WO2008050405A1 - Wire discharge processing machine - Google Patents

Abstract

A wire discharge processing machine performs a feeding control in such a manner that there are mixed, during a discharge processing, an upper side feeding state in which a high frequency pulse voltage is applied to a wire electrode only from an upper feeding part disposed above a processed subject, a lower side feeding state in which a high frequency pulse voltage is applied to the wire electrode only from a lower feeding part disposed beneath the processed subject and a two-side feeding state in which the high frequency pulse voltages are synchronously applied to the wire electrode from both the upper and lower feeding parts, thereby suppressing the short-circuiting between the wire electrode and the processed subject and also suppressing the wire brakes, thereby facilitating the improvement of productivity.

Description

 Wire discharge power machine

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to a wire electric discharge machine that processes a workpiece into a predetermined shape by generating an electric discharge between a wire electrode and the workpiece.

 Background art

 [0002] In a wire discharge machine, a high-frequency pulse voltage is applied to a wire electrode, and at this time, the workpiece is removed minutely by a discharge generated between the wire electrode and the workpiece, and the workpiece is removed. The workpiece is processed into a predetermined shape. The wire electrode travels in a predetermined direction, for example, in a vertical direction, by a pair of upper and lower wire guides, and the machining fluid is supplied around the wire electrode while the workpiece is being processed. For example, the workpiece can be precisely machined by generating the electric discharge while moving the table on which the workpiece is placed in a predetermined direction by numerical control.

 [0003] From the standpoint of accurately and stably covering a workpiece by wire discharge carriage, the distance between the wire electrode and the workpiece is kept within a predetermined range. It is important to do this, and if the wire electrode and workpiece are short-circuited, the discharge stops and the machining stops. In addition, discharge concentration (hereinafter referred to as “concentrated discharge”) occurs due to accumulation of machining waste between the wire electrode and the workpiece, and as a result, the discharge energy is locally excessively increased. Disconnection (hereinafter referred to as “wire disconnection”) often occurs. When wire breakage occurs, the wire electrode must be guided again by the wire guide, which greatly reduces productivity. Thus, various techniques for preventing wire breakage have been devised.

[0004] For example, in Patent Document 1, two or more energizing terminals for supplying a pulse voltage from a machining power source to a wire electrode are provided above and below the workpiece, and each energizing terminal and the machining power source are provided. A discharge power device is described in which an energization switching switch is provided between them and the energization switching switch is switched and controlled each time a plurality of continuous pulse voltages are applied from a machining power source to one energization terminal. In this discharge carriage device, the discharge location between the wire electrode and the object to be moved periodically moves up and down, so that even if a large current is applied, the wire electrode Heat generation is suppressed, and furthermore, the discharge points between the wire electrode and the workpiece are also dispersed, so that the wire breakage is prevented.

 [0005] Further, Patent Document 2 discloses that electrons for supplying a carburizing pulse to the wire electrode are provided on the upper side and the lower side of the workpiece and between the upper side electrons and the workpiece. A wire-cut discharge calorie device is described in which a machining pulse power supply is provided between the lower electronic device and the workpiece. In this wire-cut discharge cache device, the concentration of discharge points is prevented by flowing pulse currents asynchronously to the force wire electrodes of the upper and lower electrons, and as a result, wire breakage is prevented.

 [0006] In Patent Document 3, two contacts are provided along the wire electrode so as to be positioned at both ends of the processing area of the workpiece (cage piece). An electric discharge machining apparatus is described that supplies a cathode current to one or both of two contacts depending on the position of discharge between the two and the object. In this electric discharge machining apparatus, the contact to which machining current is to be supplied is changed according to the discharge position to prevent local heating due to concentrated discharge, and as a result, wire breakage is prevented.

 [0007] Patent Document 1: JP 59-47123 A

 Patent Document 2: JP-A-1-97525

 Patent Document 3: Japanese Patent Publication No. 6-61663

 Disclosure of the invention

 Problems to be solved by the invention

 [0008] Each of the electric discharge machining devices described in Patent Documents 1 to 3 is a force that is useful in improving productivity by preventing wire breakage and improving productivity in wire electric discharge machining. For this purpose, it is desired to prevent the wire breakage and the short circuit between the wire electrode and the object to be covered. According to the inventors' experiments, the short circuit described above applies a voltage of several pulses to the wire electrode via one of the current-carrying terminal arranged above the workpiece and the current-carrying terminal arranged below. It may occur even when only applied.

[0009] For this reason, as in the electric discharge machining apparatus described in Patent Document 1, the power supply from one power supply terminal to the wire electrode and the power supply from the other power supply terminal to the wire electrode are merely performed alternately. Short circuit cannot be suppressed efficiently. It was described in Patent Document 2 One power supply terminal force as in the wire-cut electric discharge machining apparatus When the power supply to the wire electrode and the power supply from the other power supply terminal to the wire electrode are performed asynchronously, or in the electric discharge machining apparatus described in Patent Document 3 Thus, even when the power supply to one wire terminal and the power supply from the other power supply terminal to the wire electrode are changed according to the discharge position, the above short-circuiting is efficient in these power supply configurations. It cannot be suppressed well. When the wire electrode and the workpiece are short-circuited, the electric discharge does not occur, so that the electric discharge machining itself stagnates and the average machining speed decreases.

[0010] The present invention has been made in view of the above circumstances, and it is desirable to obtain a wire electric discharge machine that can easily improve productivity by suppressing short-circuiting and wire breakage between a wire electrode and a workpiece. Objective.

 Means for solving the problem

[0011] The wire electric discharge machine of the present invention that achieves the above-mentioned object is capable of covering the workpiece while supplying the machining fluid between the wire electrode running in the plate thickness direction of the workpiece and the workpiece. A high-frequency pulse voltage is applied to the wire electrode through a pair of power supply units arranged above and below the wafer, and the object to be driven is covered by a discharge generated between the wire electrode and the object to be cured. A high-frequency pulse voltage is applied to the upper power supply unit disposed above the workpiece among the pair of power supply units via the first switching element unit. A main power source that applies a high-frequency pulse voltage to the lower power feeding section disposed below the workpiece via the second switching element section, and an opening / closing operation of the first switching element section on the first switching element section. The first pulse oscillator that supplies the pulse signal to be controlled and the second switching A second pulse oscillator for supplying a pulse signal for controlling the switching operation of the second switching element unit to the slave unit, and the switching operation of each of the first switching element unit and the second switching element unit. Only force Upper power supply state where high frequency pulse voltage is applied to wire electrode, Lower power supply force only Lower power supply state where high frequency pulse voltage is applied to wire electrode Both upper power supply portion and lower power supply portion Power supply control data for controlling power supply is stored so that both sides of the power supply state in which a high-frequency pulse voltage is applied to the wire electrode synchronously are mixed, and the first pulse oscillator and the second pulse generator are stored based on the storage unit and the power supply control data. A pulse oscillation control unit for controlling the operation of each of the pulse oscillators. The

 The invention's effect

 [0012] In the above-described upper power supply state and lower power supply state, a short circuit between the wire electrode and the workpiece is likely to occur. However, when the upper power supply state and the lower power supply state appear alternately, the wire electrode Since the position of the discharge point between the workpiece and the workpiece changes in the plate thickness direction (thickness direction) of the workpiece, the occurrence of concentrated discharge can be suppressed and wire breakage can be prevented. In addition, since the discharge between the wire electrode and the workpiece is stabilized in the both-side power supply state, a short circuit between the wire electrode and the workpiece can be prevented.

 In the wire electric discharge machine of the present invention, since the pulse oscillation control unit controls the operations of the first pulse oscillator and the second pulse oscillator based on the power supply control data, the upper power supply state is changed during the electric discharge machining. The lower power supply state and the both-side power supply state can be mixed in any pattern. Appropriate power supply control data according to the planned electric discharge machining conditions, for example, is obtained in advance by experiments and stored in the storage unit, thereby suppressing short-circuiting and wire breakage between the wire electrode and the workpiece. Can do. Therefore, it is easy to improve productivity.

 Brief Description of Drawings

 FIG. 1 is a configuration diagram schematically showing an example of a wire electric discharge machine of the present invention.

