JPS625742B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a machine tool equipped with an automatic tool changer for changing tools between a spindle and a tool magazine, and more particularly to the above machine tool equipped with two sets of tool magazines.

An object of the present invention is to enable various usage patterns by attaching two sets of tool magazines and to improve machining efficiency.

Another object of the present invention is to simplify the tool changing device by making it possible to exchange tools between the spindle and two sets of tool magazines using a common tool changing unit.

Yet another object of the present invention is to allow tools to be changed in one tool magazine while the other tool magazine is in an idle state.

Conventionally, it has been known to install a tool magazine exchange device and remove the entire tool magazine from the machine to perform tool magazine setup changes, and this method is advantageous in that it can significantly reduce the idle time required for setup changes. However, on the other hand, there is a drawback that a large and heavy tool magazine must be replaced, and furthermore, there is a problem that the next machining cannot be started unless the tool magazine is replaced.

The present invention has been made in view of the above-mentioned conventional problems. Two sets of tool magazines are provided spaced apart from each other, and tools are exchanged between these tool magazines and the spindle using a common tool exchange unit. While machining is being performed using one tool magazine, it is possible to change the setup of tools in the other tool magazine.

Embodiments of the present invention will be described below based on the drawings.
In FIG. 1, 10 is a bed of a machine tool, and a spindle head 12 is mounted on a column 11 fixed to this bed 10 so as to be movable up and down.
A main shaft 13 into which a tool T is removably inserted is rotatably supported around a horizontal axis. Further, a saddle 14 is mounted on the bed 10 in front of the column 11 so as to be movable back and forth.
A table 15 is mounted on the top so that it can move laterally, and an indexing table 16 is mounted on the table 15 so that it can be rotated and indexed. Index table 16
A pallet 17 on which a workpiece W is placed is carried in as appropriate and is positioned and clamped at a predetermined position. The spindle head 12, the table 15, and the saddle 14 are each controlled in feed according to a numerical control program by an unillustrated screw feeder using feed motors 18, 19, and 20 as drive sources, and the spindle head 12 is used for tool exchange. is positioned at the rising end.

Two sets of tool magazines 21 and 22 storing a large number of tools T in a horizontal state orthogonal to the axis of the main spindle 13 are installed on both sides of the column 11 symmetrically with respect to the main spindle 13. Although the details of these two tool magazines 21 and 22 are omitted from the illustration, for example, tools are stored on an endless chain 23 (see Fig. 2) that is wound around one drive sprocket and a plurality of driven sprockets connected to a drive motor. The tool socket 24 into which the T has been inserted is tightened by the pivot pin 25 at 90°.
A known structure that is held tiltable may be used.
The two sets of tool magazines 21 and 22 are provided with tool exchange positions P1 and P2, respectively, at positions equidistant from the spindle 13. At these tool exchange positions P1 and P2, the tool socket 24 is tilted at 90 degrees, and the tool T The axes of are transformed so that they are parallel to the principal axes. As is clear from the tool exchange operation described later, used tools are returned to the tool socket 24 from which the requested tool was taken out. As described in ``Exchange Control Device'', a control function is added to sequentially rewrite the storage address of the tool.

Two support blocks 2 are mounted on the column 11.
6 and 27 are installed with an interval in the left-right direction, and a pair of pilot bars 28 and 29 are arranged in parallel to these support blocks 26 and 27. A tool changing unit 30, which will be described below, is guided and supported on the pilot bars 28 and 29 so as to be slidable in the left and right directions.

In FIG. 2, 31 is a tool changing unit 30.
An arm shaft 32 is supported on this main body 31 so as to be rotatable around an axis parallel to the main axes and movable in the axial direction, and an exchange arm 33 is fixed to the tip of this arm shaft 32. . A cylinder 34 for advancing and retracting the arm is formed within the arm shaft 31, and a fixed piston 35 fixed to the main body 31 is fitted into the cylinder 34 so as to be relatively slidable therein. A support shaft 36 is supported by the main body 31 in parallel with the arm shaft 31, and a spur gear 37 is rotationally supported on the support shaft 36. The arm shaft 3 is attached to the spur gear 37.
The spur gear 37 has a length sufficient to maintain meshing with the gear 38 at all positions of the forward and backward movement of the arm shaft 31. A rack piston 40 that is slidably fitted into an arm rotation cylinder 39 formed on the main body 31 is meshed with the spur gear 37.
The arm shaft 31 is rotated in the forward and backward directions by the forward and backward movements of the arm 31.

