JP2004154875A - Electrical discharge machining device and electrical discharge machining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrical discharge machining device which is for use in electrical discharge machining of a workpiece in continuous procedures without elongating the workpiece even if the workpiece has stretching properties, and to provide an electrical discharge machining method. <P>SOLUTION: The electrical discharge machining device comprises a winding means 16 for winding the workpiece 12 like a roll, a discharge machining section 22 arranged in a passage where the workpiece 12 is wound in by the winding means 16, and a nonstretchable reinforcing band 24a which makes intimate contact with the workpiece 12 in the passage where the workpiece 12 is wound in by the winding means 16, and travels on the discharge machining section 22 in synchronous with the workpiece 12. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric discharge machining apparatus and an electric discharge machining method capable of performing an electric discharge machining process without elongating a workpiece in a case where electric discharge machining is continuously performed on an elastic workpiece.
[0002]
[Prior art]
Conventionally, corona discharge treatment or plasma discharge treatment has been applied to the surface of a workpiece in order to improve the adhesiveness, dyeability, hydrophilicity, etc. of natural fibers, synthetic fibers, plastic films, etc. (hereinafter referred to as the workpiece). Attempts have been made to perform such electrical discharge machining. For example, see Patent Documents 1 and 2.
[0003]
[Patent Document 1]
JP-A-5-078974 [Patent Document 2]
JP 2000-302902 A
FIG. 8 shows a conventional electric discharge machining apparatus 30. In the case where the electric discharge machining process is continuously performed on the workpiece 34, as shown in FIG. 8, the workpiece 34 wound by one side is wound by the electric discharge processing unit 32 along the other path. Electric discharge machining. On the other hand, when the workpiece 34 is wound, tension is applied to the workpiece 34 in the winding direction. This is because the work 34 is pulled when the work 34 is wound.
[0005]
[Problems to be solved by the invention]
The amount of electric discharge machining to be performed on the workpiece is determined based on the use of the workpiece, material properties, surface fiber density, and the like. When performing EDM on a workpiece having elasticity, when tension is applied to the workpiece, the EDM is performed while the workpiece is stretched. In this case, the fiber density on the surface of the workpiece is different from that before elongation, and a predetermined discharge machining amount cannot be obtained. That is, since the electric discharge machining is not sufficiently performed, the workpiece becomes defective.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide an electric discharge machine which can perform an electric discharge machining without stretching a workpiece even when the workpiece is stretched by electric discharge machining in a continuous process. An object of the present invention is to provide a processing apparatus and an electric discharge machining method.
[0007]
[Means for Solving the Problems]
An electric discharge machining apparatus according to the present invention includes a winding unit configured to wind a workpiece in a roll shape, an electric discharge processing unit disposed on a path along which the workpiece is wound by the winding unit, and the workpiece. Is a path wound by the winding means, and is provided with a non-stretchable reinforcing band that is in close contact with the workpiece and that runs through the electric discharge treatment section in synchronization with the workpiece. .
[0008]
In addition, the electric discharge machining apparatus according to the present invention is the electric discharge machining apparatus described above, further comprising: a sending unit that rotates the workpiece wound in a roll in a circumferential direction to send out the workpiece; It is characterized in that a configuration is provided in which an object is wound by the winding means.
[0009]
In the electric discharge machining apparatus according to the present invention, the above-mentioned reinforcing band is formed endlessly, and the endless reinforcing band is rotated at a peripheral speed equal to a speed at which the winding means winds the workpiece. It is characterized by being wound around a driving drum.
[0010]
Further, the electric discharge machining apparatus according to the present invention includes a cooling unit for cooling the reinforcing band.
[0011]
Further, in the electric discharge machining method according to the present invention, the workpiece is wound in a roll shape on one side and the electric discharge machining process is performed on a path wound on the other side. Sending out the processed workpiece, and bringing a reinforcing band into close contact with the sent out workpiece, and running the reinforcing band at the same speed as winding the workpiece around the other. A step of subjecting the workpiece closely contacted to the reinforcing band to electrical discharge machining, and a step of separating the workpiece subjected to electrical discharge machining from the reinforcing band and winding it around the other. It is.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
An electric discharge machining apparatus 10 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic side view of an electric discharge machining apparatus 10 according to the present embodiment. FIG. 2 is a schematic top view of the electric discharge machining apparatus 10 according to the present embodiment. The description of the present embodiment will be made with reference to FIG. 1 unless otherwise specified.
