JP2010005735A - Multi-wire electrical discharge machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-wire electrical discharge machine that can suppress a current flowing from an adjacent cutting wire into a discharge point generated in a certain cutting wire. <P>SOLUTION: The multi-wire electrical discharge machine includes: a plurality of guide rollers 3 disposed at certain intervals; an electrode wire 1 forming a plurality of cutting wires 2 separated from one another between a pair of guide rollers 3, the electrode wire wound around each of the plurality of the guide rollers 3; and a plurality of power feeding elements feeding power from the power source to the cutting wires 2, the power feeding elements contacting with a plurality of the cutting wires 2 individually, wherein electric resistance from each of the power feeding elements to each of the cutting wires contacting with the power feeding elements individually is smaller than the electric resistance up to the adjacent cutting wires by not lower than 50 Ω. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  In the present invention, a plurality of parallel cutting wire portions spaced apart from each other are formed between a pair of guide rollers by winding a single electrode wire a plurality of times on a plurality of guide rollers arranged at intervals. Further, the present invention relates to a multi-wire electric discharge machining apparatus in which a plurality of power supply electrons for individually supplying electric power are provided in contact with each of the cutting wire portions.

  When slicing a thin plate from a columnar member by wire electric discharge machining, a single electrode wire is wound between a plurality of spaced apart guide rollers to form a plurality of spaced apart cutting wire portions, each of which is cut A so-called multi-wire electric discharge machining apparatus has been proposed in which electric power is individually supplied to the wire portions to simultaneously generate electric discharge to improve productivity. Such a multi-wire electric discharge machining apparatus performs electric discharge machining with a plurality of cutting wire portions arranged at narrow intervals, and is used, for example, when slicing a plurality of wafers simultaneously from a columnar silicon ingot (for example, , See Patent Document 1).

  In the multi-wire electric discharge machining apparatus having such a configuration, all the cutting wire portions are electrically connected to each other. Therefore, by forming the coil between the adjacent cutting wire parts by winding the electrode wire a plurality of times for a specific guide roller, the insulation between each cutting wire part is improved by the impedance of each coil, The voltage applied to the predetermined cutting wire portion is prevented from being distributed to the cutting wire portion adjacent thereto.

  However, in the multi-wire electric discharge machining apparatus configured as described above, each coil is formed by winding the electrode wire around the same guide roller a plurality of times, so that the magnetic field generated by the current flowing through one coil is It passes through the other coil. Therefore, when a discharge occurs in one cutting wire portion and voltage fluctuation occurs, the influence appears in the other cutting wire portions, and it becomes difficult to individually supply power to each cutting wire.

  For this reason, conventionally, high frequency insulators using cores that are magnetically insulated from each other have been provided between adjacent cutting wire portions, whereby each cutting wire portion has been proposed to be insulated from each other at high frequency ( For example, see Patent Document 2).

JP 2000-94221 A JP 2006-75952 A

  However, the proposal for installing the high-frequency insulator has a problem in apparatus cost and complexity of wiring work. Therefore, there has been a demand for an improvement in which the influence of the discharge does not reach the adjacent cutting wire portion even without a high frequency insulator.

  On the other hand, most of the conventional multi-wire electric discharge machining devices are manufactured by remodeling the electric discharge machining part (machining power source, electrodes, etc.) based on the existing multi-wire saw device. Many are not equipped with an automatic connection function for easy wiring.

  In such a multi-wire electric discharge machining apparatus, when the electrode wire is passed through the guide roller, the adjacent cutting wire portions are bonded with an adhesive tape so that the wire wound several times is not unwound. Fix it. On the other hand, there is a drawing die for suppressing the vibration of the power supply group and the cutting wire portion around the cutting wire portion in order to apply the machining voltage, and the tape interferes with these. For this reason, the power supply group and the drawing die must be removed prior to the line work, and the power supply group and the wire drawing die must be attached again after the completion of the line work, resulting in poor work efficiency.