 [FIG. 2] FIG. 2 shows the relationship between the pulse oscillator waveform shown in FIG. 1 and the waveform of the pulse signal supplied to the first switching element part or the second switching element part and the power supply state to the wire electrode. FIG.

 FIG. 3 is a configuration diagram schematically showing an example of a main power source having a first main power source and a second main power source in the wire electric discharge machine according to the present invention.

 FIG. 4 is a graph schematically showing the relationship between the discharge position and the discharge current value when the wire electric discharge machine shown in FIG.

 [Fig. 5] Fig. 5 is a configuration diagram schematically showing an example of a wire discharge machine of the present invention that can prevent wire breakage due to impedance deviation between feeding circuits. .

[FIG. 6] FIG. 6 is a graph showing impedances between power feeding circuits in the wire electric discharge machine of the present invention. It is a block diagram which shows roughly the other example which can prevent the wire breakage resulting from bias | biasing.

 [FIG. 7] FIG. 7 schematically shows still another example of the wire discharge machine of the present invention that can prevent wire breakage caused by impedance deviation between power supply circuits. FIG.

 [FIG. 8] FIG. 8 is a diagram showing the adjustment of the high-frequency pulse voltage supply condition to each power supply circuit in accordance with the impedance of each of the upper and lower power supply circuits in the wire electric discharge machine of the present invention. It is a block diagram which shows an example of a thing roughly.

 [FIG. 9] FIG. 9 is a diagram showing the adjustment of the high-frequency pulse voltage supply condition to each power supply circuit according to the impedance of each of the upper and lower power supply circuits in the wire electric discharge machine of the present invention. It is a block diagram which shows schematically the other example of a thing.

 FIG. 10 is a configuration diagram schematically showing an example of a wire electric discharge machine of the present invention to which a wire disconnection avoidance function is added.

 FIG. 11 is a schematic diagram showing an example of a power feeding pattern when a power feeding ratio recovery function is added to the pulse oscillation control unit of the wire electric discharge machine shown in FIG.

FIG. 12 is a configuration diagram schematically showing an example of a wire electric discharge machine to which a short-circuit prevention function is added, according to the present invention.

 [FIG. 13] FIG. 13 shows a first pulse oscillator and a first pulse oscillator according to the flow rate of the machining liquid supplied to each of the upper nozzle and the lower nozzle in the wire electric discharge machine of the present invention. FIG. 6 is a configuration diagram schematically showing an example in which a function for controlling the operation of each of the second pulse oscillators is added.

 [FIG. 14] FIG. 14 converts the appearance pattern of the upper power supply state, the lower power supply state, and the both-side power supply state input from the input section of the wire electric discharge machine of the present invention into power supply control data. It is a block diagram which shows roughly an example of what the data conversion part was provided in the control apparatus.

 FIG. 15 is a configuration diagram schematically illustrating an example of the wire discharge machine of the present invention in which only one switching element unit is provided in one power supply unit.

Explanation of symbols 1 Wire electrode

20a Upper power feeding part

20b Lower power supply

25a, 28a First switching element

25b, 28b Second switching element

30 Main power supply

30a 1st main power supply

30b Second main power supply

35a First pulse oscillator

35b Second pulse oscillator

50 Voltage detector

55 Table drive unit

57 Speed measuring device

60 Processing fluid supply device

65a Upper nozzle

65b lower nozzle

70 Impedance measurement section

75 Disconnection sign detector

80, 80A ~ 80D Karoe machine itself

85 Memory

 90, 90a to 90f Operation / control unit

 95, 95a to 95f Pulse oscillation controller

00 Thickness determination section

05 Flow rate comparison part

10, 110A ~ 110J Controller

30, 140, 150, 160, 170, 180, 190 Wire EDM 00, 210, 220, 230, 240 Wire EDM

W Workpiece BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, embodiments of a wire electric discharge machine of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments described below.

 [0017] Embodiment 1.

 FIG. 1 is a block diagram schematically showing an example of a wire electric discharge machine of the present invention. The wire electric discharge machine 130 shown in the figure includes a processing machine main body 80 that performs electric discharge machining of the workpiece W into a predetermined shape under numerical control, a control device 110 that numerically controls the operation of the processing machine main body 80, and an existence. An input unit 115 connected to the control device 110 by wire or wireless to input commands and data to the control device 110, and displays the commands and data input to the control device 110 or the operating status of the processing machine body 80, etc. The display unit 120 is provided.

 [0018] The processing machine main body 80 applies a high-frequency pulse voltage to the wire electrode 1 that travels in the thickness direction of the workpiece W and is generated between the wire electrode 1 and the workpiece W. The workpiece W is processed by electric discharge. The workpiece W is placed on a table that can move on the X—Y plane (horizontal plane), and the wire electrode 1 crosses the workpiece W in the thickness direction with tension applied. Travel like so.

 In order to run the wire electrode 1 in a predetermined direction, a wire bobbin 10, a tension roller 12 a, a guide roller 14 a, and a wire guide 16 a are disposed above the table 5, and a wire guide is disposed below the table 5. 16b, guide roller 14b, and tension roller 12g are arranged. The wire electrode 1 wound around the wire bobbin 10 is pulled out by the tension roller 12a, guided in the vertical direction by the guide roller 14a, the wire guide 16a, the wire guide 16b, and the guide roller 14b, and then pulled by the tension roller 12b. It is recovered in the carrier recovery box 18. The pulling speed of the wire electrode 1 by the tension roller 12b is set to be faster than the pulling speed of the wire electrode 1 by the tension roller 12a. As a result, the wire electrode 1 can be applied to the workpiece W in a tensioned state. Drive across the thickness direction.

In addition, a pair of power feeding units 20 a and 20 b are arranged separately above and below the table 5 in order to apply a high-frequency pulse voltage to the wire electrode 1. A power supply unit 20a (hereinafter referred to as “upper power supply unit 20a”) disposed above the table 5 is positioned above the wire guide 16a. Thus, the power feeding portion 20b disposed below the table 5 (hereinafter referred to as “lower power feeding portion 20b”) is located below the wire guide 16b. A first switching element unit 25a having at least one switching element is connected to the upper power feeding unit 20a, and a main power source 30 and a first pulse oscillator 35a are connected to the first switching element unit 25a. Yes. In addition, a second switching element unit 25b having at least one switching element is connected to the lower power feeding unit 20b, and a main power supply 30 and a second pulse oscillator 35b are connected to the second switching element unit 25b. ing. The main power supply 30 is also connected to the central portion in the thickness direction of the workpiece W.

[0021] The main power supply 30 supplies a voltage having a predetermined height to each of the first switching element unit 25a and the second switching element unit 25b during operation, and the first pulse oscillator 35a and the second pulse The oscillator 35b supplies the first switching element unit 25a or the second switching element unit 25b with a pulse signal that controls the opening / closing operation of the switching element unit 25a, 25b. The operations of the first pulse oscillator 35a and the second pulse oscillator 35b are controlled by a pulse oscillation control unit _95, which will be described later, so that the switching element units 25a and 25b are opened and closed with a predetermined pattern, whereby the upper power feeding unit 20a or The above-described high frequency pulse voltage can be applied to the wire electrode 1 from the lower power supply unit 20b to the wire electrode 1 or both forces of the upper power supply unit 20a and the lower power supply unit 20b.

[0022] When starting or restarting the discharge force of the workpiece W, first, it is necessary to determine whether the gap between the wire electrode 1 and the workpiece W is within a predetermined area. In order to detect this, the sub-power supply 40 is relatively low, and the pulse voltage is supplied to the upper power feeding unit 20a through the third switching element unit 45a and the lower power feeding unit through the fourth switching element unit 45b. Supplied to 20b. At this time, each of the third switching element unit 45a and the fourth switching element unit 45b is closed in synchronization with each other. Then, the potential difference between each of the power supply units 20a, 20b and the power receiver W is detected by the voltage detection device 50, and the main power supply 30 operates only when the detection result falls within a predetermined range. On the other hand, when the detection result is not within the predetermined range, the width of the gap between the workpiece W and the wire electrode 1 is adjusted by moving the table 5. In order to move the table 5, a table driving device 55 is connected to the table 5. This table drive device 55 is a workpiece While discharging W, the table 5 is moved in a predetermined direction. The table 5 includes a speed sensor (not shown) such as a linear encoder or a rotary encoder. Based on the detection result of the speed sensor, the speed measuring device (not shown) The degree is measured and the measurement result is transmitted to the calculation and control unit 90 described later.

