JPH0818186B2 - Wire cut electrical discharge machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a state in which wire electrodes are sequentially set along a predetermined path and processing can be started during an automatic wire passing operation of the wire electrodes prior to processing. The present invention relates to a wire-cut electric discharge machining device provided with an automatic line-passing confirmation device that determines whether or not a route up to the point is appropriate and continues or stops the line-passing work.

[Conventional technology]

When performing contour machining such as die cutting with a wire cut electric discharge machining device, a machining starting pilot hole for passing the wire electrode is formed in the workpiece in advance, and the wire electrode is inserted into the pilot hole and the workpiece is machined. The body is positioned between two ordinary arms, and the wire electrode is given a proper tension between a pair of electrode guides provided at the tips of the two arms to form a straight line through the machining starting pilot hole. Positioning and tensioning are performed as described above, and during processing, a working liquid is supplied between the wire electrode and the work piece, and an intermittent voltage pulse is applied between them to generate an electric discharge. Giving a relative machining feed between workpieces in a direction almost perpendicular to the wire electrode axis between the guides,
Thereby, desired contour processing is performed.

In addition, when performing multiple contour processing on one work piece continuously, after one work is completed, the wire electrode inserted into the work piece is cut to collect the used wire electrode. After moving the work piece to a predetermined position, insert the wire electrode into the next processing start pilot hole, set the wire electrode along the predetermined path, and then perform the same processing as above. is there.

[Problems to be solved by the invention]

However, the wire electrode is a very thin wire with a diameter of 1 mm or less, usually about 0.05 to 0.4 mm, and it is automatically inserted into the processing start pilot hole formed on the workpiece before each processing is started. In addition, it is a very difficult work to securely stretch the pair of guides.

In the conventional device, since the wire electrodes are sent out one after another during the above work, when the wire electrodes are not properly inserted into the processing start pilot hole, or even when the wire electrode is successfully inserted into the pilot hole, the wire electrode is not passed through the predetermined route. If the wire electrode is deviated from the above path, the wire electrode becomes entangled, the work is interrupted, the subsequent processing cannot be performed continuously, and the feed roller and its driving device are damaged.

In particular, after the wire electrode sent through the wire electrode positioning guide in one processing head is inserted into the processing start pilot hole of the workpiece and is received by the wire electrode positioning guide in the other processing head, Although it is necessary to change the direction of the wire electrode and guide it to the wire electrode collecting portion, the wire electrode often deviates from a predetermined path at the direction changing portion, and it is necessary to detect this promptly.

The present invention has been made to solve the above problems, and its purpose is to insert a wire electrode into a preformed pre-forming hole and to install a wire electrode in a stretched state. In the confirmation in the above, and after inserting the pilot hole, when a trouble such as the wire electrode deviating from a predetermined guide path occurs in the path where the wire electrode changes direction and is transferred to the wire electrode collecting portion, this is immediately detected, By stopping the feeding of the wire electrode and the like, it is possible to prevent the wire electrode from being entangled with each other so that the subsequent processing can be promptly performed, and also to prevent the feed roller and its driving device from being damaged.

[Means for solving problems]

Thus, the above-mentioned object is to provide a plurality of wire electrode detectors sequentially provided along the wire passage path of the wire electrode, and at least the following three locations, that is, the wire electrodes are the processing start pilot holes of the workpiece. Wire electrode passage path portion of the machining head having one positioning guide on the side of feeding to and the wire electrode inserted through the machining start prepared hole, and the other positioning guide facing the one positioning guide. And a wire electrode of a wire electrode take-out device for redirecting the wire electrode coming through the wire electrode wire passage part of the latter machining head and transferring the wire electrode to the collecting part. The wire passage part, a plurality of wire electrode detectors sequentially provided at a plurality of places on the wire passage including three places, and the output of each of the wire electrode detectors at the three or more places as an input, After the ear electrode detector has transmitted the wire electrode tip passage detection signal, the wire electrode detector of the subsequent stage similarly detects whether or not the wire electrode tip passage detection signal is transmitted within a predetermined time. A wire check circuit that detects the part where the detection signal has stopped and sends an output signal for continuing or stopping the wire electrode wire work depending on the situation, and automatic wire wire connection of the wire electrode before the start of processing. This can be achieved by the wire-cut electric discharge machine according to the present invention, which is equipped with an automatic passage confirmation device that is activated during work.

