KR20080044200A - Wire-discharge machining apparatus - 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 Machine {WIRE-DISCHARGE MACHINING APPARATUS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire discharge machine for processing a workpiece into a predetermined shape by causing a discharge between the wire electrode and the workpiece.

In the wire discharge machine, a high frequency pulse voltage is applied to the wire electrode, and at this time, a small amount of the workpiece is removed by the discharge generated between the wire electrode and the workpiece, and the workpiece is processed into a predetermined shape. The wire electrode is guided in a predetermined direction, for example, a vertical direction, by a pair of upper and lower wire guides, and travels in the corresponding direction, and a machining fluid during machining of the workpiece around the wire electrode. Is supplied. For example, the workpiece can be precisely processed by causing the discharge to occur while moving the table on which the workpiece is placed in a predetermined direction by numerical control.

While processing the workpiece precisely and stably by wire discharge machining, it is important to process the wire electrode and the workpiece within a predetermined range, and if the wire electrode and the workpiece are short-circuited, discharge will not occur. Machining stops. In addition, as a result of concentration of discharge (hereinafter, referred to as "intensive discharge"), such as gathering of processed powder or the like, between the wire electrode and the workpiece, localized excessive discharge energy causes disconnection of the wire electrode ( Hereinafter, "wire disconnection" often occurs. If a wire break occurs, since the wire electrode must be guided again by the wire guide, productivity is greatly reduced. Here, various techniques for preventing wire breakage have been devised.

For example, Patent Literature 1 provides two or more energization terminals for supplying a pulse voltage to a wire electrode from a processing power supply, above and below a workpiece, and an energization switching switch between each electricity supply terminal and the processing power supply. Then, the electric discharge machining apparatus which switches-controls the said electricity supply switching switch every time the continuous pulse voltage is applied to one electricity supply terminal from a process power supply is described. In this electric discharge machining apparatus, since the discharge position between the wire electrode and the workpiece periodically moves up and down, the heat generation of the wire electrode is suppressed even when energizing a large current, and the discharge point between the wire electrode and the workpiece is also dispersed, so that the wire Disconnection is prevented.

In addition, Patent Document 2 discloses a through hole for supplying a processing pulse to a wire electrode on the upper side and the lower side of the workpiece, and also between the upper side through-hole and the workpiece, and between the lower side through-hole and the workpiece. A wire-cut electric discharge machining apparatus is provided which individually installs a pulse power supply for processing. In this wire-cut electric discharge machining apparatus, the concentration of the discharge point is prevented by flowing a pulse current asynchronously to the wire electrode from each of the upper through hole and the lower through hole, thereby preventing wire breakage.

In Patent Document 3, two contacts are provided along the wire electrode so as to be located at both ends of the processing region in the workpiece (workpiece), and two contacts are provided along the discharge position between the wire electrode and the workpiece. The electric discharge machining apparatus which supplies a process electric current to either or both of the is described. In this electric discharge machining apparatus, by changing the contact which should supply a process electric current according to a discharge position, local heating by intensive discharge is prevented, and as a result, wire disconnection is prevented.

Patent Document 1: Japanese Patent Application Laid-Open No. 59-47123

Patent Document 2: Japanese Patent Application Laid-Open No. 1-97525

Patent Document 3: Japanese Patent Application Laid-Open No. 6-61663

Each of the electric discharge machining apparatuses described in Patent Literatures 1 to 3 is useful for preventing wire breakage and improving productivity.However, in order to improve productivity in wire discharge machining, the wire breakage is prevented while the wire electrode and the workpiece are prevented from being shorted. It is desirable to. According to an experiment by the inventors of the present invention, the short circuit may occur only by applying a voltage of several pulses to the wire electrode through one of the conducting terminal arranged above the workpiece and the conducting terminal arranged below.

For this reason, the said short circuit can be suppressed efficiently only by alternately feeding electric power from one power supply terminal to a wire electrode, and the other electric power supply terminal to a wire electrode like the electric discharge processing apparatus of patent document 1 Can not. As in the wire-cut electric discharge machining apparatus described in Patent Document 2, when 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 performed asynchronously, the discharge described in Patent Document 3 The same is true in the case where the power feed from one feed terminal to the wire electrode and the power feed from the other feed terminal to the wire electrode are changed according to the discharge position as in the processing apparatus. Cannot be suppressed efficiently. When the wire electrode and the workpiece are short-circuited, no discharge occurs, so that the discharge machining itself is stagnant and the average processing speed is lowered.

This invention is made | formed in view of the said situation, and an object of this invention is to obtain the wire electric discharge machine which is easy to improve productivity by suppressing the short circuit and wire disconnection of a wire electrode and a to-be-processed object, respectively.

The wire discharge processing machine of the present invention which achieves the above object provides a wire electrode through a pair of feed sections disposed above and below the workpiece, while supplying the processing liquid between the wire electrode traveling in the plate thickness direction of the workpiece and the workpiece. A wire discharge machine which applies a high frequency pulse voltage to the workpiece and processes the workpiece by the discharge generated between the wire electrode and the workpiece, wherein the first switching element is provided in the upper feed section disposed above the workpiece among the pair of feed sections. A main power supply for applying a high frequency pulse voltage through the unit, and for applying a high frequency pulse voltage through the second switching element unit to the lower power supply unit disposed below the workpiece; A first pulse oscillator for supplying a pulse signal for controlling an opening and closing operation of the first switching element portion to a first switching element portion; A second pulse oscillator for supplying a pulse signal for controlling an opening and closing operation of the second switching element portion to a second switching element portion; The opening and closing operation of each of the first switching element portion and the second switching element portion is defined, and an upper feeding state in which a high frequency pulse voltage is applied to the wire electrode from only the upper feeding portion, and a high frequency pulse voltage is applied to the wire electrode only from the lower feeding portion. A storage unit for storing power supply control data for feeding and controlling the lower feed state to be applied and the both feed states for applying a high frequency pulse voltage to the wire electrode in synchronization with both the upper feed unit and the lower feed unit; And a pulse oscillation control unit for controlling operations of each of the first pulse oscillator and the second pulse oscillator based on the power supply control data.

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

FIG. 2 is a schematic diagram showing the relationship between the waveform of a pulse signal supplied from each pulse oscillator shown in FIG. 1 to the first switching element portion or the second switching element portion and the power feeding state to the wire electrode.

3 is a configuration diagram schematically showing an example in which the main power source has a first main power source and a second main power source in the wire discharge processing machine of the present invention.

FIG. 4 is a graph schematically showing the relationship between the discharge position and the discharge current value when the wire discharge processing machine shown in FIG. 3 is placed in both power feeding states. FIG.

5 is a configuration diagram schematically showing an example in which the wire breakage caused by the variation in the impedance between the power feeding circuits can be prevented in the wire discharge processing machine of the present invention.

6 is a configuration diagram schematically showing another example in which the wire breakage caused by the variation in the impedance between the power feeding circuits can be prevented in the wire discharge processing machine of the present invention.

FIG. 7 is a configuration diagram schematically showing still another example of preventing wire breakage due to variation in impedance between power supply circuits in the wire discharge processing machine of the present invention.

8 is a configuration diagram schematically showing an example in which the supply condition of the high frequency pulse voltage to each power supply circuit can be adjusted in accordance with the impedance of each of the upper and lower power supply circuits in the wire discharge processing machine of the present invention.

9 is a schematic view showing another example in which the supply conditions of the high frequency pulse voltage to each power supply circuit can be adjusted in accordance with the impedance of each of the upper and lower power supply circuits in the wire discharge processing machine of the present invention.

10 is a configuration diagram schematically showing an example in which a wire break prevention function is added to a wire discharge machine of the present invention.

