JPS62124825A - Wire cut electric spark machining method and device therefor - Google Patents

Abstract

PURPOSE:To obtain a good machined surface for a thick workpiece by turning a wire electrode about the center axis thereof for machining at angular velocity of 2piV/T or the integral multiples thereof, provided that the speed of the wire electrode is 'V' and the thickness of a workpiece is 'T'. CONSTITUTION:A wire electrode 31 passes from an electrode feed drum 3 to an electrode recovery drum 17 at a lower position for storage therein via a nozzle 11 supported on an arm 32a, a workpiece 30 and another nozzle 25 supported on an arm 32b. The nozzles 11 and 25 are turned by a motor 34 fitted within a column 32, via pulleys 37 and 38, timing belts 39 and 40, and pulleys 13 and 27. The angular velocity of the turning is controlled by a control circuit 41 to keep (2pi X electrode speed)/(plate thickness of workpiece as inputted from a plate thickness setting device 43) or the integral multiple thereof. It follows, therefore, that the electrode 31 is turned once or by integral numbers during passage through a workpiece 30 and machining is carried out on a surface free from damage and deterioration, thereby ensuring a good machined surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wire-cut electrical discharge machining method and an apparatus for carrying out the above-described machining method.

[Conventional technology]

A wire-cut electrical discharge machining device places a workpiece facing a wire electrode that is renewed in the axial direction in a tensioned state, with an appropriate machining gap from a direction approximately perpendicular to the wire electrode axis. A machining voltage pulse is applied between the wire electrode and the workpiece while machining fluid is supplied to the machining gap, and non-contact machining is performed by utilizing the discharge phenomenon that occurs at that time.

The wire-cut electric discharge machining apparatus described above is capable of machining even complex cross-sectional shapes relatively easily and in a short time, and is therefore used for various machining operations.

However, the wire electrode of a wire-cut electrical discharge machining apparatus has the property that it is softened by electrical discharge and its tensile strength is also reduced. Furthermore, the wire electrode not only suffers from numerous scratches due to electrical discharge, but also deteriorates its material quality. In other words, the area where electric discharge machining is first performed using a new wire electrode is free from scratches and the material has not deteriorated. However, when machining deeper parts, the electric discharge gradually causes scratches and the material has deteriorated. There is a problem in that it is impossible to obtain a good machined surface especially in the machined part where the wire electrode is used and the machined part is on the opposite side, that is, on the side where the wire electrode is recovered.

[Problems to be Solved by the Present Invention] The present invention has been made based on the above-mentioned viewpoints, and its purpose is to keep the machined part of the workpiece constantly connected to the wire electrode during processing. The structure is such that the processing is performed using a wire electrode that causes almost no scratches and material deterioration on the machined surface, or extremely little scratches and material deterioration, so that thick workpieces can always be machined with a good surface. The object of the present invention is to provide a wire-cut electric discharge machining method and an apparatus for carrying out the above-mentioned machining method.

[Means for solving problems]

Therefore, the above purpose is to achieve, when performing the wire cut electric discharge machining method using the conventional method, an angular velocity determined by ω=2πV/T, where the moving speed of the wire electrode is ■, and the thickness of the workpiece is T. This can be achieved by rotating the wire electrode around its central axis at an angular velocity of 1.5 or more, preferably an integral multiple of the angular velocity.

Further, the wire-cut electric discharge machining apparatus according to the present invention includes a mechanism for rotating the wire electrode around its axis, a plate thickness setting device, and a rotation of the wire electrode according to the plate thickness input to the plate thickness setting device. A device is provided for determining the speed.

[For production]

With the above configuration, during machining, the machined surface of the workpiece is always treated by the wire electrode with almost no scratches and material deterioration on the machined surface, or with very little scratches and material deterioration. Since processing is performed, a good machined surface can always be obtained even if the workpiece is thick.

〔Example〕

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

The drawing is an explanatory view showing one embodiment of an apparatus for carrying out the wire-cut electrical discharge machining method according to the present invention.

