JPS63109937A - Tool change method - Google Patents

Abstract

PURPOSE:To shorten a time a spindle stops at a tool change position, by providing the spindle with a tentative clamp mechanism for detachably locking a tool inserted into a tool inserting hole. CONSTITUTION:When a tool T on a spindle 5 is to be changed, the tool T on the spindle 5 is held by a tool holding unit 15 of a tool holding member 13, then the tool holding member 13 moves forwardly to remove the tool T from a tool insert hole of the spindle 5. Next, the tool holding member 13 is turned and then moved backwardly so that a tool T in the tool holding member 13 is inserted into the tool inserting hole and tentatively clamped. Holding of the tool by the tool holding unit is released before clamping of the tool T in the spindle 5 has been completed. With the arrangement, the new tool T is mounted on the spindle 5 and the new tool T is clamped by the tentative clamp mechanism, whereby a clamping action is effected after the new tool has been released by the tool holding member 15 (e.g., in parallel with a movement for next machining). As a result, a time the spindle 5 stops at a tool change position can be shortened.

Description

[Detailed description of the invention] Industrial applications This invention relates to a tool changing method for a machine tool.

BACKGROUND ART Conventionally, in a tool changer for a machine tool, a tool holder that holds a plurality of tools (including a tool magazine of a magazine direct exchange type that does not use a tool change arm or a rotating tool change arm) is mounted in a column. Some machines are equipped with a clamping mechanism that can be freely rotated back and forth and rotated in a direction parallel to the main shaft, and the main shaft is equipped with a clamping mechanism for clamping the tool. What is the tool exchange operation using this device?

After moving the spindle to a predetermined tool changing position and making sure that the tool holder holds the stoned tool inserted into the spindle, the tool on the spindle is unclamped, and then the tool holder is After being moved forward in the axial direction, it is rotated and moved backward, and the new tool is inserted into the spindle while being held in the tool holder of the tool holder. After clamping is completed, the holding by the tool holder is released and the spindle is moved to the next one. Now it is time to move on to processing.

Problems to be Solved by the Invention According to the conventional method, after the spindle completes clamping the new tool held in the tool holder, the tool holder releases the new tool from holding the new tool. There was a problem that when a new tool was inserted into the spindle at the tool exchange position, the spindle could not immediately start moving for the next machining, resulting in a long time when the spindle was stopped at the tool exchange position. .

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a temporary clamp mechanism that releasably locks the tool inserted into the tool insertion hole of the main spindle. When replacing a tool, hold the tool on the spindle in the tool holder of the tool holder, move the tool holder forward and remove the tool from the tool insertion hole on the spindle, then rotate the tool holder, and then , the tool holding body is moved backward to insert the tool in the tool insertion hole of the spindle and temporarily clamped, and the holding of the tool by the tool holding portion is released before the tool on the spindle is completely clamped.

According to the method described above, a new tool is inserted into the spindle and the new tool is temporarily clamped by the temporary clamping mechanism, so that the clamping operation is performed after the tool holder releases the new tool (for example, when the next machining is started). (parallel to the movement operation for tool exchange), which can shorten the time the spindle is stopped at the tool exchange position for tool exchange.

Embodiment In Fig. 1.2, 1 is a column that moves back and forth on the base, 5a is a spindle head that is attached to the column 1 so that it can move up and down by guide rails 60, 60. It is designed to move up and down. The main shaft 5 is rotatably supported on the main shaft head 5a via a bearing 61, as shown in FIG. This main shaft 5 has a built-in clamp mechanism 62. In this clamp mechanism 62, 63 is a tool mounting hole formed at the tip of the main shaft 5, and a pull rod 6 is inserted into the through hole 64 following this hole.
5 is inserted so as to be freely slidable in the axial direction, and is biased rearward by a disc spring 66. The pull rod 65 has a holding part 6 in which four steel balls 67 are movably incorporated in the tip of the pull rod 65 in the radial direction.
It is equipped with 8. This steel ball 67 is a pull rod 65
cooperates with the cam surface 69 in front of the through hole 64 by moving in the axial direction, and engages with the pull stud 70 at the rear end of the tool T to clamp the tool T to the main shaft 5, and also engages with the pull stud 70. It is designed to be unclamped to the main shaft 5 by removing it. The rear end of the pull rod 65 faces a piston rod 72 of an unglamp cylinder 71 arranged at the rear end of the spindle head 5a at a predetermined distance. Note that in this embodiment, the tip 65a of the pull rod 65 does not come into contact with the rear end 70a of the pull stud of the tool T when the pull rod 65 is in the unclamped state, and is configured to prevent the tool T from being pushed forward.
figure).