It is a schematic diagram which shows an example of the power feeding pattern at the time of adding the feed ratio return function to the pulse oscillation control part of the wire electric discharge machine shown in FIG.

It is a block diagram which shows schematically an example in which the short circuit prevention function was added in the wire electric discharge machine of this invention.

FIG. 13 is a view illustrating controlling the operation of each of the first pulse oscillator and the second pulse oscillator in accordance with the flow rate of the processing liquid supplied from the processing liquid supply device to the upper nozzle and the lower nozzle in the wire discharge machine of the present invention. It is a block diagram which shows schematically an example in which a function was added.

14 is a configuration diagram schematically showing an example in which a data conversion unit for converting the appearance patterns of the upper feed state, the lower feed state, and the both feed states input from the input unit into the feed control data in the wire discharge processing machine of the present invention is provided in the control device. to be.

It is a block diagram which shows schematically an example in which only one switching element part was provided in one feeding part in the wire electric discharge machine of this invention.

<Description of the code>

11 wire electrode

20a upper feed section

20b lower feeder

25a, 28a first switching element

25b, 28b second switching element

30 mains power

30a first mains power supply

30b 2nd main power supply

35a first pulse oscillator

35b second pulse oscillator

50 voltage detection device

55 Table Drive

57 speed measuring device

60 Processing Fluid Supply Unit

65a upper nozzle

65b lower nozzle

70 impedance measuring unit

75 disconnection indication detector

80, 80A ~ 80D machine body

85 memory

90, 90a ~ 90f Computation & Control Unit

95, 95a to 95f pulse oscillation control

100 Plate Thickness Determination

105 flow comparator

110, 110A ~ 110J control unit

130, 140, 150, 160, 170, 180, 190 wire electric discharge machine

200, 210, 220, 230, 240 Wire Discharge Machine

W Workpiece

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of the wire electric discharge machine of this invention is described in detail with reference to drawings. In addition, this invention is not limited to embodiment described below.

Embodiment 1.

1 is a configuration diagram schematically showing an example of the wire electric discharge machine of the present invention. The wire discharge processing machine 130 shown in the same drawing includes a processing machine main body 80 which discharge-processes the workpiece W into a predetermined shape under numerical control, a control device 110 which numerically controls the operation of the processing machine main body 80; An input unit 115 that is connected to the control device 110 by wire or wirelessly and inputs a command or data to the control device 110, and a command or data or the like which is input to the control device 110 or the main body of the processor 80. ) Is provided with a display unit 120 for displaying the driving conditions and the like.

The machine body 80 applies a high frequency pulse voltage to the wire electrode 1 traveling in the plate thickness direction of the workpiece W, and processes the workpiece W by discharge generated between the wire electrode 1 and the workpiece W. do. The workpiece W is placed on a table 5 that is movable on the X-Y plane (horizontal plane), and the wire electrode 1 travels to traverse the workpiece W in the sheet thickness direction in a state where tension is applied.

In order to drive the wire electrode 1 in a predetermined direction, a wire bobbin 10, a tension roller 12a, a guide roller 14a, and a wire guide 16a are disposed above the table 5. ) Is disposed, and a wire guide 16b, a guide roller 14b, and a tension roller 12g are disposed below the table 5. The wire electrode 1 wound on the wire bobbin 10 is pulled out by the tension roller 12a, and guide roller 14a, wire guide 16a, wire guide 16b, and guide roller 14b. After being guided in the vertical direction by the &lt; RTI ID = 0.0 &gt;), it is picked up by the tension roller 12b, and collected in the wire collecting box 18. As a result of the pulling speed of the wire electrode 1 by the tension roller 12b being set faster than the pulling out speed of the wire electrode 1 by the tension roller 12a, the wire electrode 1 is tensioned. It travels so that the to-be-processed object W may cross in the plate thickness direction in this attached state.

Moreover, in order to apply a high frequency pulse voltage to the wire electrode 1, a pair of power supply part 20a, 20b is divided | segmented and arrange | positioned up and down of the table 5, and is arranged. The feeder 20a (hereinafter referred to as "upper feeder 20a") disposed above the table 5 is located above the wire guide 16a, and the feeder disposed below the table 5. 20b (hereinafter, referred to as "lower power feeding part 20b") is located below the wire guide 16b. In addition, a first switching element portion 25a having at least one switching element is connected to the upper feeder portion 20a, and a main power supply 30 and a first pulse oscillator 35a are connected to the first switching element portion 25a. ) Is connected. In addition, a second switching element portion 25b having at least one switching element is connected to the lower feeder portion 20b, and the main power supply 30 and the second pulse oscillator 35b are connected to the second switching element portion 25b. ) Is connected. The main power supply 30 is also connected to the plate | board thickness direction center part in the to-be-processed object W. FIG.

The main power supply 30 supplies a voltage having a predetermined magnitude to each of the first switching element portion 25a and the second switching element portion 25b during its operation, and the first pulse oscillator 35a and the second pulse. The oscillator 35b supplies a pulse signal for controlling the opening and closing operations of the switching element portions 25a and 25b to the first switching element portion 25a or the second switching element portion 25b. By controlling the operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b by the pulse oscillation control unit 95 described later to open and close the switching element portions 25a and 25b in a predetermined pattern, The above-described high frequency pulse voltage is applied to the wire electrode 1 from the upper feed section 20a or the lower feed section 20b, or to the wire electrode 1 from both the upper feed section 20a and the lower feed section 20b. Can be authorized.

In addition, when starting or resuming the electric discharge machining of the workpiece W, first, a relatively low pulse from the sub power source 40 is used to detect whether or not the distance between the wire electrode 1 and the workpiece W falls within a predetermined width. The voltage is supplied to the upper feed part 20a through the third switching element part 45a and to the lower feed part 20b through the fourth switching element part 45b. At this time, each of the third switching element portion 45a and the fourth switching element portion 45b is closed in synchronization with each other. Then, the voltages of the power feeding sections 20a and 20b and the workpiece W are detected by the voltage detecting device 50, and the main power supply 30 operates for the first time when the detection result is within a predetermined range. On the other hand, when the detection result does not fall within the predetermined range, the gap width 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 drive device 55 is connected to the table 5. The table drive device 55 moves the table 5 in a predetermined direction even during the discharge machining of the workpiece W. FIG. In addition, the table 5 includes a speed sensor (not shown), such as a linear encoder or a rotary encoder, and a speed measuring device (not shown) based on the detection result of the speed sensor. ) Measures the drive speed of the table 5 and transmits the result of the measurement to the calculation / control unit 90 described later.

Moreover, in order to suppress overheating of the wire electrode 1 at the time of electrical discharge machining of the workpiece | work W, and to prevent the disconnection of the said wire electrode 1, from the process liquid supply apparatus 60 at the time of discharge machining of the workpiece | work W The processing 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 workpiece W, and the lower nozzle 65b is disposed below the workpiece W. FIG. The processing liquid supply device 60 has a flow rate measuring function for separately measuring the supply amount (flow rate) of the processing liquid to the upper nozzle 65a and the supply amount (flow rate) of the processing liquid to the lower nozzle 65b, respectively.

On the other hand, the control apparatus 110 which controls the operation | movement of the processing machine main body 80 is equipped with the memory | storage part 85, the calculation / control part 90, and the pulse oscillation control part 95. As shown in FIG.

The storage unit 85 stores numerical control data used for controlling the operation of the table drive device 55, the processing liquid supply device 60, and the like, and the first switching element unit 25a and the second switching. The power supply control data for controlling the power supply mode to the wire electrode 1 by defining the opening and closing operations of the element portions 25b is stored. The power supply control data is set to prevent short-circuit or wire disconnection between the wire electrode 1 and the workpiece W under standard electric discharge machining conditions, and the power supply control data is first switched with the second switching element portion 25b open. Data for opening and closing the element portion 25a, data for opening and closing the second switching element portion 25b with the first switching element portion 25a open, and the first switching element portion 25a and the second switching 25b. Each data) is opened and synchronized with each other.

