JPS6247647B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire cut machining apparatus, and more particularly to an improved wire cut electric discharge machining apparatus capable of fully automatically carrying out contour electric discharge machining in which a core falls out of a workpiece.

Wire-cut electrical discharge machining equipment is well-known, and is capable of producing a desired machined shape by generating electrical discharge between an electrode wire stretched through the workpiece and the workpiece. Suitable for production.

FIG. 1 shows a schematic configuration of a machining device using this type of wire-cut electric discharge machining. A machining table 12 on which a workpiece 10 is supported and fixed is moved two-dimensionally in the Can move freely on a plane. A CNC device 16 is provided to supply desired drive signals to both motors 14, and the signals are recorded on a paper tape 18 or the like.
Two-dimensional driving of the machining table 12, that is, the workpiece 10, is performed based on the NC information.

An electrode wire 20 is disposed through the workpiece 10 and is passed through the wire automatic threading device 2 from the feed reel 22.
4 through the workpiece 10 and the used wire 20 is discharged into a winding tank 26.

The automatic wire threading device 24 is used to correctly position and pass the electrode wire 20 through the machining start hole 28 of the workpiece 10, and the automatic wire threading device 24 also has the function of passing the electrode wire 20 through the machining start hole 28 of the workpiece 10.
It has a wire cutting machine for cutting the workpiece 10 and removing the workpiece 10 or moving it to another processing position, and these wire threading and cutting are controlled by a CNC device 16.

Figure 2 shows how the electrode wire 20 is passed through the workpiece 10.
are correctly positioned and held by an upper guide 30 and a lower guide 32 above and below the workpiece 10,
The workpiece 1 is
0 is subjected to predetermined electrical discharge machining. Note that machining fluid 36 is supplied to the electrical discharge machining section from a nozzle 34 to effectively cool the machining section or remove chips.

FIG. 3 shows a state in which a plurality of contour electrical discharge machining processes are continuously performed on a workpiece 10. Three machining start holes 28 corresponding to each machining are previously drilled in the workpiece 10, and Three contour electrical discharge machining operations are performed as shown below.

FIG. 4 shows the final state of the contour electric discharge machining described above.
0 must be relatively moved to the position 100 where the end of the electric discharge machining meets the already machined electric discharge locus, but in the case of contour electric discharge machining, if this final complete machining is performed, the core from the workpiece 10 will be removed. It is known that various problems occur when a 38 is dropped.

That is, as shown in FIG. 4, when the machining trajectory is completed correctly, the core 38 falls and separates, but at this time, it collides with the wire 20 or the nozzle 34, resulting in irregular wire breakage or nozzle deformation. As a result, electrical discharge machining itself is exposed to power outages due to sudden cutting. Furthermore, in Figures 5 and 6,
There was a problem that the core 38 was twisted when it was dropped or cut and separated, resulting in an accidental contact with the workpiece 10 or the wire 20.

Therefore, in the conventional apparatus, in order to prevent accidents during the core separation, the wire 20 is stopped at a position 200 degrees before the contour is completed, as shown by the chain line in FIG. A method has been adopted in which the core 38 is supported by the workpiece and the core 38 is manually separated and removed from the workpiece 10 after machining is completed.

However, such a conventional method has a problem in that it is not possible to fully automate contour electrical discharge machining, resulting in a significant decrease in machining efficiency.

When machining a progressive mold or a composite mold, it is necessary to perform continuous contour discharge machining on multiple parts of the workpiece. In order to ensure reliable support, the machining stop position 200 before the contour is completed is
is selected at a position well in front of the machining completion position 100, and therefore, depending on the size of the core 38, the machining stop position 200 is normally set several mm before the machining completion position 100.
is selected, the electrical discharge machining is temporarily interrupted, the wire 20 is once cut by the wire cutting machine, the wire is moved to the next machining start hole, and the same machining is performed for the entire contour machining, and this is completed. Later, the plurality of cores 38 were separated manually.

Therefore, during such multiple continuous processing, a great deal of effort is required to manually separate and remove the core in the final process, and there are particular problems such as the core being unable to be removed correctly due to the large amount of remaining processing. It was happening.

Further, there was a problem in that it became impossible to perform continuous unmanned operation using one electric discharge machining device, and the automatic machining function of the device could not be fully demonstrated.

The present invention has been made in view of the above-mentioned conventional problems, and its object is to provide an improved wire-cut electric discharge machining apparatus that can perform contour electric discharge machining fully automatically.

In order to achieve the above object, the present invention provides a wire cut electric discharge machining system that is equipped with an automatic wire electrode threading device capable of automatically inserting a wire electrode into a machining start hole of a workpiece and automatically cutting the wire electrode, and performing continuous automatic contour electric discharge machining. The device includes a core remover that is inserted into and engaged with the machining start hole immediately before the contour is completed, and separates the core from the workpiece by means of an external force applying means provided therein, and also holds the separated core in a predetermined position. It is characterized by being equipped with a core separation and removal section that transports and accumulates the cores.

Preferred embodiments of the present invention will be described below based on the drawings.

7 and 8 show a schematic configuration of an electric discharge machining apparatus to which the present invention is applied, and the same members as those of the conventional apparatus shown in FIGS. 1 and 2 are given the same reference numerals and their explanations will be omitted.

