JP3099197B2 - Work delivery device for machine tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a machine tool such as a machining center in which tool change is automated (hereinafter, these are simply referred to as machine tools).
The present invention relates to a work transfer device that transfers work between a stocker and a work setting position by effectively using the operation of a movable unit in the above.

[Prior art]

In the machine tool, automatic work change in mass production processing of relatively small items is performed by various robots and loaders attached to the side of the machine tool, and these are devices independent of the machine tool. Therefore, for example, when one work is selected and taken out from a large number of works arranged in a stocker, a three-dimensional movement is required to position a work holding portion of a robot or a loader to a work holding position. A mechanism was needed. For example, JP-A-64-16344 discloses that a separate magazine / workpiece exchange device is arranged near a workpiece processing device, and a pneumatic cylinder is used as a driving member different from a driving member of the workpiece processing device. There is disclosed a workpiece exchange device in which a workpiece is taken out of a workpiece storage magazine by a transport arm provided with the same and transported to a workpiece processing device, and returned after processing is completed. In addition, the machine tool has at least turning and
A change arm of an automatic tool changer that linearly moves in a predetermined direction is provided.

[Problems to be solved by the invention]

In recent years, there has been an increasing need for automatic long-time operation of machine tools, but robots and loaders that are indispensable for automation are individually designed and designed according to the shape and weight of the work.
Because it is adjusted, it is very expensive and can be an over-investment unless very large volume processing is required. In addition, as described in the above publication, only the software portion included in the control means for controlling the movement of the transfer arm is individually adapted, and unnecessary portions remain because of a general structure, which is large and complicated. It will be something.

[Means for Solving the Problems]

The present invention focuses on the fact that although the exchange arm is provided exclusively for exchanging a spare tool and a spindle tool in the ATC magazine, the exchange arm has a structure capable of performing NC-controlled operation. The operation of the exchange arm is used for the work transfer operation.The configuration is equipped on the machine tool, the work hand is attached to the exchange arm of the NC tool-controlled automatic tool changer, and the chuck for gripping the work is attached. A work stocker is provided on the placed table,
The work hand is moved in the vertical movement direction of the exchange arm, and the work hand is placed on the table by a three-dimensional combined motion using a tool changing operation of the work hand and a movable portion operation during processing of the work hand and the table. Between the work stocker and the work setting position of the chuck. Note that the three-dimensional combined movement of grasping the work is a comprehensive operation of the work hand and the work stocker, and the control of the work stocker approaching the work hand is performed in the two-dimensional direction or the one-dimensional direction in which the control information is less. It may be.

[Action]

In addition to the tool exchanging operation by the exchanging arm, the gripping operation of the work by the work hand attached to the exchanging arm is performed by a three-dimensional compound motion by a drive mechanism with a movable body such as a table along with the tool exchange according to the instruction of the work exchanging program, The work is delivered in a very close space between the work stocker placed on the table and the work setting position.