[Work]

With the above-mentioned structure, the wire electrode detector is provided at a plurality of positions including at least three main parts on the path of the wire electrode, and the wire electrode is detected during the automatic wire passing operation before the start of processing. The passage of the tip of the wire is sequentially detected, their outputs are input to the wire confirmation circuit, and the wire confirmation circuit sends a signal that the wire electrode detector at each stage has detected the tip of the wire electrode. It is confirmed whether or not the wire electrode detector of the subsequent stage has transmitted the wire electrode detection signal within the time of, and by this, the adequacy of the progress status of the automatic wiring work is confirmed, and the transmission of the wire electrode detection signal is confirmed. In addition to detecting a squeezed line obstacle, an output signal is sent according to the situation, and the line work is immediately stopped when an abnormality occurs, thereby entanglement or feeding of the wire electrode. It is capable of preventing damage such as over la.

〔Example〕

 Hereinafter, the details of the present invention will be described with reference to the drawings.

1 to 5 show an embodiment of a wire-cut electric discharge machining apparatus according to the present invention, in which a wire electrode is inserted into a machining start pilot hole and tensioned along a predetermined route is automatically automatically performed. It is an explanatory view showing the process performed in a stepwise manner,
Of these, FIG. 1 shows the state when one processing on the workpiece is completed, FIG. 2 shows the work step of cutting the wire electrode, and FIG. 3 detects bending of the cut wire electrode. FIG. 4 and FIG. 5 show working steps, in which the wire electrode is inserted into the working starting pilot hole in preparation for the next working.

Thus, in FIGS. 1 to 5, 1 is a column provided upright on a base (not shown), 2 is a column extending horizontally from the column 1, and is vertically mounted so as to be vertically movable and positionably fixed. A processing arm, 3 is a processing head provided at the tip of the processing arm 2, 4 is a processing liquid jet nozzle, 5 is a guide holder having a wire electrode positioning guide, 6 is a power feeding die, and 7 is a feed roller which also serves as a brake roller. , 8
Is a pinch roller, 9 is a guide roller, 10 is a wire electrode,
11 is a wire cutting device, 12 is a wire cutting arm, 13 is a cylinder, 14 and 14 'are wire bending detecting devices, 15 and 15' are wire detecting arms, 16 is a cylinder, and 17 is (Figs. 2 to 4).
(See the drawing), a pair of wire electrode positioning guides 17 that are provided so as to face the processing head 3 and that can be opened and closed at a position that faces the wire electrode positioning die holder 5.
The other machining head provided with a and 17b, 18, 18 'is a cylinder, 19 is a capstan, 20 is a pinch roller, 21 is a wire pulling device, 22 and 23 are wire pulling rollers that can be opened and closed as necessary, 24 is a wire guide, 25 and 25 are feed rollers, 26
Is a pinch roller, 27 is a wire collection box, 28 is a work piece, 29
Numerals 35 to 35 are a plurality of wire electrode detectors sequentially provided along the wire path of the wire electrodes, 36 to 42 are preamplifiers, and 43 is a wire line confirmation circuit.

A power supply device for supplying a machining voltage pulse to the wire electrode 10 through the power feeding die 6, a driving device for providing a relative machining feed between the wire electrode and the workpiece, a control device for controlling the driving device, and a machining fluid. The supply device and the like are omitted in the figure.

First, the configuration of an embodiment of the wire-cut electric discharge machine according to the present invention will be briefly described with reference to FIG.

The processing arm 2 extends horizontally from the column 1 and is vertically movable by a drive device (not shown).

A guide holder 5 having a wire electrode positioning guide, a power feeding die 6, a feed roller 7 also serving as a brake roller, and a pinch roller 8 are provided in the processing head 3 having a processing liquid jetting nozzle 4 attached to the tip thereof, and the periphery thereof. A wire cutting device 11 and a wire bending detection device 14 are attached.

