JPH0526610B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wire cut electrical discharge machining device,
In particular, the purpose is to extend the life of the feeder electron that supplies machining power to the wire electrode.

[Conventional technology]

FIG. 4 schematically shows a wire guide section in a conventional wire electric discharge machining apparatus having a pipe guide.

In the figure, 1 is a wire electrode, 2 is a workpiece, 3 is a machining start hole drilled in the workpiece 2 through which the wire electrode 1 is passed, and 4 is a pipe guide, with a die guide 5 supporting the wire electrode 1 at the tip. and is fixed to the pipe 7 with screws 6. Note that when inserting the wire electrode 1 into the machining start hole 3, the pipe guide 4
is raised and lowered by a lifting device (not shown). 8 is a feeder installed in the pipe guide 4 and has a wire contact hole inside; 9 is an eccentric die;
10 is a conductive tape, 11 is a pipe holder for positioning the pipe guide 4, 12 is a cutter for cutting the wire electrode 1, 13 is a power source for supplying power for processing, 14 is a processing fluid, and 15 is a processing fluid to be described later. machining fluid inlet for supplying machining fluid into the machining fluid nozzle, 17
18 is a machining fluid nozzle that supplies machining fluid 14 into the minute gap between wire electrode 1 and workpiece 2; 18 is an inlet port through which machining fluid 14 flows to cool and clean the inside of pipe guide 4; and 19 is an inlet that flows inside pipe guide 4. This is an outlet through which the machining fluid 14 that has passed flows out.

In the conventional apparatus described above, the operation of supplying machining power to the wire electrode will be explained.

Processing power is supplied from the power source 13 to the pipe holder 11,
is carried out via the pipe guide 4 and the feeder 8,
The eccentric die 9 makes the wire electrode 1 eccentric from the center of the pipe guide 4 and brings it into contact with the side surface of the hole of the feeder 8, thereby supplying power to the wire electrode 1. on the other hand,
As the machining process progresses, wear gradually progresses on the part of the feeder 8 that contacts the wire electrode 1 on the hole side, and a groove is gradually formed deeper as the wire electrode 1 travels, and eventually the wire electrode 1 and the feeder 8 are no longer in contact with each other, and power cannot be supplied to the wire electrode 1. FIG. 5 shows a state where the wear of the feeder 8 has progressed until it becomes impossible to feed power to the wire electrode 1 as described above. Generally, the wire electrode 1 is used for processing with a wire diameter of about 0.1 mm to 0.3 mm, but if we take the case where the wire electrode diameter is 0.3 mm as an example, the inner diameter of the feeder 8 is about 0.5 mm,
The inner diameter of the eccentric die 9 is about 0.4 mm, the maximum eccentricity is about 0.6 mm due to manufacturing considerations, and the outer diameter of both the feeder 8 and the eccentric die 9 is about 3 mm. The maximum value is about 0.2mm.

Next, the path of the machining fluid will be explained. The machining fluid 14 sent from a machining fluid pump (not shown) flows through the inlet 15 and fills the machining fluid nozzle 17, and most of it is ejected from the outlet of the machining fluid nozzle 17, causing the wire electrode 1 and the workpiece to is supplied to the electrical discharge machining gap.

On the other hand, a part of the machining fluid 14 flows into the pipe guide 4 from the inlet 18 provided in the pipe guide 4, and flows into the feeder 8a, the eccentric die 9, and the feeder 8b.
flows in order and flows out of the pipe guide 4 from the outlet 19, cooling the power feeding surface between the wire electrode 1 and the feeder 8, and removing dust from wear of the wire electrode 1 inside the pipe guide 4. It also has an effect on the emission of other substances.

[Problem that the invention seeks to solve]

Conventional wire electrical discharge machining equipment is configured as described above, so there is a limit to the amount of eccentricity of the eccentric die due to manufacturing considerations.On the other hand, the inner diameter of the feeder must be at least larger than the wire electrode, and If the inner diameter of the electron is made smaller, the amount of machining fluid flowing inside the pipe guide will decrease, making it impossible to sufficiently cool the power supply surface where the wire electrode and the feeder come into contact, resulting in significant wear of the feeder due to high temperatures, which will increase the wear allowance. There was a problem in that it was difficult to extend the life of the source and source electrons. Normally, when the wire electrode diameter is large, relatively larger machining power is supplied than when the wire electrode diameter is small.If we take a wire electrode with a diameter of 0.3 mm as an example, the life of the feeder of the conventional wire electric discharge machining equipment is 10~ under maximum processing conditions
In some cases, it took 20 hours, making long-term unmanned operation impossible. In addition, the feeder is expensive because it has a minute cylindrical shape and is machined to have a smooth surface with high precision, which also causes high running costs.

This invention was made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a wire electrical discharge machining device that is equipped with a long-life and inexpensive feeder, that enables unmanned operation for long periods of time, and that can reduce running costs. With the goal.

[Means for solving problems]

The wire electrical discharge machining apparatus according to the present invention has a wire electrode inserted into the pipe guide, and a feeder having an arcuate side surface and a cutout surface in the wire electrode feeding direction in the arcuate part is provided in the pipe guide. A wire electrode is brought into contact with this feeder, and die guides are provided on both sides of the feeder.

[Effect]

The wire electric discharge machining apparatus according to the present invention uses the feeder having the above-mentioned shape to increase wear allowance and prolong the life of the feeder, and also reduces manufacturing cost by having a simple shape.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, the same reference numerals as in FIG. 4 indicate the same or corresponding parts.