This main shaft 5 has a temporary clamp pin 7 in a direction perpendicular to the axis.
3 are movably fitted together, and the main shaft 5 is moved by a spring 74.
is biased toward the center of the temporary clamp mechanism 75 , and with the tip of the temporary clamp pin 73 protruding into the hole of the holding portion 68 , the stepped portion of the temporary clamp pin 730 is inserted into the storage hole 76 .
Even when the pull stud 70 of the tool T and the steel ball 67 are disengaged and the tool T is in an unclamped state as shown in FIG. 7
0 from the radial direction to temporarily clamp the tool T with the force of the spring 74.

Next, the tool magazine will be explained. An L-shaped first support 2 is fixed to the upper surface 1a of the column 1, and a second support 2 extending like an arm toward the main shaft 5 is attached to the front surface of the first support 2.
A support body 3 is fixed to the support body 4, and the two constitute a support body 4. The second support body 3 has a space 6 formed inside. The shaft support 3a at the tip of the second support 3 has bearings 7, 7.
A swing support body 8 is rotatably supported via the swivel support body 8, and a flange portion 9 is formed at the center in the axial direction. Also.

About 172 mm of the shaft section in front of the flange part 9 of the swing support body 8 is cut away, leaving a wall part 10 (FIG. 3) that supports a swinging arm, which will be described later, and the tip of the piston rod, which will be described later. The piston rod insertion hole 9a is cut out in a semicircular shape so that the circumference 172 of the portion is exposed. This flange portion 9 has two guide bars 11 facing forward.
is provided protrudingly, and the tip of this guide bar 11 is connected to a connecting plate 12 fixed to the tip of the swing support 8. The guide bar 11.11 is inserted into the guide hole 14 of the disc-shaped tool holder 13, so that the pivoting support 8 and the tool holder 1
3 and are prevented from rotating relative to each other, and are movable in the axial direction by a predetermined amount. The tool holder 13 has a tool holder 15 on its outer periphery that holds the tool T. The tool holder 15 has a known mechanism, supports two gripping claws 16, 16 at its intermediate portion, and is supported by a compression spring. 17 gripping claw 16
゜16 is to be closed. 18, 18 are gripping claws 1
When the tool T is not gripped by 6, 16, the compression spring 17
To prevent the gripping claws 16, 16 from closing too much, the gripping claws 1
This is a stopper that comes into contact with the rear ends of 6 and 16. Also, 19
is a known tool locking mechanism that locks the tool gripping state,
A sliding shaft 20 disposed between the projecting pieces 22 of the gripping claws 16, 22 and sliding back and forth is biased rearward, and a roller 21 is rotatably supported at the rear end. This sliding shaft 20 has a large diameter portion in the axially intermediate portion, and normally has a protruding piece 22,
22, and prevents the gripping claws 16, 16 from opening from the state where the tool T is gripped between the gripping claws 16, 16,
Only when it is in the tool exchange position, it engages with the cam 23 fixed to the tip of the spindle head, and the large diameter portion moves forward, no longer facing the protruding pieces 22, 22, and releases the locked state of the first gripping claws 16, 16. It's Nishide.