[0013]
The electric discharge machining apparatus 10 according to the present embodiment includes a sending unit 14 that rotates a workpiece wound in a roll shape in a circumferential direction and sends it out, and a winding unit that winds the fed workpiece 12 in a roll shape. 16, a discharge processing unit 22 disposed on a path along which the fed-out workpiece 12 is wound by the winding means 16, and a discharge processing unit 22 on which the fed-out workpiece 12 is wound by the winding means 16. And a non-stretchable reinforcing band 24a which is in close contact with the object 12 and runs on the electric discharge processing section 22 in synchronization with the workpiece 12.
[0014]
The feeding means 14 is constituted by two parallel rollers 18 and a holder 20 for receiving the workpiece 12. Both ends of the two rollers 18 are supported by bearings on the frame of the electric discharge machining apparatus 10. The holder 20 has a shape in which a curved bottom portion of a U-shaped receiving portion is cut off, and the holder 20 is arranged such that the cut-out portion of the holder 20 is positioned on the upper surface of the roller 18. The workpiece 12 wound in a roll is placed on two parallel rollers 18. Two rollers 18 contact the workpiece 12 at the cut-off portion of the holder 20. The holder 20 receives the workpiece 12 placed on the roller 18 at the curved portion, and prevents the workpiece 12 from swinging. When sending out the workpiece 12, by rotating the roller 18 using a driving device connected to one end of the roller 18, the workpiece 12 placed on the roller 18 is moved in the circumferential direction (the direction of the arrow L). Is rotated. The roller 18 can be driven in either the direction of the arrow L or the direction of the arrow R by the driving device.
[0015]
The peripheral speed of the roller 18 is controlled by a rotation control device. The driving device is constituted by a DC motor, and the rotation control device controls the rotation of the DC motor by adjusting the voltage supplied to the DC motor. As shown in FIG. 2, the length of the two rollers 18 in the width direction is longer than the length of the workpiece 12 in the width direction.
[0016]
For the workpiece 12, for example, a cotton fiber cloth is used. As shown in FIG. 2, the length of the workpiece 12 in the width direction is shorter than the length of the roller 18 in the width direction. As long as the workpiece 12 is in the form of a sheet, the workpiece 12 can be applied to electric discharge machining of a woven fabric, a knitted fabric using a natural fiber or a synthetic fiber, or a film made of a polymer compound.
[0017]
The discharge processing unit 22 includes a discharge electrode 22a, a counter electrode 22b, and a power supply unit. The discharge electrode 22a is composed of two cylindrical electrodes. The counter electrode 22b is formed of a cylindrical electrode, and grounds the potential discharged from the discharge electrode 22a. Discharge electrodes 22a are arranged symmetrically about the counter electrode 22b. The gap between the discharge electrode 22a and the counter electrode 22b is a discharge region. The distance of the gap between the discharge electrode 22a and the counter electrode 22b is several millimeters. The length in the width direction of the discharge electrode 22a and the counter electrode 22b is substantially the same as the length of the roller 18 in the width direction. A high frequency voltage is generated in the power supply unit and supplied to the two discharge electrodes 22a.
[0018]
By applying a high-frequency voltage generated by the power supply unit to the two discharge electrodes 22a, corona discharge is generated in the discharge region. This corona discharge is performed in an atmosphere under atmospheric pressure.
[0019]
The reinforcing band 24a is formed of a non-stretchable material in order to restrict the extension of the workpiece 12. Non-stretching means that the workpiece 12 hardly expands or contracts with respect to the tension in the winding direction. The reinforcing band 24a is formed of, for example, polypropylene having a width of 0.1 mm and a thickness of 0.1 mm. If it is polypropylene of such a thickness, there is almost no elasticity with respect to the tension in the winding direction. In the present invention, the workpiece 12 is pressed against the reinforcing band 24a so that both are brought into close contact with each other. When the workpiece 12 is about to extend, the extension of the workpiece 12 is regulated by the frictional force generated between the reinforcing band 24a and the workpiece 12.