In the figure, the machining table 12 is placed in a machining tank 40 filled with machining fluid, and a part of the machining tank 40 stores the core separated and removed from the workpiece 10 by electrical discharge machining. A core accumulating section 42 is provided, and in the embodiment, the core accumulating section 42 is provided on a part of the bottom surface of the processing tank 40.

A characteristic feature of this embodiment is that the device is provided with a core separation and removal section 44, and a core removal element is provided at the tip of the core separation and removal section 44. The core remover consists of an engaging claw 48 provided at the tip of the main shaft of the rocking body 46, and the core remover made of the engaging claw 48 can engage with the machining start hole 28 of the core 38.

As shown in FIGS. 9 and 10, the engaging claw 48 is
It has a three-jaw structure and is slightly press-fitted into the machining start hole 28 to hold the core 38. By rocking or vibrating the rocking body 46 in this holding state, the core 38 can be easily separated from the workpiece 10 even if it is supported by the workpiece 10 and a small portion left unprocessed, as will be described later. Can be removed.

The wire cut electric discharge machining apparatus according to the present invention will be explained below using the above-described embodiment apparatus.

As mentioned above, in electrical discharge machining, desired contour machining is performed sequentially under the control of the CNC device 16 with the wire 20 passed through the start hole 28, and the diameter of the machining start hole 28 is usually about 1 to 5 mm. is set to .

As the contour machining progresses in the same manner as in the past and reaches its final step, in the present invention, the contour electric discharge machining is stopped just before its completion, as shown in FIG. CNC so that the remaining amount of machining is about microns.
The device 16 issues machining instructions. Therefore, when the machining shown in FIG. 11 is completed, the core 38 is supported by the workpiece 10 with a small portion left unmachined.

In this state, the automatic wire threading device 24 cuts the wire 20 using its wire cutting machine.

Next, the CNC device 16 moves the machining table 12, that is, the workpiece 10, and opens the machining starting hole 28.
is moved to a position corresponding to the engaging claw 48 of the core separating and removing section 44. The engaging claws 48 protrude in the axial direction and are inserted into and engaged with the machining start holes 28, and the core 38 is held by the engaging claws 48.

Next, the oscillating body 46 is moved to the engaging claw 48, that is, the core 3.
8 is swung or vibrated in a predetermined direction, thereby cutting the slightly remaining unprocessed portion described above, and separating and removing the core 38 from the workpiece 10.

Since the core 38 is held by the engaging claws 48 even after this separation and removal, it does not fall freely.
The engaging claws 48 move upward to attach the core 38 to the workpiece 1.
After taking out the core 38 from the workpiece 10, the CNC device 16 moves the processing table and moves the core 38 separated and removed from the workpiece 10 to the core accumulating section 42, where it is accumulated and stored.

After the above machining is completed, the wire 20 moves again to the next machining start hole and repeats the next series of machining, and according to the present invention, one or more contour electric discharge machining is sequentially performed according to a predetermined program. It is possible to do this continuously and fully automatically.

In the embodiment described above, the core separation and removal section 4
8 is in charge of separating the cores and moving them to the accumulating section at the same time, but it is also possible to perform these with separate devices, and the core accumulating section can be placed not only in the processing tank but also in columns of other machine bodies or It is also possible to provide it in the bed, and it is also preferable to add a device for draining the core taken out from the processing fluid at this time.

Furthermore, although the cores are separated by rocking or vibration in the embodiments, they can also be separated by other impactful external forces.

As explained above, according to the present invention, the final core separation and removal during contour electrical discharge machining is effectively performed using the machining start hole essential for electrical discharge machining,
It is possible to provide an extremely efficient electrical discharge machining device that does not require manual work as in the past, and is particularly capable of continuous automatic machining of multiple pieces such as progressive molds and composite molds. is possible.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of a conventional wire-cut electrical discharge machining device, Figure 2 is an enlarged cross-sectional view of the main part showing the machining part in Figure 1, and Figures 3, 4, 5, and 6 each show a conventional electrical discharge machining method. FIGS. 7 and 8 are schematic perspective views and sectional views of essential parts of a preferred embodiment of a device to which the wire cut electric discharge machining method according to the present invention is applied, and FIGS. 9 and 10 are middle views in FIG. 8. FIG. 11 is an explanatory view showing the operation of the present invention. The same members in each figure are given the same reference numerals, 10 is the workpiece, 20 is the electrode wire, 24 is the wire automatic threading device, 28 is the machining start hole, 38 is the core, 42 is the core accumulation part, 44 is the In the core separation/removal section, 46 is a rocking body, and 48 is an engaging claw.

Claims (1)

[Scope of Claims] 1. A wire cut electric discharge machining device that performs continuous automatic contour electric discharge machining, which is equipped with a wire electrode automatic threading device capable of automatically inserting and automatically cutting a wire electrode into a machining start hole of a workpiece. It has a core remover that is inserted into and engaged with the immediately preceding machining start hole and separates the core from the workpiece by means of its own external force applying means, and also has a core remover that is inserted into and engaged with the immediately preceding machining start hole and that separates the core from the workpiece, and that the separated core is transported to a predetermined position and accumulated. A wire cut electrical discharge machining device characterized by comprising a child separation and removal section. 2. The wire-cut electric discharge machining apparatus according to claim 1, wherein the core remover is comprised of a rocking body and an engaging pawl provided at the tip of its main shaft.