Next, the axial movement mechanism 24 will be explained. A cylinder chamber 25a is formed at the rear of the swing support 8, and a piston 26 integral with a piston rod 27 is fitted in the cylinder 25 so as to be slidable in the axial direction. A rack 28 is carved in the circumferential portion of the tip of the piston rod 27 exposed from the insertion hole 9a of the piston rod 27.

On the other hand, a swinging arm 30 having a pinion 29 formed at its base that engages with the rack 28 is pivotally supported on the wall 10 of the swing support 8 so as to swing 180 degrees in the axial direction (back and forth direction).
A cam follower 31 is rotatably supported at the tip of the swing arm 30.

This cam follower 31 has a rectangular hole 33 (a third
(Fig.), and is engaged so as to roll vertically between vertical U-shaped guide grooves 35 formed in a moving guide plate 34 inserted into a rectangular hole 33. ing. Therefore, when the piston rod 27 is moved backward in the state shown in FIG. is the guide groove 35
The tool holder 13 moves from its retracted end to its forward end. Moreover, the movement of the tool holder 13 from the forward end to the backward end is the opposite.

Next, a detection mechanism for detecting the backward and forward ends of the tool holder 13 will be explained. As shown in FIG. 4, a detection ring 36 is loosely fitted around the outer periphery of the shaft support 3a at the tip of the second support 3, and two sliding pins 37 are inserted from the rear surface of the detection ring 36.
．． 37 is installed protrudingly.

These sliding pins 37, 37 are connected to the guide hole 38.3 of the shaft support 3a.
8 so as to be slidable in the axial direction. Detection ring 36
A ring-shaped protruding edge portion 36a is formed at the front portion, and a limit dog 39 is fixed to one location on the outer periphery of the ring-shaped protruding edge portion 36a. A flange 41 at the rear of the detection bar 40 is engaged with the protruding edge 36a so as to be immovable in the front-rear direction. This detection bar 4
0 has two notches at its tip, and is designed to slide in the axial direction within the guide hole of the guide block 42 fixed to the aforementioned connecting plate 12. Inside this guide block 42 is a ball 43 which is biased in the direction of engagement with the notch.
Either notch is engaged to hold the detection bar 40 in that position.

An abutment ring 44 that abuts the front surface of the tool holder 13 is fixed in the middle of the detection bar 40 at a distance of L2 in FIG. 4. Furthermore, push pins 45 that push the front surface of the detection ring 36 are protruded from three locations on the rear surface of the tool holder 13. Therefore, at the backward end of the tool holder 13, the push pin 45 pushes the detection ring 36 and activates the limit switch SWl to confirm the backward end.
is engaged. When the tool holder 13 moves forward, the contact ring 4
4 is moved forward by the tool holder 13 to move the detection bar 40 forward, and this forward movement causes the collar 41 to move forward with the detection ring 36 hooked on, activate the limit switch SW2 to confirm the forward end, and then move the detection bar 40 forward. The ball 43 is designed to engage with the notch. In addition, 46 is a timing belt pulley attached to the rear end of the swing support 8, 47 is a timing belt pulley that is integrally attached to the shaft of the intermediate gear 48 that is pivotally supported on the first support 2, and 49 is a timing belt. A timing belt 50 is wound between the pulleys 46 and 47, and a drive gear 50 is connected to the output shaft of an index motor 51 and meshes with the intermediate gear 48. The rotation support body 8 is rotated and indexed integrally with the tool holder 13 via the timing belt 49. Further, as shown in FIG. 5, each tool holding part 1 of the tool holding body 13 is
A positioning hole 52 is formed corresponding to the second support 3.
The positioning pin 53 protruding forward from is inserted into the positioning pin 53.