There may be only one type of power supply control data stored in the storage unit 85, and when the production of a plurality of types of products is expected or scheduled by the wire electric discharge machine 130, a plurality of types of power supply control data corresponding to each product are expected. It may be.

The operation / control unit 90 firstly activates the sub power supply 40 when a command for instructing the operation of the wire discharge processing machine 130 is input from the input unit 115 described later. Then, it is judged whether or not the detection result of the voltage detecting device 50 is within a predetermined range, and when the detection result is within the predetermined range, the main power supply 30 is started. Thereafter, the operation of the table drive device 55, the processing liquid supply device 60, and the like is controlled based on the numerical control data stored in the storage unit 85. 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 so that the table 5 moves in a predetermined direction, and the processing liquid supply device 60 based on the numerical control data. From each of the nozzles 65a and 65b is supplied with a processing liquid having a predetermined flow rate.

The calculation / control unit 90 calculates the energy of the high frequency pulse voltage applied from the wire electrode 1 to the workpiece W from the wire electrode 1 based on the detection result of the voltage difference by the voltage detection device 50, and measures the speed described above. The machining speed is determined based on the driving speed of the table 5 by the apparatus. Then, the sheet thickness of the workpiece W is sequentially calculated from the energy of the high frequency pulse voltage, the processing speed, and the like, and the control data corresponding to the sheet thickness is read out from the numerical control data, and the wire electrode 1 The energy of the high frequency pulse voltage applied to the feedback is controlled. Specifically, feedback control is performed on the pulse interval of the high frequency pulse voltage to be applied. In addition, the operation / control unit 90 controls the operation of the display unit 120 and displays, on the display unit 120, the command or data input to the control device 110, the operation status of the machine main body 80, and the like. Let's do it.

The pulse oscillation control unit 95 starts an operation under the control of the operation / control unit 90, reads the predetermined power supply control data stored in the storage unit 85, and based on the power supply control data, the first pulse. The operation of each of the 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 the desired power supply control data by the input unit 115 prior to the discharge machining of the workpiece W. FIG. 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 the desired power supply control data.

As described above, the power supply control data read out by the pulse oscillation control unit 95 includes data for opening and closing the first switching element unit 25a while the second switching element unit 25b is opened, and the first switching element unit ( Data for opening and closing the second switching element section 25b while the 25a is open and data for opening and closing the first switching element section 25a and the second switching 25b in turn are synchronized. Therefore, during the period during which the workpiece W is discharge-discharged, the upper feed state in which the high frequency pulse voltage is applied to the wire electrode 1 from only the upper feed part 20a and the wire electrode 1 only from the lower feed part 20b. The lower power supply state in which the high frequency pulse voltage is applied to the two sides and the high power supply state in which the high frequency pulse voltage is applied to the wire electrode 1 from both the upper feed part 20a and the lower feed part 20b are mixed in a predetermined pattern. do.

2 shows the relationship between the waveforms of pulse signals supplied from the respective pulse oscillators 35a and 35b to the first switching element portion 25a or the second switching element portion 25b and the feeding state to the wire electrode 1. It is a schematic diagram showing.

As shown in the same figure, the second pulse oscillator in a pulse waveform in which the pulse signal supplied from the first pulse oscillator 35a to the first switching element section 25a repeats the low level L and the high level H at a predetermined period. As a result of the opening and closing of the first switching element portion 25a with the second switching element portion 25b open when the pulse signal supplied from 35b to the second switching element portion 25b remains low level L, The upper power supply state UF is obtained. On the contrary, the pulse supplied from the second pulse oscillator 35b to the second switching element portion 25b while the pulse signal supplied from the first pulse oscillator 35a to the first switching element portion 25a is at the low level L. When the signal is a pulse waveform in which the low level L and the high level H are repeated at a predetermined cycle, the second switching element portion 25b is opened and closed while the first switching element portion 25a is opened, resulting in the lower feed state LF. The pulse signal supplied from the first pulse oscillator 35a to the first switching element portion 25a and the pulse signal supplied from the second pulse oscillator 35b to the second switching element portion 25b are synchronized with each other. In the case of a waveform, since the 1st switching element part 25a and the 2nd switching element part 25b open and close in synchronism with each other, it turns into the both sides power supply state BF.

The inventors of the present invention have found that the frequency of occurrence of short circuit between the wire electrode 1 and the workpiece W and the difficulty of wire disconnection are determined by the material and wire diameter of the wire electrode 1, the liquid quality of the processing liquid used, and the respective nozzles 65a. , 65b) varies depending on the processing conditions such as the supply amount of the processing liquid, the material of the workpiece W, and the shape of the product to be manufactured from the workpiece W. However, when the above-described feeding states are switched at short intervals, the short circuit occurs frequently. Experiments clearly show that speed is unlikely to rise. In addition, experiments clearly showed that wire breakage easily occurs when the number of pulses in each power supply state is too large.

For example, the sum of the number of pulses of the high frequency pulse voltage applied to the wire electrode 1 in the upper feed state and the number of pulses of the high frequency pulse voltage applied to the wire electrode 1 in the lower feed state is wired under the both feed states. In the case where the number of pulses of the high frequency pulse voltage applied to the electrode 1 is the same, if the number of pulses is less than 3 under each power supply state, the short-circuit between the wire electrode 1 and the workpiece W is frequent and the processing speed is large. It may fall in width. When the number of pulses is 10000 or more under each power supply state, the position of the discharge point between the wire electrode 1 and the workpiece W is not so dispersed in the sheet thickness direction of the workpiece W, so that the wire breakage It is easy to get up.

In addition, the inventors of the present invention have a short frequency of occurrence of short circuits between the wire electrode 1 and the workpiece W when the ratio of the number of pulses is too small under both feeding states, which occupy the total number of pulses applied to the wire electrode 1, Experiments clearly show that wire breakage is likely to occur when the amount is large. For example, when the said ratio is less than 50%, a short circuit will be easy to occur, and when 95% or more, a wire break may occur easily.

Considering this, it can be seen that the short circuit and the wire disconnection between the wire electrode 1 and the workpiece W can be suppressed by appropriately mixing the upper feed state, the lower feed state, and the both feed states.

In the above-described wire discharge processor 130, the pulse oscillation control unit 95 controls the first pulse oscillator 35a and the second pulse oscillator 35b based on the power supply control data stored in the storage unit 85. As a result of controlling the operation, the power feeding control is performed such that the upper feed state, the lower feed state and the both feed states are mixed in a predetermined pattern. Therefore, the appropriate power supply control data are experimentally obtained and stored in the storage unit 85 in advance, whereby short-circuits and wire breaks of the wire electrode 1 and the workpiece W can be suppressed, respectively. Therefore, in the wire electric discharge machine 130, it is easy to improve productivity.

Embodiment 2.

In the wire electric discharge machine of this invention, in order to suppress overheating of the wire electrode in the plate | board thickness direction center part of a to-be-processed object, a main power supply can be divided into two of a 1st main power supply and a 2nd main power supply.

It is a block diagram which shows schematically an example of the wire electric discharge machining apparatus in which a main power supply has a 1st main power supply and a 2nd main power supply. In the wire electric discharge machining apparatus 140 shown in the same figure, the main power supply 30 has the 1st main power supply 30a and the 2nd main power supply 30b. The 1st main power supply 30a is connected to the upper power feed part 20a via the 1st switching element part 25a, and is connected to the upper part in the plate | board thickness direction in the to-be-processed object W. FIG. Moreover, the 2nd main power supply 30b is connected to the lower power supply part 20b via the 2nd switching element part 25b, and is connected to the lower part of the board | substrate direction in the to-be-processed object W. Moreover, as shown in FIG. The operation of the first main power supply 30a and the second main power supply 30b is controlled by the operation / control unit 90a.

