JP2001347424A - Machining liquid supply nozzle of wire cut electric discharge machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machining liquid supply nozzle capable of surely supplying a machining liquid at a high speed to a machining area between a wire electrode and a workpiece, capable of preventing disconnection of the wire electrode and capable of increasing a machining speed without complicating the constitution of the nozzle. SOLUTION: Besides a main blowout port, auxiliary blowout ports having a diameter smaller than the main blowout port are arranged in a plurality as blowout ports for blowing out the machining liquid, and these auxiliary blowout ports are arranged on a concentric circle with the main blowout port so as to surround the periphery of the main blowout port.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machining fluid supply nozzle for ejecting and supplying a machining fluid to a machining region in a gap between a wire electrode and a workpiece in a wire electric discharge machine.

[0002]

2. Description of the Related Art FIG. 9 shows a conventional processing liquid supply nozzle.
FIG. 9A illustrates a cross section, and FIG. 9B illustrates a cross-sectional view taken along line PP of FIG. 9A. The processing liquid supply nozzle is provided for the purpose of jetting the processing liquid to a processing area 101 between the wire electrode 1 and the workpiece 6. A nozzle 2 surrounds a wire guide 3 that holds the wire electrode 1, and a jet port 4 for jetting a working fluid is provided at the tip of the nozzle 2.

Further, in another conventional processing liquid supply nozzle shown in FIG. 10, a double annular nozzle having an auxiliary nozzle 202 having an annularly opened auxiliary nozzle 201 is arranged around a nozzle 2 having an nozzle 4. In addition, the processing liquid is jetted to the processing area.

Further, a working fluid supply nozzle shown in FIG. 11 is disclosed in Japanese Patent Application Laid-Open No. 61-103727. FIG. 11A and FIG. 11 in which the Z portion is enlarged.
As shown in (b), an annular groove 301 having a rectangular cross section is provided at the tip of the nozzle 2.

When electric discharge machining is performed using this machining liquid supply nozzle, the machining fluid ejected from the ejection port 4 hits the workpiece 6 and a gap between the tip end surface of the nozzle 2 and the workpiece 6. 9 spreads radially outward toward the outside.

At this time, if the size of the gap 9 is reduced, the machining liquid flows into the groove 301 as shown by the arrow W, and forms a vortex flow 302. Since the flow resistance in the gap 9 increases due to the rebound of the vortex flow 302, the amount of the working fluid (arrow U in the drawing) flowing outward decreases, and the working fluid flows into the machining groove 12 (in the drawing). Arrow V) increases. Therefore, the supply of the working fluid to the periphery of the wire electrode becomes fast and reliable.

[0007]

In the conventional processing liquid supply nozzle shown in FIG. 9, a high-pressure processing liquid tries to jet uniformly from the jet port 4 at the tip of the nozzle 2. Therefore, when the processing has already been performed and the processing groove 12 has been formed in the workpiece 6, the ejected processing liquid flows in the direction of the processing groove 12 with low resistance as shown by the arrow 102, and the processing area 101 , The flow rate of the machining fluid decreases. A decrease in the flow rate of the working fluid significantly reduces the wire electrode cooling effect and the sludge discharge effect by the working fluid, and leads to disconnection of the wire electrode.

In order to supply the machining fluid to the machining area 101 at high speed and reliably, the pressure of the gap 9 between the nozzle tip surface and the workpiece 6 is reduced as in the machining fluid supply nozzle shown in FIG. By increasing the pressure and increasing the component of the pressure in the direction of the arrow 203, it is necessary to suppress the flow 204 that is going to be away from the processing region to be a flow 205, and to keep the flow of the high-speed processing liquid from the wire electrode 1. .

However, in the machining fluid supply nozzle shown in FIG. 10, since the machining fluid flow path to the auxiliary ejection port 201 and the machining fluid flow path to the ejection port 4 are different, the pressure difference between the two ejection ports is different. As a result, there is a problem that the processing liquid flows backward to the auxiliary jet port 201 as shown by an arrow 206. Further, since the cross-sectional area of the auxiliary ejection port 201 located on the outside is large, a large amount of machining liquid is required particularly when the nozzle tip and the workpiece 6 are separated from each other, or because the nozzle is doubled, There are problems in that the configuration is complicated and large, the shape and dimensions that can be processed are restricted, and it is necessary to provide another pump for pressurizing the auxiliary jet port.