  The present invention has been made in view of the above, and a first object is to eliminate the need for coiling the electrode wire a plurality of times around a predetermined guide roller, and to provide high-frequency insulation between the cutting wire portions. It is to obtain a multi-wire electric discharge machining apparatus capable of suppressing the voltage applied to a predetermined cutting wire part from being distributed to the cutting wire part adjacent thereto without providing a tool. A second object is to obtain a multi-wire electric discharge machining apparatus that improves the workability by eliminating the need to remove and attach the power supply group and the drawing dies or their equivalents when passing through.

  In order to solve the above-described problems and achieve the object, the multi-wire electric discharge machining apparatus of the present invention winds around each of a plurality of guide rollers arranged at intervals and a plurality of guide rollers. Thus, a single electrode wire forming a plurality of cutting wire portions spaced apart from each other between the pair of guide rollers, and a plurality of members that individually contact each of the cutting wire portions and supply power from the processing power source to the cutting wire portions. In the multi-wire electric discharge machining apparatus having the above-mentioned power supply, the electrical resistance from the respective power supply to the respective cutting wire portions that come into contact with each other is smaller than the electrical resistance to the adjacent cutting wire portions by 50Ω or more. To do.

  In addition, the main component of the electrode wire is iron, the diameter is 0.1 mm or less, and the length from each power supply to each cutting wire part that comes into contact with each other is the length to the adjacent cutting wire part. It is characterized by being 2 m or more shorter than that.

  Further, the present invention is characterized in that a plurality of supply electrons are arranged to form a supply electron group, and further provided with a supply electron group retracting section for retracting the supply electron group in a direction away from the electrode wire.

  Furthermore, it has a push rod which contacts the cutting wire portion and suppresses vibration of the cutting wire portion, and further has a push rod retracting portion for retracting the push rod away from the electrode wire.

  Furthermore, the camera further includes a camera for taking an enlarged image of a contact portion between the power supply group and the cutting wire portion.

  According to the present invention, since the electrical resistance from the respective supply electrons to the respective cutting wire portions that are in contact with each other is 50 Ω or more smaller than the electrical resistance to the adjacent cutting wire portion, the electrodes to the adjacent cutting wire portions When the wire resistance becomes sufficiently large and a predetermined cutting wire portion discharges, the influence of this discharge does not wrap around the adjacent cutting wire portion. This eliminates the need for a high-frequency insulator and produces an effect that the wiring work process can be reduced.

  Further, according to the present invention, the main component of the electrode wire is iron, the diameter is 0.1 mm or less, and the lengths from the respective feeders to the respective cutting wire portions that are in contact with each other are adjacent to each other. Since it is 2m or more shorter than the length to the cutting wire section, the electrical resistance from each power supply to each cutting wire section that comes into contact with each other is 50Ω or less smaller than the electrical resistance to the adjacent cutting wire section. There is an effect that it is possible.

  In addition, according to the present invention, the power supply group retracting section for retracting the power supply group in the direction away from the electrode wire and the push rod retracting section for retracting the push rod (equivalent to a drawing die) from the electrode wire are provided. Therefore, there is an effect that the work of removing and attaching the power supply group and the push rod at the time of the line connection is unnecessary and the workability is improved.

  Furthermore, according to the present invention, since the camera further has a camera that shoots an enlarged image of the contact portion between the power supply group and the cutting wire portion, the power supply group can be easily brought into contact with the cutting wire portion after the line is connected. There is an effect of improving the performance.