 [0023] In addition, in order to prevent overheating of the wire electrode 1 and prevent disconnection of the wire electrode 1 during discharge caching of the driven object W, the discharge carriage of the driven object W In some cases, the machining liquid is supplied between the workpiece W and the wire electrode 1 through the upper nozzle 65a and the lower nozzle 65b. The upper nozzle 65a is disposed above the force-receiving object W, and the lower nozzle 65b is disposed below the force-receiving object W. The machining fluid supply device 60 has a flow rate measurement function for separately measuring the machining fluid supply amount (flow rate) to the upper nozzle 65a and the machining fluid supply amount (flow rate) to the lower nozzle 65b. The

 On the other hand, the control device 110 that controls the operation of the processing machine main body 80 includes a storage unit 85, a calculation / control unit 90, and a pulse oscillation control unit 95.

 The storage unit 85 stores numerical control data used for controlling operations of the table driving device 55 and the machining fluid supply device 60, and the first switching element unit 25a and the second switching unit unit 25a. The power supply control data for controlling the mode of power supply to the wire electrode 1 by defining the opening / closing operation of each switching element unit 25b is stored. This power supply control data is set so as to prevent a short circuit or wire breakage between the wire electrode 1 and the workpiece W under standard discharge cab conditions. Data for opening and closing the first switching element part 25a with the second switching element part 25b open, data for opening and closing the second switching element part 25b with the first switching element part 25a open, and And data for opening and closing each of the first switching element portion 25a and the second switching 25b in synchronization with each other.

 [0026] The power supply control data stored in the storage unit 85 may be only one type, or when it is expected or scheduled to produce a plurality of types of products by the wire electric discharge machine 130, for each product. A plurality of types of power supply control data associated with each other may be used.

The calculation / control unit 90 first activates the sub power supply 40 when a command for instructing the start of operation of the wire electric discharge machine 130 is input from the input unit 115 described later. And the voltage detection device It is determined whether or not the detection result of the device 50 is within a predetermined range, and when it is within the predetermined range, the main power source 30 is activated. Thereafter, based on the numerical control data stored in the storage unit 85, the operations of the table driving device 55, the force liquid supply device 60, and the like are controlled. At the time of electric discharge machining of the workpiece W, the operation of the table driving device 55 is controlled based on the numerical control data to move the table 5 in a predetermined direction, and the force application liquid supply device 60 based on the numerical control data 60 The machining fluid of a predetermined flow rate is supplied from the nozzles 65a and 65b.

 [0028] Further, the calculation / control unit 90 obtains the energy of the high-frequency pulse voltage applied from the wire electrode 1 to the target object W based on the detection result of the potential difference by the voltage detection device 50, and the speed described above. The machining speed is obtained based on the driving speed of the table 5 by the measuring device. Then, the plate thickness of the workpiece W is sequentially calculated from the energy of the high-frequency pulse voltage, the carriage speed, and the force, and the control data corresponding to the plate thickness is also read out from the above numerical control data force. The feedback control is performed on the energy of the high-frequency pulse voltage applied to the wire electrode 1. Specifically, the pulse interval of the high frequency pulse voltage to be applied is feedback controlled. In addition, this calculation / control unit 90 controls the operation of the display unit 120 to display the command and data input to the control device 110 or the operation status of the processing machine body 80 on the display 120. .

 [0029] The pulse oscillation control unit 95 starts operation under the control of the arithmetic and control unit 95, reads predetermined power supply control data stored in the storage unit 85, and performs a first operation based on the power supply control data. The operation of each of the one pulse oscillator 35a and the second pulse oscillator 35b is controlled. When a plurality of types of power supply control data are stored in the storage unit 85, the user designates desired power supply control data with the input unit 115 prior to the electric discharge machining of the workpiece W. At this time, the power supply control data stored in the storage unit 85 is displayed on the display unit 120 so that the user can easily select desired power supply control data.

[0030] As described above, the power supply control data read by the pulse oscillation control unit 95 includes data for opening and closing the first switching element unit 25a with the second switching element unit 25b open, and the first switching element unit The data for opening and closing the second switching element portion 25b with 25a kept open is the same as each other of the first switching element portion 25a and the second switching element 25b. Data to be opened and closed. For this reason, during the period during which discharge of the object W is carried out, only the upper power supply unit 20a is applied with a high-frequency pulse voltage to the wire electrode 1, and the upper power supply state is applied only to the lower power supply unit 20b. The lower power supply state where a high-frequency pulse voltage is applied to the wire electrode 1 and the both-side power supply state where the high-frequency pulse voltage is applied to the wire electrode 1 are mixed in a predetermined pattern. It will be.

 FIG. 2 shows the relationship between the waveform of the pulse signal supplied to the first switching element unit 25a or the second switching element unit 25b and the power supply state to the wire electrode 1 for each pulse oscillator 35a, 35b. FIG.

 [0032] As shown in the figure, the pulse signal supplied from the first pulse oscillator 35a to the first switching element unit 25a has a pulse waveform in which the low level L and the high level H repeat at a predetermined cycle, and the second pulse When the pulse signal force supplied from the oscillator 35b to the second switching element section 25b remains at one level L, the first switching element section 25a opens and closes while the second switching element section 25b remains open. State UF. On the other hand, the pulse signal supplied from the second pulse oscillator 35b to the second switching element unit 25b while the pulse signal supplied from the first pulse oscillator 35a to the first switching element unit 25a remains at the low level L. Is a pulse waveform that repeats low level L and high level H in a predetermined cycle, the second switching element 25b opens and closes with the first switching element 25a open, so the lower power supply state It becomes LF. When the pulse signal supplied from the first pulse oscillator 35a to the first switching element unit 25a and the pulse signal supplied from the second pulse oscillator 35b to the second switching element unit 25b have a pulse waveform synchronized with each other. Since the first switching element portion 25a and the second switching element portion 25b open and close in synchronization with each other, the both-side power feeding state BF is obtained.

[0033] The inventors of the present invention determined that the frequency of occurrence of a short circuit between the wire electrode 1 and the workpiece W and the difficulty of occurrence of wire breakage depend on the material and wire diameter of the wire electrode 1 and the quality of the working fluid used. The above-mentioned power supply states vary depending on the processing conditions, such as the amount of processing fluid supplied from each nozzle 65a and 65b, the material of the workpiece W, and the shape of the product to be manufactured from the workpiece W. Experiments have shown that short-circuiting frequently occurs and machining speed does not increase easily when switching at a short cycle. Revealed. It was also experimentally clarified that wire breakage is likely to occur if the number of pulses under each power supply condition is too large.

 [0034] For example, the sum of the number of high-frequency pulse voltages applied to the wire electrode 1 under the upper power supply state and the number of high-frequency pulse voltages applied to the wire electrode 1 under the lower power supply state If the number of high-frequency pulse voltages applied to wire electrode 1 is the same as the number of pulses in each power supply state, the number of pulses under each power supply state will be less than 3, causing short-circuiting between wire electrode 1 and workpiece W. The speed may be significantly reduced. Also, if the number of pulses under each power supply state is 10000 or more, the position of the discharge point between the wire electrode 1 and the workpiece W is not so dispersed in the thickness direction of the workpiece W. Wire breakage may occur easily.

 [0035] Further, the inventors of the present invention have short-circuited the wire electrode 1 and the driven object W if the ratio of the number of pulses under the double-sided feeding state in the total number of pulses applied to the wire electrode 1 is too small. It has been experimentally clarified that wire breakage is likely to occur if the frequency of occurrence increases. For example, if the above ratio is less than 50%, short circuit is likely to occur, and if it is 95% or more, wire breakage is likely to occur.