Since the structure other than what was mentioned above in the wire discharge processing machine 140 is the same as the structure in the wire discharge processing machine 130 shown in FIG. 1, what is common with the structural member shown in FIG. 1 among the structural members shown in FIG. The same reference numerals as those used in FIG. 1 are given, and the description thereof is omitted. In addition, the machine main body which comprises the wire electric discharge machine 140 is given the new reference | standard 80A, and the control apparatus has attached the new reference | standard 110A.

In the wire discharge processing machine 140 configured as described above, the first main power supply 30a is connected to the upper part in the sheet thickness direction in the workpiece W, and the second main power supply 30b is connected to the lower part in the sheet thickness direction in the workpiece W. Since 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 in both of the power feeding states are different, the position of the discharge point is the thickness of the workpiece W. The closer to the center of the direction, the larger. As a result, the discharge current value between the wire electrode 1 and the workpiece W decreases as the position of the discharge point gets closer to the center portion of the workpiece thickness in the plate thickness direction.

4 is a graph schematically showing the relationship between the discharge position (the position of the discharge point) and the discharge current value when the wire discharge processing machine 140 is in the both-side power supply state. The solid line L ₁ in the figure shows the relationship. For reference, represented by the broken line L ₂ in FIG. 4, the relationship in the wire electric discharge machine 130 shown in Fig. The discharge current value represented by the solid line L ₁ and the discharge current value represented by the broken line L ₂ are obtained under the same processing conditions.

As can be clearly seen from FIG. 4, in both the wire discharge machines 130 and 140, the discharge current value between the wire electrode and the workpiece decreases as the position of the discharge point gets closer to the center of the plate thickness direction of the workpiece. The degree of the decrease is larger in the wire discharge machine 140 than in the wire discharge machine 130. And if the electric current value itself in the plate | board thickness direction center part of a to-be-processed object is also under the same process conditions, the side in the wire discharge machine 140 is smaller than in the wire discharge machine 130. FIG.

Generally, in a wire discharge machine, overheating of a wire electrode is suppressed at the time of electric discharge machining by supplying a process liquid between a wire electrode and a workpiece, but in the plate thickness direction center part of a workpiece, The cooling by the processing liquid is less likely to be performed compared to the lower part of the plate thickness direction, and therefore, the wire electrode is excessively overheated in the center of the plate thickness direction of the workpiece, which often causes wire breakage.

However, in the wire electric discharge machine 140 shown in FIG. 3, since the discharge current value in the both-side feeding state becomes nearer to the plate thickness direction center part of the to-be-processed object W, the plate thickness direction center part of the workpiece W is reduced. Also, excessive overheating of the wire electrode 1 can be easily suppressed. Therefore, compared with the wire electric discharge machine 130 (refer FIG. 1) demonstrated in Embodiment 1, it is easy to prevent wire disconnection.

Therefore, according to the wire electric discharge machine 140, the wire electrode 1 and the workpiece W of the workpiece W are mixed with the wire electric discharge machine 130 by mixing the upper feed state, the lower feed state and the both feed states in a predetermined pattern. The short circuit can be prevented and the wire breakage can be easily suppressed as compared with the wire electric discharge machine 130. As a result, it becomes easy to improve productivity compared with the wire electric discharge machine 130.

Embodiment 3.

In the wire electric discharge machine, when the Z-axis height (relative height of the upper feeder) or the plate thickness of the workpiece is changed, the distance from the discharge point to each feeder is changed, and accordingly, the feed that reaches the discharge point through the upper feeder Variations occur in the impedance of each of the circuit (hereinafter referred to as the "top feed circuit") and the feed circuit that reaches the discharge point via the lower feed section (hereinafter referred to as the "bottom feed circuit"). Such a deviation in impedance causes a difference in the magnitude of the discharge current in each power supply circuit, and wire breakage tends to occur in a power supply circuit having a large discharge current (a power supply circuit having a small impedance).

In the wire discharge machine of the present invention, the supply conditions of the high frequency pulse voltage to the upper feeder circuit and the lower feeder circuit are adjusted according to the deviation of the impedance between the upper feeder circuit and the lower feeder circuit, and the impedance of the impedance is changed between the feeder circuits. The reduction can be configured to prevent wire breakage.

5-7 is a block diagram which shows schematically an example of the wire electric discharge machine which can prevent the wire disconnection resulting from the dispersion | variation of an impedance between power supply circuits, respectively. Of the constituent members shown in these drawings, the same reference numerals as those used in FIG. 1 are given to those common to the constituent members shown in FIG. 1, and the description thereof is omitted.

The wire electric discharge machine 150 shown in FIG. 5 is provided with the control apparatus 110B which has the pulse oscillation control part 95a. The pulse oscillation control part 95a reads out the data of the Z-axis height (height of the upper feed part 20a with respect to the lower feed part 20b) previously stored in the memory | storage part 85 by the user, or the memory | storage part 85 The Z-axis height is obtained from the numerical control data stored in the above). The Z-axis height is compared with the reference value to obtain the magnitude relationship between the impedances in the upper feed circuit and the lower feed circuit. Then, the power supply control data read out from the storage unit 85 is modified by, for example, calculation so that the discharge current value in the power supply circuit with a small impedance approaches the discharge current value in the power supply circuit with a large impedance, Based on the modified power supply control data, the corresponding pulse oscillation control unit 95a controls the operations of each of the first pulse oscillator 35a and the second pulse oscillator 35b.

For example, the discharge current value can be adjusted by changing the pulse length or pulse interval at the high frequency pulse voltage or by changing the number of pulses to supply the high frequency pulse voltage supplied to the wire electrode 1. When the first switching element portion 25a and the second switching element portion 25b each have a plurality of switching elements, the high frequency pulses supplied to the wire electrode 1 by changing the number of switching elements to be opened. It is also possible to adjust the energy of the voltage. As the reference value, the Z-axis height assumed at the time of preparation of the power supply control data 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 preferable when a flat plate is used as the workpiece W. FIG.

The wire electric discharge machine 160 shown in FIG. 6 is provided with the control apparatus 110C which has the operation and control part 90b and the pulse oscillation control part 95b. The calculation / control unit 90b is the same as the calculation / control unit 90 (refer to FIG. 1) shown in FIG. 1 and uses energy and processing speed of the high frequency pulse voltage applied from the wire electrode 1 to the workpiece W. FIG. It has the function of calculating the plate | board thickness of the to-be-processed object W in order, and sends a calculation result to the pulse oscillation control part 95b. FIG. 6 shows a speed measuring device 57 not shown in FIG. 1.

The pulse oscillation control section 95b compares the calculation result sent from the calculation / control section 90b with a reference value and calculates the magnitude relationship of the impedance in each of the upper feed circuit and the lower feed circuit. Then, the power supply control data read out from the storage unit 85 is modified by, for example, calculation so that the discharge current value in the power supply circuit with a small impedance becomes close to the discharge current value in the power supply circuit with a large impedance. Based on the power supply control data, the corresponding pulse oscillation controller 95b controls the operations of each of the first pulse oscillator 35a and the second pulse oscillator 35b. As the reference value, the sheet thickness assumed at the time of preparation of the power supply control data is used, and the reference value is stored in advance in the storage unit 85, for example. This wire electric discharge machine 160 is preferable not only in the case of using the flat plate as the workpiece W but also in the case where the recessed portion or the hole is formed in the workpiece W in advance.

