JPH01140923A - Automatic method for wire connection - Google Patents

Abstract

PURPOSE:To insert a wire through the work starting hole of an extremely small diameter by moving the work starting hole of a work piece through which a wire is inserted, to a place underneath a wire supporting section on the feeding side, moving said wire supporting section on the feeding side close to the work piece together with the wire, and constituting the wire to be transferred to the extracting side so that said connection is made. CONSTITUTION:After clipping work starting from No.1 work starting hole 7 has been processed, a wire 1 is cut off by a cutting blade 27 in proximity to an upper supporting section 16, the wire 1 left on the extracting side is taken out. Then, No.2 work starting hole 7' is positioned underneath the supporting section 16, a feed screwing mechanism 17 is driven so as to let the wire 1 on the feeding side is lowered down to just above the work piece 6 together with a wire guide 5 while the wire is being held between a feeding roller 18 and a pinch roller 19 for alignment with the hole 7'. And then, the wire 1 is carried out by the roller 18 so as to be penetrated through the through hole 7' for passing by the lower supporting section 21 of a wire guide 8 on the extracting side, following which, it is transferred to a delivery device 11 by way of a guide belt 10 for completing the connection of the wire 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a method for automatically connecting wires as electrodes in a wire-cut electrical discharge machine.

In the conventional wire-cut electric discharge machining process, a machining start hole is formed at the beginning of machining, into which a wire is inserted, but this start hole has an extremely small diameter when machining a precise shape. On the other hand, in the wire cut electric discharge machine (hereinafter simply referred to as electric discharge machine), machining from the first machining start hole is finished,
When moving to the second machining start hole or during machining, the wire (
When the wire serving as an electrode (hereinafter the same) is disconnected,
The performance of the automatic wire connection device that automatically connects the wire from the supply side to the feed side has a significant influence on the automatic continuous operation of the electrical discharge machine, and is applicable to various structures.

A method is proposed.

However, the conventional methods and structures do not necessarily have a high rate of successful connection when it comes to extremely small diameter holes (about 0.8φ), and the structures are relatively complicated.

For example, the device disclosed in Japanese Patent Application Laid-Open No. 55-164437 utilizes a wire picking member, and when cutting the wire, the member is fed past the wire guide and the workpiece, and the wire end on the feeding side is fed. It has a structure in which the sending-out wire is connected and the wire is pulled back, and a device for feeding the picking-up member and a means for connecting the sent-in picking-up member and the wire are required. The method and device disclosed by the above utilize the hardening and straightness (by heating) of the wire located in the processing part. Since the wire is once pulled out and inserted into the processing start hole again, a means is required to ensure the straightness of the wire located in the processing section. In addition, JP-A-56
The method disclosed in JP-A-52135 involves inserting a linear or rod-shaped guide in advance into a machining start hole provided in a workpiece, and connecting this guide to a supply wire when changing the machining start hole. In this case, even if the electrode used for the shape of the machining start hole is used as a guide, it is difficult to insert the guide into each machining start hole in advance. Furthermore, the device disclosed in Japanese Patent Application Laid-Open No. 56-82133 inserts the pipe that guides the wire during automatic wire connection into the processing start hole of the workpiece to the lower guide position. However, it is difficult to apply this method to a case where the machining start hole has an extremely small diameter.

In addition, after cutting the wire near the wire support part on the supply side, the sub-nozzle is tightly attached to this guide so that the diameter is 1 to 2 m1I.
There is also a device configured to emit a thin water stream of about 100 liters and use this water stream to guide the wire to the extraction side while driving the wire feeding device. However, since a sufficient amount of water is required to guide the wire, it is difficult to apply this method to automatic wire connection through an extremely small diameter machining start hole.

Problems to be Solved by the Invention It is an object of the present invention to provide an automatic wire connection method for an electric discharge machine (\) that can accurately insert a wire into an extremely small diameter machining start hole and automatically connect the wire. shall be.

Means to solve the problem When automatically connecting wires, cut the wire near the wire support on the supply side, and after discharging the wire left on the output side,
The machining start hole of the workpiece into which the wire is to be inserted is moved directly below the supply-side wire support part, and then the supply-side wire support part is moved close to the workpiece together with the wire, and the wire feeding device is driven. Then transport the wire to the extraction side and complete the wiring.

