JPH02279216A - Wire electric discharge machining method and apparatus thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention involves running a wire electrode under tension, generating an electric discharge between the workpiece and the wire electrode, and using the discharge energy to move the workpiece. The present invention relates to a wire electrical discharge machining method and apparatus for electrical discharge machining.

[Conventional technology]

Regarding wire electric discharge machines, the current situation is that a workpiece is machined using a portion where the wire electrode runs in a vertical direction, in other words, in an up-down direction. The wire electrode is guided by a row fixed to the main body of the wire electric discharge machine and is supplied to a wire head having a wire guide.

On the other hand, the work table on which the workpiece is attached is operated in the X direction and Y direction according to the machining status of the workpiece according to commands from the NC device
The movement of the two is combined, and machining progresses between the wire electrode and the wire electrode supplied to the wire head. During machining, the wire electrode repeats servo movement, and the relative movement of the two causes the workpiece to move. It is electrical discharge machined into a predetermined shape.

By the way, in recent years, with the automation of wire electrical discharge machines,
Wire electrical discharge machines are now equipped with automatic wire electrode connection devices, and it has become necessary to remove the core from the workpiece due to demands such as cutting multiple parts of one workpiece and tapering the cutting edge. . However, conventional wire electrical discharge machines are not equipped with a means for removing the core from the workpiece by cutting off the workpiece, making it impossible to remove the core. It may fall and get caught between the upper and lower nozzles where machining fluid is spouted, making it impossible to continue machining. Therefore,
When machining multiple parts of one workpiece, do not process the entire contour, but leave a part of the machining area to prevent the core from separating from the workpiece and falling. Currently, multiple locations are machined one after another, and after the machining is complete, the core is manually separated from the workpiece and removed.

Alternatively, as a conventional core extraction device, a robot arm can be used as a separate device for a wire electrical discharge machine.
A robot arm with a magnet attached thereto is disclosed. Immediately before electrical discharge machining a workpiece using a wire electrical discharge machine and cutting off the core, the robot arm of the core extraction device is swung to the area where the core is located, and the core is attracted to a magnet attached to the robot arm. A method for removing cough cores from a workpiece is disclosed.

[Problem to be solved by the invention]

However, in conventional wire electric discharge machines, those that are not equipped with a core removal means for removing the core cut from the workpiece by wire electric discharge machining,
Only part of the machined part of the workpiece is left without wire electrical discharge machining, and after machining the machined parts one after another, the core must be manually separated from the workpiece and removed. It takes a considerable amount of time to remove. Also,
Even when automatic operation is performed with a wire electrical discharge machine equipped with an automatic wire connecting device, etc., there is work to remove the core from the workpiece, and there is a problem that wire electrical discharge machining cannot be performed continuously due to manual handling. be.

In addition, in a core takeout device in which a robot arm is installed as a separate AM from a conventional wire electric discharge machine, the robot arm interferes with the wire head, and the direction in which the robot arm moves is limited, making it difficult to take out the core. In addition, since the robot arm is installed as a separate device, the device itself becomes complicated, and the installation space is also a problem due to interference with automatic wiring devices, taper processing devices, etc., making it difficult to install the robot arm. The problem is that there is no degree of freedom.

The purpose of this invention is to solve the above problems,
When machining a workpiece, it is possible to smoothly, immediately and reliably remove the core produced by the machining, and in particular, to automatically perform wire electrical discharge machining at multiple locations one after another on one workpiece. It is possible to perform continuous processing, and also when machining the shape of a part several times, for example, when machining multiple times such as second cut, third cut, etc., when performing taper cut machining of the cutting edge of the mold. It is essential to remove the cores that are separated from the workpiece, etc., but these cores can be automatically removed (
An object of the present invention is to provide a wire electrical discharge machining method and an apparatus therefor.

[Means to solve the problem]

In order to solve the above problems and achieve the above objects, the present invention is configured as follows.

