WO2011089648A1 - 数値制御装置、これを用いたワイヤ放電加工装置、及びこれを用いたワイヤ放電加工方法 - Google Patents
数値制御装置、これを用いたワイヤ放電加工装置、及びこれを用いたワイヤ放電加工方法 Download PDFInfo
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- WO2011089648A1 WO2011089648A1 PCT/JP2010/000353 JP2010000353W WO2011089648A1 WO 2011089648 A1 WO2011089648 A1 WO 2011089648A1 JP 2010000353 W JP2010000353 W JP 2010000353W WO 2011089648 A1 WO2011089648 A1 WO 2011089648A1
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- disconnection
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- threshold value
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
- B23H7/00—Processes or apparatus applicable to both electrical discharge machining and electrochemical machining
- B23H7/14—Electric circuits specially adapted therefor, e.g. power supply
- B23H7/20—Electric circuits specially adapted therefor, e.g. power supply for programme-control, e.g. adaptive
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
- B23H7/00—Processes or apparatus applicable to both electrical discharge machining and electrochemical machining
- B23H7/02—Wire-cutting
- B23H7/08—Wire electrodes
- B23H7/10—Supporting, winding or electrical connection of wire-electrode
- B23H7/102—Automatic wire threading
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
- B23H7/00—Processes or apparatus applicable to both electrical discharge machining and electrochemical machining
- B23H7/14—Electric circuits specially adapted therefor, e.g. power supply
Definitions
- the present invention relates to a wire electric discharge machining apparatus, and more particularly to a wire electric discharge machining apparatus having a function of preventing a wire electrode from being disconnected.
- the machining speed In a wire electric discharge machine, the machining speed generally increases as the machining energy increases. Therefore, in order to increase the processing speed, the processing energy is increased by increasing the peak value of the discharge current or increasing the discharge frequency.
- the greater the peak value of the discharge current or the higher the discharge frequency the greater the risk that the wire electrode will break. That is, there is a limit (disconnection limit) in the peak value of the discharge current and the discharge frequency at which discharge can be continued without disconnection of the wire electrode.
- a limit disconnection limit
- the peak value and the discharge frequency of the discharge current related to the disconnection limit are determined by the processing state such as the diameter and material of the wire electrode, the plate thickness and material of the workpiece, and the jet state of the processing liquid.
- the processing state such as the diameter and material of the wire electrode, the plate thickness and material of the workpiece, and the jet state of the processing liquid.
- the wire electric discharge machining apparatus of Patent Document 1 calculates the plate thickness and controls the machining conditions.
- the plate thickness is calculated from the processing energy and processing speed per unit time.
- Equation (1) the machining volume per unit time in electric discharge machining is expressed as shown in Equation (1) by the plate thickness of the workpiece, machining allowance, and the machining feed amount per unit time, that is, the machining speed.
- Machining volume plate thickness x machining allowance x machining speed (1)
- the processing volume is proportional to the processing energy. Normally, the machining allowance is controlled to be constant by servo control. Therefore, if equation (1) is modified, equation (2) can be obtained.
- Plate thickness coefficient x machining energy / machining speed (2)
- the coefficient can be obtained in advance if the workpiece is processed with a known thickness. That is, if the machining energy and the machining speed are calculated, the values other than the coefficient in Expression (2) are known, and therefore the coefficient can be calculated. If the coefficient can be determined, the plate thickness can be calculated from Equation (2) by obtaining the machining energy and the machining speed. Patent Document 1 switches an appropriate processing condition determined in advance according to the calculated plate thickness.
- the wire electrode may be disconnected even if the processing conditions are changed according to the plate thickness. This is because the machining may become unstable depending on the machining shape or the jet state of the machining liquid. For example, a case where a steep step or a corner is processed, or a case where the processing liquid injection nozzle is processed away from the workpiece may be used. Therefore, a technique for detecting a sign of wire electrode disconnection caused by such processing instability and avoiding this is also disclosed. For example, in Patent Document 1, a disconnection sign signal for detecting a sign of disconnection is provided, and when the disconnection sign signal exceeds a predetermined threshold, disconnection is avoided by lowering the machining energy.
- a short-circuit discharge pulse ratio (number of short-circuit discharge pulses / number of normal discharge pulses) indicating the rate at which a short-circuit occurs between the workpiece and the wire electrode within a predetermined time.
- disconnection threshold value varies depending on the diameter and material of the wire electrode, the thickness and material of the workpiece, etc., it is necessary to determine whether the threshold is determined by performing trial processing for each condition to determine whether or not the disconnection occurs. Don't be.
