JPH0736965B2 - Core processing equipment for wire electric discharge machine - Google Patents

Description

The present invention relates to a core processing device using a magnet in a wire electric discharge machine.

[Conventional technology]

The wire electric discharge machine winds a vertically arranged wire (thin wire) on the lower side and uses this as an electrode to perform electric discharge machining on a workpiece (hereinafter referred to as a work) in a sawtooth manner to cut out a predetermined contour shape. This is a device for performing so-called wire cutting. Since such a wire electric discharge machine can perform complicated machining with high accuracy, it is suitable for performing die machining, irregular hole machining and the like, but has the following problems inherent in its structure.

That is, immediately after the wire cutting is completed, the part separated from the work (generally called the core) falls down because the support is lost, and it is directly hit by the guide mechanism that guides the wire on the lower side. There is an inconvenience.

In the current situation, it pauses just before the completion of wire cutting,
After performing a pressing process to prevent the core from falling, the process is restarted to process the uncut portion.

Alternatively, in order to improve this and further automate the processing, there has been proposed a core processing apparatus including a magnet that attracts and holds the core so that the core does not drop.

[Problems to be Solved by the Invention]

However, the core processing device that only attracts the core with the magnet proposed above does not allow confirmation of core adsorption, so if such a device is incorporated into a wire electric discharge machine, it will be processed. The reliability and reliability of the system as a whole are not improved, and thus unmanned processing is difficult.

In view of such a point, the present invention is configured so that the presence or absence of core adsorption can be simply and surely confirmed by itself, and therefore, not only automation of processing but also complete unmanned can be realized. An object of the present invention is to provide a core processing device of such a wire electric discharge machine having high reliability.

[Means for Solving the Problems]

The present invention relates to the processing of a core, which has been an obstacle to automation or unmanned processing in a wire electric discharge machine, so that whether or not the core is attracted to a magnet can be determined simply and easily and reliably. Configure and ensure the processing
The reliability is dramatically improved so that the intended purpose can be achieved.

That is, according to the present invention, in the core processing apparatus of the wire electric discharge machine including the magnet for adsorbing and holding the core to convey the core generated during wire cutting of the workpiece, A voltage applying means for applying a predetermined voltage between the magnet attracting the core and the workpiece, and at least one of them for contacting the core and the workpiece are set in a direction substantially perpendicular to the wire feeding direction. Moving means for moving a distance, contact detecting means for detecting the presence or absence of electrical contact between the core and the workpiece, and whether the core is attracted to the magnet according to the presence or absence of electrical contact There is provided a core processing device that includes a suction determination means that determines whether or not the suction signal is output and outputs an abnormal signal.

[Action]

A predetermined voltage is applied between the magnet that attracts the wire-cut core and the workpiece, and at least one of the core and the workpiece is fixed in a direction substantially perpendicular to the wire feed direction so that the core and the workpiece contact each other. It is moved a distance and the presence or absence of its electrical contact is detected. Depending on the presence or absence of the contact, it is determined whether or not the core is attracted to the magnet, and an abnormal signal is output. This eliminates the uncertainty of core adsorption.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
Description and illustration of parts (parts) that are not particularly different from the conventional structure will be omitted, and only characteristic parts will be described in detail.

FIG. 1 is a head part 1 of a wire electric discharge machine equipped with a guide mechanism for guiding a wire 2 on the upper side of a work (not shown).
FIG. 2 is a schematic front view of the main part of FIG.

The illustrated head portion 1 corresponds to a Z axis (up and down) with respect to a work and a core, and an X axis (not shown) corresponding to three axial directions of an X axis and a Y axis orthogonal to each other in a plane perpendicular to the Z axis (up and down).
It is movable by being driven by a shaft, a Y-axis, and a Z-axis motor. On the front side of the head portion 1, a mechanical structure 4 forming an essential part of the core processing device of this embodiment is attached.

The mechanical structure 4 is basically a magnet 6 for attracting a core, an arm 7 to which the magnet 6 is attached at the tip, and an operating portion connected to the rear end of the arm 7.
It consists of two actuators 9 and 10. Two magnets 6 are provided so that one core is attracted to the core and the other is attracted so as to bridge the work and the core, the former reliably attracts the core, and the latter immediately after wire cutting. This is for eliminating relative movement (rattle) of the work.