  Embodiments of a multi-wire electric discharge machining apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment FIG. 1 is a configuration diagram (perspective view) of a main part of an embodiment of a multi-wire electric discharge machining apparatus according to the present invention. FIG. 2 is a configuration diagram (front view) of a main part of the multi-wire electric discharge machining apparatus according to the present embodiment. 1 and 2, in the multi-wire electric discharge machining apparatus according to the present embodiment, four electrode rollers 1 that are unwound from a wire bobbin are sequentially wound and are separated from each other in parallel in the axial direction. 3 is provided. Among the electrode wires 1, between the pair of guide rollers 3, a plurality of cutting wire portions 2 stretched in parallel with each other are configured. In the vicinity of the cutting wire portion 2, a workpiece 6 made of, for example, conductive silicon having a rectangular parallelepiped shape is held with an appropriate discharge gap length by a position control device (not shown). A working fluid is supplied between the workpiece 6 and the cutting wire portion 2 between the workpiece 6 and the cutting wire portion 2 by spraying or dipping between the workpiece 6 and the cutting wire portion 2 in the same manner as in a normal wire electric discharge machining apparatus. It is like that.

  Unlike the wire saw, the machining principle of the multi-wire electric discharge machining apparatus uses an electric discharge phenomenon. Corresponding electron supply is prepared for each cutting wire portion 2. The number of cutting wire portions 2 is arranged side by side, and a plurality of these feeding electrons are unitized to form a feeding group 4. In order to supply a machining voltage to the corresponding cutting wire portion 2, the power supply needs to be arranged at a pitch suitable for the machining application, similarly to the arrangement of the cutting wire portion 2. For example, in the case of the apparatus according to the present embodiment for cutting a wafer from a silicon ingot for a solar cell, the pitch is several hundred μm.

  Since a plurality of adjacent cutting wire portions 2 are composed of one electrode wire 1, each cutting wire portion 2 is electrically conductive. Therefore, a machining voltage applied to a corresponding cutting wire portion 2 from a certain power supply may be distributed to the adjacent cutting wire portions 2. In contrast, the conventional apparatus not only hangs the electrode wire 1 on the guide roller 3 as described above, but also places the electrode wire 1 on the guide roller 3 so that a coil is formed between adjacent cutting wire portions 2. It was insulated in high frequency by winding in a coil shape a plurality of times.

  On the other hand, in the present embodiment, a plurality of guide rollers 3 are arranged apart from each other so that the distance between them is sufficiently large, and each of the supply electrons for supplying power to each of the plurality of cutting wire portions 2 is sufficient. Closely arranged. In this manner, each supply electron is arranged sufficiently close to each cutting wire portion, and the electrode wire is wound around the guide roller 3 arranged sufficiently further away, so that each supply electron to the corresponding cutting wire portion 2 is provided. By setting the difference between the wire length of the wire and the wire length to the two adjacent cutting wire portions 2 large, the electrical resistance from the respective power supply to each of the cutting wire portions that are individually in contact with each other can be reduced. A state in which the electric resistance to the wire part is 50Ω or more is realized. For example, when a saw wire having a diameter of 0.1 mm is used, the wire length from each supply electron to the corresponding cutting wire portion 2 may be shorter than the wire length to the adjacent cutting wire portion 2 by about 2 m or more. Thereby, since the electric current flowing from the adjacent cutting wire portion to the discharge point generated in the cutting wire portion can be sufficiently suppressed, the influence from the adjacent cutting wire portion can be reduced to an extent that there is no practical problem. According to the above configuration, it is not necessary to wind the electrode wire a plurality of times for a specific guide roller to form a coil, and a high frequency insulator is not provided between the cutting wire portions 2, and a certain cutting wire portion is generated. The current flowing from the adjacent cutting wire part to the discharge point can be suppressed. Further, since there is no high frequency insulator, there is no cost increase, and the labor and time for wiring can be greatly reduced.