In the working fluid supply nozzle shown in FIG. 11, the pressure in the gap 9 periodically fluctuates due to the swirling flow 302 formed in the groove 301. Due to this pressure fluctuation, the nozzle 2 vibrates in the vertical direction, and the machining finish accuracy decreases,
There is a problem that it leads to failure of the entire device.

The present invention solves the above problems, and supplies a machining liquid reliably and at high speed to a machining area between a wire electrode and a workpiece without complicating the structure of a nozzle. The present invention provides a processing liquid supply nozzle capable of preventing disconnection of a wire electrode and achieving a high processing speed.

[0012]

The present invention is characterized in that a plurality of auxiliary jets having a smaller diameter than the main jet are arranged concentrically with the main jet, around the main jet.

[0013] In addition to a simple circular through hole,
It may be a divergent conical shape.

The direction of the auxiliary jet may be inclined with respect to the direction of the main jet.

The auxiliary jets may be arranged on a plurality of circles concentric with the main jet to form a multi-split auxiliary jet.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A working fluid supply nozzle according to the present invention will be described with reference to the accompanying drawings.

Embodiment 1 FIG. 1 shows an embodiment of a working fluid supply nozzle according to the present invention. FIG. 1A shows a cross section of the present embodiment, and FIG.
(B) shows the arrow QQ in FIG. 1 (a).

In FIG. 1, 1 is a wire electrode, 2 is a nozzle, and 3 is a wire guide holding the wire electrode.

The working fluid flows into the nozzle 2 as shown by an arrow 7 and the pressure is recovered by a pressure recovery section 5. The working fluid in the pressure recovery section 5 flows out toward a gap 9 between the workpiece 6 and the tip end surface of the nozzle 2.

In the present embodiment, an auxiliary outlet 8 is provided in addition to the main outlet 4 as an outlet for outflow of the machining fluid. A plurality of auxiliary jets 8 are provided, and are arranged at equal intervals on a concentric circle of the main jets 4 so as to surround the main jets 4.

Due to the auxiliary jet 8, the working fluid in the gap 9 becomes high in pressure over a wide range from the center of the wire electrode 1 to the vicinity of the auxiliary jet 8, and spreads radially toward the outer end 10 of the nozzle and the processing groove 12. Spills into the interior. The flow that has flowed into the processing groove 12 moves away from the wire electrode 1 as indicated by an arrow 13.

FIG. 2 shows the distribution of the pressure in the gap 9 as follows.
The radial direction centering on the wire electrode 1 is shown. The horizontal axis represents the distance from the wire electrode 1 and the vertical axis represents the pressure in the gap 9. The auxiliary jet 8 is connected to the wire electrode 1
And the outer end 10 of the nozzle 2.

In FIG. 2, a curve A represents the pressure distribution in the case where there is no auxiliary ejection port 8. On the other hand, auxiliary jet 8
Is provided by a curve B.
When the auxiliary jet 8 is provided, since the auxiliary jet 8 communicates with the pressure recovery unit 5, there is no auxiliary jet 8 at all positions from the position of the wire electrode 1 to the outer end 10 of the nozzle 2. The pressure is higher than in the case.

For example, if the position where the pressure in the gap 9 becomes I is read from FIG. It is a position D close to the outer end 10.

FIG. 3 shows the flow of the machining fluid in the machining groove 12 in detail. At the position C, when the auxiliary ejection port 8 is not provided, the force for flowing the working fluid along the wire electrode 1 is assumed to be the force E. When the auxiliary jet port 8 is provided, the pressure G in the gap 9 increases as described above, so that the force G for flowing the working fluid along the wire electrode 1 becomes larger than the force E. Due to the increase in the force, the flow of the working fluid changes from the arrow H to the arrow J in the drawing, and the phenomenon that the flow of the working fluid is separated from the wire electrode 1 is suppressed.