In the figure, 1 is a wire cutter 1 to an electric discharge machining device, 2 is a wire electrode supply device, 3 is a wire electrode supply drum rotatably attached to a rod 4, and 5 is a guide roller 6 to 7.
8 is a support plate that rotatably supports the guide, pinch roller 9, and brake roller 10; 11 is a nozzle attached to the support plate 8; 12 is the inside of the nozzle 11; 13 is a die for guiding the upper position of the wire electrode provided in the nozzle 11.
14 and 15 are bearings, 16 is a wire electrode recovery device, 17 is a wire electrode recovery drum rotatably attached to a rod 18, and 19 rotates guide rollers 20 and 21. 22 is a support plate that rotatably supports the pinch roller 23 and capstan 24; 25 is the support plate 2;
2 is a nozzle attached to the nozzle 2, 26 is a lower positioning guide die provided in the nozzle 25, 27 is a pulley attached to the outer periphery of the nozzle 25, 28 and 29 are bearings, 30 is a workpiece, 30a is the above-mentioned workpiece 30
31 is a wire electrode, 32 is a pore for starting processing formed in
is a column erected on a base 33, 32a and 32b are integrally formed with the column 32, and bearings 14.1
5 and 28. A support arm rotatably supports the wire electrode supply device 2 and the wire electrode collection device 16 through 29, 34 is a motor, 34a is a shaft of the motor 34,
35 is a cambling ring, 36 is a rod attached to the shaft 34a of the motor 34 via the coupling 35, 37 and 38 are pulleys attached to the rod 36, and 39 and 40 are outer peripheries of the nozzles 11 and 25, respectively. pulleys 13 and 27 attached to the rod 36
41 is a rotational speed control circuit for controlling the rotational speed of the motor 34, 42 is a motor drive power source, and 43 is a plate thickness setting device.

The wire-cut electrical discharge machining device 1 includes a wire electrode supply device 2, a wire electrode recovery device 16, and support arms 32a and 32b that rotatably support the wire electrode supply device 2 and the wire electrode recovery device 16. It is comprised of a column 32, a base 33 on which the column 32 is mounted, a plate thickness setter 43, a rotation speed control circuit 41 that controls the rotation of the wire electrode based on the set value of the plate thickness setter 43, and others.

The wire electrode supply drum 3 is rotatably supported by a rod 4 attached to a support plate 8, and the wire electrode 3I pulled out from the wire electrode supply drum 3 is rotatably supported by a roller support arm 5. It passes through the guide rollers 6 and 7, passes between the guide and pinch roller 9, and the brake roller 10, is sent into the nozzle 11, and passes through one positioning guide die 12 provided in the nozzle 11, After that, it passes through the processing start small hole 30a formed in the workpiece 30, passes through the other positioning guide die 26 provided in the nozzle 5, and passes through the pinch roller 23.
and guide rollers 21 and 20 that pass between the capstan 24 and are rotatably supported by the roller support arm 19.
The wire electrodes are collected into a wire electrode collection drum 17 through the wire electrode collection drum 17.

Although not shown in the drawings, the nozzles 11 and 25 are provided with a machining fluid supply device, and are configured to spray and supply machining fluid to the machining portion of the workpiece 30. Further, the entire wire electrode recovery device 16 is covered with a cover etc. to prevent machining fluid from getting into it during normal machining.
In order to make the explanation easier to understand, the above-mentioned cover etc. are omitted.

A motor 3 is installed inside the column 32 that stands up on the base 33.
4 is accommodated, and the shaft 34a of the motor 34 is
A rod 36 is attached to via a coupling 35. Further, the rod 36 has pulleys 37 and 38.
are installed, and the above respective pulleys 37 and 3
8 and the pulley 1 attached to the outer periphery of the nozzle 11.25
3 and 27 have timing belts 39 and 40, respectively.
But the stakes have been passed. Therefore, the nozzle 1 rotates as the motor 34 rotates.

Note that when the plate thickness is set by the plate thickness setter 43, the rotation speed control circuit 41 controls the frequency or voltage supplied to the motor 34 from the motor drive power source 42 according to a predetermined program, and the wire electrode 31 is the angular velocity ω determined by ω=2πV/T (where, ■ is the wire electrode 3
1 is the moving speed, and T is the thickness of the workpiece 30.