The wire electric discharge machine 170 shown in FIG. 7 is provided with the control apparatus 110D which has the arithmetic and control part 90c, the pulse oscillation control part 95c, and the plate | board thickness determination part 100, The memory | storage part 85 has Three-dimensional data of the workpiece is further stored. The arithmetic control unit 90c controls the operation of the plate thickness determining unit 100, and the plate thickness determining unit 100 stores numerical control data (a table driving device (3) stored in the three-dimensional data and the storage unit 85). 55), the discharge machining position is specified, and the sheet thickness of the workpiece W at the discharge machining position is determined, and the data of the sheet thickness is sent to the pulse oscillation control unit 95b. The pulse oscillation control section 95c compares the sheet thickness data sent from the calculation / control section 90c with a reference value, and obtains the magnitude relationship of the impedance in each of the upper feed circuit and the lower feed circuit. Then, the power supply control data read out from the storage unit 85 is modified by, for example, calculation so that the discharge current value in the power supply circuit with a small impedance becomes close to the discharge current value in the power supply circuit with a large impedance. Based on the power supply control data, the corresponding pulse oscillation control unit 95c controls the operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b. As the reference value, the plate thickness assumed at the time of preparation of the power supply control data is used, and the reference value is stored in advance in the storage unit 85, for example. This wire electric discharge machine 170 is preferable not only when a flat plate is used as the workpiece W but also when recesses and holes are formed in the workpiece W in advance.

In each of the above-described wire electric discharge machines 150, 160, 170, the supply conditions of the high frequency pulse voltage to each of the upper feeder circuit and the lower feeder circuit are adjusted according to the magnitude (deviation) of the impedance between the feeder circuits. It is easy to prevent wire breakage caused by the deviation of the impedance between. Therefore, according to such a wire electric discharge machine 150, 160, 170, a wire is mixed with the wire electric discharge machine 130 shown in FIG. 1 by the upper side, the lower side, and both sides of a state in a predetermined pattern. The short circuit of the electrode 1 and the workpiece W can be prevented, and the wire breakage can be easily suppressed as compared with the wire discharge machine 130. As a result, it becomes easy to improve productivity compared with the wire electric discharge machine 130.

Embodiment 4.

In the wire discharge processing machine of the present invention, the supply conditions of the high frequency pulse voltage to each power supply circuit are adjusted according to the impedance of the upper power supply circuit and the impedance of the lower power supply circuit, so as to prevent wire disconnection due to the deviation of the impedance between the power supply circuits. Can be configured.

8 and 9 are schematic diagrams each showing an example of a wire discharge processing machine capable of adjusting the supply conditions 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. Among the structural members shown in these drawings, the same reference numerals as those used in FIG. 1 are given to those common to the structural members shown in FIG. 1, and the description thereof is omitted.

The wire electric discharge machine 180 shown in FIG. 8 is provided with the processing machine main body 80B which has the impedance measuring part 70, and the control apparatus 110E which has the pulse oscillation control part 95d. The impedance measuring unit 70 measures the impedance between the main power supply 30 and the upper power supply 20a in the upper power supply circuit, and the impedance between the main power supply 30 and the lower power supply 20b in the lower power supply circuit, respectively. The measurement is carried out and the measurement result is transmitted to the pulse oscillation controller 95d. The pulse oscillation control part 95d compares the actual measurement result by the impedance measuring part 70 with a reference value, and calculates the magnitude relationship of an impedance in each of an upper feeder circuit and a lower feeder circuit. Then, the power supply control data read out from the storage unit 85 is modified by, for example, calculation so that the discharge current value in the power supply circuit with a small impedance becomes close to the discharge current value in the power supply circuit with a large impedance. Based on the power supply control data, the corresponding pulse oscillation control unit 95d controls the operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b. As the reference value, the impedance assumed at the time of preparation of the power supply control data is used, and the reference value is stored in advance in the storage unit 85, for example.

The wire electric discharge machine 190 shown in FIG. 9 is equipped with the control apparatus 110F which has the pulse oscillation control part 95e, and the memory | storage part 85 previously measured by the manufacturer or user of the wire electric discharge machine 190. The impedance of each of the upper feed circuit and the lower feed circuit is stored in advance. Specifically, impedance measurement data between the main power supply 30 and the upper power supply unit 20a in the upper power supply circuit and impedance measurement data between the main power supply 30 and the lower power supply unit 20b in the lower power supply circuit are preliminary. It is stored. The pulse oscillation control unit 95e directly compares the measured data of the respective impedances stored in the storage unit 85 or compares them with a reference value, and obtains the magnitude relationship between the impedances in each of the upper feed circuit and the lower feed circuit. Then, the power supply control data read out from the storage unit 85 is modified by, for example, calculation so that the discharge current value in the power supply circuit with a small impedance becomes close to the discharge current value in the power supply circuit with a large impedance. Based on the power supply control data, the corresponding pulse oscillation control unit 95e controls the operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b. As the reference value, the impedance assumed at the time of preparation of the power supply control data is used, and the reference value is stored in advance in the storage unit 85, for example.

In each of the above-described wire discharge machines 180 and 190, the supply conditions of the high frequency pulse voltage to each of the power supply circuits are adjusted according to the impedance of the upper power supply circuit itself and the impedance of the lower power supply circuit itself. It is easy to prevent the wire disconnection resulting from (case relationship). Therefore, such wire discharge machines 180, 190 achieve the same technical effects as the wire discharge machines 150, 160, 170 described in the third embodiment.

Embodiment 5.

The wire discharge processing machine of the present invention has a wire break avoidance function for controlling the operation of each of the first pulse oscillator and the second pulse oscillator so that the wire break is prevented when a sign of the wire break (hereinafter referred to as a "break signal") is detected. Can be added.

It is a block diagram which shows schematically an example of the wire electric discharge machine to which the wire break prevention function was added. The wire electric discharge machine 200 shown in the same figure is equipped with the processor main body 80C which has the disconnection indication detection part 75, and the control apparatus 110G which has the pulse oscillation control part 95f, and the memory | storage part 85 has In addition to the power supply control data described in the first to fourth embodiments (hereinafter referred to as "basic power supply control data" in the present embodiment), the power supply control data for avoiding wire disconnection when there is a disconnection indication (hereinafter, "for disconnection avoidance"). Power supply control data) is additionally stored. Of the structural members shown in FIG. 10, the same reference numerals as those used in FIG. 1 are assigned to those common to the structural members shown in FIG. 1, and the description thereof is omitted.

The disconnection symptom detection unit 75 is electrically connected to the upper feed section 20a, the lower feed section 20b, and the workpiece W. For example, the split ratio of the current in the upper feed circuit and the lower feed circuit. The position of the discharge point is determined, and it is judged that there is a sign of wire disconnection when the concentrated discharge in which the discharge point concentrates in one position is detected, and the predetermined signal (hereinafter referred to as the "disconnect signal detection signal") is referred to as a pulse oscillation control unit. Send to 95f.

The pulse oscillation control unit 95f which has received the disconnection indication detection signal changes the power supply control data by reading the disconnection avoidance feed control data from the storage unit 85, and based on the disconnection avoidance feed control data, the first pulse. Operation of each of the oscillator 35a and the second pulse oscillator 35b is controlled to avoid wire breakage. For example, the first pulse oscillator 35a and the second pulse oscillator 35b are operated and controlled so that the upper feed state and the lower feed state alternately appear, thereby over time the position of the discharge point. To prevent wire breakage.

Since the wire electric discharge machine 200 has the above-mentioned wire disconnection avoidance function, it is easy to prevent wire break compared with each wire electric discharge machine demonstrated in Embodiment 1-4. Therefore, according to the said wire electric discharge machine 200, the wire electrode 1 is mixed with the wire electric discharge machine 130 shown in FIG. 1 by the upper-side feeding state, the lower side feeding state, and the both-side feeding state in a predetermined pattern. The short circuit between the workpiece W and the workpiece W can be prevented and the wire breakage can be easily suppressed as compared with the wire discharge machine 130. As a result, it becomes easy to improve productivity compared with the wire electric discharge machine 130.