A processing head 17 is provided below the workpiece 28 so as to face the processing head 3 with the workpiece 28 interposed therebetween (second
See FIGS. It is omitted in FIGS. 1 and 5 in order to prevent complication of the drawings. ), The processing head 17 has
A pair of wire electrode positioning guides 17a and 17b are provided so as to face the wire electrode positioning guides of the guide holder 5, and a wire drawing device is provided below the processing head 17.
21 are provided.

In this embodiment, the wire electrode detectors 29 to 35 are wire electrodes.
The wire detection arm 15, the wire electrode positioning guides 17a and 17b, the wire take-up roller 22 of the wire take-up device 21, the feed rollers 25 and 25, and the pinch roller along the wire passage path of 10
It is established in order in 26.

Of these wire electrode detectors 29 to 35, the three detectors that are essential at least in the present invention are the wire electrode 10 and the wire electrode 10 to be processed.
Wire electrode detectors 29, 29 '(in the present embodiment, wire detection arm 15, in the present embodiment, provided in the wire electrode wire passage portion of the processing head 3 having a positioning guide on the side for sending out toward b (see FIG. 3)) 15 ', which is attached to the tip of 15' and is brought to the wire passage portion at the time of wire passing), and the other positioning guide which receives the wire electrode inserted through the processing start pilot hole and faces the positioning guide 3. One or both of the wire electrode detectors 30, 30 'and the detectors 31, 31' provided in the wire electrode wire passage portion of the machining head 17 having 17a, 17b, and the wire electrode wire passage portion of the machining head 17. One or both of the wire electrode detector 32 and the detector 35 provided in the wire electrode wire passage portion of the wire electrode take-up device 21 that redirects and transfers the wire electrode that has come via the wire electrode, Other detectors 33, 34 and both The other one, which is not the one, is provided as necessary.

The wire electrode detectors 29 to 35 are connected to preamplifiers 36 to 42 provided corresponding to the wire electrode detectors 29 to 35, and the outputs of the wire electrode detectors amplified by these preamplifiers are input to the line confirmation circuit 43.

In accordance with a predetermined sequence control program, the line confirmation circuit 43 sends the wire electrode detection signal from each of the wire electrode detectors in the respective stages described above, and then the wire electrode detectors in the succeeding stages transmit the wire electrode detection signals within a predetermined time. Is transmitted and an output signal is transmitted according to the situation.

The output signal of the line confirmation circuit 43 is sent to the control device that controls the motor that drives the feed roller 7, and the wire electrode 10
Is controlled.

Referring to FIG. 1 to FIG. 4 in sequence below, the process of automatically setting the wire electrode in preparation for the next machining after one machining is completed by the wire cut electric discharge machining apparatus according to the present invention will be described in detail. Explained.

FIG. 1 shows a state in which one processing is completed. In this state, the wire electrode 10 is supplied from a wire supply drum (not shown), passes through a guide roller 9 and a feed roller 7 also serving as a brake roller and a pinch. Roller 8
Through the wire feeding electrode 6 and the wire electrode positioning guide attached to the guide holder 5, and is drawn out from the tip of the working liquid jetting nozzle 4 to form the processed hole of the workpiece 28.
A pair of wire electrode positioning guides 17a, 17b that penetrate through 28a
The wire take-up roller 22 and 23, the wire guide 24, the feed rollers 25 and 25, and the pinch roller 26 are passed through the wire take-up device 21 to reach the wire recovery box 27.

From this state, as shown in FIG. 2, after moving the pair of wire electrode positioning guides 17a, 17b to the open position, the arm 2 is moved upward along the column 1 to move the machining head 3 to the workpiece 28. Move to a position away from.

At this position, the wire cutting arm 12 of the wire cutting device 11
The wire electrode 10 is cut by the cutter 12a provided at the tip thereof while being moved downward and rotated.

Next, as shown in FIG. 3, the wire cutting arm 12 is moved upward and rotated to return to the original position shown in FIG. 1, and then the wire detection arms of the wire bending detection devices 14 and 14 '. By moving and rotating 15 and 15 ′ downward, detectors 29 and 29 ′ provided at their tips are made to face each other with the wire electrode 10 sandwiched therebetween, and the bending of the wire electrode 10 is detected.