【Example】

An example in which a workpiece transfer device in a machine tool according to the present invention is implemented in a vertical machining center will be described with reference to the drawings. In FIG. 1 and FIG. 2, a spindle head 2 is provided above a column 1 of a vertical machining center equipped with an NC-controlled automatic tool changer so as to be movable in the Y-axis direction. A table 3 on which a workpiece W or the like is placed is disposed below the table so as to be movable by NC control in a two-dimensional compound motion in the X-axis and Z-axis directions. Spindle head 2
Has a main shaft 4 rotatably mounted thereon, and an NC controlled exchange arm unit 5 and an ATC magazine 6 provided beside it. An NC rotary table 7 with a work clamp chuck and a simple work stocker 8 are arranged on the operation range of the table 3, and the work W is stored in a predetermined position in the work stocker 8. FIG. 3 shows the exchange arm unit 5 with a work hand. Reference numeral 9 denotes a hollow turning center shaft having a ball screw and spline shaft shape, which is supported by a ball screw nut 10 and a spline nut 11 fixed to the ATC frame so as to be able to turn and move in the Y-axis direction. At one end of the turning center shaft 9, a turning hydraulic joint 12, which will be described later, is pivotably supported. Reference numeral 13 denotes a hollow arm turning shaft fitted to the other end of the turning center shaft 9, and a twin-arm exchange arm 14 for holding the tool T at a target position is fixed to one end of the arm turning shaft 13. ing. Reference numeral 15 denotes an up / down servomotor that drives the ball screw nut 10 meshing with the turning center shaft 9 via a gear and a speed reducer. The turning servomotor 15 rotates the turning center shaft 9 and the arm turning shaft. 13 can be moved up and down in the Y-axis direction, which is the direction of the pivot center axis. Instead of the ball screw and the ball screw nut 10, a rack and pinion drive or the like is also possible.
Reference numeral 16 denotes a turning servomotor that drives the spline nut 11 meshing with the turning center shaft 9 via a gear. The turning servomotor 16 rotates the spline nut 11 to rotate the turning center shaft 9 and the arm turning. The shaft 13 can be turned. The servomotors 15 and 16 have built-in position detectors.
Is turned, up, down, position,
It can be operated while controlling the speed. Reference numeral 17 denotes a work hand fixed to a center portion of the exchange arm 14 by a bolt. The work hand 17 has a hollow center of the turning center shaft 9 and the arm turning shaft 13 through the turning hydraulic joint 12. A pair of grips 19 that grip the work W by sliding a crank piston 18 using a fluid hydraulic pressure that is inserted and connected to and supplied to the portion is mounted to be openable. A spring 20 is inserted between the grips 19, closed by the urging force of the spring 20 to hold the work W, and the grip 19 is opened against the urging force of the spring 20 by the wedge action of the clamp piston 18 to open the work W. release. The control of the hydraulic pressure is performed by a hydraulic control unit (not shown) and an SOL valve by an NC control device.
However, a known gripping means such as a chuck can be used depending on the shape of the workpiece, the gripping position, and the like. Next, the operation of the present invention will be described. When the machining operation of the work W is completed, the completed work W1 is gripped by the chuck 21 of the NC rotary table 7 which is the work setting position, and the next work is stored on the work stocker 8. Unprocessed work W2 is accommodated, and the spindle is
At the standby position of the magazine, in the first machining step, when the tools to be used are gripped, the work W1 is transferred to the work stocker 8 from the NC rotary table 7 fixed to the table 3 of the machining center. First, the NC rotary table 7 is exchanged while controlling the table 3 in accordance with a command from the NC controller, while controlling the two-dimensional compound motion in the X-axis and Z-axis directions constituting a plane orthogonal to the turning axis as the Y-axis. 14
It is moved to the vicinity and positioned above the workpiece W1 to be gripped next. At this time, the exchange arm 14 turns so that the longitudinal direction is parallel to the X axis, and prevents interference with the tool held by the main shaft. The exchange arm 14 having the grip 19 opened by the same NC controller is lowered along the Y-axis direction to the height of the work W1, and the work W1 gripped by the chuck 21 is inserted into the opened grip 19, and the chuck 21 Is released, the grip 19 is closed, and the work W1 is connected to the work hand 17. Subsequently, the work stocker 8 is moved to the vicinity of the exchange arm while controlling the two-dimensional composite movement of the table 3 in the X-axis and Z-axis directions by the same NC controller, and the exchange arm holding the work W1 is moved to the work 1. Y on any position to place
When the workpiece W1 is indexed to a position where the workpiece W1 can be placed, the grip 19 is released. Next, the NC fixed on the table 31 of the machining center
In order to transfer the unfinished work W2 from the work stocker 8 to the circular table 7, the table 3 is first sent by the NC controller.
Is moved to the vicinity of the exchange arm 14 while controlling the two-dimensional composite motion in the X-axis and Z-axis directions, and is positioned above the workpiece W2 to be gripped next. The exchange arm 14 having the grip 19 opened by the same NC controller is lowered along the Y-axis direction to the height of the work W2, and the work W2 is moved into the opened grip 19.
Is inserted, the grip 19 is closed, and the work W2 is gripped by the work hand 17. Subsequently, while controlling the two-dimensional composite movement of the table 3 in the X-axis and Z-axis directions by the same NC controller, the NC rotary table 7 is moved to the vicinity of the exchange arm, and the exchange arm 14 holding the work W2 is opened. The table 3 is slightly moved in the Z-axis direction when the work W2 is indexed to a position where the work W2 can be inserted into the opened chuck 21, and the table 3 is moved to the height of the opened chuck 21. After the work W2 is inserted into the, the grip 19 is released, and the chuck 21 is closed, so that the work W2 is gripped by the chuck 21. Then, while controlling the table 3 in the X-axis and Z-axis directions, the table 3 is moved to a position below the main spindle of the machining center.
In addition to indexing the NC rotary table 7 to a position where the machining operation is started, the exchange arm 14 is turned so that the longitudinal direction is parallel to the Z-axis, and the exchange of tools for the final process and the first process is performed by a known technique. If the operations performed by the above are performed at the same time, the setup time can be further reduced. This tool exchange involves holding the workpieces W1 and W2 and moving the table 3 in the X-axis and Z-axis directions while controlling the two-dimensional composite motion.
This can be performed while moving from the NC rotary table 7 to the work stocker 8 or in the opposite direction. However,
With the exchange arm 14 of the twin arm type, the workpieces W1 and W2 gripped by the workpiece hand are rotated by 180 degrees with respect to the Y-axis along with the exchange of the tool, so the processing direction of the workpiece W on the workpiece stocker 8 is processed. It is desirable to rotate 180 degrees with respect to the Y axis as compared with the case.