The two actuators 9 and 10 are both attached to the head portion 1, and the rod 11 (actuating portion) projecting downward from the actuator 10 located on the lower side is directly connected to the inside so that a complex operation can be performed. There is. That is, the actuator 9 is a pneumatic cylinder, and the actuator 10 is a pneumatic rocking type cylinder having a rocking angle adjusting mechanism. The rod 11 is reciprocated in the longitudinal axis direction (vertical direction) by these two actuators 9 and 10. , And about a coaxial line.

Since the arm 7 is integrally connected to the rod 11 at the rear end portion thereof, as shown in FIG. 2, the arm A is accommodated along the head portion 1 and is opened (rotated) from the position A by a predetermined angle. It is possible to take four different positions, a position B, a position C further lowered by a predetermined distance from the position B, and a position D which is closer to the wire 2 which is rotated in the opposite direction by a predetermined angle.

The actuators 9 and 10 are provided with sensors 12 and 13 and sensors for detecting or capable of detecting respective positions.
14 and 15 are attached.

Next, in order to explain the control system for driving the mechanical structure 4 and the like, referring to FIG. 3, in the present embodiment, an NC of the wire electric discharge machine is provided without separately preparing a dedicated control device. The control device 51 serves as the main control part.

The NC control device 51 includes an operation control unit 53, a CPU 54, a program storage unit 55, a communication control unit 56, a data storage unit 57, an I / O control unit 58, and a motor control unit 59, which are interconnected by an internal bus 52. It is basically composed of a motor drive unit 60, the operation control unit 53 is electrically connected to an external operation panel 62, and the motor drive unit 60 is electrically connected to the X, Y, Z axis motors 63 for driving the head unit 1 described above. Has been done.

To the I / O control unit 58, the sensor 13 indicating that the operating portion of the actuator 9 is at the lower limit is connected, and the actuators 9 and 10 are connected via the actuator driving unit 65.

Further, a circuit system 67 between the arm and the work table and a circuit system 68 between the arm and the chip bucket are connected to the I / O control unit via a contact power supply and a signal detection unit 69.

These are for determining whether or not the core is attracted to the magnet 6 (or the arm 7).
In the former case, a predetermined voltage is applied between the arm 7 and the work table, and in the latter case, a predetermined voltage is applied between the arm 7 and the chip bucket. If not, it is not adsorbed). That is, referring to FIG. 4 showing the outline thereof, when the arm and the work table conduct (contact) with each other via the core and the work, the comparator 70 outputs High (C) and there is no conduction. In this case, Low is output (C). Since the comparator 70 outputs one of the predetermined binary signals depending on the magnitude of the two input (A, B) signals, this is sent to the NC controller 51. If input, it is possible to determine the presence or absence of core adsorption.

An example of the operation of the core processing device of the present embodiment having the above configuration will be described with reference to the flowchart shown in FIG.

The control routine of FIG. 5 is executed in a state before the core is completely cut off from the work by wire cutting, in other words, in a state where the core and the work are still connected, and the core is sucked and separated from the work. Up to the operation.

First, in step 501, electric discharge machining is stopped immediately before the completion of wire cutting, and the machining power supply is turned off to remove the high voltage between the wire and the work.

Next, the entire head unit 1 is raised upward by a predetermined amount by the Z-axis motor (step 503), and the arm 7 is set to the lower side (position D in FIG. 2) by the actuators 9 and 10 (step 505).

Next, the contact detection circuit is activated (step 507).

That is, as described above, an electric system that can be obtained by applying a predetermined voltage between the magnet 6 (arm 7) and the work (the work table on which the work is placed) and detecting the presence or absence of conduction (contact) of the work 67,69 Operate.

