]

2. Description of the Related Art Conventionally, this type of attachment is generally large and cannot be accommodated in a tool magazine. A mounting table is provided separately from the tool magazine. It was moved to the position of the mounting table and was mounted. At the time of mounting on the spindle head, as shown in FIG. 6, the piston 9 of the fluid pressure cylinder device on the spindle head side is attached to the jaw 92 of the large diameter coupling 91 provided on the attachment.
It has been known to engage an L-shaped hook 94 at the three ends and pull up and clamp by a piston 93.

[0003]

The large attachment described in the prior art has a problem that the structure is complicated because a hydraulic cylinder is disposed on the spindle head side and hydraulic piping is required, and the piping equipment is expensive and expensive. Had. In addition, replacement of the attachment requires a separate table, which requires an installation place, and is subject to restrictions such as interference. If you try to use the automatic tool change arm to exchange this attachment, the dimensions of the gripping part of the exchange arm can be changed only for the attachment with the same dimensions as the tool, and the overall dimensions are limited, and the internal components are reduced in size. However, there is a problem that the attachment has a small processing ability.

The present invention has been made in view of these problems of the prior art, and has as its object to provide a special device such as a hydraulic piston for attaching a relatively large attachment to a spindle head. An object of the present invention is to provide an attachment fastening device for a machine tool which can easily and automatically clamp a powerful clamp without using it.

[0005]

SUMMARY OF THE INVENTION An attachment fastening device for a machine tool according to the present invention is a cutting tool which is fitted to the tip of a spindle head of a machine tool such as a machining center which pulls up a tool via a collet with a draw bar inserted through the center of the spindle. In the attachment to be machined, an attachment body provided with a mating coupling on the upper end face that engages with the inner peripheral flanged coupling on the lower end face of the spindle head, a pull stud gripped by a collet at the upper end, and a spindle drive key at the lower end A small diameter shaft having a member that is notchable and has a member that can move in the axial direction with respect to the attachment body and that bears the weight of the attachment body at the shaft end is provided at the center of the lower end. Member to be attached and attached to the attachment body weight receiving member of the small diameter shaft A first elastic member interposed between the attachment main body and the urging member in a direction to pull up the attachment main body, and a center line of the attachment main body provided at a plurality of locations on an inner circumference of a mating coupling on an upper end surface of the attachment main body. The other arm facing the center of the attachment body and having a clamp claw at the tip of one arm that can swing and face upward in a plane including the upper surface of the inner peripheral flange of the coupling. L-shaped clamp arms whose upper end faces abut against the lower surface of the flange portion of the shank member, and a plurality of forces urging the clamp claws of each of the L-shaped clamp arms to always engage with the inner peripheral flange portion. A second projectile member which is weaker than the first projectile member, wherein when the attachment is mounted on the main shaft, the coupling is engaged and the clamp pawl is coupled. So as to engage the inner peripheral flange portion, in which disengaging the clamp jaws of the L-shaped clamp arm by lowering the shank member by releasing the pulling collet.

According to the attachment device for a machine tool attachment configured as described above, the pull-stud is simply gripped and pulled up by the collet in the spindle so as to mount a normal tool, and the attachment is provided by the first elastic member. Is pressed against the large-diameter first coupling at the tip of the spindle head, and the clamp claw automatically engages with the upper surface of the inner peripheral flange of the first coupling on the spindle head side, The attachment is clamped to the spindle head with a force that does not move even with a large cutting force.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of a machining center,
2 is an explanatory view of a tool magazine and a replacement arm of a machining center, FIG. 3 is a cross-sectional view showing a state where an attachment is attached to a spindle head, FIG. 4 is a partially enlarged portion of FIG. 3 showing a clamp arm, and FIG. FIG. 9 is a top view mainly illustrating a state where the clamp arm is provided when the clamp arm is not mounted on the spindle head.

In the machining center shown in FIG. 1, a table 2 is mounted on a bed 1 installed on a floor so as to be movable and positioned in the X-axis (front-back) direction. A column 3 is erected on the floor on both sides of the bed 1, and a top beam 4 is fixed on the column 3. The column 3 has a W-axis (up and down) guide on the front surface, and a cross rail 5 is mounted on the W-axis guide so as to be movable and positionable. Cross rail 5
Has a guide in the Y-axis (left / right) direction on the front surface, and a spindle head 6 is mounted on the Y-axis guide so as to be movable and positionable.
The main shaft ram 7 is provided so as to be movable and positioned in the Z-axis (vertical) direction.