Next, the effect will be explained. When machining with the tool T attached to the spindle 5 is completed, the rotation of the spindle 5 is stopped, the column 1 is moved back to a predetermined position, and the spindle head 5a is raised by the lifting motor to hold the tool at the retreating end. body 13
approach. At a predetermined timing from when the main spindle 5 stops to when the main spindle 5 is positioned at the tool exchange position, the unclamp cylinder 71 is activated, the pull rod 65 moves forward, and the steel ball 67 of the clamp mechanism 62 and the tool The pull stud 70 of the tool T is disengaged and the tool T becomes unclamped, but the temporary clamp pin 73 of the temporary clamp mechanism 75 is still engaged with the pull stud 70 of the tool T.
is temporarily clamped to the spindle 5, and the tool T is held against the force of the spring 74.
It cannot be easily removed from the main shaft unless it is pulled forward.
When the spindle head 5a approaches the tool exchange position, the cam 23 of the spindle head 5a engages with the roller 21 of the tool locking mechanism 19 to advance the sliding shaft 20, unlocking the gripping claws 16, 16, and then , the main shaft 5 is held between the gripping claws 16° and 16°.
When the tool T is gripped, the main shaft 5 is located at the tool exchange position.Then, the piston 26 is immediately moved back from the forward end in FIG. 1 by the action of pressure fluid.

The rack 28 of the piston rod 27 also moves back, causing the swinging arm 30 to swing 180 degrees. Along with this swinging, the cam follower 31 at the tip of the swinging arm 30 moves to the moving guide plate 3.
4, and moves the tool holder 13 by Ll from the retreat end to the forward end while gripping the spindle tool T, and as a result of this movement, the spindle tool T in the temporarily clamped state is released from its pull. The stud 70 pushes the temporary clamp pin 73 against the force of the spring 74, disengages it, and is pulled out from the main shaft 5. In this movement, the circular arc movement drawn by the cam follower 31 is changed to the back-and-forth movement of the tool holder 13. Therefore, even if the linear movement of the piston rod 27 is uniform, the moving speed of the tool holder 13 follows a sine curve. so that you can start moving,
There is less impact at the end of the movement, and the moving speed of the piston rod 27 can be increased. While the tool holder 13 is moving forward (
When it moves by L2), its front surface pushes the contact ring 44, and at the backward end, the detection ring 36, which was held at the backward end detection position by the front notch of the detection bar 40, moves to the stroke 5.
The detection bar 40 is moved forward by T=L1-L2, and the ball 43 engages with the rear notch, and the limit switch SW2 is activated.
detects the limit dock 39 and the tool holder 13 reaches the forward end.Next, the index motor 51 is driven by a command from an NC device (not shown), and the timing belt 49 is driven.
The swinging support 8 is pivoted and indexed with the tool holder 13 at the forward end, and this pivoting causes the tool holder 13 to
are rotated and indexed together, and the tool T to be used next is indexed onto the axis of the main spindle 5. During this indexing, the detection bar 40 has its collar 41 engaged with the protruding edge 36a of the detection ring 36 that does not rotate, and the piston 26, which has been retracted to the 0th position, rotates together with the rotation support 8. This causes the tool holder 13 to move from the forward end to the backward end in the reverse operation. At the backward end, the positioning pin 53 is fitted into the positioning hole 52 of the tool holder 13, and the tool holder 1
3 is positioned, and the push pin 45 pushes the detection ring 36 at the forward end detection position by the stroke ST, moves the detection bar 40 to the right and engages the ball 43 with its front notch, and the limit dog 39 is activated. Limit switch SW
When the tool holder 13 reaches the retreat end, the tool lock mechanism 19 of the tool holder 15, which holds a new tool T indexed on the axis of the main spindle 5, engages with the tool holder 1 to confirm the retreat end. The sliding shaft 20 engages with the cam 23 and is moved forward to become unlocked, and the tool holder 1 is attached to the main shaft 5 of the main shaft head 5a.
A new tool T, which is still held at 5, is inserted, and the tool T
The pull stud 70 is temporarily clamped by the temporary clamp pin 73 after once pushing out the temporary clamp pin 73 of the temporary clamp mechanism 75 against the force of the spring 74. In this temporarily clamped state, the spindle head 5a immediately begins to descend downward in FIG. The piston rod 72 of the cylinder 71 retreats, the pull rod 65 retreats due to the force of the spring 66, and the pull stud 70 of the tool T is retracted. Complete the clamping of the T to the main shaft 5.