The detectors 29, 29 'may be of a contact type and configured to output an abnormal signal when they come into contact with the wire electrode 10.
Further, as an optical method, a normal detection signal may be output when the wire electrode 10 passes a predetermined position.

In FIG. 3, the wire bend detecting device 14 'is illustrated only partially for convenience of drawing, but the wire bend detecting devices 14 and 1 are not shown.
A pair of 4'is provided so as to face the outer periphery of the processing head 3, and when the wire detection arms 15, 15 'are set, the detectors 29, 29' provided at the tips thereof sandwich the wire electrode 10. It is configured to face each other.

At this time, the wire detection arms 15 and 15 'are set appropriately below the tip of the wire electrode 10 cut by the wire cutting device 11, and in that state, the feed roller 7 also serving as a brake roller is operated. The wire electrode 10 may be slightly fed out and operated to detect whether or not the wire electrode 10 is linearly fed out.

In parallel with the above operation, the wire take-up device 21 is operated to collect the cut used wire electrode 10 ′ in the wire recovery box 27, and a drive device (not shown) is operated to start the next processing. The object 28 to be processed is moved so that the center of the pre-processing hole 28b provided in advance in the object 28 and the axis of the position at which the wire electrode 10 is stretched are aligned with each other.

Next, the arm 2 is gradually moved downward along the column 1 so that the tip of the processing head 3 approaches the upper surface of the workpiece 28, as shown in FIG.

Feed roller 7 also serving as a brake roller at this position
To slowly feed out the wire electrode 10, insert the wire electrode 10 into the prepared hole 28b of the workpiece 28, pass through the pair of wire electrode positioning guides 17a and 17b in the open position, and further downward. Extend it.

When the tip of the wire electrode 10 reaches the take-up rollers 22 and 23 of the wire take-up device 21, the take-up rollers 22 and 23 are rotated as they are or the take-off rollers 22 and 23 that have been separated are closed. After sandwiching the wire electrode 10 by rotating the rollers, the wire electrode 10 is pulled by rotating these rollers, and the wire guide 24 provided below the wire electrode 10 changes the direction to the right in the figure.

After that, the wire electrode 10 is sequentially fed along the wire guide plate 24 by the feed rollers 25, 25 and is collected in the wire collecting box 27 via the pinch roller 26.

Thus, in the above process, when the wire electrode 10 passes through the pair of wire electrode positioning guides 17a, 17b, optical detectors 30, 30 'and 31, 31' provided on these guides are provided.
Thus, the passage of the wire electrode 10 is detected, and further the detector 32 provided on the take-up roller 22 near the position where the wire electrode changes direction is detected. If this direction change is not performed properly and the wire electrode 10 that should go to the right is bent and sent to the front side, for example, the wire electrode will be rolled.
22 and 23, or the detector 32 or 35, out of the guide 24,
Or it becomes impossible to detect by 33, 34.

In addition, as a detection method in these roller parts,
For example, by applying a weak voltage to the wire electrode 10 via the power feeding die 6, the wire electrode 10 is pulled by the take-up roller.
When the wire 22, the feed rollers 25, 25, and the pinch roller 26 are sequentially contacted with each other, electrical continuity occurs in the tube between the wire electrode 10 and each part, which is sequentially detected by the detectors 32 to 35.

The signals from the detectors 29 to 35 are amplified by the preamplifiers 36 to 42 and sent to the line confirmation circuit 43. The line confirmation circuit 43 outputs the wire electrode detection signals from the wire electrode detectors at the respective stages and then the succeeding parts. When the signal from the wire electrode detector of 1 does not arrive within a predetermined time, the signal is transmitted to a control device (not shown) that controls the motor that drives the feed roller 7,
The feed roller 7 is stopped to prevent the wire electrode 10 from being entangled or wound around the feed roller or the like.

Further, by knowing the part of the detectors 29 to 35 where this signal has stopped, it is possible to know where on the route the trouble has occurred.

By the above operation, the insertion of the wire electrode 10 into the processing start pilot hole 28b in preparation for the next processing and the tensioning work along the predetermined path are completed.

