JP2586956B2 - Core removal method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for removing a core generated by wire electric discharge machining.

2. Description of the Related Art When machining a closed figure from a workpiece in wire electric discharge machining, the inside of the figure is cut out as a core.

Since this core is usually put on the lower nozzle of the wire electric discharge machine, the work is moved to continuously process a plurality of figures from the same work (movement of the table).
At this time, the lower nozzle may be rubbed with the lower nozzle, or may be obliquely caught between the workpiece and the lower nozzle depending on the shape of the core or the position of the center of gravity, and may damage the lower nozzle. In addition, the core may be scratched, which may impair its value as a product.

Therefore, various methods have been studied for removing the core generated each time one figure is processed, and a method of placing the core on a smooth support plate provided on the lower nozzle side and dropping it with a moving workpiece, Do not completely separate the core from the work, but connect it slightly and hit it with a hammer from above, or hold the separated core with a suction means such as a magnet, suction pad, etc., so that it will not be in the way away from the processing position For example, a method of transporting to a position has been proposed.

Among them, the method of holding and transporting by the suction means is excellent in that the product is not damaged, but if there is a step where the core upper surface is lower than the work upper surface at the processing location, the suction means sufficiently approaches the core upper surface. May not be able to hold the core.

SUMMARY OF THE INVENTION The present invention relates to a method for removing a core that can hold a core sufficiently and reliably transport it to a removal position even when a step where a core upper surface is lower than a work upper surface at a processing location as described above. Providing is an issue.

Means for Solving the Problems A method for removing a core generated in wire electric discharge machining, comprising the following steps sequentially performed.

After finishing the processing of one figure on the work, the core suction means is arranged above the core separated from the work by the processing (step a).

The fluid is discharged from the lower nozzle, and the core is lifted and held by the suction means (step b).

Action The steps a and b ensure that the core approaches the adsorption means.

Embodiment FIG. 3 shows the whole of a wire electric discharge machine 1 for carrying out the method of the present invention. An upper nozzle 3, a UV axis mechanism 4, an automatic wire connection device (AWF device) 5, a core removing device 6 are provided on a Z axis 2. With
These are moved up and down together with the Z axis 2.

Reference numeral 7 denotes a lower arm, which is provided with a lower nozzle 8 at the tip thereof, which is located at a position facing the upper nozzle 3.

Reference numeral 9 denotes a wire, and reference numeral 10 denotes a table. The wire electric discharge machine 1 is operated under the control of the NC controller 11.

The specific configurations and operations of the wire electric discharge machine 1 and the AWF device 5 are known, respectively.

As shown in FIG. 2, the core removing device 6 includes a horizontal cylinder 12 fixed to a machine frame of the UV shaft mechanism 4 and a piston 13 thereof.
A vertical cylinder 14 fixed to the tip of FIG.
Core holding part at the tip of piston 15 in vertical cylinder 14
16 (core adsorption means) is fixed horizontally. piston
Numeral 15 is rotated by a motor 17 mounted on the vertical cylinder 12, and reciprocates the core holding portion 16 in a range of about 180 °.

The core holding portion 16 has an attraction surface 18 to which a permanent magnet is attached, on the lower surface closer to the distal end side than the position attached to the piston 15.

In FIG. 2, reference numeral 19 denotes a work (magnetic material),
Reference numeral 20 denotes a core, the upper surface of the formed core 20 is lower than the upper surface of the work 19, and there is a step in the processing position.

When the processing of one closed figure for the work 19 is completed
The AWF device 5 operates to cut the wire 9, the Z-axis 2 rises, and the NC control device 11 enters the core removal mode (FIG. 1 (a)). At this time, the cut core 20 is hooked on the lower arm 8, and the core holding portion 16 of the core removing device 6 rises and is drawn toward the upper nozzle 3. In addition, the suction surface 18 is at a home position where the suction surface 18 is turned to a position away from the upper nozzle 3.

In FIG. 1A, the inclination of the core 20 is illustrated in an emphasized manner. Actually, the lower surface of the work 19 and the lower nozzle 8
Since the distance from the tip is about 0.2 mm, the inclination of the core is very small.

When the core removing operation is started, the vertical cylinder 14 is driven in the core removing device 6, and the core holding unit 16 is lowered,
Next, the core holder 16 is moved by the motor 17 through the piston 15.
Is rotated so that the suction surface 18 is disposed below the upper nozzle 3 (FIG. 1 (a), position indicated by a broken line).