In addition, in the case of adding the wire break avoidance function to the wire discharge processing machine, the pulse oscillation control section sets the power supply ratio when entering the long-term (about 1 to 2 seconds) field of view based on a predetermined ratio, that is, basic power supply control data. The function of returning to the feed rate by the upper feed state, the lower feed state, and the both feed states when controlling the operation of each of the 1 pulse oscillator and the second pulse oscillator (hereinafter, referred to as the "feed rate return function") Can be added.

FIG. 11 is a schematic diagram showing an example of a power feeding pattern when the power supply ratio return function is added to the above-mentioned pulse oscillation control section 95f. In the example shown in the same figure, until the time T ₁ , the pulse oscillation control part 95f controls the operation of each of the 1st pulse oscillator 35a and the 2nd pulse oscillator 35b based on basic power supply control data. Under the basic power supply control data, the operation of performing the two power feeding states for two cycles after performing the upper power feeding state and the lower power feeding state by one cycle is repeated.

When the disconnection symptom detection signal is sent from the disconnection symptom detection unit 75 to the pulse oscillation control unit 95f at the time T ₁ , the pulse oscillation control unit 95f is based on the first pulse oscillator 35a and the feed control data for avoiding disconnection. The operation of each of the second pulse oscillators 35b is started to control the operations of the first pulse oscillator 35a and the second pulse oscillator 35b so that the upper feed state and the lower feed state alternately appear. When the disconnection symptom detection signal from the disconnection symptom detection unit 75 stops at time T ₂ , the pulse oscillation control unit 95f expresses the feed ratio return function, and the upper feed state, the lower feed state, and the both feed states, respectively. The operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b is controlled so that the power supply ratio by this becomes the power supply ratio under the basic power supply control data.

Specifically, since the _two- sided feed state is not performed for one cycle from the time T ₁ to the time T ₂ , the first pulse oscillator 35a such that the ratio of the upper feed state, the lower feed state and the both feed states is 1: 1: 1: 2. ) And the operation of each of the second pulse oscillator 35b, each of the upper feed state and the lower feed state appear one cycle each from time T ₂ to time T ₃ , and the two feed states for eight cycles. Appear Thereby, the power feeding ratio by each of the upper side feeding state, the lower side feeding state, and the both side feeding states is returned to the feeding rate under the basic feeding control data.

The feed ratio recovery function provided to the pulse oscillation control unit 95f has a function of calculating the feed ratio under the basic power supply control data, and the number of occurrences of the upper feed state, the lower feed state, and the both feed states under the feed control data for avoiding disconnection. And a function of calculating a deviation from a power supply ratio caused by feeding power under feed control data for avoiding disconnection, that is, a deviation from a power supply ratio under basic power supply control data, and a function of correcting the deviation. have. After the time T ₃ , the pulse oscillation controller 95f controls the operations of the first pulse oscillator 35a and the second pulse oscillator 35b again based on the basic power supply control data.

Embodiment 6.

The wire electric discharge machine of the present invention has a function of controlling the operation of each of the first pulse oscillator and the second pulse oscillator so that the short circuit is prevented when the short circuit indication or short circuit of the wire electrode and the workpiece is detected or the short circuit is eliminated. Hereinafter, the "short circuit prevention function" can be added.

It is a block diagram which shows schematically an example of the wire electric discharge machine to which the short circuit prevention function was added. The wire electric discharge machine 210 shown in the same figure is provided with the control apparatus 110H which has the operation and control part 90d and the pulse oscillation control part 95g, and when the memory part 85 has the said short circuit indication or a short circuit, Power supply control data (hereinafter referred to as "short circuit prevention control data") for preventing a short circuit or eliminating the short circuit is further stored. Of the constituent members shown in FIG. 12, the same reference numerals as those used in FIG. 1 are assigned to those common to the constituent members shown in FIG. 1, and the description thereof is omitted.

The arithmetic and control unit 90d indicates a short circuit or short circuit between the wire electrode 1 and the workpiece W based on the voltage difference between the power feeding units 20a and 20b and the workpiece W detected by the voltage detecting device 50. Is detected. Specifically, the discharge voltage value is calculated from the voltage difference between the power supply units 20a and 20b and the workpiece W detected by the voltage detecting device 50, and the value is the material of the wire electrode 1 and the workpiece W. When it is smaller than the predetermined average discharge voltage value based on the material, the liquid quality of the processing liquid, the magnitude of the high frequency pulse voltage applied to the wire electrode 1, it is determined as a sign of short circuit or occurrence of short circuit. Then, when a sign or a short circuit of a short circuit is detected, the operation / control unit 90d sends a predetermined signal (hereinafter, referred to as a "short / signal detection signal") to the pulse oscillation control section 95g. In addition, the said average discharge voltage value is calculated | required by the manufacturer or user of the wire electric discharge machine 210, and is stored in the memory | storage part 85 beforehand.

The pulse oscillation control unit 95g, which has received the short circuit / signal detection signal from the operation / control unit 90d, reads out the short circuit prevention feed control data from the storage unit 85, thereby modifying the power supply control data, and the power supply control data for preventing the short circuit. To control the operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b and prevent the short-circuit of the wire electrode 1 and the workpiece W, or the wire electrode 1 and the workpiece W; Eliminate paragraphs. For example, by controlling the operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b so as to be in a both-side power supply state, the discharge between the wire electrode 1 and the workpiece W is stabilized, whereby The short circuit of the wire electrode 1 and the workpiece W is prevented, or the short circuit of the wire electrode 1 and the workpiece W is eliminated.

Since the wire electric discharge machine 210 has the above-mentioned short circuit prevention function, it is easy to prevent the short circuit of the wire disconnection 1 and the workpiece W compared with each wire electric discharge machine demonstrated in Embodiment 1-5. Therefore, according to the said wire electric discharge machine 210, the wire-electrode 1 is mixed with the wire electric discharge machine 130 shown in FIG. 1 by the upper-side feeding state, the lower side feeding state, and the both-side feeding state in a predetermined pattern. The short circuit between the workpiece W and the workpiece W can be prevented, and the short circuit between the wire electrode 1 and the workpiece W can be suppressed as compared with the wire discharge machine 130. As a result, it becomes easy to improve productivity compared with the wire electric discharge machine 130. Moreover, even when a short circuit prevention function is added to a wire electric discharge machine, the power supply ratio return function demonstrated in Embodiment 5 can be added to a pulse oscillation control part.

Embodiment 7.

The wire discharge processing machine of the present invention can be provided with a function of controlling the operation of each of the first pulse oscillator and the second pulse oscillator in accordance with the flow rate of the processing liquid supplied from the processing liquid supply device to each of the upper nozzle and the lower nozzle.

It is a block diagram which shows schematically an example of the wire electric discharge machine to which the said function was added. The wire electric discharge machine 220 shown in the same figure is provided with the control apparatus 110I which has the operation and control part 90e, the pulse oscillation control part 95h, and the flow volume comparison part 105. As shown in FIG. Of the constituent members shown in FIG. 13, those common to the constituent members shown in FIG. 1 are given the same reference numerals as those used in FIG. 1, and the description thereof is omitted.

The calculation / control unit 90e controls the operation of the processing liquid supply device 60 based on the numerical control data (the numerical control data for the processing liquid supply device 60) stored in the storage unit 85. Data on the flow rate of the processing liquid supplied from the processing liquid supply device 60 to the upper nozzle 65a and the flow rate of the processing liquid supplied to the lower nozzle 65b are sent to the flow rate comparison unit 105. The flow rate comparison part 105 which received this data compares each data with a reference value, and sends the result to the pulse oscillation control part 95h. The flow rate comparison part 105 has, for example, data of the flow rate of the processing liquid assumed at the time of preparation of the power supply control data as the reference value.