After cutting the working wire, the step of moving the supply side wire supporting part close to the workpiece together with the wire is to move the supply side end of the cut wire close to the processing start hole of the workpiece into which the wire is to be inserted. , to ensure that the wire tip enters the starting hole when the wire is fed out.

In the embodiment diagram, the wire 1 is passed from the wire supply reel 2h1 through the wire tension device 3, and then the direction is changed vertically by the guide roller 4, and the wire 1 is moved from the supply side wire guide 5 to the machining start hole 7 of the workpiece 6. The wire passes through the take-out wire guide 8 to reach a lower guide roller 9, where it is turned around and connected to a wire feed device 11 by a guide belt 10. Further, reference numeral 12 indicates a wire cutting device, which is attached to the supply side wire guide 5.

The wire tensioning device 3 consists of a brake roller 13 and a pinch roller 14 that rotates in contact with the outer peripheral surface of the brake roller 13, and applies appropriate tension to the wire by resisting the wire feeding force from the wire feeding device @11. ing.

The supply wire guide 5 includes a wire feeding device 15 and an upper wire support portion 16 therein, and is mounted so as to be movable up and down with respect to the electrical discharge machine main body by a two-axis motor Z and a feed screw mechanism 17. The wire feeding device 15 consists of a feeding roller 18 driven by a motor M1 and a pinch roller 19 in contact with the outer peripheral surface of the feeding roller 18, and the pinch roller 19 is controlled to move toward and away from the feeding roller 18 by a solenoid 19'. .

The workpiece 6 is fixed on a mounting table 20 whose planar position can be selected by an X-axis motor X and a Y-axis motor Y.

The take-out wire guide 8 includes a lower wire support part 21 facing the upper support part 16, and is fixed in a fixed position. Guide belt 10 is driven by motor M2.

The wire feeding device 11 includes a feed roller 22 and a pinch roller 23 that rotates in contact with the outer periphery of the feed roller 22. The feed roller 22 is driven and rotated by a feed motor M3.

The wire cutting device 12 is connected to the machine frame 24 of the supply side wire guide 5.
It has an arm 26 which supports a shaft 25 at one end so as to be horizontally rotatable, and a cutting blade 27 for pinching and cutting the wire 1 is attached to the other end of the arm 26. Arm 26
is rotated by an arm rotation solenoid 28 and a link mechanism 29, and the cutting blade 27 is rotated by a solenoid 30 on the arm 26.
operated by. A control device 31 having an NC function for controlling the above mechanism as a whole is provided to constitute an automatic wire connection mechanism.

During electric discharge machining, the supply wire guide 5 is located above and away from the workpiece 6, the pinch roller 19 of the wire feed device 15 is separated from the feed roller 18, and the wire 1 is separated from the upper support part 16 and the lower support. 21, and machining is performed by electrical discharge between the workpiece 6 and the workpiece 6 during that time. The wire 1 that has passed through the lower support part 21 is fed by the guide belt 10, connected to the wire feeding device 11, and fed by the feed roller 2.
2 and pinch roller 23, and is stored in a wire collection box (not shown). Note that during electrical discharge machining, the wire 1 is fed out at a constant speed by the feed roller 22.

When the cutting process from the first machining start hole 7 in the workpiece 6 is completed, M2. The M3 motor stops and wire 1 stops feeding. At the same time, the discharge power between the wire 1 and the workpiece 6 is cut off, and then automatic wire connection operation begins.

In the automatic wire connection operation, first, the solenoid 19' is activated to press the pinch roller 19 against the outer peripheral surface of the feed roller 18 to pinch the wire 1.

Next, the solenoid 28 is activated, the arm 26 is rotated between the wire guide 5 at the upper position and the workpiece 6 via the link mechanism 29, the wire 1 is sandwiched between the cutting blades 27, and the solenoid 30 is activated. Cut wire 1. That is, the wire 1 is cut near the upper support portion 16 on the supply side.