Next, the Z-axis 2 is lowered and the suction surface 18 of the core holding unit 16 is set to be equal to or slightly separated from the upper surface of the work 19, and the core holding unit 16 is arranged above the core. on the other hand,
The table 10 is slightly moved and the center of gravity of the core 20 (NC
(Set in the control device 11 in advance) is moved to the tip position of the lower nozzle 8.

Then, the working fluid is discharged from the lower nozzle 8 at about 15 atm, and the core 20 is lifted by the force, and the core 20 is suctioned.
18 is held by magnetic force. (FIG. 1 (b)).

At the time of close contact, the position of the suction surface 18 with respect to the work 19 is controlled by the descending distance of the Z-axis 2 set in the touch sensor or the NC control device 11.

The strong working fluid is supplied for a set time (2 to 3 seconds) and then stopped, and then the table 10 is driven to move the work 19 in a predetermined direction. The air is fed in and the suction surface 18 is also moved by the piston 13.

As a result, the core 20 moves a predetermined distance (50 to 60 mm) together with the work 19 while being held by the core holding unit 16.
(FIG. 1 (c)).

In this embodiment, the predetermined direction is determined by the direction in which the piston 13 extends, and the predetermined distance is limited by the length of the piston 13.

The table 10 and the core holder 16 are moved or stopped when the moved core 20 is out of the core drop-prohibited area, such as the lower nozzle 8 and the upper part of the lower arm 7.

Then, while the table 10 is stopped, only the core holder 16 is returned to the position of the upper nozzle 3 by the horizontal cylinder 12, so that the core 20 is detached from the core holder 16 so as to be scraped off by the work 19, It falls to that position (FIG. 1 (d)).

Next, the Z-axis 2 is raised, and at the upper end position, the piston 15 is rotated by the motor 17, and further, the core holder 16 is raised by the vertical cylinder 14 to bring the used holder 16 to the home position. .

As a result, the core removing operation is completed, the NC controller 11 moves the work 19 to a position for processing the next graphic, and shifts to an automatic wire connection operation.

The control for moving the core 20 to the outside of the drop-prohibited area is performed by storing the necessary moving distance in the set moving direction in the NC control device 11 in advance.

In this manner, the core 20 is reliably removed to a position deviating from the positions of the lower nozzle 8 and the lower arm 7 each time processing of one figure is completed. In addition, the core 20 does not come into contact with the lower nozzle 8 at the time of removal, and does not collide with the nozzle or the lower arm 7 when dropped.

When there is no step between the upper surface of the work and the upper surface of the core, or when the upper surface of the core is higher, it is unnecessary to discharge the fluid from the lower nozzle 8, but there is no particular inconvenience even if it is discharged.

When the lower surface of the core 20 adsorbed in the above is positioned higher than the upper surface of the work, the core 20 does not engage with the work 19,
Since the above scraper action cannot be expected, the upper surface on the high side of the work 19 comes to the wire side at the time of processing so that the processing is completed.

 The above is the embodiment.

The attraction surface 18 may be formed by the magnetic force of an electromagnet or a combination of this and a suction pad utilizing a vacuum. In the case of using an electromagnet, it is easy to release a core made of a magnetic material by suction.

The suction surface 18 can be constituted only by a suction pad using a vacuum. In this case, air may be used as the fluid for lifting the core.

In the embodiment, the core is removed after the wire is cut and removed. However, the core can be removed without cutting the wire. However, since the tip of the lower nozzle is on the processing path, the lifting capacity of the core by the discharged fluid is reduced.

After the held core is pulled upward from the work, only the core may be moved horizontally to the removal position.

Advantageous Effects of the Invention Even at a step where the core upper surface is lower than the work upper surface, the core can be reliably removed.

Because it is absorbed, it does not damage the product,
The core does not damage the lower nozzle, etc.

 The mechanism of the core removing device can be configured relatively easily.

[Brief description of the drawings]

1 (a) to 1 (d) are front views showing an operation process, and FIG.
The figure is a front view of the main part, and FIG. 3 is a perspective view showing the whole. 16 core holding unit (core suction means), 18 suction surface, 20
...... Koko.

Claims (1)

(57) [Claims] 1. A method for removing a core generated in wire electric discharge machining, comprising: after finishing machining of one figure on a workpiece, disposing a core suction means above the core separated from the workpiece by machining; A method for removing a core, comprising discharging a fluid from a nozzle and holding the core by a suction means having lifted the core.