Then, the head unit 1 is lowered this time (step 50
9) Check the contact between the core connected to the work and the magnet 6 (step 513). At this time, if the magnet 6 and the core do not come into contact with each other for some reason (for example, dust is sandwiched between them), the head unit 1 continues to descend and collides with the work. Therefore, in order to prevent this, the sensor 13 of the actuator 9 for moving the arm 7 up and down is monitored (step 511), and when the head part 1 approaches the work more than necessary, the arm located between them is the head. 1, the sensor of the actuator 9 is moved upward relative to 1.
Since 13 is cut off (OFF), using the signal, for example, the movement of the head unit 1 is stopped (step 515), and an alarm is displayed on a monitor (not shown) or the like to indicate an abnormal situation (step 517). .

In step 513, when the magnet 6 and the core contact (adsorb), the descent of the head unit 1 is immediately stopped (step 519).

Next, in steps 521 to 525, the contact detection circuit is turned off, and the machining power source is turned on instead to perform wire cutting on the uncut portion of the workpiece and the core, and when that is completed, turn off the machining power source to the next step. move on.

The steps following step 527 are for determining whether or not the core is attracted to the magnet 6, and first,
The head portion 1 is raised by a predetermined amount (amount that does not completely remove the core from the work, for example, 1 mm to several mm) (step 527). This is done by magnet 6
This is because one of them adsorbs them in such a positional relationship as to bridge the work and the core as described above.

Then, the contact detection circuit is activated again (step 52
9) Check the contact (conduction) between the core and the work (step 5)
31). At this time, if there is no conduction, either the core is not simply attracted to the magnet 6, or even if it is attracted, the work and the core happen to be separated from each other with a predetermined gap. In order to discriminate this, the whole head part 1 is in the direction in which the core, which may be attracted to the magnet 6, comes into contact with the work, specifically, in any direction in the XY plane (further In other words, move a predetermined amount in the direction substantially perpendicular to the wire feed direction (step
533), the conduction (contact) between the work and the core (accordingly, the magnet 6 or the arm 7) is checked (step 535).

Then, at this time, if there is still no contact, it is considered that the core is not attracted to the magnet 6 (the core is likely to have dropped), and immediately the related operation is stopped (step 537). A warning is displayed on the monitor or the like that the is not adsorbed (step 539).

If there is contact between the work and the core in step 535, this means that the core is clearly attracted by the magnet 6, as in the case of contact in step 531.

Therefore, at this stage, the contact detection circuit is not needed, so it is cut off (step 541), the entire head unit 1 is raised by the Z-axis motor, and the core is completely pulled out from the work (step 543).

In the core processing control described above, whether or not the core is attracted to the magnet 6 is checked each time, and when an abnormality such as a core drop occurs, the machine is always stopped and the fact is displayed. Therefore, the uncertainty of the entire apparatus is eliminated, and automation or unmanned operation can be easily configured.

By the way, although the core is attracted by the magnet 6 and its confirmation can be surely obtained by the above, it is not enough to only attract the core in the actual work, and it is surely dumped to a predetermined place (for example, a tip bucket). The degree of perfection required is required.

Hereinafter, an example of an operation capable of realizing this will be described with reference to the flowchart shown in FIG.

First, in step 601, the arm 7 is moved to a predetermined upper position inside the tip bucket by using the movement function of the head 1 in the three-axis directions, and the arm 7 is arranged.

FIG. 7 is a perspective view showing the positional relationship between the arm 7 and the tip bucket 30 at this time. The tip bucket 30 includes a core killing plate 31 and a bucket body 32. 20
Is a core that is attracted to the magnet and conveyed.

At this time, the actuator 10 is driven to position the arm 7 at the position C (FIG. 2).

Next, the contact detection circuit is activated (step 603).
However, it is a magnet 6 (arm 7) and a tip bucket.
This is because a predetermined voltage is applied between 30 and 30 to detect the presence or absence of conduction (contact).

Next, at step 605, the condition flag F indicating that the core is attracted to the magnet 6 (or the tip bucket and the core contact each other) is reset (0).

Then, the arm 7 is pulled outward from the inside of the tip bucket 30 so that the core adsorbed by the magnet 6 can be killed inside by the side wall of the inside of the tip bucket 30 (step 607).

At this time, the conduction between the tip bucket 30 and the arm 7 (magnet 6) is monitored (step 609), and if this is not the case, the state of the flag F is determined in the next step 611 (in this case, obviously F = O. Yes, go to step 613.