 [0036] In consideration of the above, the short circuit and the wire breakage between the wire electrode 1 and the driven object W can be suppressed by appropriately mixing the upper power supply state, the lower power supply state, and the both-side power supply state. I know that there is.

 [0037] In the wire discharge force machine 130 described above, the pulse oscillation control unit 95 operates based on the above-described power supply control data stored in the storage unit 85, and the operations of the first pulse oscillator 35a and the second pulse oscillator 35b, respectively. As a result of controlling the power supply, the power supply is controlled so that the upper power supply state, the lower power supply state, and the both-side power supply state are mixed in a predetermined pattern. Therefore, by obtaining appropriate power supply control data through experiments and storing them in the storage unit 85 in advance, it is possible to suppress short-circuiting and wire breakage between the wire electrode 1 and the driven object W, respectively. Therefore, it is easy to improve productivity in the wire discharge power machine 130.

 [0038] Embodiment 2.

In the wire electric discharge machine of the present invention, the main power source is divided into two main power sources, the first main power source and the second main power source, in order to suppress overheating of the wire electrode at the center of the workpiece in the plate thickness direction. be able to.

 FIG. 3 is a configuration diagram schematically illustrating an example of a wire electrical discharge machining apparatus in which the main power source includes a first main power source and a second main power source. In the wire electric discharge machining apparatus 140 shown in the figure, the main power supply 30 has a first main power supply 30a and a second main power supply 30b. The first main power supply 30a is connected to the upper power feeding part 20a via the first switching element part 25a, and is connected to the upper part in the plate thickness direction of the workpiece W. The second main power supply 30b is connected to the lower power feeding unit 20b via the second switching element unit 25b, and is also connected to the lower part of the workpiece W in the thickness direction. The operations of the first main power supply 30a and the second main power supply 30b are controlled by the calculation / control section 90a.

 [0040] Since the configuration of the wire discharge power machine 140 other than the above is the same as that of the wire discharge power machine 130 shown in FIG. 1, among the components shown in FIG. The same reference numerals as those used in FIG. 1 are given to those common to the constituent members, and the description thereof is omitted. Note that the processing machine main body constituting the wire electric discharge machine 140 is given a new reference numeral 80A, and the control device is given a new reference numeral 110A.

 [0041] In the wire discharge power machine 140 configured as described above, the first main power supply 30a is connected to the upper part in the plate thickness direction of the workpiece W and the second main power supply 30b is connected to the workpiece W. Since it is connected to the lower part of the plate thickness direction, the impedance from the first main power supply 30a to the discharge point and the impedance from the second main power supply 30b to the discharge point when both sides are fed are the position of the discharge point, respectively. However, the closer to the center of the workpiece W in the plate thickness direction, the larger it becomes. As a result, the discharge current value between the wire electrode 1 and the workpiece W decreases as the position of the discharge point approaches the center of the workpiece W in the plate thickness direction.

 FIG. 4 is a graph schematically showing the relationship between the discharge position (position of the discharge point) and the discharge current value when the wire electric discharge machine 140 is in a power supply state on both sides. The solid line L in the figure is the above

 1 Indicates a relationship. For reference, the above relationship in the wire discharge force machine 130 shown in FIG. 1 is indicated by a broken line L in FIG. The discharge current value indicated by the solid line L and the discharge current indicated by the broken line L

 2 1 2

 The flow value is obtained under the same processing conditions.

[0043] As shown in FIG. 4, in both of the wire electric discharge machines 130 and 140, the discharge current value between the wire electrode and the workpiece is the position of the discharge point at the plate of the workpiece. Thickness center The force that decreases as it gets closer to the part is greater in force than that in the wire electric discharge machine 140 than in the S wire electric discharge machine 130. Also, the discharge current value itself at the center portion in the plate thickness direction of the workpiece is smaller in the wire discharge force machine 140 than in the wire discharge force machine 130 under the same machining conditions.

 [0044] In general, in a wire discharge machine, the force applied to suppress overheating of the wire electrode during the discharge cage by supplying a machining fluid between the wire electrode and the workpiece. At the center of the workpiece in the plate thickness direction, the workpiece is less cooled by the machining fluid than in the upper and lower portions of the workpiece in the plate thickness direction. In many cases, the wire electrode is overheated, causing wire breakage.

 [0045] However, in the wire discharge force machine 140 shown in FIG. 3, the discharge current value in the double-sided power supply state becomes smaller as it approaches the central portion in the plate thickness direction of the workpiece W. In the center of the workpiece W in the thickness direction, it is easy to suppress excessive overheating of the wire electrode 1! Therefore, it is easier to prevent the wire breakage compared to the wire electric discharge machine 130 (see FIG. 1) described in the first embodiment.

 Therefore, according to the wire discharge power machine 140, similarly to the wire discharge power machine 130, the upper power supply state, the lower power supply state, and the both-side power supply state are mixed in a predetermined pattern. Short circuit between the wire electrode 1 and the workpiece W can be prevented, and wire breakage can be easily suppressed as compared with the wire discharge calorifier 130. As a result, it becomes easier to improve productivity as compared with the wire electric discharge machine 130.

 [0047] Embodiment 3.

 In wire electric discharge machines, when the Z-axis height (relative height of the upper power supply unit) or the thickness of the workpiece changes, the distance from the discharge point to each power supply unit changes. The impedances of the power supply circuit that reaches the discharge point via the power supply (hereinafter referred to as “upper power supply circuit”) and the power supply circuit that reaches the discharge point via the lower power supply section (hereinafter referred to as “lower power supply circuit”). Is biased. Such a bias in impedance causes a difference in the magnitude of the discharge current in each power supply circuit, and wire breakage easily occurs in the magnitude of the discharge current and in the power supply circuit (low impedance! /, Power supply circuit).

[0048] In the wire electric discharge machine of the present invention, the impedance between the upper feeding circuit and the lower feeding circuit is reduced. Adjust the supply conditions of the high-frequency pulse voltage to each of the upper power supply circuit and the lower power supply circuit according to the bias of the dance, and configure to prevent the wire breakage due to the impedance bias between the power supply circuits be able to.

 FIG. 5 to FIG. 7 are configuration diagrams schematically showing an example of a wire electric discharge machine that can prevent wire disconnection caused by impedance deviation between power feeding circuits. Among the constituent members shown in these drawings, those common to the constituent members shown in FIG. 1 are given the same reference numerals as those used in FIG. 1 and their description is omitted.

 [0050] A wire discharge power machine 150 shown in Fig. 5 includes a control device 11OB having a pulse oscillation control unit 95a. The pulse oscillation control unit 95a reads the data of the Z-axis height (the height of the upper power feeding unit 20a with respect to the lower power feeding unit 20b) stored in advance in the storage unit 85 by the user or stored in the storage unit 85. The numerical control data force also determines the Z-axis height, and compares the Z-axis height with the reference value to determine the magnitude relationship between the impedances of the upper and lower power supply circuits. Then, the power supply control data read from the storage unit 85 is modified by, for example, calculation so that the impedance is small, the discharge current value in the power supply circuit is close to the impedance, and the discharge current value in the power supply circuit is approximated, for example. The pulse oscillation control unit 95a controls the operations of the first pulse oscillator 35a and the second pulse oscillator 35b based on the supplied power supply control data.

 [0051] For example, by adjusting the energy of the high frequency pulse voltage supplied to the wire electrode 1 by changing the pulse length or pulse interval in the high frequency pulse voltage or changing the number of pulses to be supplied, the discharge current value Can be adjusted. When each of the first switching element unit 25a and the second switching element unit 25b has a plurality of switching elements, the number of switching elements to be opened is changed to change the high-frequency pulse voltage supplied to the wire electrode 1. You can also adjust the energy. As the reference value, the Z-axis height that was assumed when the power supply control data was created is used, and the reference value is stored in advance in the storage unit 85, for example. This wire electric discharge machine 150 is particularly suitable when a flat plate is used as the workpiece W.