Further, an encoder 41 connected to the spur gear 37 via a gear mechanism is provided on the main body 31, and the arm shaft 31,
That is, the rotation angle of the exchange arm 33 is detected. Furthermore, on the main body 31 is a cylinder 4 for actuating the dowel pin.
2 is installed, and a notch pin 43 moved back and forth by this cylinder 42 is configured to removably engage with a plurality of circumferential notch holes 44 formed at the rear of the spur gear 37. The knock pin 43 is advanced based on a signal from the encoder 41 to position the exchange arm 33 at a plurality of angular positions.

At both ends of the exchange arm 33, as shown in FIG.
Movable pawls 47 and 48 are provided which grip the tool T in cooperation with the movable claws 47 and 48. The exchange arm 33 normally moves between the tool exchange positions P1 and P2 of each tool magazine 21 and 22 and the main shaft 1 at a first position or a second position, which will be described later.
It is waiting at a predetermined angle (90°) inclined position with respect to the line connecting 3.
゜forward rotation, axial forward rotation, 180゜forward rotation or reverse rotation,
Tools are simultaneously exchanged between the tool magazines 21, 22 and the main spindle 13 through a series of sequential operations of axial retraction and 90° reversal.

A series of sequence operations by the exchange arm 33 will be explained based on the hydraulic system diagram shown in FIG. will be withdrawn due to Subsequently, the switching valve V1 is switched to the left, and the easy piston 40 is moved by the arm rotation cylinder 39.
is slid to the left. As a result, the exchange arm 33 is rotated forward through the spur gear 37 and the arm shaft 31, and the rotation angle of the exchange arm 33 is determined by the encoder 4.
Detected at 1. When the exchange arm 33 is rotated approximately 90 degrees in the normal direction, this is detected by the encoder 41.
The switching valve V3 is switched to the original position. As a result, the notch pin 43 is advanced and engaged with a predetermined notch hole 44, and the exchange arm 33 is positioned at a normal rotation position of 90 degrees (tool gripping position). Next, the switching valve V2 is switched to the right, and the exchange arm 33 is advanced by a predetermined amount by the arm advancing/retracting cylinder 34.
Subsequently, as described above, the knock pin 43 is moved back, the switching valve V1 is now switched to the right, the rack piston 40 is slid to the right, and the exchange arm 33 is reversed. When the encoder 41 detects that the replacement arm 33 has been reversed by approximately 180 degrees, the knock pin 43 is moved forward.
The exchange arm 33 is positioned at a 180° half-rotation position. Here, the direction of 180° rotation of the exchange arm 33 is sequentially electrically memorized and controlled so that the 180° rotation is always performed alternately in forward and reverse directions.

Thereafter, the switching valve V2 is switched to the original position, the exchange arm 33 is moved back by a predetermined amount, and then the knock pin 43 is moved back, and the switching valve V1 is switched to the right again, and the exchange arm 33 is reversed. . When the encoder 41 detects that the exchange arm 33 has been reversed by approximately 90 degrees, the knock pin 43 is advanced to position the exchange arm 33 at a 90 degree reverse position (original position).

A tool change cycle is executed by such a series of sequence operations, whereby the rack piston 40 is positioned at a position deviated by 180 degrees from its original position. Since the rotation is controlled in the opposite direction, that is, forward rotation, the rack piston 4
0 is returned to its original position in two cycles.

The configuration of the tool exchange unit 30 described above merely shows one mode suitable for implementing the present invention, and the gripping configuration of the exchange arm 33 or the configuration of the exchange arm 3
The drive mechanism No. 3 can take various forms.