That is, in the present invention, a workpiece placed opposite a wire head is electrically discharge-machined into a predetermined shape using electric discharge energy generated between the workpiece and a wire electrode. In the wire discharge IS machining method for cutting off the middle f, the step of performing electric discharge machining on the one crop into a predetermined machined shape, energizing an electromagnet disposed on the outer periphery of the jet nozzle attached to the wire head immediately before cutting off the middle f. a step of attracting and holding the core to the electromagnet; a step of cutting the wire electrode while moving the wire head to extract the core from the workpiece after separating the core from the L crop; i; 1) moving the table on which the wire nod is attached to move the wire head to a predetermined position; and releasing the core from the electromagnet by de-energizing the magnet; A wire discharge application consisting of] a method.

The present invention also provides a wire electrical discharge application (L) for electrical discharge machining (4) of electrical discharge machining a workpiece placed opposite a wire head to a predetermined machined shape using electrical discharge energy generated between the workpiece and a wire electrode. In the apparatus, the wire head is equipped with a wire guide for guiding the wire electrode, a jet nozzle attached to the wire head for spraying machining fluid, and a jet nozzle disposed on the outer periphery of the jet nozzle to produce one crop by electric discharge machining. An electromagnet capable of attracting and holding a core to be separated by electromagnetic force, an attracting surface of the electromagnet is arranged with a gap between it and the crop, and a gap is formed between the electromagnet 71 and the jet nozzle. The present invention relates to a wire electrical discharge machining apparatus which is characterized in that it is arranged in a V state.

[Effect]

The wire j attack and attack method according to the present invention is configured as described in section 4-7, and operates as follows. That is, in this invention, the core of the electromagnet can be attracted and removed from the workpiece by simply energizing the electromagnet disposed around the outer periphery of the jet nozzle. Moreover, by controlling the excitation timing of the electromagnet just before the core is separated from the workpiece, there is no possibility that the accuracy J2 will be adversely affected by the electrical discharge machining of the workpiece (and also for L crops). Even when performing electric discharge 1 on multiple wires, one core is separated from the workpiece, the core is expelled by excitation of an electromagnet,
Next, the workpiece is twisted at another location j11. Electrical machining can be performed successively one after another by the same process, and wire electric discharge machining can be automated.

In addition, the wire electrical discharge machining device according to the present invention requires only a simple change to the conventional wire electrical discharge machining device by arranging an electromagnet around the outer periphery of the C jet nozzle, and the structure of the device itself is simple. In terms of installation space, there are no problems with the wire head, automatic wire connection device, Qiba I + device, etc. In addition, since the electromagnet can be moved integrally with the wire head, after the core is attracted to the electromagnet, the wire head can be moved up and down in the
By moving the table to move the throat in the X and Y directions, the core can be easily moved to a predetermined storage location and removed.

〔Example〕

Hereinafter, an embodiment of the apparatus according to the present invention will be described in detail with reference to the present invention. FIG. 1 is a schematic diagram showing an embodiment of a wire electrical discharge machining apparatus according to the present invention.

In this wire device, the workpiece 5 is set on the work table in an appropriate state using a support means 8 and the like. Generally, the no-cut groove is placed in a liquid tank that constitutes a machining fluid supply device, and there is a groove adjacent to the workpiece groove in this machining liquid tank.
- A core storage container (not shown) is arranged to accommodate cores 6, which are cut-off IT materials from the crop 5. J-wire head; 3 is a guide for the wire electrode 10 in the Z-axis direction 1i11
It is equipped with a wire guide 4 that The upper nozzle 1, which is a jet nozzle fixed to the navel which forms the Z axis of the upper wire head 3, is arranged on the outer periphery of the wire guide 4.