The wire discharge force machine 160 shown in FIG. 6 includes a control device 110C having an arithmetic / control unit 90b and a pulse oscillation control unit 95b. The calculation control unit 90b Similar to the control unit 90 (see FIG. 1), the plate thickness of the workpiece W is sequentially calculated using the energy of the high-frequency pulse voltage applied from the wire electrode 1 to the workpiece W and the machining speed. It has a function and sends the calculation result to the pulse oscillation control unit 95b. FIG. 6 shows a speed measuring device 57 that is not shown in FIG.

 [0053] The pulse oscillation control unit 95b compares the above calculation result sent from the arithmetic and control unit 90b with a reference value, and obtains a magnitude relationship between the impedances of the upper power supply circuit and the lower power supply circuit. . Then, the power supply control data read from the storage unit 85 is modified by, for example, computation so that the impedance is small, the value of the discharge current value S in the power supply circuit is large, and the value of the discharge current in the power supply circuit is approximated. The pulse oscillation controller 95b controls the operations of the first pulse oscillator 35a and the second pulse oscillator 35b based on the power supply control data. As the reference value, the plate thickness assumed when the power supply control data is created is used, and the reference value is stored in advance in the storage unit 85, for example. The shear electric discharge machine 160 is suitable not only when a flat plate-like object is used as the workpiece W, but also when a concave portion or a hole is formed in advance in the workpiece W.

A wire discharge force machine 170 shown in FIG. 7 includes a control device 110D having a calculation / control unit 90c, a pulse oscillation control unit 95c, and a plate thickness determining unit 100. It also stores 3D data of caloche objects. The arithmetic control unit 90c controls the operation of the plate thickness determining unit 100. The plate thickness determining unit 100 stores the three-dimensional data and the numerical control data (V for table driving device 55) stored in the storage unit 85. And the thickness of the workpiece W at the electrical discharge machining location is determined, and the thickness data is sent to the pulse oscillation control unit 95b. The pulse oscillation control unit 95c compares the plate thickness data sent from the calculation / control unit 90c with a reference value to determine the magnitude relationship between the impedances of the upper and lower power supply circuits. Then, the power supply control data read from the storage unit 85 is modified by, for example, calculation so that the discharge current value in the power supply circuit with low impedance approaches the discharge current value in the power supply circuit with high impedance, and the modified power supply control is performed. Based on the data, the pulse oscillation controller 95c controls the operations of the first pulse oscillator 35a and the second pulse oscillator 35b. As the reference value, the plate thickness that was assumed when the power supply control data was created is used. Is stored in advance in the storage unit 85, for example. This wire discharge power machine 170 is suitable not only when a flat plate-like object is used as the workpiece W but also when a recess or a hole is formed in advance in the workpiece W.

 [0055] In each of the above-described wire discharge force machines 150, 160, and 170, the high-frequency pulse to each of the upper power supply circuit and the lower power supply circuit according to the magnitude relationship (bias) of the impedance between the power supply circuits. Since the voltage supply conditions are adjusted, it is easy to prevent wire breakage due to impedance imbalance between power supply circuits. Therefore, according to these wire discharge power machine 150, 160, 170, the upper power supply state, the lower power supply state, and the both-side power supply state are determined in the same manner as the wire discharge power machine 130 shown in FIG. By mixing them in this pattern, it is possible to prevent a short circuit between the wire electrode 1 and the workpiece W, and it is easier to suppress wire breakage than the wire discharge power machine 130. As a result, it becomes easier to improve productivity as compared with the wire discharge power machine 130.

 [0056] Embodiment 4.

 In the wire electric discharge machine of the present invention, the supply condition of the high-frequency pulse voltage to each power supply circuit is adjusted according to the impedance of the upper power supply circuit and the impedance of the lower power supply circuit, so that the impedance between the power supply circuits is uneven. It can be configured to prevent the resulting wire breakage.

 [0057] Figs. 8 and 9 show wire electric discharge machining that can adjust the supply condition of the high-frequency pulse voltage to each power supply circuit according to the impedance of the upper power supply circuit and the impedance of the lower power supply circuit, respectively. It is a block diagram which shows an example of a machine roughly. Among the constituent members shown in these drawings, those common to the constituent members shown in FIG. 1 are given the same reference numerals as those used in FIG. 1 and their description is omitted.

A wire electric discharge machine 180 shown in FIG. 8 includes a main body 80B having an impedance measuring unit 70, and a control device 110E having a pulse oscillation control unit 95d. The impedance measurement unit 70 measures the impedance between the main power supply 30 and the upper power supply unit 20a in the upper power supply circuit and the impedance between the main power supply 30 and the lower power supply unit 20b in the lower power supply circuit. This measurement result is transmitted to the pulse oscillation control unit 95d. The pulse oscillation control unit 95d compares the measurement result of the impedance measurement unit 70 with the reference value. Compare the magnitude relationship between the impedances of the upper and lower power supply circuits. Then, the power supply control data read from the storage unit 85 is modified by, for example, computation so as to approach the small impedance V, the large value of the discharge current value impedance in the power supply circuit, and the discharge current value in the power supply circuit. The pulse oscillation control unit 95d controls the operations of the first pulse oscillator 35a and the second pulse oscillator 35b based on the supplied power supply control data. As the reference value, the impedance assumed when the power supply control data is created is used, and the reference value is stored in advance in the storage unit 85, for example.

 A wire discharge power machine 190 shown in FIG. 9 includes a control device 11 OF having a pulse oscillation control unit 95e, and the storage unit 85 has a manufacturer or user of the wire discharge power machine 190 The impedances of the upper and lower power supply circuits measured in advance are stored in advance. Specifically, the actual measurement data of the impedance between the main power supply 30 and the upper power supply unit 20a in the upper power supply circuit, and the actual measurement data of the impedance between the main power supply 30 and the lower power supply unit 20b in the lower power supply circuit. And are stored in advance. The pulse oscillation control unit 95e is stored in the storage unit 85 and directly compares the measured data of each of the impedances described above or compared with a reference value, so that the impedance of each of the upper feeding circuit and the lower feeding circuit is compared. Find the magnitude relationship. Then, the power supply control data read from the storage unit 85 is modified by, for example, calculation so as to approach the discharge current value in the power supply circuit having a large impedance S, and the power supply control data thus modified Based on the data, the pulse oscillation control unit 95e controls the operations of the first pulse oscillator 35a and the second pulse oscillator 35b. As the reference value, an impedance that is assumed when power supply control data is created is used, and the reference value is stored in advance in the storage unit 85, for example.

[0060] In each of the wire discharge power machines 180 and 190 described above, the supply condition of the high-frequency pulse voltage to each power supply circuit depends on the impedance of the upper power supply circuit itself and the impedance of the lower power supply circuit itself. Therefore, it is easy to prevent wire breakage due to impedance deviation (magnitude relationship) between the feeder circuits. Therefore, these wire electric discharge machine 180, 190 has the same technical effect as each wire electric discharge machine 150, 160, 170 described in the third embodiment. [0061] Embodiment 5.

 The wire discharge machine according to the present invention prevents the wire breakage of the operations of the first pulse oscillator and the second pulse oscillator when a wire breakage sign (hereinafter referred to as a “breakage sign”) is detected. It is possible to add a wire breakage avoiding function for controlling the above.

 FIG. 10 is a configuration diagram schematically showing an example of a wire electric discharge machine to which a wire breakage avoiding function is added. The wire electric discharge machine 200 shown in the figure includes a processing machine main body 80C having a disconnection sign detection unit 75 and a control device 110G having a pulse oscillation control unit 95f. In addition to the power supply control data described in Embodiments 1 to 4 (hereinafter referred to as “basic power supply control data” in this embodiment), power supply control for avoiding wire disconnection when there is a sign of disconnection Data (hereinafter referred to as “power supply control data for disconnection avoidance”) is further stored. Of the constituent members shown in FIG. 10, those common to the constituent members shown in FIG. 1 are given the same reference numerals as those used in FIG. 1, and description thereof is omitted.

 [0063] The disconnection sign detection unit 75 is electrically connected to the upper power supply unit 20a, the lower power supply unit 20b, and the workpiece W, and for example, currents in the upper power supply circuit and the lower power supply circuit are detected. The shunt ratio also determines the position of the discharge point, and when a concentrated discharge with a single discharge point is detected, it is determined that there is a sign of wire breakage. Is sent to the pulse oscillation controller 95f.