An attachment 8 is removably attached to the tip of the spindle ram 7, and a tool magazine device 9 that can store the attachment together with tools is provided at the left end of the left column 3. An exchange arm unit 11 is provided at the lower left portion of the cross rail 5 so as to be pivotable on the tool magazine side and the main spindle side in a horizontal plane, to be able to pivot the arm pivot axis horizontally and vertically, and to be able to move horizontally linearly. Replacement arm unit 11
Are tool grippers A1, corresponding to V-shaped grip grooves of tools having different grip diameters and V-shaped grip grooves of attachments.
A twin-arm composite exchange arm 12 having A2 and attachment grippers B1 and B2 symmetrically about
At C, it is possible to index the rotation around the rotation center axis 52 and to move and position in the direction of the rotation center axis.

In FIG. 2, a large attachment 8 having the same shank size as a normal tool is housed in a tool magazine 9 in addition to a normal tool. An exchange arm unit 11 that can rotate and axially move a tool and an attachment 8 between the tool magazine 9 and the spindle head 6 has a pair of centrally symmetric tool exchanges used when exchanging a normal tool. B1 for exchanging attachments used for exchanging and transporting attachments 8 having grip dimensions different from those of ordinary tools, in addition to the grippers A1 and A2.
And an attachment indexing gripper B2 used to index the attachment 8 at the position of the spindle head 6.
And a composite exchange arm 12 having a total of four grippers formed as a pair symmetrically with each other.

Although not shown, a gripping tool and an auxiliary finger that opens and closes to prevent the attachment from falling off are provided at the tip of each gripper. A pair of tool exchange grippers A1 and A2 and an attachment exchange gripper B
1 is provided with detents 14 for preventing rotation of the tool and the attachment 8, respectively, so that the tool and the attachment 8 do not shift during transport. However, attachment indexing gripper B2
Since the entire attachment needs to be rotated in the gripper, no detent claw is attached, and the auxiliary finger is not strongly tightened when gripping the attachment.

In FIG. 3, a spindle ram 7 is provided in the spindle head 6 so as to be movable in the axial direction of the spindle, and a large-diameter coupling 21 for fixing the attachment 8 is provided at a lower end surface of the spindle ram 7. The coupling 21 is provided integrally with an inner peripheral flange 21a that engages with a clamp claw described later.

A spindle 22 having a through hole in the spindle ram 7
Are rotatably supported by bearings 23. Spindle 2
The tip of the second through hole 22a is formed in a taper capable of receiving the shank portion of the tool. A draw bar 24 operated by a fluid pressure cylinder device (not shown) is inserted into the through hole of the main shaft 22 so as to be movable in the axial direction. The pull stud 31 is engageable with the tip of the draw bar 24 and fixed to the tool shank. Is provided.

The attachment 8 has a gripping V-shaped groove having a large size different from the V-shaped groove for gripping a normal tool on the outer periphery of the main body 26.
A shape groove 26a is cut and receives the attachment grippers B1 and B2. Further, a key groove 27 for engaging with the claw 14 of the attachment replacement gripper B1 is formed in the V-shaped groove 26a. A large-diameter coupling 29 that meshes with a large-diameter coupling 21 provided on the lower surface of the main spindle ram 7 is attached to a surface of the main body 26 of the attachment 8 facing the main spindle ram 7. The attachment 8 has a shank portion 30 that fits into the tapered hole 22b of the spindle 22 when attached to the spindle head 6, and a pull stud 31 that is gripped by a collet 25 that is engaged with the draw bar 24.

On the lower end surface of the flange 32 of the shank portion 30, a small-diameter coupling 33 concentric with the large-diameter coupling 29 is formed. At the center of the lower end surface of the shank portion 30, a spline shaft 34 having a small diameter 37 at the tip end is protruded integrally, and a female shaft of a bevel gear 36 is rotatably supported by a bearing 35 at the center of the attachment body 26. Spline and spline fit. The bevel gear 36 and the spline shaft 34
The bevel gear 36 and the attachment body 26 and the shank 30 are provided by a disc spring 39 interposed between the collar 38 fixed to the end of the small diameter portion 37 and fastened with a nut.
And the spline shaft 34 is urged in a projecting state so as to always approach the spline shaft 34.