In this step 613, it is judged whether or not it has moved a sufficient distance to kill the core, and if it is still moving (NO), it returns to step 607 and repeats these series of operations. On the other hand, when the arm 7 has already moved a predetermined distance (YES), it is considered that the core is not originally attracted to the magnet 6 because the flag F = 0. Therefore, the related operation is stopped (step 615), and a warning is displayed on the monitor or the like that the core has dropped before the above-mentioned killing work, that is, during transportation (step 617).

At step 609, tip bucket 30 and arm 7
When there is conduction (contact) with the (magnet 6), it is considered that the core is adsorbed to the magnet 6 of the arm 7, and the arm 7 and the tip bucket 30 are conducted through it, and In step 619, the flag F is set (1).

Next, in step 621, it is determined whether or not the predetermined distance sufficient to kill the core has been moved, and if it has already moved (YES), the core and tip bucket 30 are still in contact (F = 1), the killing of the core is incomplete (unsuccessful). Therefore, the related operation is stopped (step 623), and a warning to that effect is displayed on the monitor (step 625).

On the other hand, if the predetermined distance has not been moved in step 621, the process returns to step 607, and then steps 609, 61.
Run this loop like 9,621. In the meantime, if there is no contact between the core and the tip bucket (step 60
9) Go to step 611, and since the flag F = 1 at this time, go to step 627. At this stage, F = 1 and no conduction (contact) between the arm 7 and the tip bucket 30 means that the core adsorbed by the magnet 6 comes into contact with the tip bucket 30 during the killing work. (F = 1), which means that the core has been killed as it is (contact NO), in other words, the core has fallen into the tip bucket 30 and is well accommodated. Therefore, the movement of the arm 7 may be stopped (it may be possible to move the above predetermined distance according to a fixed form),
The contact detection circuit is turned off (step 629), the head unit 1 and the arm 7 are returned to their initial positions (step 631), and this subroutine is finished.

According to the core processing control shown in FIG. 6 explained above, the core is not dropped during the transportation, or the chip bucket
Since it is possible to ascertain whether or not the core has been killed within 30, by combining this control with the control shown in Fig. 5 described above, consistent and highly reliable control from core adsorption to dumping is possible. It is possible to achieve automation and complete unmanned operation.

〔The invention's effect〕

As described above, according to the present invention, the presence or absence of core adsorption can be easily confirmed by itself and the corresponding output can be performed. Therefore, highly reliable automation or unmanned core processing can be easily constructed. obtain.

[Brief description of drawings]

FIG. 1 is a schematic front view of a main portion of a head portion according to an embodiment of the present invention, FIG. 2 is a side view of the head portion of FIG. 1, FIG. 3 is a general schematic configuration diagram of a control system, and FIG. FIG. 5 is a schematic configuration diagram of a contact detection circuit for detecting the presence or absence of core adsorption, FIG. 5 is a flowchart showing an example of control for adsorbing the core, and FIG. 6 is an example of control for discarding the adsorbed core. FIG. 7 is a perspective view when the arm moves to a predetermined position of the tip bucket. 1 ... Head part, 2 ... Wire, 4 ... Mechanical structure, 6
…… Magnet, 7 …… Arm, 9 …… Pneumatic cylinder (actuator), 10 …… Pneumatic oscillating type cylinder (actuator), 11 …… Rod, 12, 13, 14, 15, …… Sensor, 20 …… Middle Child, 30 ... Tip bucket, 31 ... Killing plate, 32 ... Bucket body.

Claims (1)

[Claims] 1. A core processing device for a wire electric discharge machine, comprising a magnet for adsorbing and holding a core for conveying a core produced during wire cutting of an object to be processed. Voltage applying means for applying a predetermined voltage between the magnet and the workpiece, and at least one of them is moved by a predetermined distance in a direction substantially perpendicular to the wire feeding direction so as to bring the core and the workpiece into contact with each other. Moving means, contact detection means for detecting the presence or absence of electrical contact between the core and the workpiece, and whether or not the core is attracted to the magnet depending on the presence or absence of the electrical contact. A core processing device for a wire electric discharge machine, comprising: suction determination means for determining and outputting an abnormal signal.