 [0064] Upon receiving the disconnection sign detection signal, the pulse oscillation control unit 95f modifies the feed control data by reading the disconnection avoidance power supply control data from the storage unit 85, and based on this disconnection avoidance feed control data, Wire breakage is avoided by controlling the operation of the 1-pulse oscillator 35a and the second-pulse oscillator 35b. For example, each of the first pulse oscillator 35a and the second pulse oscillator 35b is operated and controlled so that the upper power supply state and the lower power supply state appear alternately, thereby dispersing the position of the discharge point with the passage of time. Avoid disconnection.

[0065] Since the wire electrical discharge machine 200 has the above-described wire disconnection avoidance function, it is easier to prevent wire disconnection than the wire electrical discharge machines described in Embodiments 1 to 4. It is. Therefore, according to the wire discharge force machine 200, the upper power supply state, the lower power supply state, and the both-side power supply state are set in a predetermined pattern as in the wire discharge calorie machine 130 shown in FIG. By mixing them together, it is possible to prevent a short circuit between the wire electrode 1 and the workpiece w, and it is easier to suppress wire breakage than the wire discharge force machine 130. As a result, it becomes easier to improve productivity compared to the wire discharge power machine 130.

[0066] When a wire breakage avoidance function is added to the wire electric discharge machine, the pulse oscillation control unit is provided with a power supply ratio when a long-term view (about 1 to 2 seconds) is reached. In other words, the function to return the power supply ratio to the upper power supply state, lower power supply state, and both-side power supply state when the operations of the first and second pulse oscillators are controlled based on the basic power supply control data (hereinafter referred to as the power supply ratio). "Power supply ratio recovery function") can be added.

 FIG. 11 is a schematic diagram showing an example of a power supply pattern when a power supply ratio return function is added to the pulse oscillation control unit 95f described above. In the example shown in the figure, until the time T

 1

 Based on the electric control data, the pulse oscillation controller 95f controls the operations of the first pulse oscillator 35a and the second pulse oscillator 35b. Under the basic power supply control data, the operation of performing the upper power supply state and the lower power supply state for each cycle and then performing the both-side power supply state for two cycles is repeated.

[0068] At time T, a disconnection sign detection unit 75 sends a disconnection sign detection signal to the pulse oscillation control unit 95f.

 1

 Then, the pulse oscillation control unit 95f starts controlling the operations of the first pulse oscillator 35a and the second pulse oscillator 35b based on the disconnection avoidance power supply control data, and the upper power supply state and the lower power supply state are changed. The operations of the first pulse oscillator 35a and the second pulse oscillator 35b are controlled so that they appear alternately. When the disconnection sign detection signal from the disconnection sign detection unit 75 stops at time T, the pulse oscillation control unit 95f exhibits the power supply ratio recovery function.

 2

 Therefore, the first pulse oscillator 35a and the second pulse oscillator 35b are set so that the power supply ratios in the upper power supply state, the lower power supply state, and the both-side power supply state become the power supply ratios under the basic power supply control data. Control each action.

[0069] Specifically, the both-side power supply state is performed for one cycle from time T to time T, and

 1 2

Therefore, the operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b is controlled so that the ratio of the upper power supply state, the lower power supply state, and the both-side power supply state is 1: 1: 2, and the time Between T and time T, the upper power supply state and the lower power supply state are each one cycle.

twenty three

 Appear, and the power supply state on both sides appears for 8 cycles. As a result, the power supply ratio in each of the upper power supply state, the lower power supply state, and the both-side power supply state is returned to the power supply ratio under the basic power supply control data.

 [0070] The power supply ratio recovery function assigned to the pulse oscillation control unit 95f includes a function for calculating a power supply ratio under the basic power supply control data, an upper power supply state under the power supply control data for disconnection avoidance, The difference between the power supply ratio caused by power supply under the power supply control data for disconnection avoidance, that is, the power supply ratio under the basic power supply control data It includes a function to calculate the force deviation and a function to correct the deviation. After the time T, the pulse oscillation control unit 95f

 Three

 The operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b is controlled based on the basic power supply control data.

 [0071] Embodiment 6.

 In the wire discharge machine of the present invention, the short circuit is prevented or the short circuit is eliminated when a short circuit sign or short circuit between the wire electrode and the workpiece is detected. As described above, a function for controlling the operations of the first pulse oscillator and the second pulse oscillator (hereinafter referred to as “short-circuit prevention function”) can be added.

 FIG. 12 is a configuration diagram schematically showing an example of a wire electric discharge machine to which a short circuit prevention function is added. The wire electric discharge machine 210 shown in the figure includes a control device 110H having a calculation / control unit 90d and a pulse oscillation control unit 95g, and the storage unit 85 is short-circuited when a short-circuit sign or short circuit occurs. In addition, power supply control data (hereinafter referred to as “short-circuit prevention power supply control data”) for preventing a short circuit or eliminating a short circuit is stored. Of the constituent members shown in FIG. 12, those common to the constituent members shown in FIG. 1 are given the same reference numerals as those used in FIG.

[0073] The above calculation. The control unit 90d determines that the wire electrode 1 and the driven object W are based on the potential difference between the power supply units 20a, 2 Ob and the driven object W detected by the voltage detection device 50. Detects short circuit or short circuit. Specifically, the potential difference force between each of the power feeding units 20a, 20b detected by the voltage detection device 50 and the object W is also calculated as a discharge voltage value, and this value is the material of the wire electrode 1. When the average discharge voltage falls below a preset average discharge voltage based on the material of the workpiece W, the quality of the machining fluid, the magnitude of the high-frequency pulse voltage applied to the wire electrode 1, etc. It is determined that it has occurred. And when a short circuit sign or short circuit is detected

The calculation / control unit 90d sends a predetermined signal (hereinafter referred to as a “short circuit / prediction detection signal”) to the pulse oscillation control unit 95g. The average discharge voltage value is obtained by the manufacturer or user of the wire electric discharge machine 210 and stored in the storage unit 85 in advance.

[0074] The pulse oscillation control unit 95g that has received the short circuit / predictive detection signal from the arithmetic / control unit 90d modifies the power supply control data by reading the power supply control data for short circuit prevention from the storage unit 85, and this short circuit prevention Based on the power supply control data, the operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b is controlled to prevent a short circuit between the wire electrode 1 and the workpiece W or the wire electrode 1 and the workpiece Eliminate the short circuit with W. For example, by controlling the operations of the first pulse oscillator 35a and the second pulse oscillator 35b so as to be in a double-sided power supply state, the discharge between the wire electrode 1 and the target object W is stabilized, thereby Prevent short circuit between wire electrode 1 and workpiece W or eliminate short circuit between wire electrode 1 and workpiece W.

 [0075] Since the wire electric discharge machine 210 has the above-described short-circuit prevention function, the wire breakage 1 and the load W are compared with the wire electric discharge machine described in the first to fifth embodiments. It is easy to prevent short circuit. Therefore, according to the wire electric discharge machine 210, the upper electric supply state, the lower electric supply state, and the both-side electric supply state are mixed in a predetermined pattern in the same manner as the wire electric discharge machine 130 shown in FIG. It is possible to prevent a short circuit between the electrode 1 and the workpiece W and to easily suppress a short circuit between the wire electrode 1 and the workpiece W compared to the wire discharge power machine 130. Become. As a result, it becomes easier to improve productivity as compared with the wire discharge power machine 130. Even when a short-circuit prevention function is added to the wire electric discharge machine, the power supply ratio return function described in the fifth embodiment can be added to the pulse oscillation control unit.

 Embodiment 7.

The wire electric discharge machine of the present invention includes a first pulse oscillator and a second pulse generator according to the flow rate of the machining liquid supplied from the machining liquid supply device to each of the upper nozzle and the lower nozzle. A function for controlling the operation of each vibrator can be added.