A small-diameter coupling 40 that meshes with a small-diameter coupling 33 engraved on the lower surface of the flange 32 is attached to the surface of the attachment body 26 facing the end surface of the flange 32. There is a step between the meshing position of the large-diameter couplings 21 and 29 and the meshing position of the small-diameter couplings 33 and 40. When the large-diameter coupling is engaged when the attachment is attached to the main shaft, the small-diameter coupling does not mesh. In the attachment body 26, a tool spindle 42 having a bevel gear 41 meshing with the bevel gear 36 has a bearing 43 at an angle with the axis of the spindle 22.
It is rotatably supported by. The angle formed by the tool spindle 42 and the spindle is a right angle in this embodiment, but is not limited thereto.

A drive key 44 is attached to the tip end surface of the main shaft 22 to reliably transmit the rotation of the main shaft 22 to the tool, and can be fitted with a key groove 45 cut out on the flange 32 of the shank portion 30. It is. Then, the pull stud 31 is released from the collet 25, the shank portion 30 approaches the attachment main body 26 by the disc spring 39, and the small-diameter couplings 33 and 40 are engaged with each other. After that, the attachment main body 26 is separated from the main shaft ram 7 to have a large diameter. Even when the couplings 21 and 29 are disengaged and a slight gap is formed between both ends of the couplings 21 and 29, the drive key 44 still maintains the engagement state with the key groove 45 of the flange 32. It extends long in the direction of the main shaft axis.

4 and 5, the attachment body 2
In this example, a plurality of notches 29a, two sets in total, four notches 29a are formed at centrally symmetrical positions of the lower end surface of the large diameter coupling 29 attached to the upper end surface of the 6 and the inner peripheral surface following the lower end surface. A clamp claw member 80 is attached to each notch 29a symmetrically with respect to the center. A bracket 82 of the clamp claw member 80 is fixed to the notch 29a of the large diameter coupling 29 so as to protrude inward by a plurality of bolts 81. An L-shaped clamp arm 83 is attached to the bracket 82 by a pivot pin 84. The attachment body 26 is provided so as to be swingable in a plane including the center line.

In the L-shaped clamp arm 83, an arm 83a facing upward and an arm 83b facing laterally, that is, toward the center of the attachment body, are integrally formed substantially at right angles.
The upper end of one arm 83a has a clamp claw 83c that removably engages with the upper surface of the inner peripheral flange 21a of the large diameter coupling 21 fixed to the tip of the ram 7, and the other arm 83b has A contact surface 83e that contacts the lower end surface of the flange 32 is formed on the upper surface of the distal end portion.

Further, a blind hole 26b is formed vertically below the tip of the other arm 83b of each L-shaped clamp arm 83 in the attachment body 26 from above, and an upper end surface is formed in the blind hole 26b as a spherical surface. A head spring 86 is inserted so as to be vertically movable, and a disc spring 85 whose total thrust at four locations is smaller than the thrust of the disc spring 39 between the step end surface of the head pin 86 and the bottom of the blind hole 26b. The L-shaped clamp arm 83 is interposed, and is urged by a disc spring 85 in a direction in which the clamp claw 83c at the upper end of the one arm 83a can engage with the inner peripheral flange 21a.

Accordingly, the pull stud 31 is released from the collet 25, and the shank 30 approaches the attachment body 26 by means of the disc spring 39 so that the small diameter couplings 33, 4 are provided.
0 engages, the contact surface 83e of the other arm 83b of the L-shaped clamp arm 83 comes into contact with the lower surface of the flange 32 and swings, so that one arm 83a is in a substantially vertical posture, and the clamp claw 83c is connected to the flange 21a. Off the top.

When the pull stud 31 is engaged with the collet 25 and the shank portion 30 is pulled up and the large diameter couplings 21 and 29 are engaged by the force of the disc spring 39, the flange 32
The lower surface is separated from the contact surface 83e, and the L-shaped clamp arm 83 is swung by the disc spring 85, so that one arm 83a is inclined from the substantially vertical position to the outside, and the vertical position of the clamp claw 83c changes at this time. The attachment 8 is engaged by a wedge effect acting to hold down the upper surface of the inner peripheral flange 21a, and the attachment 8 is strongly clamped to the spindle head 6 assuming that the large-diameter couplings 21 and 29 are firmly engaged.

Next, the operation of the embodiment will be described.
When the attachment 8 is housed in the tool magazine 9, the shank portion 30 and the attachment body 26 are brought close to each other by the disc spring 39, and the small-diameter couplings 33, 4 are provided.
0 is maintained in an engaged state, the arm 83a of the L-shaped clamp arm 83 maintains a vertical posture substantially parallel to the center line of the attachment body 26, and the shank portion 30 cannot rotate with respect to the attachment body 26. Accordingly, the tool spindle 42 is not rotated with respect to the attachment main body 26, and the key position of the tool spindle 42 can maintain a fixed positional relationship with the keyway of the flange 32 of the shank 30.