20 is a feeder installed in the pipe guide 4 and has a notched surface in the feeding direction of the wire electrode 1 on an arc-shaped side surface; 21 is a guide die for positioning the wire electrode at the center of the pipe guide 4; It is attached to the tip of pipe 7 with solder.

Figures 2a to 2c show the shape of the feeder 20 in detail, and a cutout surface having a cross section between A and C shown in Figure 2a is provided in a part of the arcuate portion. .
The cross section between B and B' is a straight line, and the sections between A and B and B' and C are a parabola or a circular arc with a larger curvature continuing from the straight line.

In addition, FIG. 2a is a front view, FIG. 2b is a side view,
FIG. 2c is a plan view.

In this embodiment, the operation of supplying machining power to the wire electrode 1 will be described. The power for processing is
From the power supply 13 to the pipe holder 11, pipe guide 4,
and is supplied via the feeder 20 to the wire electrode 1
runs from top to bottom, pipe 7, guide die 21
, along the notched surface of the feeder 20 , and then passes through the die guide 5 , and the wire electrode 1 is guided to the center of the pipe guide 4 on both sides of the feeder 20 by the guiding die 21 and the die guide 5 . Since it is supported, it is squeezed into contact with the cutout surface of the feeder 20 and is supplied with power. In this case, if the wire electrode diameter is expressed as D (mm), the wear allowance is expressed as ba/2+D/2 from the dimensions a and b in Figure 2c, and the wire electrode diameter is 0.3 mm. For example, since a and b are about 3 mm and 2.6 mm, respectively, the wear margin is about 1.25 mm. As described above, in this embodiment, the wear allowance, which is the primary cause of wear of the feeder 20, can be significantly increased compared to the conventional example, and furthermore, the die guides 21 and 5 are disposed above and below the feeder 20. By providing the wire electrode 1 and the feeder 20, the wire electrode 1 and the feeder 20 are always in contact with the entire power feeding surface, as shown in the worn state of the feeder 20 shown in FIG. 3, which lowers the current density and lowers the contact resistance. . The inventor conducted an experiment and found that the life of the feeder under maximum machining conditions when using a wire electrode with a diameter of 0.3 mm was 90 to 120 hours, and the conventional problems were resolved. has been confirmed. In addition, during this experiment, it was confirmed that the curves between A and B and B' and C shown in FIG. 2 have the longest service life when the radius is approximately 25 mm.

Next, the flow path of the machining fluid flowing inside the pipe guide 4 will be explained. The machining fluid 14 sent from a machining fluid pump (not shown) flows through the inlet 15 and fills the machining fluid nozzle 17, and most of it is ejected from the outlet of the machining fluid nozzle, causing the wire electrode 1 and the workpiece 2. is supplied to the electrical discharge machining gap. On the other hand, a part of the machining fluid 14 flows into the pipe guide 4 from the inlet 18 provided in the pipe guide 4 and flows into the feeder 20 and the pipe 7.
, passes through the guide die 21 , and flows out of the pipe guide 4 through the outlet 19 . Regarding the flow path cross section of the machining fluid flowing inside the pipe guide 4, the part corresponding to the inner diameter of the feeder 8 in the conventional example is the gap formed by the feeder 20 and the pipe 7 in this embodiment, but the cross-sectional area S When calculating, in the conventional example, S = (0.5/2) ² π, in this example, S = 2∫ ^a _b √ ² − ² dx (however, a = 3.0, b = 2.4), and the flow path cross-sectional area is They are 0.196 mm ² and 0.737 mm ² , respectively, and in this embodiment, the cross section of the machining fluid flow path in the pipe guide 4 can be made wider than in the conventional example.
The flow rate of the machining fluid flowing inside the pipe guide 4 is increased to increase the efficiency of cooling the power feeding surfaces of the wire electrode 1 and the feeder 20, thereby reducing the acceleration of wear at high temperatures, which is a secondary cause of wear of the feeder 20. It can be prevented. In addition, due to the increase in flow rate, the discharge of abrasion particles of the wire electrode 1 in the pipe guide 4 is promoted, and the die guide 5
This also eliminates wire electrode running problems caused by clogging.

In addition, since the shape of the feeder 20 has been simplified,
The product can be completed by grinding the round bar material in one step, significantly reducing processing costs and making it possible to supply the product at a low cost.

Note that the cutout cross section of the feeder in the embodiment may be another curve, and the dimensions of each part of the feeder may be changed.

〔Effect of the invention〕

As described above, according to the present invention, the feeder has a shape with a cutout surface on the arcuate side surface, which increases the wear allowance and increases the amount of cooling water on the feeder surface. Since die guides supporting the wire electrodes are provided on both sides of the wire, the life of the feeder is extended, and the feeder has a simple shape, which reduces manufacturing costs.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an embodiment of the present invention, Fig. 2 is a detailed drawing of the feeder, Fig. 3 is an explanatory diagram showing the state of wear of the feeder, and Fig. 4 is a schematic diagram showing a conventional example. , FIG. 5 is an explanatory diagram showing the state of wear of the feeder in the conventional example. In the figure, 1 is a wire electrode, 4 is a pipe guide, 5 is a die guide, 20 is a feeder, and 21 is a guide die. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A feeder is provided in the pipe-shaped wire guide to contact the wire electrode and supply processing power to the wire electrode, and a die guide is provided on both sides of the feeder to support the wire electrode. A wire cut electric discharge machining apparatus characterized in that the feeder has a cutout surface formed in the feeding direction of the wire electrode on an arcuate side surface.