) or more, preferably an integral multiple of the rotational speed of the motor 34.

When electrical discharge machining is performed by the wire-cut electrical discharge machining apparatus l that implements the method of the present invention, the wire electrode 31 is routed along the wire electrode supply and recovery path described above, and a power supply circuit (not shown) is routed. A voltage pulse for machining is applied between the workpiece 30 and the wire electrode 31, and machining fluid is jetted and supplied from the nozzles 11 and 25 to the workpiece part of the workpiece 30, and further the wire electrode supply device 2 and the wire The electrode recovery device 16 is rotated, giving rotational motion to the wire electrode 31, and electrical discharge machining is performed.

The wire electrode 31 has the property of being softened by electric discharge and its tensile strength is reduced, and furthermore, the wire electrode 31 has many scratches due to electric discharge. When machining is performed on a thicker workpiece 30, the machining part on the supply side of the wire electrode 31, that is, the part where electric discharge machining is first performed with a new wire electrode, is free of scratches and has no deteriorated material. However, subsequent machining is performed using a wire electrode whose material has deteriorated due to scratches caused by electrical discharge, especially on the opposite side from the above, that is, on the wire electrode collection side 16. It becomes impossible to obtain a good machined surface in the machined part.

However, in the apparatus of the present invention, the workpiece 30
When the thickness T of the wire electrode 31 in the processing section is set by the plate thickness setting device 43, the rotation speed control circuit 41 adjusts the frequency or voltage supplied to the motor 34 from the motor drive power source 42.
However, since the motor 34 is driven to rotate at an angular velocity determined by ω=2πV/T or an angular velocity that is an integral multiple thereof, the wire electrode 31 rotates around its central axis at the angular velocity during processing. It turns out.

For this reason, since the wire electrode 31 is rotated once or several times while passing through the workpiece 30 having a thickness T, the workpiece 30 always has almost no scratches or material deterioration on the surface of the workpiece.
Alternatively, since processing is performed using the wire electrode 31, which has extremely few scratches and deterioration, a uniform and good machined surface can be obtained as a whole even if the workpiece is thick.

〔Effect of the invention〕

Since the present invention is configured as described above, during processing, the machined surface of the workpiece 30 is always free from scratches and material deterioration, or has almost no scratches or material deterioration. Since processing is performed using an extremely small number of wire electrodes 31, a good processed surface can always be obtained even if the workpiece 30 is thick.

Note that the present invention is not limited to the embodiments described above. That is, for example, in this embodiment, a pulley and a timing belt are used to impart rotational motion to the wire electrode, and this is configured to rotate the nozzle and impart rotational motion to the wire electrode. , gears, etc. can be used to achieve the same effect. In addition, the rotation method is not limited to the above-described rotation method, and any known rotation mechanism can be used. In addition, nozzle support method, wire electrode supply,
The method of collection, the method of controlling each part, etc. can be freely changed within the scope of the purpose of the present invention, and the present invention encompasses all of them.

[Brief explanation of drawings]

The drawing is an explanatory view showing one embodiment of an apparatus for carrying out the wire-cut electrical discharge machining method according to the present invention.

Claims (1)

[Claims] 1) A wire electrode is routed along a straight line and moved along the straight line, and a workpiece is faced to the wire electrode routed along the straight line while maintaining a small gap, A wire-cut electrical discharge machining method in which a voltage pulse is applied between the two, machining fluid is supplied into the machining gap, and machining feed is applied to the wire electrode and/or the workpiece to perform contour machining on the workpiece. When the moving speed of the wire electrode is V and the thickness of the workpiece is T, the wire electrode is moved to the center of the straight line at an angular velocity determined by ω=2πV/T or an integral multiple thereof. The wire cut electric discharge machining method described above is characterized in that machining is performed by rotating around an axis. 2) A wire electrode supply and recovery device for guiding the wire electrode along a straight line and moving it along the straight line is rotatably supported around the straight line, and the wire electrode supply and recovery device is rotated around the straight line. A wire-cut electrical discharge machining apparatus characterized in that it is provided with a device that switches and sets the rotational speed of the wire electrode supply and recovery device according to the thickness of the workpiece.