When the attachment 8 is taken out from the tool magazine 9 and transported, the gripper B1 for replacing the attachment of the combined replacement arm 12 of the replacement arm unit 11 is used.
The grip 14 grips the V-shaped groove 26a of the attachment body 26, and at this time, the claw 14 of the gripper B1
The engagement with the key groove 27 cut in the portion prevents the attachment 8 from being displaced in the gripper B1. For this reason, the key groove 45 of the flange 32 of the shank portion 30 is conveyed to the main shaft without being displaced, and the key groove 45 of the flange 32 can be correctly engaged with the drive key 44 of the main shaft 22.

When the attachment 8 is conveyed to the position of the main shaft, the shank portion 30
b, the draw bar 24 is pulled by a disc spring (not shown), and is pulled up to the rear of the main shaft 22.
Is held by the collet 25. At this time, the attachment main body 26 is also pulled up through the disc spring 39 to some extent, but the large-diameter coupling 29 on the attachment main body side is connected to the large-diameter coupling 21 provided on the end face of the spindle ram 7.
At this time, the attachment main body 26 is fixed, and the pulling up is prevented.

In this state, when the pull stud 31 is further pulled up and both the shank portion 30 and the flange 32 are pulled up, the disc spring 39 is compressed by the collar 38 attached to the small diameter portion 37 at the tip of the spline shaft 34. Since the attachment body 26 is fixed by meshing the large diameter couplings 21 and 29, the small diameter couplings 33 and 40 are attached.
Is disengaged. As a result, the contact surface 83e of the L-shaped clamp arm 83 is released from the lower surface of the flange 32, and one arm 83a facing upward swings by the force of the disc spring 85 to change from a substantially vertical posture to an inclined posture, and the clamp pawls become inclined. 83c is engaged with the upper surface of the inner peripheral flange 21a of the large coupling 21, and the engagement of the large couplings 21 and 29 is strengthened by a wedge effect utilizing a change in the vertical position of the clamp claw 83c at this time. I do.

Thereafter, the pulling is completed when the shank portion 30 is pressed against the inner surface of the tapered hole 22b at the tip end of the main shaft 22. At this time, since the disc spring 39 is compressed and deflected, the spring force is transmitted to the contact surfaces of the large-diameter couplings 29 and 21 through the bevel gear 36 and the bearing 35, and the attachment body 26 is strongly pressed to the main shaft ram 7. However, a strong pressing force by the clamp claw 83c is applied to this, and a large clamping force that can withstand strong cutting without requiring other elements such as a hydraulic mechanism is obtained.

Next, a method of indexing the attachment body 26 will be described. Spindle head 6 and exchange arm unit 11
Is positioned at the tool change position, and the turning servomotor is driven by the command of the NC device to turn the composite changing arm 12 so that the attachment indexing gripper B2 having no detent key has the V-shaped groove 2 of the attachment body 26.
6a is gripped.

Drawbar 2 pulled up by a spring
4 is advanced by a fluid pressure cylinder device (not shown) to release the grip of the pull stud 31 by the collet 25 and release the engagement of the clamp claw 83c. At the same time, the insertion / removal servomotor is driven by the command of the NC device, and the composite exchange arm 12 is moved by the first-stage extraction operation in the main shaft axis direction to disengage the large diameter couplings 21 and 29.

At this time, the moving distance is large coupling 2
It is assumed that the distance between the front ends of the first and the 29th has a slight gap. The shank portion 30 is drawn to the attachment main body 26 by the disc spring 39, and the small diameter coupling 33,
As a result, the engagement of the clamp claws 83c is released.

However, the drive key 44 attached to the tip of the main shaft 22 is still in a state of being engaged with the key groove 45 of the flange 32. In this state, if the spindle 22 is rotated by a servo motor (not shown) at a predetermined angle in accordance with an NC command, the rotation is transmitted to the drive key 44, the flange 32, the small diameter couplings 33 and 40, and the attachment body 26, and the rotation is transmitted to the inside of the gripper B2. The entire attachment 8 is indexed.