- the trial processing process cannot be automated and the time required for the entire processing is long.
- a numerical controller of a wire electric discharge machining apparatus controls an oscillator that outputs a discharge pulse of the wire electric discharge machining apparatus and a servo amplifier that controls a servo motor that drives a wire electrode or a workpiece to move relative to each other.
- a breakage sign signal generating means for generating a breakage sign signal based on the machining state quantity input from the oscillator, and a machining condition reset command based on the breakage sign signal and the breakage threshold
- a disconnection threshold value detection means for outputting a disconnection threshold value reset command
- a disconnection threshold value setting means for setting the disconnection threshold value based on the disconnection threshold value reset command and an input disconnection signal
- a discharge pulse input from the oscillator Machining energy calculating means for calculating machining energy based on the number, and position information input from the servo amplifier Machining speed measuring means for measuring a machining speed
- plate thickness calculating means for calculating a plate thickness of the workpiece based on the machining energy and the machining speed, the plate thickness, the machining condition reset command, and the disconnection
- a machining condition switching means for outputting a machining condition switching command according to a predetermined algorithm based on the signal, and a control for sending an oscil
- the wire electric discharge machining apparatus also provides a servo amplifier that controls a servo motor that drives a wire electrode or a workpiece to move the workpiece relative to each other, and a voltage is applied to a machining gap between the wire electrode and the workpiece.
- An oscillator that outputs a discharge pulse to a machining power source for applying and machining a workpiece, a numerical control device that controls the oscillator and the servo amplifier so as to satisfy desired machining conditions, and detecting wire electrode disconnection
- a wire breakage detector that outputs a breakage signal to the numerical control device, wherein the numerical control device generates a breakage sign signal based on a machining state quantity input from the oscillator Generation means, disconnection sign detection means for outputting a machining condition reset command and a disconnection threshold reset command based on the disconnection sign signal and the disconnection threshold value, A disconnection threshold value setting means for setting the disconnection threshold value based on a disconnection threshold value reset command and the disconnection signal, a processing energy calculation means for calculating processing energy based on the number of discharge pulses input from the oscillator, and a servo amplifier Machining speed measuring means for measuring the machining speed based on the input position information, plate thickness calculating means for calculating the plate thickness of the workpiece based
- the numerical controller controls the oscillator and the servo amplifier so that the desired machining conditions are obtained, and the servo amplifier drives the wire electrode or the workpiece to move relative to each other.
- Controls the motor, and the oscillator outputs a discharge pulse to a machining power source and applies a voltage to the machining gap between the wire electrode and the workpiece to process the workpiece and detect disconnection of the wire electrode.
- a step of outputting a machining condition switching command so that the machining condition is reduced by a predetermined amount when the disconnection of the wire electrode is detected, machining energy and machining speed,
- a step of calculating the plate thickness based on the above, and if the plate thickness changes, the processing conditions are switched so that the processing conditions set according to the changed plate thickness are satisfied.
- the present invention since it is possible to automatically acquire the disconnection threshold value and appropriate machining conditions for each plate thickness in the trial machining process, it is possible to automate the setting of the machining conditions.
- the development man-hours can be reduced with the automation of the machining condition setting. Further, as a result of the reduction of the development man-hour, the time required for the entire processing can be shortened. Furthermore, since the processing is performed using the disconnection threshold value for each plate thickness obtained by the trial processing and an appropriate processing condition in the main processing, the processing productivity can be improved.
- FIG. 2 is a block diagram illustrating a configuration of an oscillator 4 in FIG. 1. It is a figure for demonstrating adjustment of the disconnection threshold value at the time of trial processing and processing conditions in Embodiment 1 of this invention. It is a flowchart which shows the procedure which adjusts the disconnection threshold value and processing conditions at the time of trial processing in Embodiment 1 of this invention. It is a block diagram for demonstrating the operation
- FIG. 1 is a block diagram illustrating the entire apparatus of the wire electric discharge machining apparatus according to Embodiment 1 of the present invention, and is a block diagram for explaining an operation during trial machining.
- FIG. 2 is a block diagram showing the configuration of the oscillator in FIG. A pair of power supply 3 connected to the processing power source 2 is in contact with the wire electrode 1. The machining power supply 2 applies a pulse voltage to the power supply 3 according to the oscillation output of the oscillation means 41 of the oscillator 4.
- the workpiece 5 is placed on the workpiece table 6, and machining is performed by generating electric discharge in the machining gap between the workpiece 5 and the wire electrode 1.
- the wire electrode 1 is moved at a predetermined speed with respect to the workpiece 5 by a servo motor 8 driven by a servo amplifier 7.