Next, the main shaft 5 is rotated to start the next machining.

The timing to issue the clamp command to clamp the new tool inserted into the spindle may be before or at the same time as the new tool is released from the holding state by the tool holder; in short, the clamping of the new tool is completed when the release is completed. In addition, in this example, when the tool on the spindle is unclamped, the tip of the pull rod does not come into contact with the rear end of the tool, but the pull rod does not touch the rear end of the pull stud of the tool. Even if the tool is pushed forward by pressing , it is sufficient that the temporary clamp pin of the temporary clamp mechanism engages with the pull stud to maintain the temporary clamp state.
Since the spindle head is vertically disposed vertically below the tool indexing position of the tool holder, the width of the column can be narrowed. Furthermore, the tool holder may be a tool changing arm mounted on the spindle head so as to be movable and pivotable in the axial direction of the spindle axis, in which case the tool magazine can be pivotably indexed on a fixed machine base. It is sufficient if it is installed.

Effects of the Invention As described above, in the present invention, the main spindle is provided with a temporary clamp mechanism that releasably locks the tool inserted into the tool insertion hole, and when replacing the tool on the main spindle, the main spindle is After holding the tool in the tool holder of the tool holder, move the tool holder forward to remove the tool from the tool insertion hole of the spindle, then rotate the tool holder, move it backward, and remove the tool. The tool on the holder is inserted into the tool insertion hole of the spindle and temporarily clamped, and before the tool on the spindle is completely clamped, the tool holding part is released from holding the tool, so a new tool can be inserted into the spindle. Then, it is possible to immediately move toward the next machining, and the tool clamping operation can be performed in parallel, for example, during the movement time from when the spindle leaves the tool exchange position to when it moves to the next primary machining.

The time the spindle is stopped at the tool exchange position can be reduced.

[Brief explanation of the drawing]

Figure 1 is a 1-1 cross-sectional view of Figure 2, Figure 2 is a front view of Figure 1, Figure 3 is an enlarged cross-sectional view of Figure 2, and Figure 4 is a cross-sectional view of Figure 3.
Fig. 5 is an explanatory diagram of the positioning pin, Fig. 6 is
The figure is a sectional view of the spindle head, FIG. 7 is an enlarged view of the temporary clamp mechanism, and FIG. 8 is a sectional view taken along line IV-fV in FIG. 7. 1... Machine base, 4... Support body, 5... Main shaft,
8... Rotating support body, 11... Guide bar, 13.
...Tool holder, 15...Tool holder, 24...
・Axis direction movement mechanism, 25... cylinder, 27...
・Piston rod, 28... rack, 29...
Pinion, 30... Swinging arm, 35...
Guide groove, 62... Clamp mechanism, 71... Unclamp cylinder, 75... Temporary clamp mechanism

Claims (1)

[Claims] 1. A tool holder having a plurality of tool holders is provided on a column or spindle head so that it can move back and forth in a direction parallel to the spindle and can rotate, and the tool inserted into the tool insertion hole is clamped to the spindle. In a tool exchange method that includes a clamp mechanism and exchanges a tool inserted into a tool insertion hole of a spindle and clamped with a tool held in a tool holding part of a tool holder in advance, the tool is attached to the spindle. A temporary clamp mechanism that releasably locks the tool inserted into the insertion hole is provided, and when replacing the tool on the spindle, after holding the tool on the spindle in the tool holder of the tool holder, Move the holder forward to remove the tool from the tool insertion hole in the spindle, then rotate the tool holder, move it backwards, insert the tool in the tool holder into the tool insertion hole in the spindle, and temporarily remove the tool. A tool changing method characterized in that the tool is clamped and the tool holding part is released from the tool holding part before the tool on the spindle is completely clamped.