[0020]
One end of the reinforcing band 24a is connected to the first rotating drum 24b, and the reinforcing band 24a is wound around the first rotating drum 24b. The other end of the reinforcing band 24a is connected to the second rotating drum 24c. By rotating the second rotary drum 24c in the direction of the arrow R shown in FIG. 1, the reinforcing band 24a is wound around the second rotary drum 24c. As shown in FIG. 2, the length in the width direction of the reinforcing band 24a is about several percent longer than the length in the width direction of the discharge electrode 22a and the counter electrode 22b. The length of the reinforcing band 24a in the winding direction is about 10% longer than the length of the workpiece 12 in the winding direction. In this case, the length of the reinforcing band 24a in the winding direction is longer than the length of the workpiece 12 in the winding direction so that the reinforcing band 24a is brought into close contact with the workpiece 12 and moves along.
[0021]
The first and second rotating drums 24b and 24c are formed in a cylindrical shape. The length of the first and second rotating drums 24b and 24c in the width direction is about several percent longer than the length of the reinforcing band 24a in the width direction. Further, the material is not limited to polypropylene. Other polymer compounds such as polyethylene, polyethylene terephthalate, and polyvinyl chloride can also be used as long as they are non-stretchable in the form of a film.
[0022]
The reinforcing band 24a wound around the first rotating drum 24b is guided by a guide roller 28 and passes through a discharge region. After that, it is guided by the guide roller 28 and wound around the second rotating drum 24c. The second rotating drum 24c on the winding side is driven by a driving device. The first and second rotating drums 24b and 24c rotate in the circumferential direction, and can rotate in either the arrow L direction or the arrow R direction.
[0023]
The peripheral speed of the second rotating drum 24c is controlled by a rotation control device. The peripheral speed of the second rotating drum 24c is controlled such that the speed at which the reinforcing band 24a flows is detected by a speed sensor, and the reinforcing band 24a is always fed at a constant transport speed. For example, when a large number of reinforcing bands 24a are wound around the second rotating drum 24c and the diameter of the rotating drum is large, the rotation speed of the second rotating drum 24c is reduced, and conversely, the reinforcing band 24a is wound around the second rotating drum 24c. When the roller 24a is wound only a little, the rotation speed of the second rotary drum 24c is controlled to be increased. Hereinafter, a combination of the first and second rotating drums 24c and the reinforcing band 24a is referred to as a reinforcing band portion 24.
[0024]
The rotation control device controls the peripheral speed of the roller 18 and the peripheral speed of the second rotating drum 24c. The control of the peripheral speed of the roller 18 is performed by sensing the transport speed at which the workpiece 12 is transferred to the winding means 16 by a speed sensor. The peripheral speed of the second rotary drum 24c is controlled by sensing the transport speed at which the reinforcing band 24a wound around the first rotary drum 24b is transferred to the second rotary drum 24c by a speed sensor. I have. The rotation control device controls the transport speed of the workpiece 12 and the transport speed of the reinforcing band 24a in synchronization.
[0025]
The guide rollers 28 are provided one by one symmetrically on both sides of the electric discharge processing unit 22 in order to stably guide the workpiece 12 and the reinforcing band 24 a which are in close contact with the electric discharge processing unit 22. In one guide roller 28, two cylindrical guide rollers 28a are arranged close to and parallel to the width direction. The gap between the two guide rollers 28a is several millimeters. The workpiece 12 and the reinforcing band 24a are conveyed to this gap, and are sandwiched between the two guide rollers 28a to press the workpiece 12 against the reinforcing band 24a to make it closely adhere. The length in the width direction of the guide roller 28a is substantially the same as the length in the width direction of the first and second rotating drums 24b and 24c constituting the reinforcing band portion 24.