That is, by providing the auxiliary jet port 8, the pressure in the gap 9 increases, and the machining fluid is ejected from the high-pressure gap 9 into the machining groove 12, so that the ejected machining fluid has low resistance. The phenomenon of flowing out in the direction of the arrow 13 (see FIG. 1) is suppressed, and the flow rate of the working fluid in the working area around the wire electrode 1 is improved.

In the conventional processing liquid supply nozzle shown in FIG. 10, the auxiliary injection port 20 for processing liquid indicated by an arrow 206 is provided.
There are problems such as a backflow to 1 and an increase in the flow rate of the working fluid when the gap 9 becomes large. However, according to the present embodiment, the working fluid immediately flows out of the pressure recovery unit 5 through the main jet port 4 and the auxiliary jet port 8, and there is no flow path serving as a resistance on the way. The change in the pressure is immediately fed back to the pressure recovery section 5, and the auxiliary jet port 8
Backflow to the air and pressure fluctuation in the gap 9 do not occur.

FIG. 4 shows the achievable machining speed as a function of the area ratio between the main jet 4 and the auxiliary jet 8.

The sectional area of the auxiliary outlet 8 is S0, and the number is n.
The sectional area of the main outlet 4 is denoted by S, and the ratio of the total sectional area of the auxiliary outlet 8 to the sectional area of the main outlet 4 is e = (n × S0) /
S is the horizontal axis, and the vertical axis is the processing speed. The processing speed is
It is improved in the range of 0.2 <e <1.0. However, in consideration of the fact that machining is performed in all directions, the angle θ at which the two auxiliary ejection ports 8 adjacent to each other with the wire electrode 1 as a center is θ ≦ 120 °, and the number n of the auxiliary ejection ports 8 is n ≧ 3
Must.

According to the present embodiment, a high-speed and sufficient amount of processing fluid can be supplied to the processing area between the wire electrode 1 and the workpiece 6, so that the cooling effect of the wire electrode 1 and the processing efficiency can be improved. The sludge discharge effect in the processing area is improved, the disconnection of the wire electrode 1 can be prevented, and the processing speed can be improved.

Further, as shown in FIG. 5, since the pressure in the area 14 opposite to the processing area of the wire electrode 1 is also increased, the deflection K of the wire electrode 1 and the vibration L during the processing are suppressed. Processing accuracy is also improved.

Embodiment 2 FIG. 6 shows another embodiment of the working fluid supply nozzle of the present invention. FIG. 6A shows a cross section of the present embodiment, and FIG.
(B) shows the arrow RR in FIG. 6 (a).

The present embodiment is characterized in that, in the first embodiment described above, the auxiliary outlet 8 has a truncated conical shape whose diameter increases toward the gap 9 side.

Since the pressure loss at the auxiliary outlet 8 is reduced by making the shape of the auxiliary outlet 8 divergent, the pressure distribution in the gap 9 is as shown by the curve M in FIG. Even higher.

Since a high-speed and sufficient amount of processing liquid can be supplied to the processing area between the wire electrode 1 and the workpiece 6, the cooling effect of the wire electrode 1 and the sludge discharge effect of the processing area are further improved. It is possible to prevent the disconnection of the wire electrode 1 and improve the processing speed.

Further, as shown in FIG.
And the vibration L during processing are suppressed, and the processing accuracy is also improved.

Embodiment 3 FIG. 7 shows another embodiment of the working fluid supply nozzle of the present invention. FIG. 7A shows a cross section of the present embodiment, and FIG.
(B) represents the arrow SS in FIG. 7 (a).

In Embodiments 1 and 2 described above,
Although the central axis of the auxiliary jet 8 is parallel to the wire electrode 1,
The present embodiment is characterized in that the central axis of the auxiliary ejection port 8 is inclined with respect to the wire electrode 1. The direction of the inclination is such that the flow of the working fluid from each auxiliary jet 8 is directed to the wire electrode 1.