Next, a configuration for selectively positioning the tool changing unit 30 in two positions will be described. A drive motor 50 is installed in the main body 31 of the tool changing unit 30, and a pinion 51 connected to the drive motor 50 meshes with a lock tooth 52 formed on one of the pair of pilot bars 28, 29.
Therefore, when the drive motor 50 is driven, the tool changing unit 30 is moved along the pilot bars 28, 29 via the pinion rack mechanisms 51, 52. The tool exchange unit 30 is placed in a first position where the rotation center (arm axis 31) of the exchange arm 33 coincides with the midpoint between the tool exchange position P1 of the first tool magazine 21 and the main shaft 13, and in the second tool magazine. Positioning cylinders 53 are respectively installed at two positions on the column 11 in order to position the tool at a second position corresponding to the intermediate point between the tool exchange position P2 of 22 and the main shaft 13. A notched pin 54 is appropriately engaged with a notched hole 55 formed on the rear surface of the main body 31.

Next, the operation of the machine tool of the present invention configured as described above will be explained. In the following description, the first tool magazine 21 stores tools T necessary for machining workpiece A, and the second tool magazine 22 stores tools T necessary for machining workpiece B. , an example in which two types of workpieces A and B are processed without setup changes will be described.

A workpiece W positioned and clamped on the indexing table 16 by a tool T inserted into the main spindle 13
While machining, the first tool magazine 21 is operated to index the next tool T to be used at the tool change position P1, and when the requested tool T is indexed to the tool change position P1, the tool socket 24 is The next tool T is tilted so that it is parallel to the spindles, and it waits in that state.

When the predetermined machining with the tool T inserted into the spindle 13 is completed, the spindle head 12 is raised to change the tool, and at the rising end position, a command is issued to start the tool change. In response to this tool exchange command, the exchange arm 33 is rotated forward by 90 degrees by the arm rotation cylinder 34, and the main shaft 1 is rotated by the gripping claws 45, 46.
3 and the tool T to be used next inserted into the tool socket 24 at the tool exchange position P1 are held respectively. Subsequently, the exchange arm 33 is advanced by a predetermined amount in the axial direction by the arm advancing/retracting cylinder 34, and the respective tools T gripped by the gripping claws 45, 46 are removed from the main shaft 13 and the tool socket 24. After that, the arm rotation cylinder 39
The exchange arm 33 is reversed by 180 degrees, and the exchange arm 3 is moved from the arm advance/retreat cylinder 34.
3 is retracted by a predetermined amount in the axial direction, thereby inserting the used tool T into the tool socket 24 and the tool T to be used next into the spindle 13, respectively. Thereafter, the exchange arm 33 is reversed by 90 degrees by the arm rotation cylinder 39 and returns to its original position, completing the tool exchange cycle. In this state, the spindle head 12 is lowered in accordance with a numerical command for machining with the tool T inserted into the spindle 13.

When a different tool T is inserted into the tool socket 24 at the tool exchange position P1 each time such a tool exchange cycle is performed, the contents of the storage device that register the correspondence between the tool socket 24 and the number of the tool T inserted therein are stored. is appropriately rewritten to enable random selection of tools T in the case of direct exchange between the tool magazine 21 and the spindle 13.

In this way, repeat the above-mentioned tool exchange sequentially, and
All prescribed machining is performed on the workpiece, and the machining cycle is repeated each time the pallet 17 on which the A workpiece is placed is carried onto the indexing table 16.

Next, the operation of machining the B workpiece using the second tool magazine 22 instead of the A workpiece will be described.

First, the positioning cylinder 53 is operated according to the tool command from the tool magazine used, and the dowel pin 54 is activated.
is retracted, making the tool changing unit 30 positioned at the first position movable. Subsequently, the drive motor 50 is started to rotate in the normal direction, and as a result, the tool change unit 30 is rotated via the pinion rack mechanisms 52 and 51.
is moved to the left along the pilot bars 28, 29. The tool change unit 30 is moved to the second position, that is, close to the position where the center of rotation of the change arm 33 coincides with the midpoint between the main shaft 13 positioned at the rising end and the tool change position P2 of the second tool magazine 22. Then, the drive motor 50 is decelerated, and the positioning cylinder 53 moves the knock pin 54 forward.
engages with the notched hole 55 of the tool change unit 30 to position the tool change unit 30 in the second position.