Then, when the wire electrode 10 is stretched as shown in FIG. 5, the pair of wire electrode positioning guides 17a and 17b are closed, and the workpiece is processed from the power supply device (not shown) through the power feeding die 6. A machining voltage pulse is applied between the wire electrode 28 and the wire electrode 10, and the machining liquid is supplied to the machining portion from the machining liquid jet nozzle 4 and the wire electrode positioning guides 17a and 17b. A desired processing feed is given in between to perform the next processing.

Thus, in the above description, the insertion work after the completion of one processing is explained, but in the present embodiment, the work of tensioning the first wire electrode on one workpiece can also be performed. In this case, the work may be started from the state shown in FIG.

The present invention is not limited to the above embodiments. That is, for example, the positions where the wire electrode detectors are provided can be expanded to appropriate positions along the path of the wire electrodes, if necessary, other than the above-mentioned three essential positions of the present invention, and the number thereof can be freely set. Can, processing head, wire cutting device,
The configurations of the wire bending detection device, the wire electrode positioning guide, the wire drawing device, etc. can be freely designed and modified within the scope of the object of the present invention, and the present invention includes all the modified examples.

〔The invention's effect〕

Since the present invention is configured as described above, according to the present invention, during the insertion work of the wire electrode into the pre-formed machining starting pilot hole, and the inserted wire electrode is changed in direction to the collecting portion. In the process of guiding, even if a trouble such as the wire electrode deviating from the predetermined guide path occurs, the wire electrode is prevented from being entangled in the middle of the path, and subsequent processing can be performed promptly, and the feed roller and its drive This is to prevent damage to the device.

[Brief description of drawings]

1 to 5 show an embodiment of a wire-cut electric discharge machining apparatus according to the present invention, in which a wire electrode is inserted into a machining start pilot hole and tensioned along a predetermined route is automatically automatically performed. It is explanatory drawing which shows the process performed in step by step. 1 ... Column 2 ... Processing arm 3 ... One processing head 4 ... Processing liquid jet nozzle 5 ... Guide holder with wire electrode positioning guide 6 ... Feeding die 7 ... Feed roller also serving as brake roller 8 ...... Pinch roller 9 ...... Guide roller 10 ...... Wire electrode 11 ...... Wire cutting device 12 ...... Wire cutting arm 12a ...... Cutter 14, 14 '...... Wire bending detection device 15, 15' ...... For wire detection Arm 17 …… The other machining head 17a, 17b facing the machining head 3 …… The other positioning guide for the pair of openable / closable wire electrodes 19 …… Capstan 20 …… Pinch roller 21 …… Wire take-up device 22, 23 ...... Wire take-up roller 24 ...... Wire guide 25, 25 …… Feed roller 26 …… Pinch roller 27 …… Wire collection box 28 …… Workpiece 28a …… Processed hole 28b …… Preparation hole for processing 29 35 ...... wire electrode detector 36-42 ...... preamplifier 43 ...... communication line check circuit

Claims (1)

[Claims] 1. A plurality of wire electrode detectors which are sequentially provided along a wire path of a wire electrode, and at least the following three positions, that is, the side where the wire electrode is sent to a processing start pilot hole of a workpiece. A wire electrode passage path portion of a machining head having one positioning guide, and a machining head having another positioning guide that faces the one positioning guide and receives the wire electrode inserted through the machining start prepared hole. Wire electrode wire passage portion and a wire electrode wire passage portion of a wire electrode take-up device that redirects the wire electrode coming through the wire electrode wire passage portion of the latter processing head and transfers the wire electrode to the collecting portion. And a plurality of wire electrode detectors sequentially provided at a plurality of locations on the wire passage including three locations, and outputs of the wire electrode detectors at the three or more locations as inputs, and wire electrodes at each stage After the detector has transmitted the wire electrode tip passage detection signal, the wire electrode detector in the succeeding stage similarly detects whether or not the wire electrode tip passage detection signal is transmitted within a predetermined time. During the automatic wire passing work of the wire electrode before the start of machining, which consists of a wire check circuit that detects the part where the signal has stopped and sends an output signal to continue or stop the wire electrode wire work depending on the situation. A wire-cut electric discharge machine equipped with an automatic line confirmation device that can be activated.