 FIG. 13 is a configuration diagram schematically showing an example of a wire electric discharge machine to which the above function is added. The wire discharge force machine 220 shown in the figure includes a control device 1101 having a calculation / control unit 90e, a pulse oscillation control unit 95h, and a flow rate comparison unit 105. Of the constituent members shown in FIG. 13, those common to the constituent members shown in FIG. 1 are designated by the same reference numerals as those used in FIG. 1, and description thereof is omitted.

 When the calculation / control unit 90e controls the operation of the machining fluid supply device 60 based on the numerical control data (numerical control data for the machining fluid supply device 60) stored in the storage unit 85. In addition, data on the flow rate of the machining fluid supplied to the upper nozzle 65 a from the force working fluid supply device 60 and the flow rate of the machining fluid supplied to the lower nozzle 65 b are sent to the flow rate comparison unit 105. The flow rate comparison unit 105 to which these data are sent compares each data with the reference value and sends the result to the pulse oscillation control unit 95h. The flow rate comparison unit 105 has, for example, data on the flow rate of the machining fluid assumed when the power supply control data is created as the reference value.

 [0079] The pulse oscillation control unit 95h reads the power supply control data from the storage unit 85 to control the operations of the first pulse oscillator 35a and the second pulse oscillator 35b, while processing the comparison result force by the flow rate comparison unit 105. When there is a nozzle for which the flow rate of the liquid is determined to exceed the reference value, the power supply control data is modified by, for example, calculation. That is, in the upper power feeding unit 20a and the lower power feeding unit 20b, the power feeding unit force on the same side as the nozzle that is determined that the flow rate of the kale solution exceeds the reference value is the high frequency supplied to the wire electrode 1 The above power supply control data is modified so that the power supply ratio of the pulse voltage is lowered. Then, the operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b is controlled based on the modified power supply control data.

[0080] When the workpiece is subjected to wire electric discharge machining, the flow rate of the machining fluid supplied from the machining fluid supply device to each of the upper nozzle and the lower nozzle is constant throughout the entire discharge force. For example, the flow rate of the machining fluid differs between a location where the relative movement path of the wire electrode is linear and a location where the arc is circular. In addition, the flow rate of the cutting liquid may be different between the upper nozzle 65a and the lower nozzle 65b. And the upper nozzle 65a and the lower nozzle 65b make the flow rate of the cutting liquid If they are different, the amount of machining fluid flowing from the nozzle with a high machining fluid flow rate into the force working groove (gap between the wire electrode 1 and the workpiece W) is from the nozzle with a low machining fluid flow rate. The amount of machining fluid flowing into the machining groove is less, and the machining fluid flow rate is high. Machining debris and the like are likely to accumulate in the machining groove on the nozzle side. As a result, wire breakage is likely to occur due to the high discharge frequency on the nozzle side where the flow rate of the machining fluid is large.

 In the wire discharge power machine 220 shown in FIG. 13, when there is a nozzle for which the flow rate of the machining fluid is determined to exceed the reference value, the power feeding unit car on the same side as the nozzle is detected. Since the operations of the first pulse oscillator 35a and the second pulse oscillator 35b are controlled so that the feeding ratio of the high-frequency pulse voltage supplied to the wire electrode 1 is lowered, the upper nozzle 65a and the lower nozzle 65b Wire breakage is suppressed even when the flow rate of the machining fluid supplied to each fluctuates.

 Therefore, according to the wire discharge power machine 220, the upper power supply state, the lower power supply state, and the both-side power supply state are set in a predetermined pattern in the same manner as the wire discharge power machine 130 shown in FIG. In addition to preventing the short circuit between the wire electrode 1 and the workpiece W, the wire breakage can be easily suppressed as compared with the wire discharge power machine 130. As a result, it becomes easier to improve productivity as compared with the wire discharge power machine 130.

 [0083] As described above, the force explained for the wire electric discharge machine of the present invention by exemplifying the seven embodiments. The present invention is not limited to the seven embodiments described above. For example, a mixed pattern (appearance pattern) of the upper power supply state, the lower power supply state, and the both-side power supply state is displayed from the input unit so that the user can easily store desired power supply control data in the storage unit. It is possible to provide a data conversion unit in the control device so that desired power supply control data can be stored in the storage unit simply by inputting.

FIG. 14 is a configuration diagram schematically showing an example of a wire electric discharge machine in which the data conversion unit is provided in the control device. In the control device 110J of the wire electric discharge machine 230 shown in the figure, when the mixed pattern (appearance pattern) of the upper power supply state, the lower power supply state, and the both-side power supply state is also input, the appearance pattern A data conversion unit 108 for generating power supply control data corresponding to the data is provided. The power supply control data created by the data conversion unit 108 is stored in the storage unit 85 via the calculation / control unit 90f. Pulse oscillation The control unit 95 controls the operations of the first pulse oscillator 35a and the second pulse oscillator 35b based on the power supply control data. 14 that are the same as those shown in FIG. 1 are assigned the same reference numerals as those used in FIG. 1, and descriptions thereof are omitted.

 In addition, in the wire discharge machine of the present invention, the first switching element unit and the second switching element unit to which the main power source is connected are separated from the main power source. Or a component of the main power source. Similarly, the third switching element unit and the fourth switching element unit to which the sub power source is connected can be separate members from the sub power source, or can be a constituent member of the sub power source. . The same applies to each of the first pulse oscillator and the second pulse oscillator, which can be used as one component of the main power supply or sub power supply, or can be used as one component of the pulse oscillation control.

 [0086] Furthermore, only one switching element unit can be provided in one power feeding unit. FIG. 15 is a configuration diagram schematically showing an example of a wire discharge molding machine in which only one switching element unit is provided in one power feeding unit. In the processing machine main body 80D of the wire electric discharge machine 240 shown in the figure, one switching element part 28a (hereinafter referred to as “first switching element part 28a”) is provided corresponding to the upper power feeding part 20a. The switching element parts other than the first switching element part 28a are not connected to the upper power feeding part 20a. Similarly, one switching element portion 28b (hereinafter referred to as “second switching element portion 28b”) is provided corresponding to the lower power feeding portion 20b, and switching element portions other than the second switching element portion 28b are provided. Not connected to the lower power supply unit 20b. The individual switching element units 28a and 28b are shared by the main power source 30 and the sub power source 40. A first pulse oscillator 35a is connected to the first switching element section 28a, and a second pulse oscillator 35b is connected to the second switching element section 28b.

[0087] The first switching element section 28a may be a separate member from either the main power supply 30 or the sub power supply 40, or may be a constituent member of the main power supply 30 or the sub power supply 40. . Similarly, the second switching element portion 28b can be a separate member for the main power supply 30 and the sub power supply 40, or the main power supply 30 or the sub power supply 40. It can also be a component of 40.

 [0088] Regardless of how many switching element units are provided in one power supply unit, the wire electric discharge machine of the present invention can perform the upper power supply state, the lower power supply state, and the both-side power supply state during the electric discharge machining. Since it is possible to mix (appear) arbitrarily, the electrical discharge machining amount in the plate thickness direction of the workpiece is appropriately changed while preventing the short circuit between the wire electrode and the workpiece and the wire breakage, and It is also possible to improve the processing accuracy in the plate thickness direction. Increasing the power supply ratio in the upper power supply state allows electric discharge machining to proceed in the upper part in the plate thickness direction of the workpiece, and increasing the power supply ratio in the lower power supply state causes the lower part in the plate thickness direction in the work piece. Therefore, the machining accuracy in the plate thickness direction of the workpiece can be improved by appropriately combining these power supply states.

 [0089] Further, the thickness of the workpiece at the electric discharge machining location can be obtained using the three-dimensional data of the workpiece as in the wire electric discharge machine 170 shown in FIG. In a wire electric discharge calorie machine that has the function of obtaining the thickness of the workpiece at the electrical discharge machining location using data, the wire electrode force is also applied to the energy of the high-frequency pulse voltage applied to the workpiece, the machining speed, etc. It is also possible to omit the function of calculating the plate thickness of the workpiece from the above. The wire discharge machine according to the present invention can be variously modified, modified and combined in addition to the above.