After the completion of the indexing, the servo motor for insertion / removal is driven to move the composite exchange arm 12 and the gripper B2 toward the spindle head 6 in the first step insertion operation, and the large-diameter coupling 2
When the drawbar 24 is pulled up by a disc spring and the pull stud 31 is gripped and clamped by the collet 25, the attachment 8 is reattached to the spindle head 6, and the engagement of the small-diameter couplings 33 and 40 is established. Then, the clamp claw 83c is engaged with the upper surface of the inner peripheral flange 21a, and the cutting can be resumed.

As another embodiment of the composite exchange arm 12, a claw 14 for preventing rotation of the gripper B1 for attachment exchange is provided.
Can be taken in and out of the gripper by a hydraulic piston, an electromagnetic solenoid, a cam, or the like, so that the attachment replacement gripper B1 can also serve as the attachment indexing gripper B2. In addition, the gripper B2 for indexing the attachment of the composite exchange arm 12
A plurality of rollers can be attached to the inner circumference of the to facilitate the rotation of the attachment.

[0034]

Since the present invention is configured as described above, the following effects can be obtained. According to the first aspect of the present invention, since the first elastic member (disc spring) is incorporated in the attachment main body to urge the shank portion and the attachment main body always in the approaching direction, a tool for attaching the attachment to the spindle head is required. Using the operation of pulling up and clamping, the first body member is flexed to strongly press the attachment body to the main shaft ram by the elastic force of the first body member, and the clamp pawl of the L-shaped clamp arm is connected to the second body. Since the resilient force of the member (disc spring) is used to press and engage the upper surface of the inner peripheral flange on the spindle head side, the attachment can be operated by one automatic operation without using a large-scale clamping means such as another hydraulic mechanism. Can be strongly clamped to the spindle head.

[Brief description of the drawings]

FIG. 1 is an external view of a machining center.

FIG. 2 is an explanatory diagram of a tool magazine and an exchange arm.

FIG. 3 is a sectional view showing a state in which the attachment of the present invention is attached to a spindle head.

FIG. 4 is a partially enlarged cross-sectional view around a clamp claw of FIG. 3;

FIG. 5 is a top view of the attachment detached from the spindle head, and is a diagram mainly illustrating a state where clamp claws are provided.

FIG. 6 is a sectional view showing a state in which a conventional attachment is attached to a spindle head.

[Explanation of symbols]

 6 Spindle head 7 Spindle ram 8 Attachment 12 Replacement arm A1, A2 Tool gripper B1 Attachment gripper B2 Attachment indexing gripper 14 Claw 21a Inner peripheral flange 22 Main shaft 25 Collet 26 Attachment body 26a V-shaped groove 21, 29 Large Coupling 30 Shank part 31 Pull stud 33,40 Small diameter coupling 36 Bevel gear 39,85 Disc spring 42 Tool spindle 80 Clamp claw member 82 Bracket 83 L-type clamp arm 83c Clamp claw 84 Pivot pin 86 Head pin

Claims (1)

[Claims] 1. An attachment which is fitted to the tip of a spindle head of a machine tool such as a machining center which pulls up a tool via a collet with a draw bar inserted through the center of the spindle and performs cutting processing, wherein an upper end face has a lower end face of the spindle head. Attachment body provided with a mating coupling that meshes with the peripheral flanged coupling, and a pull-up stud that is gripped by a collet at the upper end and a flange formed at the lower end with a cutout that engages with the spindle drive key. A shank member protruding a small-diameter shaft having a member movable in the axial direction with respect to the attachment main body and supporting the weight of the attachment main body at the shaft end, and mounted in the main shaft tapered hole; and an attachment body weight holding member for the small-diameter shaft. And the attachment body is interposed between the A first elastic body member to be urged, and one arm which is provided at a plurality of locations on an inner circumference of a mating coupling on an upper end surface of the attachment main body and which can swing upward in a plane including a center line of the attachment main body and faces upward. L has a clamp claw that is removably engaged with the upper surface of the inner peripheral flange portion of the coupling, and the upper surface of the other arm that faces the center of the attachment body contacts the lower surface of the flange portion of the shank member. A second clamp member which urges the clamp claws of each of the L-shaped clamp arms in a direction to always engage with the inner peripheral flange portion and has a plurality of forces weaker than the first clamp member. When the attachment is mounted on the main shaft, the engagement between the coupling and the clamp claw is engaged with the inner flange of the coupling, and the pulling up of the collet is released to release the shank. Fastening device for a machine tool attachment, characterized by disengaging the clamp jaws of the L-shaped clamp arm by lowering the.