The cut sending wire 1 is sent out from the wire sending device to the wire collection box by the motors M2 and M3 being operated again. At the same time, the arm 26 of the wire cutting device 12
When the solenoid 28 is deenergized, it retreats from the lower part of the supply wire guide 5 and returns to its original position.

At the same time as feeding wire 1 on the feeding side, the X-axis motor
, the Y-axis motor Y is operated to move the workpiece 6,
The second machining start hole 7' is located directly below the upper support portion 16.

Then, the feed screw mechanism 17 is driven by the two-axis motor Z, and the cut supply side wire 1 is transferred to the feed roller 1.
8 and the pinch roller 19, it descends together with the supply wire guide 5 to just above the workpiece 6, and the cut end of the supply wire 1 is inserted into the next machining start hole 7'.
line up.

Next, the feed roller 1 is moved by the wire feed motor M1.
8 is driven, the wire 1 which was sandwiched between this and the pinch roller 19 is sent out, and the wire 1 is transferred to the second part of the workpiece 6.
The wire 1 passes through the processing start hole 7', passes through the lower support part 21 of the wire guide 8 on the take-out side, and is transported to the feeding device 11 via the guide belt 10, which has already been started, to complete the connection of the wire 1.

Then, the energization of the solenoid 19' is released and the pinch roller 19 separates from the feed roller 18, freeing the wire 1. At the same time, the feed screw mechanism is reversed by the Z-axis motor Z, and the supply side wire guide 5 returns to the normal position. It returns to the upper position, and the automatic wire connection operation of the wire 1 is completed.

Thereafter, normal electric discharge machining is performed in which the wire 1 is pulled out from the wire supply reel 2 and fed at a constant speed.

Note that the upper and lower positions of the supply wire guide 5 are set using a contact type limit switch or by NC.

The automatic wire connection described above is based on the case where the wire 1 is moved to the second machining start hole 7', but it is also possible to move the workpiece 6 if the wire 1 is broken at the location where the workpiece 6 is being machined during electrical discharge machining. There is no substantial change in the automatic wire connection method, only that it is returned to zero or to the original first machining start hole position.

Moving means for supply side wire guide 5, pinch roller 19
The moving means, the mechanism of the wire cutting device 12, etc. may be other means.

Effects of the Invention Since the cut supply wire is lowered together with the wire support on the supply side and the tip of the supply wire is aligned very close to the machining start hole before the wire is fed into the machining start hole to be inserted. It is possible to accurately insert wires even through extremely small diameters, and automatic wire connection can be reliably performed in electric discharge machining of workpieces having extremely small diameters.

The structure is simple because it can be implemented by adding a mechanism for moving the supply wire guide in the Z-axis direction to the conventional automatic wire connection mechanism.

[Brief explanation of the drawing]

The figure is a schematic diagram of a wire-cut electrical discharge machine. 1...Wire, 2...Wire supply reel, 3...
Wire tension device, 4... Upper guide roller, 5...
- Supply side wire guide, 6... Workpiece, 7... Machining start hole, 8... Wire guide on the extraction side, 8...
Lower guide roller, 10... Guide belt, 11.
... Wire feeding device, 12... Wire cutting device,
13... Brake roller, 14... Pinch roller, 115... Wire feeding device, 16... Upper support part, 17... Feed screw mechanism, 18... Feed roller,
19...Pinch roller-119'...Solenoid,
20... Placement table, 21... Lower support part, 22...
Feed roller, 23...pinch roller-124.
... Machine frame, 25 ... Axis, 26 ... Arm, 27 ...
・Cutting blade, 28...Arm operation solenoid, 29...
・Link mechanism, 30... Cutting blade operating solenoid, 31
...control device, Z...Z-axis top, Ml...wire feed motor, X...X-axis top, Y...Y
On-shaft motor, M2...Guide belt drive motor, M
3...Feed motor.

Claims (1)

[Claims] In a wire-cut electrical discharge machine equipped with a wire feed device and a wire cutting device, and an automatic wire connection mechanism that automatically supplies wire from the wire supply side to the wire take-out side via the workpiece, the supply side Cut the wire near the wire support part of An automatic wire connection method characterized by moving the wire close to the body and then driving a wire feeding device to transport the wire to the extraction side and connect the wire.