- the control means 11 controls the oscillation means 41 with an oscillation command corresponding to a desired machining condition and controls the servo amplifier 7 with an axis feed command according to the machining conditions input by the machining condition input means 10. .
- the oscillator 4 counts the number of discharge pulses generated in the machining gap for each predetermined period by the discharge pulse counting means 42 and outputs it to the NC device 9. Further, the oscillator 4 measures the machining state quantity by the machining state quantity measuring means 43 and outputs it to the NC device 9.
- the processing state quantity indicates, for example, a discharge current, a discharge voltage, a no-load time, or the number of discharge pulses.
- the processing state quantity measuring means 43 corresponding to these is, for example, a current sensor, a voltage sensor, a counter, or the like.
- the servo amplifier 7 outputs a position feedback value in a linear scale (not shown) to the NC device 9.
- the NC device 9 and its surrounding blocks will be described.
- the machining energy calculation unit 12 calculates the machining energy from the number of discharge pulses input from the oscillator 4.
- the machining speed measuring means 13 measures the machining speed from a position feedback value that is position information input from the servo amplifier 7.
- the plate thickness calculating means 14 calculates the plate thickness of the workpiece 5 from the processing energy and the processing speed.
- the disconnection sign signal calculating means 15 calculates and outputs a disconnection sign signal based on the machining state quantity input from the oscillator 4.
- the disconnection threshold value setting means 16 sets and outputs a disconnection threshold value.
- the disconnection sign detection means 17 compares the disconnection sign signal with the disconnection threshold value, and outputs a machining condition reset command and a disconnection threshold reset command.
- the disconnection detection means 18 is provided in a feed motor (not shown) of the wire electrode 1 to detect whether or not the wire electrode 1 is disconnected, and outputs a disconnection detection signal that is a disconnection signal when the wire electrode 1 is disconnected.
- the machining condition switching unit 19 sends a machining condition switching command to the control unit 11 according to a predetermined algorithm using a machining condition reset command and a disconnection signal for each plate thickness of the workpiece. Further, the machining conditions and the disconnection threshold corresponding to the plate thickness in this case are stored in the processing condition storage means 20 and the disconnection threshold storage means 21, respectively.
- FIG. 3 is a diagram for explaining the adjustment of the disconnection threshold value and the processing conditions in the trial processing step of the workpiece 5 whose thickness does not change.
- the horizontal axis indicates time, and the vertical axis indicates a disconnection predictor signal.
- machining condition 1 is set as an initial value
- threshold value 1 is set as an initial value of the disconnection threshold value.
- the value of the disconnection sign signal under the machining condition 1 is smaller than the threshold value 1 from FIG. Therefore, it is determined that there is no possibility of disconnection, and the machining condition is switched to the machining condition 2 having a large energy by one step.
- switching is performed using a step-type changeover switch called a notch. That is, the machining condition 1 is switched to the machining condition 2 by switching the set value of the notch. Specifically, by changing the set value of the notch, the peak value of the discharge current and the discharge pulse frequency are increased to increase the machining energy.
- the disconnection predictor signal is increased when the processing condition 2 is switched, the disconnection predictor signal of the processing condition 2 is still smaller than the threshold value 1, so that it is determined that there is no possibility of disconnection. Then, the machining condition 3 with a larger machining energy is switched by one step.
- the machining condition 3 is switched from FIG.
- the wire electrode 1 should be disconnected if the processing is continued.
- the first embodiment will be described assuming that the wire electrode 1 is not disconnected. Since the wire electrode 1 is not disconnected, it is determined that the threshold 1 is not a true disconnection threshold. Therefore, the disconnection threshold value is changed to a threshold value 2 that is larger than the disconnection sign signal of the processing condition 3. Since the disconnection threshold value is changed to the threshold value 2, the disconnection sign signal becomes smaller than the threshold value 2, so that it is determined that there is no danger of disconnection. Then, the machining condition 4 with a larger machining energy is switched by one more stage. In the first embodiment, it is assumed that the wire electrode 1 is disconnected as a result of the processing condition 4.
- the machining energy is larger than the machining condition 3 but is switched to the machining condition 5 smaller than the machining condition 4. That is, for example, the machining condition 5 is set by a notch intermediate between the machining condition 3 and the machining condition 4. If it is assumed that there is no disconnection under the processing condition 5, the disconnection threshold value is changed to a threshold value 3 that is larger than the disconnection sign signal under the processing condition 5.
- the disconnection threshold value approaches the true disconnection threshold value, and the processing condition also approaches an appropriate processing condition.