[0026]
Next, the electric discharge machining method will be described together with the operation of the electric discharge machining apparatus 10 described above. As shown in FIG. 1, in the electric discharge machining method according to the present embodiment, a workpiece 12 wound in a roll shape is sent out by a sending unit 14, and the workpiece 12 is taken up by a winding unit 16. . Discharge processing is performed on the workpiece 12 in a path along which the fed workpiece 12 is wound by the winding means 16. In the path along which the fed out workpiece 12 is wound by the winding means 16, the reinforcing band 24 a in close contact with the workpiece 12 is run at the same speed as the winding means 16 winds the workpiece 12. ing.
[0027]
As shown in FIG. 1, by rotating a roller 18 constituting the sending unit 14, the roll-shaped workpiece 12 placed on the roller 18 is rotated in the direction of the arrow L and sent out. Further, by rotating the roller 18 constituting the winding means 16, the roll-shaped workpiece 12 is rotated in the direction of arrow L and wound. At the beginning of winding of the workpiece 12 in the winding means 16, the end of the workpiece 12 sent out from the sending means 14 is naturally wound in a roll shape along the inside of the holder 20.
[0028]
The reinforcing band 24a wound around the first rotating drum 24b is wound around the second rotating drum 24c by rotating the second rotating drum 24c in the direction of arrow R. The conveying speed of the reinforcing band 24a is the same as the speed at which the winding means 16 winds the workpiece 12. The guide roller 28 on the left side of FIG. 1 presses the workpiece 12 sent from the sending means 14 against the reinforcing band 24a sent from the first rotating drum 24b, thereby bringing the workpiece 12 into close contact.
[0029]
The workpiece 12 in close contact with the reinforcing band 24a is sent to a discharge area of the electric discharge processing unit 22, and the surface of the workpiece 12 is subjected to electric discharge machining. After the electric discharge machining, the workpiece 12 is separated from the reinforcing band 24a at the position of the guide roller 28 on the right side in FIG. The reinforcing band 24a is wound around the second rotating drum 24c, and the workpiece 12 is wound by the winding means 16.
[0030]
As described above, the workpiece 12 is brought into close contact with the non-stretchable reinforcing band 24a and is conveyed to the electric discharge processing unit 22, so that the elastic workpiece 12 is subjected to electric discharge machining without elongation. Further, since the workpiece 12 does not directly contact the counter electrode 22b, the back surface of the workpiece 12 does not deteriorate due to friction or the like.
[0031]
When performing the electric discharge machining on the surface of the workpiece 12, a sufficient amount of the electric discharge machining may not be obtained by one electric discharge machining, and therefore it is preferable to perform the above-mentioned electric discharge machining several times. That is, after the work 12 sent out from the sending means 14 is wound by the winding means 16, the winding means 16 and the roller 18 constituting the sending means 14 are rotated in the reverse direction, and the work 12 Is repeatedly carried out to the electric discharge processing part 22, so that several times of electric discharge machining are continuously performed.
[0032]
More specifically, the workpiece 12 wound in a roll shape by the winding means 16 is rotated in the opposite direction to the direction in which the roller 18 constituting the winding means 16 is wound, and the workpiece 12 is rotated by an arrow R. Rotate in the direction to send out. The workpiece 12 is rotated in a direction indicated by an arrow R by rotating the roller 18 constituting the delivery unit 14 in a direction opposite to the direction in which the roller 18 is delivered, and is wound into a roll.
[0033]
Similarly to the workpiece 12, the reinforcing band 24a is wound around the first rotating drum 24b in the circumferential direction (FIG. 1) so that the reinforcing band 24a wound around the second rotating drum 24c is wound around the first rotating drum 24b. (In the direction of arrow L). This circumferential direction of rotation is opposite to the direction in which the above-described reinforcing band 24a is wound.
[0034]
The form of the electric discharge machining apparatus 10 of the present invention is not limited to the above embodiment. For example, the embodiment shown in FIGS. 3, 4, and 5 may be used. In the electric discharge machining apparatus 10 shown in FIG. 3, the reinforcing band 24a is formed endless. More specifically, a reinforcing band 24a to be in close contact with the workpiece 12 is formed in an endless shape, and the endless reinforcing band 24a is wound around two driving drums 24d and transported to the discharge processing unit 22. The drive drum 24d rotates at a speed equal to the speed at which the winding means 16 winds the workpiece 12.