The upper nozzle 1 is for spraying the machining fluid supplied from the machining fluid supply device onto the wire discharge application site. An electromagnet 2 is arranged on the outer periphery of the upper nozzle 1 in order to attract the medium 7-6 to be cut off from the workpiece 5. The electronic dolmen 2 is attached to the nozzle 1 by leaving a slight gap 11 between the electromagnet 2 and the outer periphery of the upper nozzle I so that the electromagnet 2 can move slightly relative to the upper nozzle 1. In FIG. 0, a locking member 13 fixed to the electromagnet 2 with a bolt 15 is attached by fitting into an annular groove 14 formed on the outer periphery of the upper nozzle l. It goes without saying that the upper nozzle 1 is preferably made of a non-magnetic material such as resin, ceramics, stainless steel, etc. so that no attraction force is exerted by the excitation of the electromagnet 2. Further, the attraction surface 9 of the electromagnet 2 is arranged to face the upper surface of the workpiece 5 placed on the work table, with a slight gap 12 therebetween. Therefore, the electromagnet 2 moves integrally with the upper wire head 3. Therefore, when the electromagnet 2 attracts the core 6 separated from the workpiece 5, the throat 3 is moved upward on two axes to the upper wire, and then the table (not shown) on which the upper wire head 3 is attached is moved. By moving the upper wire in the horizontal direction, that is, in the X-axis direction and the Y-axis direction, the throat 3 can be moved in the X-axis direction and the Y-axis direction. Thereby, the core 6 attracted to the electromagnet 2 can be positioned above the core storage container. When the core 6 is located above the core storage container, the excitation of the electromagnet 2 is released, so that the core 6 is placed into the core storage container. This wire electrical discharge machining device has an automatic wire connecting device and a taper cuff unit attached to the throat 3 to the upper wire at -C, and a 7 throat 3 and a lower wire head (
(not shown) is attached. Generally, in wire electrical discharge machining equipment, the work table is oriented horizontally, that is, in the
It is configured so that it can be moved in any direction. That is, the work table on which the workpiece 5 is attached moves in the X direction and the It is configured such that machining progresses between 10 and 10. Furthermore, the wire electrical discharge machining apparatus includes an upper wire head 3 and a lower wire head for a workpiece 5, and an upper nozzle 1 and a lower nozzle 7, which are machining fluid spray nozzles attached to these wire heads.

The wire electrical discharge machining device according to the present invention is configured as described above, and in the operation of the wire electrical discharge machining device,
The core separated from the workpiece 5 can be removed by the following method.

In the wire electrical discharge machining method using this wire electrical discharge machining device, the wire Tl pole is moved using an automatic wire connecting device so that the wire electrode 10 is run against the workpiece 5 placed opposite to the upper wire head 3. Set lO through the start hole of workpiece 5. In this state, while the wire electrode 10 is running, the work table is operated by a servo function to move relative to the wire electrode IO, that is, to move in the X direction and the X direction, by a command from the NC device. The workpiece 5 fixed to the worktable is moved by controlling the movement of the worktable.
As the movement of the workpiece 5 is controlled, the discharge energy generated between the workpiece 5 and the wire 11i pole 10 causes the wire electrode 10 to shape the workpiece 5 into a predetermined shape. Electric discharge machining is performed. Wire electrical discharge machining is performed to machine a workpiece 5 into a predetermined shape and cut a core 6 from it. , workpiece 5
It is energized just before the core 6 is separated from the core 6.

By the way, in a wire electric discharge machine, a predetermined workpiece 5
A predetermined machining shape to be subjected to wire electric discharge machining is stored, and machining progresses according to the machining shape. Therefore, since the point at which the electrical discharge machining of the workpiece 5 ends, that is, the point at which the core 6 is cut off from the workpiece 5, is stored in advance in the NC device, the excitation timing of the electromagnet 2 can be changed from the workpiece 5 to the point at which the core 6 is cut off from the workpiece 5. It is possible to set it immediately before cutting off the core 6. That is, it is possible to incorporate an electric signal that causes a current to flow through the electromagnet 2 to excite the electromagnet 2 into the control circuit of the NC device. Therefore, N.C.W.
When the electromagnet 2 is excited by a preset electric signal from [, the electromagnet 2 becomes in a state where it attracts the core 6. At this time, the part of the workpiece 5 that is not separated and faces the electromagnet 2 is also attracted by the force of the ring 651, but 1. The workpiece 5 itself is fixed to the work table, and the adsorption surface 9 of the electromagnet 2 has a gap 12 with respect to the workpiece 5, so that there is a gap 12 between the workpiece 5 and the workpiece 5. By continuing to perform wire electrical discharge machining on the L crop 5, the core 6 is separated from the workpiece 5, but at this time, the gap between the inner circumference of the electromagnet 2 and the outer circumference of the upper nozzle 1 Since a slight gap 11 is formed between the wire electrode 10 and the workpiece 5, the electromagnet 2 does not follow the moving upper nozzle 1 until the wire electrode 10 completely separates the middle F6 from the workpiece 5. The core 6 is attracted to the attraction surface 9. When the middle 76 is separated from the workpiece 5 as the wire electrical discharge machining progresses, the application of the voltage between the electrodes IO and the workpiece 5 is stopped. will be stopped.