  Next, the line work will be described. FIG. 3 is a diagram for explaining a wiring method of the multi-wire electric discharge machining apparatus according to the present embodiment. The wiring in the multi-wire electric discharge machining apparatus is usually performed in the same procedure as that of a multi-wire saw. First, the electrode wire 1 is manually wound around the plurality of guide rollers 3 several times, and the position of the wire is adjusted so that the cutting wire portion 2 has a desired interval. Next, pull the tip of the electrode wire so that it has sufficient tension, and the electrode wire head fixing tape (hereinafter simply referred to as fixing tape) with sufficient adhesive strength to prevent unwinding of the wire wound several turns. ) The adjacent cutting wire portions 2 are fixed at 7. Here, if the guide roller 3 is rotated in the forward direction, the already wound leading portion of the electrode wire 1 serves as a guide, and the wire can be pulled to run the cutting wire portion 2 in parallel for a desired number.

  In the case of a multi-wire saw, there is no problem with the above procedure. However, in the multi-wire electric discharge machining apparatus, a push rod 5 (conventional drawing) that suppresses vibrations of the power supply group 4 for applying a machining voltage and the cutting wire portion 2. Therefore, there is a concern that the fixing tape 7 that fixes the wire at the time of passing through may interfere with the power supply group 4 and the push rod 5.

  Therefore, in the multi-wire electric discharge machining apparatus according to the present embodiment, the power supply group retracting portion and the push rod for retracting the power supply group 4 and the push rod 5 in the direction away from the electrode wire 1 (cutting wire portion 2), respectively. A retracting unit is provided. FIG. 4 is an enlarged view of the vicinity of the power supply group of the multi-wire electric discharge machining apparatus according to the present embodiment. As shown in FIG. 4, the power supply group 4 is movably supported by a power supply group retreating unit 9 constituted by three drive shafts of X, Y, and Z. Similarly, the push bar 5 is supported so as to be movable by a push bar retracting portion 10 constituted by three drive shafts of X, Y, and Z.

  With the configuration of the electron supply group retracting portion 9 and the push rod retracting portion 10, the power supply group 4 and the push rod 5 are temporarily retracted when the line is connected, and the fixing tape 7 shown in FIG. And so as not to interfere with the push bar 5. Then, the guide roller 3 is fed forward, and the leading portions of the electrode wires 1 fixed to each other by the fixing tape 7 are wound and guided to obtain the desired number of the cut wire portions 2. The bar 5 is returned to the original position so that each of the feeds contacts the corresponding cutting wire part 2. At this time, in the present embodiment, the close-up camera 8 arranged to face the power supply allows the contact portion between the power supply and the cutting wire portion 2 to be enlarged and observed. With this configuration, each power supply can be easily and reliably brought into contact with the corresponding cutting wire portion 2. After contacting the power supply, the close-up camera 8 is retracted, and the workpiece 6 is moved to a predetermined position below the cutting wire portion 2. For example, the close-up camera 8 is fixed to an XYZ axis table that is a workpiece moving structure, and is movable along three axes of X, Y, and Z.

  The workpiece 6 is processed by electric discharge machining using an electric discharge phenomenon. During electric discharge machining, the relative position between the electrode wire 1 and the workpiece 6 is controlled to proceed with machining. In the case of the multi-wire electric discharge machining apparatus, since the load on the guide roller 3 is large, the cutting wire portion 2 side is fixed and the workpiece 6 is moved to control the relative position between the two. The workpiece 6 is moved by an XYZ axis table that is a workpiece moving structure.

  As described above, in the multi-wire electric discharge machining apparatus according to the present embodiment, the workpiece contact location of the cutting wire portion 2 and the supply electron are provided close to each other, and the wire from the workpiece contact location to the supply electron is provided. The wire length between adjacent workpiece contact points is greater than the length, and the electrical resistance from each power supply to each cutting wire part that makes contact individually is greater than the electrical resistance to each adjacent cutting wire part When the predetermined cutting wire portion 2 is discharged by 50Ω or more, the influence of this discharge does not wrap around the adjacent cutting wire portion 2. Moreover, the conventionally provided high-frequency insulator is not required, and the labor of the wiring work can be greatly reduced without increasing the cost.