From the first position to the second position of the tool changing unit 30
In parallel with the movement to the position, the exchange arm 33 is reversed by 90 degrees by the arm rotation cylinder 39, and the original position of the exchange arm 33 is changed by 90 degrees. By changing the original position of the exchange arm 33, the tool exchange between the tool exchange position P2 of the second tool magazine 22 and the main spindle 13 is performed by 90° forward rotation and 180° forward rotation, similar to the tool exchange cycle described above. Alternatively, it can be performed by rotating in reverse or 90° in reverse.

Therefore, according to a predetermined program, the second
The machining cycle of workpiece B is executed by sequentially taking out the tools T from the tool magazine 22 and inserting them into the main spindle 13. The first tool magazine 21 is in a dormant state while processing B workpiece.
By manually indexing the tool T, it is possible to change the setup of the tool T. For example, the tool T can be changed for the next scheduled machining of the C workpiece.

In the above embodiment, the first tool magazine 2
1 is used for machining workpiece A, and the second tool magazine 22 is used for machining workpiece B, so that tool setup changes can be performed in one tool magazine that is in a paused state while machining one workpiece. However, it goes without saying that the present invention is not limited to such embodiments.

For example, a spare tool for the tool T stored in the first tool magazine 21 is stored in the second tool magazine 22, and when the tool T reaches the end of its life or breaks, the spare tool is moved to the replacement position based on the detection signal. P2
It is also possible to call the spare tool and replace the life-limited (broken) tool T inserted in the main shaft 13 with the replacement arm 33.

Further, in the above embodiment, the two sets of tool magazines 21 and 22 are installed on the column 11, but they may also be installed on the floor.
It can also be applied to mechanical configurations in which the robot moves back and forth.

As described above, the present invention provides two
A set of tool magazines is provided, and the tool changing unit is installed at an intermediate position between one of the tool magazines and the main spindle and the other so that tools can be exchanged between the tool magazines and the spindle using a common tool changing unit. Since the tool magazine is moved between the intermediate position between the tool magazine and the spindle, the tool exchange mechanism can be simplified even though the two tool magazines are separated, and one tool magazine can be moved between the two tool magazines and the spindle. While using the machine tool for machining, it is possible to change the setup of tools in the other tool magazine, which also has the effect of improving the operating rate of the machine tool.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a front view of a machine tool equipped with an automatic tool changer, FIG. 2 is an enlarged sectional view taken along the line - in FIG. 1, and FIG. The figure is a hydraulic system diagram for explaining the operation of the tool changing unit. 10...Bed, 11...Column, 12...Spindle head, 13...Spindle, 14...Table, 15...
... Index table, 21, 22 ... Tool magazine, 28, 29 ... Pilot bar, 30 ... Tool exchange unit, 33 ... Exchange arm, 34 ...
Cylinder for arm advancement and retreat, 39... Cylinder for arm rotation, 45, 46... Tool gripping claw, 50... Drive motor, P1, P2... Tool exchange position, W...
work.

Claims (1)

[Claims] 1. A spindle head that supports a spindle with a tool inserted therein and a table that supports a workpiece are provided so as to be movable relative to each other,
Two sets of tool magazines storing a plurality of tools to be inserted into the spindle are arranged separately, each tool magazine has a tool exchange position equidistant from the spindle, and the tools are inserted into these tool exchange positions. can be indexed sequentially, and the tool can be rotated between the tool exchange position of the one tool magazine and the spindle and between the tool exchange position of the other tool magazine and the spindle. A tool changing unit including an arm is provided to be movable between the two tool changing positions, and the tool changing unit is selectively positioned at two positions corresponding to each of the tool changing positions, depending on a tool magazine in which the tool changing unit is used. A machine tool equipped with an automatic tool changer. 2. A machine tool equipped with an automatic tool changer according to claim 1, wherein the two sets of tool magazines are symmetrically arranged at fixed positions on both sides of the spindle head. 3. A machine tool equipped with an automatic tool changer according to claim 2, wherein the two sets of tool magazines are installed on both sides of a column on which the spindle head is mounted so as to be movable up and down. 4. A machine tool equipped with an automatic tool changer according to claim 3, wherein the tool change unit is horizontally moved between two positions above a column. 5. A machine tool equipped with an automatic tool changer according to claim 1 or 4, wherein the change arm has two different positions, the original position being different from the original position by a predetermined angle.