【The invention's effect】

As described above, according to the workpiece transfer device of the present invention,
Since the workpiece is transferred using the tool changing operation of the exchange arm and the operation of the movable part at the time of machining, it can be manufactured at a low cost without adding another driving member as in the related art, and the vicinity is It can be said that it can be equipped integrally without being arranged side by side with other devices as in the past, and automatic operation becomes possible without installing a robot or loader having a complicated structure. In particular, during the time when the exchange arm is performing the tool exchange, the table can be driven below it without interference so that the work stocker or the work setting position can be brought closer to the work hand, so that the setup time can be further reduced.

[Brief description of the drawings]

The drawings show an ATC exchange arm of the machining center of the present invention. FIG. 1 is a side view of the machining center, and FIG.
The figure is a front view, and FIG. 3 is a sectional view showing an ATC exchange arm. 1 ... Column, 2 ... Spindle head, 3 ... Table, 4 ...
Main shaft, 5 ATC exchange arm unit, 6 ATC magazine, 7 NC rotary table, 8 Simple work stocker, 9 Rotating center axis, 10 Ball screw nut, 11
... Spline nut, 12 ... Slewing hydraulic joint, 13 ... Arm swivel shaft, 14 ... Replacement arm, 15 ... Vertical servo motor, 16 ... Slewing servo motor, 17 ... Work hand, 18 ... Crank piston, 19 ... grip, 20 ...
... Spring, 21 ... Chuck, W, W1, W2 ... Work, T ...
…tool.

Claims (1)

(57) [Claims] 1. A work hand is attached to a change arm of an automatic tool changer controlled by an NC which is mounted on a machine tool, and a work stocker is provided on a table on which a chuck for gripping a work is mounted, and the work hand is changed. By moving the arm in the vertical movement direction, a three-dimensional composite motion using a tool changing operation of the work hand and a movable part operation at the time of machining the work hand and the table,
A work transfer device for a machine tool that enables transfer of a work between a work stocker placed on a table and a work setting position of the chuck.