The pulse oscillation control unit 95h reads the power supply control data from the storage unit 85 and controls the operations of the first pulse oscillator 35a and the second pulse oscillator 35b, respectively, while the flow rate comparator 105 When there is a nozzle judged that the flow rate of the processing liquid exceeds the reference value from the comparison result, the power supply control data is changed by calculation, for example. That is, the feeding ratio of the high frequency pulse voltage supplied to the wire electrode 1 from the feeder on the same side as the nozzle in the upper feeder 20a and the lower feeder 20b that the flow rate of the processing liquid is determined to exceed the reference value. The power supply control data is modified so as to be 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.

In the case of wire discharge machining the workpiece, the flow rate of the processing liquid supplied from the processing liquid supply device to each of the upper nozzle and the lower nozzle is not constant in all the processes of the electrical discharge machining, for example, the relative movement path of the wire electrode is straight The flow rate of the processing liquid is different at the shape position and the arc position. In addition, the flow rate of the processing liquid may differ between the upper nozzle 65a and the lower nozzle 65b. Then, when the flow rate of the processing liquid differs between the upper nozzle 65a and the lower nozzle 65b, the processing groove (the gap between the wire electrode 1 and the workpiece W) is removed from the nozzle having a large flow rate of the processing liquid. The liquid amount of the processing liquid flowing in becomes smaller than the liquid amount of the processing liquid flowing into the processing groove from the nozzle having a small flow rate of the processing liquid, and the processing powder or the like easily collects in the processing groove at the nozzle side having a large flow rate of the processing liquid. As a result, the discharge frequency is increased on the nozzle side with a large flow rate of the processing liquid, and wire breakage easily occurs.

In the wire electric discharge machine 220 shown in FIG. 13, when there exists a nozzle judged that the flow volume of a process liquid exceeds the reference value, the power supply ratio of the high frequency pulse voltage supplied to the wire electrode 1 from the power supply part on the same side as the said nozzle Since the operation of each of the first pulse oscillator 35a and the second pulse oscillator 35b is controlled so as to be lowered, even when the flow rate of the processing liquid supplied to each of the upper nozzle 65a and the lower nozzle 65b varies, the wire Disconnection is suppressed.

Therefore, according to the said wire electric discharge machine 220, the wire-electrode 1 is mixed with the wire-discharge machine 130 shown in FIG. 1 by the upper-side feeding state, the lower side feeding state, and the both side feeding state in a predetermined pattern. ) And the workpiece W can be prevented, and the wire breakage can be easily suppressed as compared with the wire electric discharge machine 130. As a result, it becomes easy to improve productivity compared with the wire electric discharge machine 130.

As mentioned above, although the wire discharge processing machine of this invention was demonstrated with the illustration of seven forms, this invention is not limited to the seven forms mentioned above. For example, the desired power supply control simply inputs a mixed pattern (appearance pattern) of the upper feed state, the lower feed state and the both feed states from the input unit so that the user can easily store the desired feed control data in the storage unit. The data conversion unit may be provided in the control device so that the data is stored in the storage unit.

It is a block diagram which shows schematically an example of the wire electric discharge machine provided with the said data conversion part in a control apparatus. In the control apparatus 110J of the wire electric discharge machine 230 shown in the same figure, when the mixed pattern (appearance pattern) of an upper side feed state, a lower side feed state, and both sides feed state is input from an input part, the power supply control data according to the appearance pattern The data conversion unit 108 for generating the data is provided. The power supply control data created by this data conversion unit 108 is stored in the storage unit 85 via the calculation / control unit 90f. The pulse oscillation control unit 95 controls operations of each of the first pulse oscillator 35a and the second pulse oscillator 35b based on the power supply control data. In addition, among the structural members shown in FIG. 14, what is common to the structural member shown in FIG. 1 is attached | subjected with the same reference code as used in FIG. 1, and the description is abbreviate | omitted.

In addition, although illustration is abbreviate | omitted, in the wire electric discharge machine of this invention, the said 1st switching element part and the 2nd switching element part to which the main power supply are connected may be made into another member, and may be made into one component of a main power supply. It may be. Orientally, the 3rd switching element part and 4th switching element part to which a sub power supply is connected may be made into a member different from the said sub power supply, and may be made into one component member of a sub power supply. Each of the first pulse oscillator and the second pulse oscillator is also oriental, and these may be one component of the pulse oscillation control, in addition to one component of the main power supply or the sub power supply.

Moreover, it is also possible to provide only one switching element part to one feed part. It is a block diagram which shows schematically an example of the wire electric discharge machine in which only one switching element part was provided in one power supply part. In the processing machine main body 80D of the wire electric discharge machine 240 shown in the same figure, one switching element part 28a (henceforth "the 1st switching element part 28a") corresponding to the upper feed part 20a is mentioned. Is provided, and switching element portions other than the first switching element portion 28a are not connected to the upper power feeding portion 20a. In the orient, one switching element portion 28b (hereinafter referred to as "second switching element portion 28b") is provided corresponding to the lower feeder portion 20b, and other than the second switching element portion 28b. Of the switching element is not connected to the lower power feeding section 20b. The individual switching element portions 28a and 28b are shared by the main power supply 30 and the sub power supply 40. The 1st pulse oscillator 35a is connected to the 1st switching element part 28a, and the 2nd pulse oscillator 35b is connected to the 2nd switching element part 28b.

The first switching element portion 28a may be a member separate from any of the main power supply 30 and the sub power supply 40, or may be a component of the main power supply 30 or the sub power supply 40. have. Orientally, the second switching element portion 28b may be a separate member from both the main power supply 30 and the sub power supply 40, and may be a component of the main power supply 30 or the sub power supply 40. You may.

Regardless of how many switching element portions are provided in one feed section, the wire discharge machine of the present invention can arbitrarily mix (appear) the upper feed state, the lower feed state and the both feed states during the discharge machining period. It is also possible to suitably change the amount of discharge machining in the plate thickness direction of the workpiece while preventing the short circuit and wire disconnection of the wire electrode and the workpiece, and to improve the machining accuracy in the sheet thickness direction. Increasing the feed rate in the upper feed state allows the discharge machining to proceed in the upper plate thickness direction in the workpiece, and increasing the feed rate in the lower feed state promotes the discharge machining in the lower plate thickness direction in the workpiece. Since it is possible to appropriately combine these power feeding states, the degree of processing in the plate thickness direction of the workpiece can be improved.

In addition, since the plate | board thickness of a to-be-processed object can be calculated | required using the three-dimensional data of a to-be-processed object like the wire electric discharge machine 170 shown in FIG. In the wire electric discharge machine which has the function of calculating | requiring the plate | board thickness of, it is also possible to abbreviate | omit the function of calculating the plate | board thickness of a to-be-processed object from the energy of a high frequency pulse voltage applied to a to-be-processed object from a wire electrode, and a processing speed. Various modifications, modifications, combinations, and the like are possible for the wire electric discharge machine of the present invention in addition to the above.

The short-circuit of the wire electrode and the workpiece tends to occur in the upper feed state or the lower feed state described above. However, when the upper feed state and the lower feed state alternately appear, the position of the discharge point between the wire electrode and the workpiece is avoided. Since it changes in the plate | board thickness direction (thickness direction) of a workpiece | work, generation | occurrence | production of a 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 both of the power feeding states, the short circuit of the wire electrode and the workpiece can be prevented.