[0035]
Since the electric discharge processing section 22 performs high-temperature processing, a film sheet having high heat resistance is used as a material forming the endless reinforcing band 24a. Further, means for cooling the endless reinforcing band 24a may be provided. For example, as shown in FIG. 3, a fan 26 for cooling the reinforcing band 24a may be provided between two drive drums 24d. Further, the surface of the drive drum 24d in contact with the reinforcing band 24a (the outer peripheral surface of the driving drum 24d) is cooled by circulating cooling water or the like from the inside, and a means for indirectly cooling the reinforcing band 24a may be employed. good.
[0036]
When the endless reinforcing band 24a shown in FIG. 3 is used, the length of the reinforcing band 24a in the winding direction can be reduced as compared with the device in FIG. In the apparatus shown in FIG. 1, the length of the reinforcing band 24 a in the winding direction needs to be longer than the length of the workpiece 12 in the winding direction in order for the reinforcing band 24 a to closely adhere to and follow the workpiece 12. However, in the apparatus of FIG. 3, since the reinforcing band 24a is formed endlessly, the long reinforcing band 24a is not required. Therefore, the electric discharge machining apparatus 10 can be reduced in size.
[0037]
As in the electric discharge machining apparatus 10 shown in FIG. 4, means for arranging two electric discharge processing units 22 side by side may be adopted. In this way, by arranging the electric discharge processing units 22 side by side, electric discharge machining can be continuously performed. Normally, the discharge means 14 and the winding means 16 take up the workpiece 12 alternately, thereby performing about 10 times of electric discharge machining. By adopting the configuration shown in FIG. 4, the number of times of alternate winding can be reduced. Therefore, the processing time can be greatly reduced, and the efficiency of the electric discharge machining process is improved. The electric discharge machining is performed at a high temperature. Therefore, the workpiece 12 that has once passed through the discharge processing unit 22 may be cooled by the fan 26 so that the workpiece 12 is not deteriorated by heat by performing the continuous processing.
[0038]
In the electric discharge machining apparatus 10 shown in FIG. 5, the combination of the electric discharge processing unit 22 and the reinforcing band 24 is turned upside down, and is disposed next to the conventional electric discharge processing unit 22 and the reinforcing band 24 for continuous processing. Means may be adopted. By employing this means, the front and back surfaces of the workpiece 12 can be subjected to electrical discharge machining at once. Therefore, the efficiency of the electric discharge machining is improved. The means shown in FIG. 5 may employ a means for cooling the work piece 12 that has once passed through the electric discharge processing section 22 to prevent the work piece 12 from deteriorating.
[0039]
Further, the shape of the reinforcing band 24a of the electric discharge machining apparatus 10 according to the present invention is not limited to the shape described in the embodiment. For example, a shape as shown in FIGS. 6 and 7 may be adopted. 6 and 7 are schematic top views of the reinforcing band portion 24. FIG. As shown in FIG. 6, a mesh-like reinforcing band 24a may be employed. By forming the reinforcing band 24a in a mesh shape, heat radiation of the workpiece 12 can be promoted.
[0040]
As shown in FIG. 7, a configuration in which a plurality of belt-shaped reinforcing bands 24a are arranged in the width direction may be employed. Thus, even if one of the plurality of reinforcing bands 24a is damaged, it is only necessary to replace the damaged one reinforcing band 24a. Therefore, even if one of the plurality of reinforcing strips 24a is damaged, only one of the reinforcing strips 24a need be replaced without replacing the entire reinforcing strip 24a, so that the cost of replacing the reinforcing strip 24a can be reduced. .
[0041]
Further, a material that is non-stretchable and has good heat conductivity may be used as a material forming the reinforcing band 24a. By using the reinforcing band 24a having good thermal conductivity, it is possible to radiate the heat generated in the workpiece 12 by the electric discharge machining by the closely adhered reinforcing band 24a. Therefore, deterioration of the workpiece 12 due to heat can be reduced.