Then, when the wire head 3 is moved upward, 1
- together with the wire head 3, the electromagnet 2 also moves in two directions. As a result, the core 6 attracted to the magnet 2 is lifted upward, and the core 6 is extracted upward from the workpiece 5. When the inner core 76 is extracted from the workpiece 5, the automatic wire connection device is activated to cut the wire electrode 10.Next, the table with the upper wire guide 3 attached is moved, and the throat 3 is connected to the upper wire of the north core. Move until the middle 76 is positioned above the storage container. Core 6 is 1. When positioned above the core storage container, the excitation of the i magnet 2 is released, and the t
Release medium Y~6 adsorbed to e1 stone 2.

The core 6 released from the electromagnet 2 falls and is stored in the core storage container.

In order to perform wire electrical discharge machining on the workpiece 5 again in the next predetermined machining shape, the wire head 3 is moved by -1-3, and the wire guide 4 fixed to the upper wire head 3 is
The movement is controlled so that it is located at the next start hole formed in the workpiece 5. When the wire guide 4 is located above the start hole, the wire electrode 10 is fed out and passed through the start hole of the workpiece 5 to automatically connect the wire electrode 10, and the above steps are repeated 1. Workpiece 5
At the same time, wire electrical discharge machining is performed, and the core separated from the workpiece 5 is removed.

Note that the wire electrical discharge machining operation for the workpiece 5 can be performed in the same manner as the conventional process, and a description of these operating processes will be omitted here.

The rear electric discharge application according to the present invention is constructed as shown in F, and the wire discharge application is performed as shown in L, so even if the workpiece is subjected to multiple applications, Even if there is a dished part, wire electrical discharge machining can be performed automatically and continuously.

Hereinafter, an embodiment of the wire electrical discharge machining method according to the present invention and the one-twir electrical discharge machining apparatus for achieving the method has been described in detail. Of course, it is not limited. For example, in the above embodiment, the operation-1 culm was explained, but it goes without saying that the operation does not necessarily have to be carried out in the same operation steps as in section 1-. That is, the present invention can be modified in various ways without departing from the spirit of the technical idea defined by the claims.

〔Effect of the invention〕

The present invention is configured as described above and has the following effects. That is, this wire electrical discharge machining method involves the step of electrical discharge machining a workpiece into a predetermined machined shape, and the step of energizing an electromagnet placed on the outer periphery of a jet nozzle attached to a wire head immediately before cutting off the core to cause the electromagnet to a step of sucking and holding the core; -After separating the core from the L crop, moving the twister head to extract the core from the workpiece and cutting the wire electrode;
The jet nozzle is composed of the step of moving the wire head to a predetermined position by moving the wire guide attached thereto, and the step of releasing the core from the electromagnet by de-energizing the electromagnet. To easily remove the core from the workpiece by attracting the core to the electromagnet by simply exciting a W1 main electromagnet placed on the outer periphery with a preset electric number from an NC device. I can do it.