In the wire discharge machine of the present invention, since the pulse oscillation control unit controls the operation of each of the first pulse oscillator and the second pulse oscillator based on the feed control data, the upper feed state, the lower feed state and the both feed states during the discharge machining period. It can be mixed in any pattern. By appropriately obtaining, in an experiment, the power supply control data according to the scheduled discharge processing conditions and the like, and storing them in the storage unit, short-circuits and wire disconnections of the wire electrode and the workpiece can be suppressed, respectively. Therefore, it is also easy to improve productivity.

Claims (13)

A high frequency pulse voltage is applied to the wire electrode through a pair of feed sections disposed above and below the workpiece while supplying a processing liquid between the wire electrode traveling in the plate thickness direction of the workpiece and the workpiece. A wire discharge processing machine for processing the workpiece by discharge generated between a wire electrode and the workpiece, The high frequency pulse voltage is applied to the upper feed part disposed above the workpiece among the pair of feed parts through a first switching element part, and the lower feed part disposed below the workpiece through a second switching element part. A main power supply for applying a high frequency pulse voltage, A first pulse oscillator for supplying a pulse signal for controlling an opening and closing operation of the first switching element portion to the first switching element portion; A second pulse oscillator for supplying a pulse signal for controlling an opening and closing operation of the second switching element portion to the second switching element portion; An upper feeding state in which opening and closing operations of the first switching element portion and the second switching element portion are defined, and applying a high frequency pulse voltage to the wire electrode from only the upper feeding portion, and the wire from only the lower feeding portion Feeding control data for feeding control such that a lower feed state for applying a high frequency pulse voltage to an electrode and both feed states for applying a high frequency pulse voltage to the wire electrode in synchronization with each other from both the upper feed part and the lower feed part are mixed. And the storage unit is stored, And 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. The method according to claim 1, The main power source A first main power source connected to said upper feed section via said first switching element section and connected to an upper part in the sheet thickness direction in said workpiece; And a second main power source connected to said lower feed section via said second switching element section, and connected to a lower part in the sheet thickness direction in said workpiece. The method according to claim 1, The pulse oscillation controller may include an impedance between a main power supply and an upper feeder in an upper feeder circuit reaching a discharge point from the main power supply through the first switching element portion and the upper feeder, and from the main power supply to the second power supply circuit. According to the impedance between the main power supply and the lower feeder in the lower feeder circuit reaching the discharge point via the switching element portion and the lower feeder, the discharge current value of the feeder of the lower impedance is higher. And modifying the feed control data so as to approximate a discharge current value in a feed circuit, and controlling the operations of the first pulse oscillator and the second pulse oscillator based on the modified feed control data. Wire electric discharge machine. The method according to claim 3, The storage section further stores data on the Z-axis height assumed at the time of creation of the power supply control data. The pulse oscillation control section uses the impedance of the upper feed circuit and the lower feed circuit on the basis of the data on the Z axis height when the workpiece is discharged and the Z axis height stored in the storage unit. The magnitude of the magnitude relationship of the said impedance is judged, The wire electric discharge machine characterized by the above-mentioned. The method according to claim 3, A table capable of moving in the biaxial direction in a state where the workpiece is placed; A table driving device which moves the table in two axial directions; A speed measuring device for measuring the drive speed of the table; A voltage detecting device for detecting a voltage difference between each of the upper feed part and the lower feed part and the workpiece; A high speed pulse voltage is applied to the workpiece from the wire electrode based on the voltage difference detected by the voltage detecting device while calculating the processing speed based on the driving speed of the table measured by the speed measuring device. And an arithmetic and control unit for calculating the energy of and calculating the plate thickness of the workpiece by using the processing speed and the energy of the high frequency pulse voltage. The pulse oscillation control unit judges the magnitude relationship between the impedance in the upper feed circuit and the impedance in the lower feed circuit based on the plate thickness of the workpiece calculated by the calculation / control unit. . The method according to claim 3, A table which can move in two axes in the state where the workpiece is placed; A table driving device for moving the table in two axial directions; An arithmetic and control unit for controlling the operation of the table driving apparatus; Further having a plate thickness determining unit for calculating the plate thickness of the workpiece at the position where the discharge is processed, The storage section further stores numerical control data for numerically controlling the operation of the table driving apparatus and three-dimensional data of the workpiece, The operation / control unit controls the operation of the table driving apparatus based on the numerical control data, The plate thickness determining unit calculates the plate thickness of the workpiece at the position where the discharge is being processed, based on the numerical control data and the three-dimensional data, The pulse oscillation controller determines the magnitude relationship between the impedance in the upper feeder circuit and the impedance in the lower feeder circuit based on the sheet thickness of the workpiece calculated by the sheet thickness determiner. . The method according to claim 3, It further has an impedance measuring part which measures the said impedance in an upper feeder circuit, and the said impedance in a lower feeder circuit, And the pulse oscillation controller determines a magnitude relationship between the impedance in the upper power supply circuit and the impedance in the lower power supply circuit based on the measured result of the impedance measuring unit. The method according to claim 3, The storage section stores in advance the measured data of each of the impedance in the upper power supply circuit and the impedance in the lower power supply circuit. The pulse oscillation controller is based on the measured data of each of the impedance in the upper power supply circuit and the impedance in the lower power supply circuit stored in the storage unit, and the impedance in the upper power supply circuit and the impedance in the lower power supply circuit. A wire discharge processor, characterized in that for determining the magnitude relationship of the. The method according to claim 1, And a disconnection symptom detection unit connected to the upper feeder, the lower feeder, and the workpiece to detect a sign of wire disconnection, The pulse oscillation control unit modifies the power supply control data so that the position of discharge is dispersed over time when the disconnection indication detection unit detects a sign of wire disconnection, And controlling the operation of each of the first pulse oscillator and the second pulse oscillator on the basis of the modified power supply control data. The method according to claim 9, And the pulse oscillation control unit changes the power supply control data so that the upper feed state and the lower feed state alternately appear when the disconnection symptom detection unit detects a sign of wire disconnection. The method according to claim 1, A voltage detecting device for detecting a voltage difference between each of the upper feed part and the lower feed part and the workpiece; And further comprising an operation / control section for determining whether there is a short circuit or the short-circuit indication of the wire electrode and the workpiece based on the detection result by the voltage detecting device, The pulse oscillation control unit modifies the power supply control data so that the discharge between the wire electrode and the workpiece is stabilized when the operation / control unit judges that there is a short circuit or a symptom of the short circuit. And controlling the operations of each of the first pulse oscillator and the second pulse oscillator based on data. The method according to claim 11, And the pulse oscillation control unit changes the power supply control data so as to be in both of the power supply states when the operation / control unit determines that there is a short circuit or a symptom of the short circuit. The method according to claim 1, An upper nozzle disposed above the workpiece, A lower nozzle disposed below the workpiece, A processing liquid supply device for supplying a processing liquid to each of the upper nozzle and the lower nozzle; An operation / control unit which controls the operation of the processing liquid supply device and supplies the processing liquid of a predetermined flow rate to each of the upper nozzle and the lower nozzle from the processing liquid supply device; Further having a flow rate comparison section for obtaining the magnitude relationship between the supply amount of the processing liquid to each of the upper nozzle and the lower nozzle and the supply amount of the processing liquid assumed at the time of creation of the power supply control data, The storage section further stores numerical control data for numerically controlling the operation of the processing liquid supply device. The operation / control unit controls the operation of the processing liquid supply device based on the numerical control data, The pulse oscillation control section is configured to be discharged from the power supply unit on the same side as the nozzle when a nozzle having a supply amount of the processing liquid is larger than the supply amount of the processing liquid assumed at the time of creation of the power supply control data as a result of the comparison by the flow rate comparison unit. And modifying the feed control data so that the feed rate to the wire electrode is lowered, and controlling the operation of each of the first pulse oscillator and the second pulse oscillator based on the modified feed control data. Processing machine.

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