[0042]
The present invention can be practiced in various modified, modified, and modified forms based on the knowledge of those skilled in the art without departing from the spirit of the present invention. For example, the combination of the electrodes of the discharge processing unit 22 is not limited to the shape of the present embodiment. Therefore, it is also within the scope of the present invention to employ the discharge processing unit 22 in which the discharge processing unit 22 has one discharge electrode 22a and one counter electrode 22b. Further, the arrangement of each electrode is not limited to this embodiment. For example, it is also within the scope of the present invention to employ a means in which a combination of the discharge electrode 22a and the counter electrode 22b is continuously arranged and a discharge machining process is continuously performed on the workpiece 12.
[0043]
【The invention's effect】
According to the electric discharge machining apparatus and the method according to the present invention, since the electric discharge machining is performed by causing the workpiece to adhere to the reinforcing band and run along, even if the workpiece has elasticity, it is not elongated. Electric discharge machining can be performed. Therefore, since a predetermined amount of electric discharge machining can be performed on the workpiece, it is possible to reduce defects of the workpiece due to an insufficient amount of electric discharge machining.
[0044]
Further, according to the electric discharge machining apparatus of the present invention, a long reinforcing band is not required by using the endless reinforcing band. Thus, the size of the electric discharge machining apparatus can be reduced.
[0045]
Furthermore, according to the electric discharge machining apparatus of the present invention, even if an endless reinforcing band is used, the reinforcing band can be prevented from being deteriorated by heat by providing a cooling means for cooling the reinforcing band.
[Brief description of the drawings]
FIG. 1 is a schematic side view of an electric discharge machining apparatus according to the present invention.
FIG. 2 is a schematic top view of an electric discharge machining apparatus according to the present invention.
FIG. 3 is a schematic side view showing another embodiment of the electric discharge machining apparatus according to the present invention.
FIG. 4 is a schematic side view showing another embodiment of the electric discharge machining apparatus according to the present invention.
FIG. 5 is a schematic side view showing another embodiment of the electric discharge machining apparatus according to the present invention.
FIG. 6 is a schematic top view showing another form of the reinforcing band in the electric discharge machining apparatus.
FIG. 7 is a schematic top view showing another form of the reinforcing band in the electric discharge machining apparatus.
FIG. 8 is a schematic side view of a conventional electric discharge machining apparatus.
[Explanation of symbols]
10: Electric discharge machining apparatus 12: Workpiece 14: Sending means 16: Winding means 18: Roller 20: Holder 22: Discharge processing part 22a: Discharge electrode 22b: Counter electrode 24: Reinforcement band 24a: Reinforcement band 24b: First rotating drum 24c: second rotating drum 24d: driving drum 26: cooling fan 28: guide roller 28a: guide roller

Claims (5)

Winding means for winding the workpiece into a roll,
An electric discharge processing unit disposed on a path on which the workpiece is wound by the winding unit;
A non-stretchable reinforcing band that travels through the discharge processing section in close contact with the workpiece and in synchronization with the workpiece, on a path along which the workpiece is wound by the winding unit;
Electrical discharge machining apparatus equipped with: Sending means for sending out the workpiece wound in a roll by rotating in the circumferential direction,
The electric discharge machining apparatus according to claim 1, wherein the fed workpiece is wound by the winding unit. 3. The endless reinforcing band is formed on an endless reinforcing band, and the endless reinforcing band is wound around a drive drum rotating at a peripheral speed equal to a speed at which the winding means winds the workpiece. An electric discharge machining apparatus according to claim 1. The electric discharge machining apparatus according to claim 3, further comprising a cooling unit for cooling the reinforcing band. In an electric discharge machining method for performing an electric discharge machining process on a path wound around a workpiece to be wound into a roll shape on one side,
Sending out the workpiece wound in a roll shape to one side,
Bringing a reinforcing band into close contact with the sent-out workpiece,
Running the reinforcing band at the same speed as winding the workpiece around the other;
Performing an electrical discharge machining process on the workpiece in close contact with the reinforcing band,
The workpiece that has been subjected to the electric discharge machining is separated from a reinforcing band and wound around the other,
And an electric discharge machining method.

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