JPS59227333A - Machining fluid injection nozzle for wire-cut electric-discharge machining - Google Patents

Abstract

PURPOSE:To prevent a machining fluid from flowing at high speed along a work body surface, by installing a cylindrical outer wall surrounding the circumference of a nozzle tip, while tapering the nozzle tip circumference away toward the termination. CONSTITUTION:A cylindrical outer wall 55 is installed in position surrounding the circumference of a nozzle tip 54, and a circumferential diameter of the nozzle tip 54 is tapered away toward the termination in design. With this constitution, a machining fluid flows in an A''' direction and hits an inner wall surface of the cylindrical outer wall 55 whereby a machining fluid wall C is produced in space between a work 8 and the cylindrical outer wall 55 so that there produces no jet stream over the work body surface at all.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to improvements in machining fluid injection nozzles used in wire-cut electric discharge machines. In particular, the present invention relates to an improvement in preventing machining fluid for wire-cut electrical discharge machining from flowing as a high-speed jet along the surface of a workpiece.

(2) Background of the technology A wire-cut electric discharge machine is a gap between a conductive workpiece such as metal and a wire electrode made of a conductive material such as brass that extends linearly through the workpiece. An electric discharge is generated intermittently in the machining fluid injected into the machining fluid, and this intermittent electric discharge softens or melts the machining area of the workpiece extremely locally, and generates intermittent changes in pressure near the machining area, This refers to a machine for processing conductive materials, particularly metals, that peels off and removes the softened or melted region of the workpiece by intermittent changes in pressure.

In the electrical discharge machining method using a wire-cut electrical discharge machine, it is essential that the electrical discharge be performed in the machining fluid.
Furthermore, since it is necessary to constantly remove cutting debris generated as machining progresses from the machining area, machining fluid is normally continuously injected into the machining area during the machining period.

In Fig. 1, which shows a cross-sectional view of an example of a machining fluid injection nozzle part in a wire-cut electrical discharge machine, l is a wire feed J0 section supported downwardly at the bottom of an upper wire support arm (not shown). The processing wire electrode 2 is extended between the lower wire support arm (not shown), which is a guide section and is provided below. A wire guide section 3 is provided on the lower surface of the two-part guide section l, and the wire guide section 3 includes wire guides such as a die guide, a groove guide, etc.
4 is accommodated. The cross-sectional area of the lower portion t of the wire guide portion 3 is made small to form the nozzle 5. The inner diameter of the nozzle 5 is set in a range of approximately 3 to 61 cm) and is selected with consideration of other factors. 6 is a machining liquid supply, and the machining liquid is injected into the machining area 7 through the nozzle 5. 8 is a workpiece, and a period of 9.2 s between its surface and the lower surface of the tip of the nozzle 5
It faces the nozzle 5 with a distance of about +s. On the other hand, machining area 7 (strips 1 formed by electrical discharge machining)
Since the width t of the knot is approximately 0.03 mm, the machining liquid passes through the machining area 7 as shown by the arrow A and is also sprayed along the surface of the workpiece 8 in the direction of the arrow A°.

If there is another slit 7° or the like already formed by electric discharge machining, there is a drawback that the water bounces off the corner of this slit 7' and splashes in the direction of arrow A'', causing problems such as water leakage around the area.

Conventionally, the machining fluid jet pressure was about 0.1 kg/cm', but recently it has been found that machining speed can be increased by increasing the machining fluid jet pressure.
It has become common to use pressures of the order of 5 Kg/cm'. As this pressure increases, the above-mentioned harmful effects of splashing become even more serious, and a solution has been desired.

(3) Prior art and problems Figures 2, 3, and 4 are examples of technologies that meet these demands.
A machining fluid injection nozzle having the structure shown in FIG. 5 has been developed.

Refer to Fig. 2. A packing 9 made of a relatively soft material is fitted to the 5° tip of the nozzle, and this packing 9 is almost in contact with the surface of the workpiece 8. In this method, although the splash prevention effect described in "-" is sufficiently achieved, problems such as breakage and wear of the packing 9 are unavoidable, so it is not necessarily a recommended method.

Referring to FIG. 3, a member 10 is provided near the tip of the nozzle 51 as a splash receiver in the form of a large flat plate. Although this method has the above-mentioned splash prevention effect,
The nozzle occupies a large area, and even if the material of the splash receiver is made transparent, water droplets will adhere to the back surface of the splash receiver, making it difficult to visually inspect the vicinity of the processing area, resulting in poor workability. I can't escape it.

Referring to FIG. 4, a cylindrical outer wall (scar) 11 is provided surrounding the outer periphery of the tip of the nozzle 5'' and separated from the outer periphery. In this method, it is not possible to effectively prevent splashing in the direction of arrow A'.