Moreover, the excitation timing of the electromagnet is maintained just before the core is separated from the workpiece, and then electric discharge machining is performed to completely separate the core from the workpiece, so that the workpiece can be machined as easily as possible. If the core was left without being completely separated from the workpiece and the core was later removed manually from the workpiece, protrusions would occur on the workpiece, but the wire electrical discharge machining method according to the present invention In this case, it is possible to obtain an extremely good machined surface in terms of machining accuracy without producing protrusions, depressions, etc. on the machined surface of the workpiece, which adversely affects the accuracy of wire electric discharge machining on the workpiece. In addition, when performing multiple wire electrical discharge machining on the workpiece, one core is cut off from the workpiece, the core is ejected by excitation of the electromagnet, and then the core is removed from the workpiece. Wire electrical discharge machining of different parts of an object can be performed one after another in a similar process, and electrical discharge machining of the wire electrical discharge machining apparatus can be automated. Moreover, the operation itself is a simple control process, and the removal operation of the core from the workpiece can be achieved reliably and quickly, and the core separated from the workpiece can be removed. It can be eliminated reliably and quickly. Therefore, it is possible to automatically perform wire electrical discharge machining at multiple locations one after another on one workpiece, and it is also possible to perform second cut and third cut where the shape of several locations is machined. It is possible to carry out electric discharge machining such as the following, and to perform taper cutting of the cutting edge of the mold.

Further, the wire electrical discharge machining apparatus according to the present invention includes a wire head equipped with a wire guide for guiding a wire electrode, a jet nozzle attached to the wire head for spraying machining fluid,
An electromagnet arranged around the outer periphery of the jet nozzle and capable of attracting and holding the core to be separated from the workpiece by wire electric discharge machining using electromagnetic force; In addition, since the electromagnet is arranged with a gap between it and the jet nozzle,
Unlike the conventional method, there is no need to swing the robot arm to take out the core, there is no interference from a wire head, etc., and there is no possibility that the direction of taking out the core becomes impossible due to an obstacle in the head.

Simply attaching the electromagnet to the outer periphery of the jet nozzle, pulling out the core from the workpiece can be achieved by normal vertical movement of the wire head, and horizontal movement in the XY direction can be achieved by attaching the workpiece. The movement of the table can be used, a special take-out device is not required, and the structure is simple and can be manufactured at low cost. Further, since gaps are provided between the electromagnet and the jet nozzle and between the electromagnet and the workpiece, the 1i magnet will not interfere with electrical discharge machining of the workpiece (machining accuracy It has no negative effect on the.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a wire electrical discharge machining apparatus according to the present invention. 1-- Upper nozzle (jet nozzle), 2-- Electromagnet, 3-- Upper wire head (wire head),
4--Wire guide, 5--Workpiece, 6-- Core, 7--Lower nozzle, 9--...
・Adsorption surface, 10---wire electrode, 11.12---
...-Gap.

Claims (2)

[Claims] (1) A wire that uses electrical discharge energy generated between a workpiece placed opposite the wire head and a wire electrode to perform electrical discharge machining on the workpiece into a predetermined machining shape to separate the core from the workpiece. In the electric discharge machining method, a step of performing electric discharge machining on the workpiece into a predetermined machined shape, an electromagnet disposed on the outer periphery of a jet nozzle attached to the wire head is energized immediately before cutting off the core, and the electromagnet is energized into the core. a step of holding the core by suction; a step of separating the core from the workpiece; a step of moving the wire head to extract the core from the workpiece and cutting the wire electrode; and a step of attaching the wire head. A wire electrical discharge machining method comprising the steps of: moving a table to move the wire head to a predetermined position; and releasing the core from the electromagnet by de-energizing the electromagnet. (2) In a wire electrical discharge machining device that electrically discharges a workpiece placed opposite a wire head into a predetermined machining shape using electrical discharge energy generated between the wire electrode and the workpiece, the wire electrode is The wire head includes a wire guide for guiding, a jet nozzle attached to the wire head that sprays machining fluid, and a core placed around the outer periphery of the jet nozzle that uses electromagnetic force to attract the core that is separated from the workpiece by wire electrical discharge machining. A wire discharge characterized by a retainable electromagnet, an attracting surface of the electromagnet being arranged with a gap between it and the workpiece, and a gap between the electromagnet and the jet nozzle. Processing equipment.