Since the energy component 16 of the working fluid in the direction perpendicular to the wire electrode 1 increases, the bending K of the wire electrode 1 and the vibration L during the working shown in FIG. 5 are further suppressed, and the working accuracy is improved. .

Embodiment 4 FIG. 8 shows still another embodiment of the working fluid supply nozzle of the present invention. FIG. 8A shows a cross section of the present embodiment, and FIG. 8B shows an arrow TT in FIG. 8A.

In the first, second and third embodiments described above, the plurality of auxiliary jets 8 are arranged on one circle concentric with the main jet 4. The present embodiment is characterized in that the plurality of auxiliary jets 8 are formed into two groups, and each group is arranged on a circle concentric with the main jet 4 and having a different diameter.

By arranging the auxiliary jets 8 in a double manner, the radial flow toward the outer end 10 of the nozzle 2 in the gap 9 is equalized, and the pressure distribution in the circumferential direction becomes uniform. In addition, the processing liquid can be reliably and rapidly supplied to the workpiece 6 having any processing shape.

It should be noted that the same effect can be obtained even if the auxiliary jet ports 8 are arranged in three or more layers.

[0044]

According to the working fluid supply nozzle of the present invention, the flow velocity of the working fluid in the working area around the wire electrode can be increased, and the wire electrode cooling effect is improved. In addition, since the supply of the processing liquid to the processing area increases, sludge discharge is improved. These effects make it difficult for the wire electrode to break, so that the processing speed can be improved.

In addition, there is an effect that bending of the wire electrode and vibration during processing are suppressed, and processing accuracy is improved.

Further, since the working fluid supply nozzle of the present invention is symmetrical with respect to the wire electrode, the above-described effects can be obtained not only when performing a straight working but also when working a bent portion.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a working fluid supply nozzle of the present invention.

FIG. 2 is a diagram showing a pressure distribution in a gap between a nozzle tip surface and a workpiece in a radial direction centered on a wire electrode.

FIG. 3 is a diagram showing details of a flow of a machining fluid.

FIG. 4 is a diagram showing the processing speed improving effect of the processing liquid supply nozzle of the present invention as a function of the ratio of the area of the main ejection port to the area of the auxiliary ejection port.

FIG. 5 is a view for explaining the effect of suppressing the deflection of the wire electrode and the vibration during the processing by the processing liquid supply nozzle of the present invention.

FIG. 6 is a view showing another embodiment of the working fluid supply nozzle of the present invention.

FIG. 7 is a view showing another embodiment of the working fluid supply nozzle of the present invention.

FIG. 8 is a view showing still another embodiment of the working fluid supply nozzle of the present invention.

FIG. 9 is a view showing a conventional processing liquid supply nozzle.

FIG. 10 is a view showing a conventional processing liquid supply nozzle.

FIG. 11 is a view showing a conventional processing liquid supply nozzle.

[Explanation of symbols]

1 wire electrode, 2 nozzles, 3 wire guides, 4
Spout (main spout), 5 pressure recovery section, 6 workpiece,
8 auxiliary jet, 9 gap between nozzle tip surface and workpiece, 201 auxiliary jet, 202 auxiliary nozzle, 301 annular groove.

Claims (4)

[Claims] In a wire-cut electric discharge machine, a nozzle for supplying a machining fluid to a machining area between a wire electrode and a workpiece is provided as a nozzle for ejecting the machining fluid. A plurality of auxiliary outlets, which are arranged concentrically with the main outlet around the main outlet, and have a smaller diameter than the main outlet,
A working fluid supply nozzle having 2. The processing fluid supply nozzle according to claim 1, wherein the shape of the auxiliary ejection port is a frustoconical shape that expands toward the direction in which the processing fluid is jetted. 3. The central axis of the auxiliary jet is inclined with respect to the central axis of the main jet, and the central axis of the auxiliary jet and the main jet are located on the side of the direction in which the machining fluid is jetted. The processing liquid supply nozzle according to claim 1, wherein the processing liquid supply nozzle is configured to intersect with a central axis of the processing liquid. 4. The working fluid supply nozzle according to claim 1, wherein the auxiliary ejection port is arranged on a plurality of circles concentric with the main ejection port.