Refer to Fig. 5. A cylindrical machining fluid injection port 12 is provided surrounding the outer periphery of the tip of the nozzle 5°' and isolated from this outer periphery, and a machining fluid jet is flowed in the direction shown by arrow B to form a curtain of machining fluid. This curtain of machining liquid prevents the surface of the workpiece 8 from being splashed in that direction. Although this method is sufficiently effective in preventing the above-mentioned splash, the structure is extremely complicated and the loss of machining fluid is large, so it cannot be said to be an excellent method in reality.

In short, in the prior art, it is difficult to effectively generate a jet of machining liquid on the surface of the workpiece, which can cause water wetting problems, especially when there is an already machined slit 7 as shown in FIG. No machining fluid injection nozzle that can prevent this and has a simple structure has yet been developed.

(4) Object of the Invention An object of the present invention is to eliminate the drawback that the machining fluid flows as a high-speed jet along the surface of the workpiece. An object of the present invention is to provide a machining fluid injection nozzle for wire-cut electrical discharge machining.

(5) Configuration of the Invention The configuration of the present invention provides a machining fluid injection nozzle 53 for wire cut electric discharge machining having a cylindrical outer wall 55 surrounding the outer periphery of the nozzle tip 54 and provided in isolation from the outer periphery. A machining fluid injection nozzle for wire-cut electrical discharge machining is characterized in that the outer periphery of the nozzle becomes smaller toward the end thereof.

That is, as shown in FIG. 8, the tip 54 of the nozzle 53
is cut off diagonally toward the center of the nozzle 53, and its outer periphery is tapered and gradually narrows toward the end of the nozzle tip 54.

Further, as shown in FIG. 9, the tip 54' of the nozzle 53 may be cut off with a curved line, or
As shown in FIGS. 10 and 11, the nozzle may be cut off at a certain interval instead of the entire circumference.

In the present invention, the relatively simple structure of the injection nozzle shown in FIG. 4 is modified to obtain an effect similar to that of the relatively complicated structure of the injection nozzle shown in FIG. 5, which will be described below. It was completed after repeated experiments to confirm its effectiveness.

Refer to Fig. 6, a columnar nozzle 51 having an inner diameter of 5 cm is vertically supported on the surface of the flat plate 81 with a clearance of about 0.2 cm, and a pressure of 4-5 Kg/crn'cy) is applied to the columnar nozzle 51. It was confirmed that the machining fluid was injected at a flow rate of 5 to 6 IL/min and a large amount of jet flowed in the direction of the arrow.

Refer to Fig. 7. While ensuring a passage for the reflected jet by gradually notching the edge 52 of the columnar nozzle 51, the machining fluid is injected downward in the same manner as above, A jet stream flowing in the direction was observed. As a result, it was confirmed that a considerable amount of flow flowed in the direction of arrow A1°. This trend is the 9th
It has been confirmed that the same result can be obtained even if the notch is curved or only a part of the outer periphery is cut out as shown in FIGS. 10 and 11.

The reason why this phenomenon occurs is not necessarily clear, but the velocity of the downward jet is sufficiently large, and therefore the velocity of its reflected jet is also sufficiently large, so that a passage for the reflected jet is secured. Therefore, it is presumed that the upward jet flow (arrow A'' direction m) increased compared to the horizontal jet flow (jet flow in the arrow direction).

Through the above experiments, the large φ upward jet (arrow A°“°
Since it was confirmed that a jet flow in the same direction as the above was obtained, a prototype injection nozzle as shown in FIG. 8 was fabricated and experiments were repeated, and extremely remarkable effects were confirmed as described below.

Refer to Fig. 8. The upward jet (jet in the direction of arrow A°P) bounces off the inner surface of the cylindrical outer wall (skirt) 55 and becomes a downward jet (jet in the direction of arrow B) again, and the cylindrical outer wall (skirt) A wall of the machining liquid is formed between the lower end of the cylindrical outer wall (skirt) 55 and the workpiece 8 as shown by C in the figure, and no jet flow is observed to flow outside the cylindrical outer wall (skirt) 55. The effect was confirmed. Note that the size of the wall of the machining fluid indicated by C in this figure is determined by the size of the gap between the dovetail of the supplied machining fluid, the cylindrical outer wall (skirt) 55, and the surface of the workpiece 8. When this gap is small, the space sandwiched between the cylindrical outer wall (skirt) 55 and the nozzle tip 54 will be filled with the machining fluid, but according to the experimental results, In both cases, no significant difference in effectiveness was observed. That is, as long as the machining liquid wall shown by C in the figure is formed, the flow of the machining liquid on the surface of the workpiece 8 is extremely slow, and the effect of achieving the object of the present invention is fully exhibited.

