JPS6126454B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a wire cut electric discharge machining apparatus that includes:
This invention relates to a device that prevents machining fluid from scattering near and around a machining part.

In general, wire cut electrical discharge machining equipment usually
Using a wire electrode with a diameter of 0.05 to 0.3 mm, a voltage is applied by a machining power supply to a micro gap facing the workpiece using a machining liquid such as water as a medium to generate an electric discharge. In addition, the relative feeding between the workpiece and the wire electrode is performed by an X-Y cross table, and the feeding is controlled by the motors provided on each of the X and Y cross tables. It is controlled by a device and used for cutting and punching general molds.

First, the structure of the wire guide section in the conventional device will be shown in detail using FIG. The figure shows the upper wire guide part of the pair of upper and lower wire guide parts, and since the lower part is the same, illustration thereof is omitted.

The wire electrode 1 is supported by a die-shaped guide 3 made of jewelry such as sapphire or diamond attached to the tip of the wire guide body 2. Further, a plurality of cut portions 4 are provided on the tapered outer periphery of the wire guide main body 2 for passage of machining fluid. Further, the wire guide body 2 is fitted into the guide attachment body 5 and fixed by screwing the die holder 6 into the guide attachment body 5. A die-shaped power feeding die 7 for feeding power to the wire electrode 1 is fitted inside the die holder 6, and is fixed by a die holder 8 with a screw force. Here, the centers of the die shape guide 3 and the power supply die 7 are usually shifted by 0.5 mm or more, and this shift presses the wire electrode 1 against the power supply die 7.

Furthermore, a groove 9 is cut out in the tip of the die holder 6 for guiding the machining fluid into the power feeding die 7. The guide attachment main body 5 is fixed to a stationary device 11 with a screw 10. moreover,
A nozzle 14 is fixed to the tip of the guide attachment main body 5 by a screw (not shown) for supplying machining liquid in a jet stream coaxially with the wire electrode 1 to the machining groove 13 formed in the workpiece 12. .

Here, the actual flow of the machining fluid will be explained.

First, the machining fluid is supplied from a machining fluid supply device (not shown), passes through the supply pipe 15, flows as indicated by an arrow 16 in the diagram, and is supplied to a portion including the machining groove 13, the power supply die 7, and the wire electrode 1. and cooling is performed. In the figure, the machining fluid is ejected upward from the die holder 8 in the A section, and the machining fluid leaks from the gap between the upper end surface of the workpiece 12 and the tip surface of the nozzle 14 in the B section. Such leakage of machining fluid in parts A and B increases due to an increase in the supply pressure or supply flow rate of machining fluid, and in the case of part A, the machining fluid is scattered directly above the part B.
In the case of a part, the machining fluid will be scattered directly to the side, and the machining fluid will be scattered to the surrounding machines and electrical systems, causing corrosion or short circuits in the electrical system. It is known that normally in wire cut electrical discharge machining, the machining speed increases as the supply pressure and amount of machining fluid increases, so the problems caused by the machining fluid scattering as mentioned above must be eliminated. That's a problem.

In view of the above-mentioned facts, the present invention provides a device for preventing the scattering of machining fluid, particularly as shown in section A in FIG.

An embodiment of the present invention will be described below.

FIG. 2 shows a die holder for preventing scattering of machining liquid, which is the central feature of the present invention, in which figure a is a front half-sectional view, figure b is a plan view, and figure c is a bottom view.

In FIG. 2, 17 is a die holder with a circular cross section, 18 is a deep groove formed on one end surface of the die holder 17, 19 is a machining fluid pool with a cylindrical cross section formed on the other end surface of the die holder 17, and 20 is a machining fluid passage hole that communicates the deep groove 18 with the machining fluid pool 19 and has a cross-sectional area smaller than that of the deep groove 18 and the machining fluid pool 19;
is composed of multiple pieces. Further, 21 is a wire passage hole formed in the center of the die holder 17.

FIG. 3 is a sectional view showing a state in which the die holder 17 shown in FIG. 2 is assembled into a wire guide section, and the same reference numerals as in FIG. 1 indicate the same or corresponding parts. Note that the wire electrode should not come into contact with the inner surface of the wire electrode passing hole 21 of the die holder 17 (contact here means that pressure is not applied to the wire electrode to the extent that it will be deformed or damaged). The positions of the die 7 and a pulley for changing the direction of the wire electrode (not shown) are determined.

When the die holder 17 according to the present invention as described above is used, the machining fluid that has passed through the power feeding die 7 from the supply pipe 15 first hits the wire passage hole 21 and increases the flow path resistance. Most of the flow changes to the low machining fluid passage hole 20, and the flow velocity when passing through this machining fluid passage hole 20 is attenuated due to the viscosity of the inner wall, and rises due to surface tension as shown in section C in Fig. 3. Once formed, it overflows and quietly flows downward. According to experiments, when the machining fluid supply pressure is around 1Kg/cm ² , if the diameter of the wire passage hole 21 is set to 0.7 mmφ or less, or if the hole diameter of the machining fluid passage hole 20 is set to approximately 2 mmφ, the machining fluid will not scatter. It was found to be effective in prevention. However, this data is based on the conditions that the depth l of the groove 9 shown in FIG. 3 is about 0.1 mm and the width is about 1 mm.

In the above embodiment, only the upper wire guide section has been described, but it goes without saying that the lower wire guide section is also effective because the flow rate of the machining fluid flowing downward is reduced (in this case, This prevents the machining fluid that has fallen strongly downward from splashing back into the machining tank.)

As described above, according to the device of the present invention, the machining fluid is supplied to the actual machining part and the power feeding die is performed only by supplying the machining fluid from the machining fluid supply pipe, that is, with only one machining fluid supply port. This has the effect of making it possible to cool the included wire electrode, and not causing any scattering of the machining fluid as seen in section C of FIG.

[Brief explanation of the drawing]

FIG. 1 is a structural schematic diagram of a conventional upper wire guide section, FIG. 2 is an embodiment diagram showing a die holder which is the center of the present invention, and FIG. 3 is a structural schematic diagram of an upper wire guide section according to the present invention. It is. In the figure, 1 is a wire electrode, 7 is a power supply die,
8 and 17 are die holders, 12 is a workpiece, 18 is a deep groove, 19 is a machining fluid pool, 20 is a machining fluid passage hole, and 21 is a wire passage hole. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A power feeding die that presses into contact with the wire electrode, in which machining is progressed by causing electrical discharge to occur in a corresponding minute gap between the wire electrode and the workpiece using a machining power source using machining fluid as a medium. and a die holder for fixing the power supply die, the die holder has a wire passage hole through which the wire electrode passes, and a machining fluid passage hole is formed in parallel with the wire passage hole, and a machining liquid passage hole is formed in parallel with the wire passage hole. A machining fluid scattering prevention device in a wire-cut electrical discharge machining device, which includes a machining fluid passage hole communicating with a press-contact portion between the wire electrode and the power supply die. 2. A machining fluid scattering prevention device in a wire cut electric discharge machining apparatus according to claim 1, wherein a machining fluid pool is formed on one end surface of the wire passage hole and the machining fluid passage hole. 3. A machining fluid scattering prevention device in a wire cut electric discharge machining apparatus according to claim 1 or 2, characterized in that a die holder is installed above the power feeding die.