JPS5852778B2 - Machining fluid supply device for electrical machining - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention supplies machining fluid (water) from a nozzle to a machining part in wire-cut electrical discharge machining, for example, but prevents the machining fluid jetted from the nozzle from scattering to the surroundings, and enables high-pressure machining. The purpose is to enable a sufficient amount of machining fluid to be supplied and circulated to the jet flow machining section at a high flow rate.

The electrical machining of the present invention includes not only wire cut electrical discharge machining but also electrolytic machining using an electrolyte, electrolytic deburring, electrolytic polishing, electrolytic discharge machining, etc.
It is also applicable to all electric machining processes in which a mixed liquid or the like is used and electricity is passed between an electric current and a workpiece to perform electrolytic action, electrical discharge machining action, or electrical discharge electrolytic machining action.

Conventionally, in wire-cut electrical discharge machining, machining liquid water is jetted from a nozzle, but when the jet is flown, the water splashes around and the jetting pressure cannot be increased. There were drawbacks such as the inability to supply a large amount of water, the occurrence of aerial discharges, low machining speeds, and wire breakage due to heating.

In addition, there are many drawbacks such as the current-carrying part of the wire being exposed to the air, causing it to heat up and stretch, break, and create air bubbles that interfere with current flow. The invention provides a nozzle that spouts the same or different liquid as the machining fluid around the machining fluid supply nozzle, and the jet fluid from the nozzle forms a liquid flow curtain around the jet machining fluid, thereby preventing the machining fluid from scattering and preventing air from flowing. This is designed to cause a blockage to occur.

The present invention will be explained below with reference to an embodiment of the drawings.

A wire electrode 1 is unwound from a reel (not shown) and moves toward the other side.

During this time, the wire 1 is under tension and moves in the direction of the arrow (from bottom to top in the figure) in a straight line between the guides 2 in a taut state.

The workpiece 3 is placed opposite the wire 1 between the guides, and a pulse discharge is applied to the opposing gap to process the workpiece.

Reference numeral 4 denotes a connection terminal of a processing power source, and the workpiece 3 is fixed to a processing table (not shown), and the processing table is fed with a processing shape feed in a plane that is normally perpendicular to one axis of the wire.

5 is a machining liquid supply nozzle, and 6 is a machining liquid. This liquid is jetted down from the tip of the nozzle 5 and is supplied along the wire electrode 1 to the machining gap where the wire 1 and the workpiece 30 face each other.

Reference numeral 7 designates a nozzle coaxially provided around the nozzle 50, from which a liquid that is the same as the machining fluid 6 or other than the machining fluid 6 is jetted out so as to surround the jet machining fluid 6, thereby creating a liquid flow. to form a liquid flow curtain 8.

The liquid jet pressure in the liquid flow curtain 8 portion is sufficiently low to avoid liquid scattering, approximately 1 #/Cm or less, and is flowed in large quantities at a low flow rate to exert sufficient curtain action.

By forming such a liquid flow curtain 8, the jet pressure of the machining liquid 6 jetted from the nozzle 5 can be increased, and can be jetted at a high flow rate at a high pressure, for example, about 1 to 5 kg/ci.

The machining fluid 6 is surrounded by a curtain 8, so it flows in a concentrated manner at the center, flows down along the wire 1, and
Distribution is involved in the processing section.

By increasing the jet pressure, the machining fluid 6 is supplied in large quantities to the machining part, flows sufficiently, and new fluid is constantly circulated, so that the electrical discharge machining action performed via this fluid is stable and high. Works efficiently and increases crab speed significantly.

Figure 2 shows machining fluid being jetted inside a liquid flow curtain.
Injection speed mIL/1niI when changing jet pressure
It is a graph diagram in which L is plotted from experimental results.

The processing uses a 0.2 mm φ Cu wire electrode with a thickness of 60 mm.
It is wire-cut from m1t 555C material,
To supply the machining fluid, a nozzle with a jet diameter of 2 mm is coaxially inserted into a nozzle with a jet diameter of 10 mm, the wire electrode is assembled so that it moves through the center of the inner nozzle, and distilled water is supplied to the outer nozzle at a flow rate of approximately 0.8 m/sec, and when the same distilled water was jetted into the inner nozzle at a liquid pressure of about 0.5 kg/ca and a flow rate of about 5 rIL/sec, the processing speed was about 32 m/sec.
! It was L/mm.

Next, when the liquid pressure of the inner nozzle was increased to approximately 2 kg/crA, the processing speed became 46 m1t/min, and the liquid pressure increased to 3 to 9.
/cA, machining speed 50i4/mm, hydraulic pressure 4/cr
The machining speed was approximately 521 ftft/m at rr.

This processing speed is approximately 1 1
．． The effect was increased by more than five times.

As described above, by forming a liquid flow curtain that is slower than the flow rate of the inner machining fluid, the machining fluid jet pressure can be increased and the flow velocity can be increased and controlled, and the machining speed can be improved. This is particularly effective in machining that uses water or a corrosive electrolyte as the machining fluid.

In addition, the wire electrode 1 is surrounded by a liquid flow in the processing part and the current-carrying part, so there is no elongation or breakage due to heat generation, and the wire electrode 1 is cut off from the outside air, eliminating air bubbles and other contamination, and ensuring a smooth supply of processing liquid to the processing part. In addition, it can be supplied in large quantities, the liquid resistance can be lowered, the current density can be increased, and the cooling effect can be improved, so that the machining speed and machining accuracy can be improved.

Note that the processing liquid supply nozzle may be configured to supply the processing liquid not only from one side of the workpiece but also from both the upper and lower sides, and the same effect can be obtained by forming a liquid flow curtain at each nozzle.

The machining fluid jet nozzle also serves as an electrode, and the same machining effect can be expected by forming a fluid curtain around the jet machining fluid when performing electrical discharge drilling other than wire cutting, such as electrolytic machining.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, and FIG. 2 is a graph diagram of machining characteristics of the embodiment. 1...Wire electrode, 2...Workpiece, 4...Bending machining power supply connection terminal, 5...Machining liquid nozzle, T...Liquid jetting Nozzle, 8...Liquid flow curtain.

Claims (1)

[Claims] 1 In electrical machining in which a machining fluid is supplied and interposed in a machining gap where an electrode and a workpiece face each other, and the machining fluid is energized for machining, a nozzle for supplying a jet of the machining fluid is provided, and a machining fluid is provided around the jet machining fluid. What is claimed is: 1. A machining fluid supply device for electrical machining, comprising a nozzle that flows the same or another fluid at least at a lower flow rate than the jet machining fluid to form a fluid curtain.