(6) Embodiments of the Invention Three examples of machining fluid spray nozzles for wire-cut electric discharge machining according to embodiments of the present invention will be further described below with reference to the drawings.

Breast±1 Refer to Figure 8 again The inner diameter of the injection nozzle 53 is 3 mm, the outer diameter of its tip 54 is 10 m, and the tip 54 is approximately 45'' as shown in the figure.
It is missing with an inclination angle of ν. The inner diameter of the cylindrical outer wall (scar, -) 55 is approximately 401 mm.

The injection nozzle 53 having such a structure is
．． 2. Isolate and support the intestines, use processing wire 2 with a straight fW of 0.2+11, and apply pressure of 4 to 5 Kg/crn' and 5 to 5 kg/crn'.
6! When electrical discharge machining is performed while supplying machining fluid at a flow rate of 1/min, the machining area 7 has a diameter of approximately 0.03 mm.
Machining is performed with high precision with a machining allowance of . Then, a machining liquid wall indicated by C is formed between the lower end of the cylindrical outer wall (skirt) 55 and the surface of the workpiece 8, and the first
No jet flow, indicated by Ao in the figure, is generated. In other words, the flow of the machining fluid flowing through the workpiece 8'2 becomes extremely slow, and due to electrical discharge machining, the machining fluid has already spread to other areas.
Even if a slit is provided as shown at 7° in the figure, there will be no problem of water splashing back there and causing problems such as water getting wet.

9. The difference from the example shown in FIG. 8 is that the outer periphery of the tip 54° of the nozzle 53 is cut out with a curve.

In this example as well, exactly the same effect as in the upper case is observed.

Shaving unit 1 See Figures 10 and 11 The difference from the above two examples is that the tip 54° of the nozzle 53 is not cut out over the entire circumference, but cutouts are provided at certain intervals. That's true.

In this example as well, almost the same effect as in the second example described above is observed, and according to experiments, the effect seems to be rather remarkable. The reason for this is not clear.

It is presumed that this is because the machining liquid flow in the area surrounded by the cylindrical outer wall (skirt) 55 is complicated, and the formation of the machining liquid wall shown by C in the figure is easier and more reliable. In any case, the object of the present invention is fully achieved.

(7) Effects of the Invention As explained above, according to the present invention, a machining fluid injection nozzle for wire-cut electric discharge machining has a cylindrical outer wall (skirt) surrounding the outer periphery of the nozzle tip and being isolated from the outer periphery. In this method, the outer periphery of the nozzle tip is gradually narrowed toward the end, which eliminates the drawback that the machining fluid flows in a high-speed jet along the surface of the workpiece, causing problems such as water wetting. There is. A machining fluid injection nozzle for wire cut electric discharge machining can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of a machining fluid injection nozzle section in a wire-cut electric discharge machine. FIGS. 2, 3, 4, and 5 are cross-sectional views of conventional machining fluid injection nozzles completed with the same purpose as the present invention. FIGS. 6 and 7 are diagrams for explaining experiments carried out to realize the idea of the present invention. Figure 8, Figure 9, Figure 1
θ diagram and FIG. 11 are sectional views, respectively, of a machining fluid injection nozzle for wire cut electrical discharge machining according to a third embodiment of the present invention.
They are a sectional view, a sectional view, and a bottom view. l......Wire feed upper guide part, 2
......Wire electrode for processing, 3...
...Wire guide part, 4...Wire guide, 5.5", 5°°, 5°pa, 5"",
53...Nozzle, 54.54'
, 54°'...Nozzle tip, 6...
・・・・・・Processing liquid supply pipe, 7・・・・・・・・・
Processing area, 7°...Slit (processed processing area), 8...Workpiece,
9...Patsukin, 10...
...The splash receiver is a member, 11, 55...
...Cylindrical outer wall (scar)), +2...
Machining fluid injection port, 51... Column nozzle, 52... Edge, 81...
・・Flat plate, A・・・・・Liquid flow that is effectively used for processing, Ao・・・・・・・Horizontal jet liquid flow, A”・・・・・・・・・・・Rebounding liquid flow, A°゛・
・・・・・・・・・Upward jet, B・・・・・・・・・
Side jet, C・・・・・・Wall of added liquid. Agent Patent Attorney Makoto Samukawa - 3rd Flash Figure 4

Claims (1)

[Claims] In a machining fluid injection nozzle 53 for wire cut electric discharge machining having a cylindrical outer wall 55 surrounding the outer periphery of a nozzle tip 54 and provided in isolation from the outer periphery, the outer periphery of the nozzle tip 54 is made smaller toward its end. A power liquid injection nozzle for wire cut electric discharge machining characterized by: