JPH11129122A - Wire electric discharge machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire electric discharge machining device with excellent working precision, capable of machining a fine width of groove and preventing vibration due to discharge pressure and wire running. SOLUTION: A wire electric discharge machining device has a guide groove 31 provided in an electrode guider 3 and a movable wire electrode 2 movable in the condition that it is fitted in the guide groove 31, to apply pulse energy between the movable wire electrode 2 and a workpiece 7 for wire electric discharge machining. The depth H of the guide groove 31 is half or larger than the thickness R of the movable wire electrode 2 in the direction of electric discharge machining.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge machining apparatus for applying a pulse voltage to a wire electrode and a workpiece to generate a pulse discharge between the wire electrode and the workpiece, and more particularly to an electrode guide structure.

[0002]

2. Description of the Related Art As shown in FIG. 9, a conventional wire electric discharge machine 9 is arranged along a guide groove 931 of an electrode guide 93.
The moving wire electrode 92 is stretched. For details,
Please refer to FIGS. 3 and 4 described below. The cross section of the moving wire electrode 92 is circular. The electrode guide 93
Has a guide groove 931 having an arcuate bottom. The moving wire electrode 92 is in close contact with the guide groove 931. However, since the depth H of the guide groove 931 is the same as the radius r of the moving wire electrode 92, the radius r of the moving wire electrode 92 does not fit in the guide groove 931 and is in a protruding state. . At this time, the effective discharge range θ
2 is approximately 180 degrees.

[0003] Incidentally, the wire electric discharge machine 9 is
As shown in FIG. 9, the workpiece 91 and the workpiece 91
A gap G is provided between the moving wire electrode 92 and the opposing moving wire electrode 92, pulse energy is applied between the two, and processing is performed in a non-contact state. Reference numeral 94 in the figure denotes a discharge gap having the gap G. The gap G
Depends on the type of machining fluid. For example, the gap G including the secondary discharge of sludge or the like is approximately 0.
02 mm and 0.01 mm or more for oil. If the type of the machining liquid is determined and the magnitude of the applied pulse energy is made constant, the gap G becomes constant.

For example, the moving wire electrode 92 is made of an ultrafine tungsten wire, the thickness (diameter) R is 0.03 mm, and the thickness t of the electrode guide 3 is 0.1 mm.
05 mm. At this time, when pure water is used as the working fluid and the above pulse energy of 100 μJ is applied,
The gap G of the discharge gap 94 is 0.02 mm.
Under the above conditions, the depth H of the guide groove 931 is set to 0.01 which is the same as the radius r of the moving wire electrode 92.
When the width is 5 mm, the groove width W2 is 0.07 mm.

[0005]

However, when a groove is formed in a workpiece using the conventional wire electric discharge machine 9, there are the following problems. That is, when the wire electric discharge machine 9 is used, the work piece 91 is processed using one kind of machining fluid and applying a constant pulse energy.
In the state where the moving wire electrode 92 faces each other, the moving wire electrode 92 is moved while always keeping a constant gap G between the two.
First, a groove having a predetermined depth is formed.

At this time, since the moving wire electrode 92 protrudes from the guide groove 931 by the radius r, the effective discharge range θ2 is approximately 180 degrees. for that reason,
Not only between the groove advancing surface 913 positioned in the electric discharge machining direction but also the groove side surface 912 positioned in the vertical direction.
Electric discharge machining is performed.

Therefore, the groove width W2 formed by using the wire electric discharge machine 9 is obtained by adding the left and right discharge gaps 94 to the diameter R of the moving wire electrode 92.
That is, the minimum groove width W2 that can be processed is equal to the discharge gap 9
The minimum limit is determined by the gap G of 4.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and enables a groove having a fine width to be formed, and prevents a discharge pressure and a vibration caused by running of the wire, thereby achieving a wire with excellent processing accuracy. An object of the present invention is to provide an electric discharge machining device.

[0009]

According to the first aspect of the present invention, there is provided an electrode guide,
It comprises a guide groove provided in the electrode guide and a moving wire electrode which moves while being fitted in the guide groove, and applies a current between the moving wire electrode and the workpiece to perform wire electric discharge machining. The depth H of the guide groove is larger than half the thickness R of the moving wire electrode in the electric discharge machining direction.

Next, the operation of the present invention will be described. In the present invention, the depth H of the guide groove is larger than half the thickness R of the moving wire electrode in the electric discharge machining direction. For this reason, half or more of the thickness R of the moving wire electrode is fitted into the guide groove, and the guide groove wall constituting the guide groove blocks the discharge in the side direction of the machining groove. Can be restricted.
Therefore, electric discharge machining in the groove side surface direction can be suppressed or reduced, and the groove width can be further reduced.

Note that the thickness R of the moving wire electrode is
Depth direction of the guide groove of the electrode guide (discharge machining direction)
Means the thickness. Therefore, when the moving wire electrode has a circular cross section (FIG. 1), the thickness R means its diameter. In the case of a polygonal cross section (FIG. 6), it refers to the length of one side in the above direction.

[0012] This also suppresses electric discharge in a direction perpendicular to the electric discharge machining direction, so that the electric discharge pressure acts mainly on the bottom of the guide groove, that is, in the counter-machining direction.
Therefore, vibration due to discharge pressure can be prevented. Further, since the half of the thickness R of the moving wire electrode is smaller than the depth H of the guide groove, the movable wire electrode moves in a restricted state in which more than half is fitted in the guide groove. Therefore, the guide groove wall can further prevent the vibration accompanying the traveling of the moving wire electrode.

The electrode guide may have various shapes such as a rotating disk-shaped or semi-disk-shaped projection.

As described above, according to the present invention, it is possible to provide a wire electric discharge machine which is capable of machining a groove having a fine width, preventing a discharge pressure and a vibration accompanying the running of a wire, and having excellent machining accuracy.

Next, the cross section of the moving wire electrode can be circular. In this case, the groove advancing surface of the processing groove can be processed into an arc shape.

Next, the moving wire electrode can have a polygonal cross section.
In this case, the groove advance surface of the processing groove can be processed into various shapes according to the cross-sectional shape of the moving wire electrode.

Next, it is preferable that the electrode guide is a rotating disk and the guide groove is provided on an outer periphery of the rotating disk. In this case, the moving speed of the moving wire electrode and the electrode guide can be synchronously rotated.

Next, as in the fifth aspect of the present invention, it is preferable that the electrode guide is a semi-disc-shaped projection, and the guide groove is provided on an outer periphery of the semi-disc-shaped projection. .
In this case, sufficient rigidity can be given to the electrode guide even against the tensile force of the moving wire electrode. For this reason, it is possible to suppress problems such as the electrode guide falling down due to the tension of the moving wire electrode.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A wire electric discharge machine according to an embodiment of the present invention will be described with reference to FIGS.

As shown in FIGS. 1 to 3, the wire electric discharge machine 1 of the present embodiment has an electrode guide 3, a guide groove 31 provided in the electrode guide 3, and a state fitted in the guide groove 31. The electric wire machining is performed by applying a current between the moving wire electrode 2 and the workpiece 7. Depth H of the guide groove 31
Is larger than half the thickness R of the moving wire electrode 2 in the electric discharge machining direction.

First, the machining portion of the wire electric discharge machine 1 will be described in detail with reference to FIGS. The cross section of the moving wire electrode 2 is a circle having a radius r as shown in FIGS. The thickness R of the moving wire electrode 2 in the electric discharge machining direction is the diameter (2r) of the moving wire electrode 2. On the other hand, the guide groove 3 in the present embodiment
1, the depth H is equal to the thickness R of the moving wire electrode 2 in the electric discharge machining direction and is larger than a half r of the thickness R.

Next, the peripheral portion of the wire electric discharge machine 1 will be described with reference to FIG. Guide groove 3
As shown in FIG. 3, the electrode guide element 3 having a reference numeral 1 is a rotating disk, and the guide groove 31 having an arcuate bottom is provided on the outer periphery thereof. The electrode guide 3 is an electrical insulator made of ceramics.

The moving wire electrode 2 is consumed by electric discharge machining. However, the moving wire electrode 2 in the processing section must always have a constant thickness. for that reason,
By moving the moving wire electrode 2 along the outer periphery of the electrode guide 3, the non-discharged moving wire electrode 2 having a constant thickness is always supplied to the processing portion. At that time, the moving wire electrode 2 is connected as shown in FIG.
A guide nozzle 251 provided before the electrode guide 3
Thus, the guide groove 31 is fitted into the guide groove 31. Further, with the movement of the moving wire electrode 2, as shown in FIG. 3, the electrode guide 3 rotates around the rotating shaft 35 in synchronization with the moving speed of the moving wire electrode 2.

Next, the overall configuration of the wire electric discharge machine 1 will be described with reference to FIG. As described above, the wire electric discharge machine 1 must supply the undischarged moving wire electrode 2 to a machining portion. For this purpose, the wire electric discharge machine 1 is, as shown in FIG.
It has a wire reel 51, a pulley 52, and a wire pulling roll 53 for supplying wires.

The non-discharged moving wire electrode 2 is wound around the wire reel 51. The wire pulling roll 53 winds up the moving wire electrode 2 after the discharge. The pulley 52 is for smoothly introducing and moving the moving wire electrode 2 to and from the guide nozzles 251 and 252, and between the wire reel 51 and the guide nozzle 251 and the guide nozzle 252. And the wire pulling roll 53 at two places.

Further, the wire electric discharge machine 1 has an X-axis direction control table for changing the relative position between the moving wire electrode 2 in the electrode guide 3 and the workpiece 7 to perform groove machining. 61, a Y-axis direction control table 62, and a Z-axis direction control device 63. X-axis direction control table 6
1, the Y-axis direction control table 62
It is slid in the axis and Y-axis directions to adjust the length of the groove. Further, the Z-axis direction controller 63 moves the electrode guide 3 up and down in the Z-axis direction to adjust the depth of the groove.
The X-axis direction control table 61, Y-axis direction control table 62, and Z-axis direction control device 63 are driven by an NC power supply 86.

Further, the wire electric discharge machine 1 has a machining power source 82 for supplying a current to the moving wire electrode 2.
And a power supply 28. The wire electric discharge machine 1 has a control device 88 for controlling the NC power supply 86 and the machining power supply 82 to control the X-axis direction control table 61 and the like.

Next, the operation of the present embodiment will be described. In the wire electric discharge machine 1 of the present embodiment, the depth H of the guide groove is set.
Is equal to the thickness R of the moving wire electrode 2 in the electric discharge machining direction. Therefore, the thickness R of the moving wire electrode 2
Are all fitted in the guide grooves 31. At this time, the guide groove wall 33 constituting the guide groove 31 is an electric insulator. Therefore, the discharge in the direction of the groove side surface 712 of the machining groove 71 is blocked by the guide groove wall 33, and the effective discharge range θ1 can be limited to less than approximately 180 degrees. Therefore, the discharge in the direction of the groove side surface 712 can be suppressed or reduced, and the groove width W1 can be reduced.

In addition, the discharge in the direction perpendicular to the electric discharge machining direction is also suppressed, so that the discharge pressure acts mainly in the direction opposite to the direction of the groove advancing surface 713 of the machining groove 71. Therefore, vibration due to discharge pressure can be prevented. Further, since the thickness R of the moving wire electrode 2 is equal to the depth H of the guide groove 31, all of the moving wire electrodes 2 move in a constrained state fitted in the guide groove 31. for that reason,
The movable wire electrode 92 is formed by the guide groove wall 33.
The vibration accompanying the traveling of the vehicle can be further prevented.

Since the cross section of the moving wire electrode 2 is circular, the groove advancing surface 713 of the processing groove 71 can be processed into an arc shape. The electrode guide 3 is a rotating disk, and since the guide groove 31 is provided on the outer periphery of the rotating disk, the moving speed of the moving wire electrode 2 and the electrode guide 3 can be synchronously rotated. it can.

In this embodiment, as shown in FIG. 2, the moving wire electrode 2 is made of a tungsten fine wire, the thickness (diameter) R is 0.03 mm, and the thickness t of the electrode guide 3 is It is 0.05 mm. At this time,
When pure water is used as the working fluid and the pulse energy of 100 μJ is applied, the gap G of the discharge gap 4 is increased.
Is 0.02 mm as shown in FIG. Under the same conditions as in the prior art, the depth H of the guide groove 31 is set to be equal to the diameter R of the moving wire electrode 2 by 0.0.
In the case of 3 mm, the groove width W1 is 0.055 mm
Becomes

Second Embodiment A wire electric discharge machine according to an embodiment of the present invention will be described with reference to FIG. The wire electric discharge machine 15 according to the present embodiment sets the depth H of the guide groove 31 of the first embodiment to
The diameter is set to 0.025 mm which is larger than the radius r (0.015 mm) of the moving wire electrode 2. Thus, the effective discharge range θ15 becomes approximately 103 degrees. Other configurations and conditions are the same as those of the first embodiment.

In this embodiment, the groove width W15 is 0.064 mm. This is wider than the groove width W1 of the first embodiment and smaller than the groove width W2 of the conventional example. In addition, in this embodiment, the same effects as those of the first embodiment can be obtained.

Third Embodiment A wire electric discharge machine according to a third embodiment of the present invention will be described with reference to FIG. In the wire electric discharge machine 10 of the present embodiment, the cross section of the moving wire electrode 2 is square. The thickness (length of one side) R3 of the moving wire electrode 2 is 0.03 mm, and the depth H of the guide groove 31 is 0.035 mm. The side surface of the moving wire electrode 2 is entirely covered by the guide groove wall 33. Other configurations and conditions are the same as those of the first embodiment.

In this example, since the discharge in the direction of the groove side 712 is suppressed and reduced, the groove width W10 is 0.05
1 mm. In addition, also in this example, the first embodiment
The same effect can be obtained.

Embodiment 4 In this embodiment, as shown in FIGS. 7 and 8, a semi-disk-shaped projection is used as the electrode guide 3. The electrode guide 3 is a semi-disc-shaped projection, and the guide groove 31 is provided on the outer periphery of the semi-disc-shaped projection. Also,
The straight portion of the semi-disc-shaped projection is sandwiched by a lower portion 631 of the Z-axis direction controller 63, and the electrode guide 3 is fixed to the Z-axis direction controller 63. Other structures are the same as those of the first embodiment.

In the present embodiment, sufficient rigidity can be given to the electrode guide 3 even with respect to the tensile force of the moving wire electrode 2. Therefore, it is possible to suppress a problem such as the electrode guide 3 falling down due to the tension of the moving wire electrode 2. In addition, in this embodiment, the same effects as those of the first embodiment can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a processing portion of a wire electric discharge machine and a workpiece according to a first embodiment.

FIG. 2 is a sectional view of a processing portion of the wire electric discharge machine according to the first embodiment.

FIG. 3 is a perspective view of a processing peripheral portion of the wire electric discharge machine according to the first embodiment.

FIG. 4 is an explanatory diagram of the overall configuration of the wire electric discharge machine according to the first embodiment.

FIG. 5 is a cross-sectional view of a processing portion of a wire electric discharge machine and a workpiece according to a second embodiment.

FIG. 6 is a sectional view of a processing portion of a wire electric discharge machine and a workpiece according to a third embodiment.

FIG. 7 is a perspective view of a peripheral portion of a wire electric discharge machine according to a fourth embodiment;

FIG. 8 is an explanatory diagram of an overall configuration of a wire electric discharge machine according to a fourth embodiment.

FIG. 9 shows a machining section of a conventional wire electric discharge machine,
And a sectional view of a workpiece.

[Explanation of symbols]

 1. . . 1. wire electric discharge machine, . . 2. moving wire electrode; . . Electrode guide, 31. . . Guide groove, 33. . . Guide groove wall, 4. . . Discharge gap, 7. . . Workpiece, 71. . . Machining groove, 712. . . Groove side surface, 713. . . Groove progression surface,

Claims (5)

[Claims] An electrode guide, a guide groove provided in the electrode guide, and a moving wire electrode that moves while being fitted in the guide groove, wherein a moving wire electrode and the workpiece are moved between the moving wire electrode and the workpiece. In a wire electric discharge machine for performing wire electric discharge machining by applying a current to a wire, the depth H of the guide groove is larger than half the thickness R of the moving wire electrode in the electric discharge machining direction. . 2. The wire electric discharge machine according to claim 1, wherein the moving wire electrode has a circular cross section. 3. The wire electric discharge machining apparatus according to claim 1, wherein the moving wire electrode has a polygonal cross section. 4. The wire discharger according to claim 1, wherein the electrode guide is a rotating disk, and the guide groove is provided on an outer periphery of the rotating disk. Processing equipment. 5. The electrode guide according to any one of claims 1 to 3, wherein the electrode guide is a semi-disk-shaped projection,
A wire electric discharge machine, wherein the guide groove is provided on the outer periphery of the semi-disk-shaped projection.