Claims

The scope of the claims

 [1] While supplying a machining liquid between a wire electrode that travels in the plate thickness direction of the workpiece and the workpiece, the pair of power feeding units disposed above and below the workpiece are used to supply the machining fluid. A wire electric discharge machine that applies a high-frequency pulse voltage to a wire electrode and processes the workpiece by discharge generated between the wire electrode and the workpiece,

 Of the pair of power feeding units, the upper power feeding unit disposed above the workpiece is not

A main power source that applies a high-frequency pulse voltage via a switching element unit, and applies a high-frequency pulse voltage to a lower power feeding unit disposed below the workpiece via a second switching element unit; A first pulse oscillator for supplying a pulse signal for controlling an opening / closing operation of the first switching element unit to the first switching element unit;

 A second pulse oscillator for supplying a pulse signal for controlling the opening / closing operation of the second switching element unit to the second switching element unit;

 The switching operation of each of the first switching element unit and the second switching element unit is defined, and only the upper power feeding unit is used. The upper power feeding state in which a high-frequency pulse voltage is applied to the wire electrode, and only the lower power feeding unit. A both-side power feeding state in which a high-frequency pulse voltage is applied to the wire electrode in synchronism with each other from a lower power feeding state in which a high-frequency pulse voltage is applied to the wire electrode The power supply control data for controlling the power supply to be mixed with the state is stored!

 A pulse oscillation control unit for controlling the operation of each of the first pulse oscillator and the second pulse oscillator based on the power supply control data;

 A wire electric discharge machine characterized by comprising:

[2] The main power supply is

 A first main power source connected to the upper power feeding portion via the first switching element portion and connected to the upper part in the plate thickness direction of the workpiece;

 A second main power source connected to the lower power feeding unit via the second switching element unit and connected to a lower part in the plate thickness direction of the workpiece;

 The wire electric discharge machine according to claim 1, characterized by comprising:

[3] The pulse oscillation control unit receives from the main power supply the first switching element unit and Impedance between the main power supply and the upper power supply unit in the upper power supply circuit that reaches the discharge point through the upper power supply unit, and the lower power supply that reaches the discharge point from the main power supply through the second switching element unit and the lower power supply unit Depending on the impedance between the main power supply in the circuit and the lower power supply section, the impedance is small, the discharge current value in the one power supply circuit is large, and the discharge current value in the other power supply circuit is close to 2. The wire according to claim 1, wherein the power supply control data is modified to control operations of the first pulse oscillator and the second pulse oscillator based on the modified power supply control data. Electric discharge machine.

 [4] The storage unit further stores all data according to the height of the Z axis, which is assumed when the power supply control data is created.

 The pulse oscillation control unit performs electrical discharge machining on the workpiece, and based on the Z-axis height when stored and data on the Z-axis height stored in the storage unit, Determining the magnitude relationship between the impedance and the impedance in the lower power supply circuit;

 The wire electric discharge machine according to claim 3.

[5] A table capable of moving in the biaxial direction with the workpiece placed thereon, a table driving device for moving the table in the biaxial direction,

 A speed measuring device for measuring the driving speed of the table;

 A voltage detection device for detecting a potential difference between each of the upper power supply unit and the lower power supply unit and the workpiece;

 A machining speed is calculated based on the driving speed of the table measured by the speed measurement device, and a high frequency applied to the workpiece from the wire electrode based on a potential difference detected by the voltage detection device. A calculation and control unit for calculating the energy of the pulse voltage and calculating the plate thickness of the workpiece using the processing speed and the energy of the high-frequency pulse voltage;

 Further comprising

The pulse oscillation control unit is configured to determine the impedance in the upper feeding circuit and the impedance in the lower feeding circuit based on the thickness of the workpiece calculated by the calculation and control unit. To determine the size relationship with

 The wire electric discharge machine according to claim 3.

[6] A table capable of moving in the biaxial direction with the workpiece placed thereon, a table driving device for moving the table in the biaxial direction,

 A calculation / control unit for controlling the operation of the table driving device;

 A plate thickness determining unit that calculates a plate thickness of the workpiece at a location where electric discharge machining is performed, and in the storage unit, numerical control data for numerically controlling the operation of the table driving device And 3D data of the workpiece are further stored, and the calculation control unit controls the operation of the table driving device based on the numerical control data,

 The plate thickness determining unit calculates the plate thickness of the workpiece at the point where the electric discharge machining is performed based on the numerical control data and the three-dimensional data,

 The pulse oscillation control unit determines a magnitude relationship between the impedance in the upper feeding circuit and the impedance in the lower feeding circuit based on the thickness of the workpiece calculated by the plate thickness determining unit.

 The wire electric discharge machine according to claim 3.

[7] It further includes an impedance measuring unit that actually measures the impedance in the upper feeding circuit and the impedance in the lower feeding circuit,

 The pulse oscillation control unit determines a magnitude relationship between the impedance of the upper power supply circuit and the impedance of the lower power supply circuit based on an actual measurement result of the impedance measurement unit;

 The wire electric discharge machine according to claim 3.

[8] The storage unit stores in advance the measured data of the impedance in the upper power supply circuit and the impedance in the lower power supply circuit,

The pulse oscillation control unit is stored in the storage unit, and based on the measured data of the impedance in the upper power supply circuit and the impedance in the lower power supply circuit, and the impedance in the upper power supply circuit. Said impeder in the side power feeding circuit To determine the magnitude relationship

 The wire electric discharge machine according to claim 3.

[9] It further includes a disconnection sign detection unit that is connected to the upper power supply unit, the lower power supply unit, and the workpiece and detects a wire disconnection sign,

 The pulse oscillation control unit is configured to cause the position of discharge between the wire electrode and the workpiece to be dispersed over time when the disconnection predictor detection unit detects a sign of wire disconnection. Modifying the control data and controlling the operations of the first pulse oscillator and the second pulse oscillator based on the modified power supply control data;

 The wire electric discharge machine according to claim 1, wherein:

[10] The pulse oscillation control unit may include the power supply control data so that the upper power supply state and the lower power supply state appear alternately when the wire breakage detection unit detects a wire breakage sign. 10. The wire electric discharge machine according to claim 9, wherein the wire electric discharge machine is modified.

[11] A voltage detection device that detects a potential difference between each of the upper power supply unit and the lower power supply unit and the workpiece;

 A calculation / control unit that determines whether the wire electrode and the workpiece are short-circuited based on the detection result by the voltage detection device or whether there is a sign of the short-circuit,

 Further comprising

 The pulse oscillation control unit controls the power supply control so that the discharge between the wire electrode and the workpiece is stabilized when the arithmetic control unit determines that the short circuit or the sign of the short circuit is present. Modifying the data and controlling the operations of the first pulse oscillator and the second pulse oscillator based on the modified power supply control data;

 The wire electric discharge machine according to claim 1, wherein:

[12] The pulse oscillation control unit modifies the power supply control data so that the both-side power supply state is obtained when the calculation / control unit determines that the short circuit or the short circuit is predicted. The wire electric discharge machine according to claim 11.

[13] an upper nozzle disposed above the workpiece;

 A lower nozzle disposed below the workpiece;

A machining fluid supply device that supplies a machining fluid to each of the upper nozzle and the lower nozzle And

 An operation / control unit for controlling the operation of the machining fluid supply device to supply a predetermined flow rate of the machining fluid from the machining fluid supply device to each of the upper nozzle and the lower nozzle, and the upper nozzle and the lower side A flow rate comparison unit for determining the magnitude relationship between the amount of machining fluid supplied to each of the nozzles and the amount of machining fluid assumed when creating the power supply control data;

 And further having

 The storage unit further stores numerical control data for numerically controlling the operation of the machining fluid supply device,

 The calculation / control unit controls the operation of the machining fluid supply device based on the numerical control data,

 As a result of comparison by the flow rate comparison unit, the pulse oscillation control unit assumes that the amount of machining fluid supplied is greater than the amount of machining fluid supplied, assuming that the power supply control data is created. The power supply force on the same side as the nozzle is modified so that the power supply ratio to the wire electrode is low, and the power supply control data is modified based on the modified power supply control data.

The wire electric discharge machine according to claim 1, wherein the operation of each of the one-pulse oscillator and the second pulse oscillator is controlled.