  Further, in the multi-wire electric discharge machining apparatus of the present embodiment, the main component of the electrode wire is iron, the diameter is 0.1 mm or less, and from each of the supply electrons to each of the cutting wire portions that come into contact individually Is shorter than the length to the adjacent cutting wire part by 2 m or more, so that the electrical resistance from the respective power supply to each cutting wire part that comes into contact individually is more than the electrical resistance to the adjacent cutting wire part. In addition, a state of 50Ω or more can be realized.

  In the multi-wire electric discharge machining apparatus according to the present embodiment, the power supply group retracting portion 9 for retracting the power supply group 4 in a direction away from the electrode wire (cutting wire portion 2) 1 and the push rod 5 are connected to the electrode wire. Since the push rod retracting portion 10 is retracted in a direction away from 1 (the cutting wire portion 2), the work of removing and attaching the power supply group 4 and the push rod 5 at the time of the wiring is unnecessary and the workability is improved.

  Furthermore, since the multi-wire electric discharge machining apparatus of the present embodiment further includes a camera that shoots an enlarged image of the contact portion between the electron supply group 4 and the cutting wire portion 2, The cutting wire portion 2 can be easily contacted to improve workability.

  As described above, according to the present invention, a plurality of parallel guides spaced apart from each other between a pair of guide rollers can be obtained by winding one electrode wire around a plurality of guide rollers arranged at intervals. It is suitable to be applied to a multi-wire electric discharge machining apparatus in which a cutting wire portion is formed and a plurality of electric power supply members that individually contact and supply power to each cutting wire portion are arranged, for example, in a columnar shape. The present invention is optimally applied to a multi-wire electric discharge machining apparatus used when simultaneously slicing a plurality of wafers from a silicon ingot.

It is a block diagram (perspective view) of the principal part of embodiment of the multi-wire electric discharge machining apparatus concerning this invention. It is a block diagram (front view) of the principal part of a multi-wire electric discharge machining apparatus. It is a figure for demonstrating the wiring method of a multi-wire electric discharge machining apparatus. It is an enlarged view of the power supply group vicinity of a multi-wire electric discharge machining apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrode wire 2 Cutting wire part 3 Guide roller 4 Electric supply group 5 Push rod (equivalent article of a drawing die)
6 Workpiece 7 Lead wire fixing tape at the time of wiring 8 Close-up camera 9 Power supply group saving part 10 Push rod saving part

Claims (5)

A plurality of guide rollers arranged at intervals, and
One electrode wire that forms a plurality of cutting wire portions spaced apart from each other between the pair of guide rollers by being wound around each of the plurality of guide rollers;
In a multi-wire electric discharge machining apparatus having a plurality of power supply units that individually contact each of the plurality of cutting wire portions and feed power from a machining power source to the cutting wire portion,
A multi-wire electric discharge machining apparatus characterized in that an electrical resistance from each power supply to each cutting wire part that comes into contact with each other is 50 Ω or more smaller than an electrical resistance to an adjacent cutting wire part. The main component of the electrode wire is iron, the diameter is 0.1 mm or less, and the length from each supply electron to each cutting wire part that comes into contact with each other is longer than the length to each adjacent cutting wire part The multi-wire electric discharge machining apparatus according to claim 1, wherein the multi-wire electric discharge machining apparatus is shorter than 2 m. 2. The multi-wire electric discharge machining according to claim 1, further comprising: a supply electron group retracting unit that arranges the plurality of supply electrons to form a supply electron group and retracts the supply electron group in a direction away from the electrode wire. apparatus. A push rod that contacts the cutting wire portion and suppresses vibration of the cutting wire portion;
The multi-wire electric discharge machining apparatus according to claim 1, further comprising a push rod retracting portion that retracts the push rod in a direction away from the electrode wire.   The multi-wire electric discharge machining apparatus according to claim 3, further comprising a camera that enlarges and photographs a contact portion between the electron supply group and the cutting wire portion.

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