JPH01321124A - Work drop sensing device of wire type electric discharge machining device - Google Patents

Abstract

PURPOSE:To prevent a lower insulation nozzle from damage by forming an electroconductive part on the whole periphery of external wall of this nozzle, which is to supply the machining liquid, and stopping the machining when a touch sensing device senses touching of a work to be machined with the electroconductive part. CONSTITUTION:Machining liquid is supplied to a work to be machined 12 from an upper and a lower insulation nozzle 26a, 26b, and a wire electrode 10 is guided and fed with current by current feed parts 34, 36 installed inside them, and electric discharge machining is made to the work 12. The whole periphery of the external wall of this lower insulation nozzle 26b is fitted with an electroconductive film 1 made of for ex. platinum, and when touching is made because of imperfect installation of the work 12 or drop of the work from the work 12, it is sensed by a touch sensing device 2, and immediately the machining is stopped from processing. Thus the lower insulation nozzle is prevented from breakage, and the machined surface of the work avoided from damage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to protection of a machining liquid jetting groove in a lower part of a wire electric discharge machining apparatus.

[Conventional technology]

FIG. 2 is a sectional view showing the machining fluid spouting part of the conventional wire electric discharge machining power.
Upper insulated nozzle (2) that supplies machining fluid to workpiece 4 below.
6a) and the lower machining fluid jetting mechanism housing the lower insulating nozzle (26b). (to), wire electrode αQ supplied with electrical discharge machining power
, and upper and lower t! that support the wire against the processing part of the workpiece @! i-guide (to).

(to) is not installed properly. Further, the upper and lower machining liquid jetting structures S, (to) are fixed to the machine body 43 (not shown).

Next, I will explain the motion. The position between the lower machining fluid ejection mechanism and the workpiece (2) (i! quantity relationship #during efficient machining, iζ is the 8th
The situation is as shown in the figure, but just before the end of machining! As shown in Figure 4, the workpiece (12a) falls from workpiece 4 and hits the lower insulating nozzle (26t)), lower machining fluid ejection mechanism C! :3: Force is applied as processing progresses.

[Problem to be solved by the invention]

Since the conventional wire electric discharge machining apparatus is configured as described above, when the workpiece (12a) is dropped and the lower machining fluid ejection mechanism ω moves for a moment, the lower insulating nozzle (261)
), etc., and also caused damage to the processed part of the workpiece (12a), causing problems such as -C.

This invention was made to solve the above problems.
It is an object of the present invention to provide a workpiece fall detection device for a wire electrical discharge machining apparatus that prevents damage to a lower insulating nozzle and the like and does not cause damage to the machined part of the workpiece.

[Means to solve the problem]

A workpiece fall detection device for a wire electric discharge machining apparatus according to the present invention has a conductive part around the entire outer wall thereof and is provided at a lower part of the workpiece, and supplies machining fluid to the machining part of the workpiece. The apparatus includes a lower insulating nozzle and a contact detection device that detects contact between the workpiece and the conductive part and stops processing.

[For production]

In this invention, the conductive part provided all around the outer wall of the lower continuous nozzle detects the falling of the workpiece.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be explained with reference to the drawings. tJ
In Figure g1, (1) is a conductive coating attached to the outer wall of the lower insulating nozzle, and (2) is a contact detection device that electrically connects the workpiece (2) and the conductive coating. Note that the same reference numerals as in FIG. 2 showing the conventional example indicate the same parts, and therefore the explanation thereof will be omitted.

Next, vJf'F will be explained. Lower insulated nozzle (
26k)) The contact detection bag @ (2) detects the contact between the conductive coating (1) on the platinum side attached to the outer wall and the workpiece 4, and detects the lower insulating nozzle (2) due to improper installation of the workpiece.
26k)) and the fall of the workpiece from the workpiece, the progress of machining is immediately stopped to prevent external force from being applied to the lower ejection mechanism due to the contact.

In the above embodiment, an example is shown in which a conductive film is attached to the outer wall of the lower insulating nozzle, but a conductive cap that matches the outer shape of the lower insulating nozzle may be attached, and the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, since the present invention is configured to detect electrical continuity between the workpiece and the lower insulating nozzle, it is possible to instantly detect that the workpiece has fallen and stop the machining. This has the effect of preventing damage to the lower insulating nozzle, etc., and not damaging the processed portion of the workpiece.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the workpiece falling detection sound m of the wire electric discharge machining apparatus according to a simple embodiment of the present invention, Fig. 2 is a diagram showing the machining part of the conventional wire electric discharge machining apparatus, and Fig. 8 is a diagram showing the workpiece falling detection sound m of the wire electric discharge machining apparatus according to an embodiment of the present invention. FIG. 4 is a diagram showing the relationship between the object and the lower machining fluid ejection mechanism, and is a diagram showing a state in which the workpiece has fallen onto the lower insulating nozzle. In the figure, (1) is a conductive coating, (2) is a contact detection device, the recess is a workpiece, and (26h) is a lower additional nozzle. Note that the same reference numerals in the figures indicate the same parts.

Claims (1)

[Claims] A lower insulating nozzle, which has a conductive part around the entire circumference of its outer wall and is provided at the bottom of the workpiece, supplies machining liquid to the machining part of the workpiece, and prevents contact between the workpiece and the conductive part. A workpiece drop detection device for a wire electrical discharge machining device, characterized by comprising contact detection equipment that detects and stops machining.