- the processing is completed within an appropriate time by terminating the processing when the adjustment range of the disconnection threshold is smaller than a predetermined value.
- the process may be performed under a condition for ending the process.
- the thickness of the workpiece 5 does not change during the trial machining.
- the thickness may change during the machining. Since the disconnection threshold value and the corresponding appropriate processing conditions differ for each plate thickness, the appropriate processing conditions also change when the plate thickness changes during processing. Therefore, in the first embodiment, the plate thickness is always detected during the trial machining, and when a different plate thickness is calculated, the same processing as shown in FIG. The threshold value and appropriate processing conditions are acquired.
- the disconnection threshold value and the processing condition acquired by the trial processing are stored in the disconnection threshold value storage means 21 and the processing condition storage means 20 for each plate thickness.
- the disconnection threshold value and appropriate processing conditions for each plate thickness are read from these storage means, and the workpiece 5 is processed using these conditions.
- the trial machining can automatically acquire the disconnection threshold value and appropriate machining conditions, thereby reducing the development man-hours.
- a process condition can be set automatically and productivity can be improved.
- FIG. 4 is a flowchart showing a procedure for acquiring a disconnection threshold and appropriate processing conditions in trial processing.
- the user selects trial machining by a machining mode selection unit (not shown).
- the user or manufacturer inputs the machining conditions by the machining condition input means 10 (step S1).
- the machining conditions input by the machining condition input means 10 are, for example, a discharge current value, a discharge voltage, a discharge pause time, a machining feed rate, and the like.
- the user or manufacturer inputs the disconnection threshold value by using a disconnection threshold value input unit (not shown) and sets it in the disconnection threshold value setting unit 16 (step S2), and then starts processing (step S3).
- the disconnection detection means 18 detects the presence or absence of disconnection of the wire electrode 1 by using an encoder or a sensor attached to the wire traveling system or the wire feed motor, and checks whether or not the wire electrode 1 is disconnected under the set processing conditions (step S4).
- the machining condition switching means 19 sends a switching command to the control means 11 to switch to a machining condition with energy lower than the machining conditions set in step S1 (step S5).
- the plate thickness calculating means 14 calculates the plate thickness (step S6). The method for calculating the plate thickness follows Formula (2).
- the method for obtaining the processing energy and processing speed on the right side of Equation (2) will be described below.
- the number of discharge pulses counted by the discharge pulse counting means 42 is sent to the machining energy calculating means 12.
- the machining energy calculation means 12 calculates the machining energy from the product of the number of discharge pulses and the discharge current, and sends it to the plate thickness calculation means 14.
- the processing speed is obtained by the processing speed measuring means 13. Specifically, using the position feedback value from the linear scale, the machining feed amount per unit time, that is, the machining speed, is measured and sent to the plate thickness calculation means 14.
- the plate thickness calculated by the plate thickness calculating unit 14 is sent to the processing condition switching unit 19, and the processing condition switching unit 19 determines that the processing conditions are switched when the plate thickness is different from the previously calculated plate thickness (step S7).
- the machining condition switching means 19 sends a machining condition switching command to the control means 11 and switches to the machining conditions set for each plate thickness (step S8), and then proceeds to step S9.
- step S8 is skipped and the process proceeds to step S9.
- the disconnection sign signal calculation means 15 calculates a disconnection sign signal based on the machining state quantity input from the machining state quantity measurement means 43 (step S9), and outputs it to the disconnection sign detection means 17.
- the short-circuit discharge pulse ratio disclosed in Patent Document 1 as a disconnection predictor signal calculated from the machining state quantity. That is, the machining state quantity measuring means 43 counts the number of normal discharge pulses and the number of short-circuit discharge pulses, and sends these to the disconnection predictor signal calculation means 15 as machining state quantities.
- the disconnection predictor signal calculating means 15 calculates the short-circuit discharge pulse ratio based on the number of pulses.
- the threshold for determining the wire electrode 1 disconnection sign is set by the disconnection threshold setting means 16 and sent to the disconnection sign detection means 17.
- the disconnection sign detection means 17 compares the disconnection sign signal calculated by the disconnection sign signal calculation means 15 with the disconnection threshold set in the disconnection threshold setting means 16 (step S10).
- the disconnection sign detection means 17 sends a disconnection threshold reset command to the disconnection threshold setting means 16.
- the disconnection threshold value setting means 16 resets the disconnection threshold value to a value larger by a predetermined value determined by the notch, and sends it to the disconnection sign detection means 17 (step S11).
- the disconnection sign detection unit 17 determines that there is no possibility of disconnection, and sends a machining condition reset command to the machining condition switching unit 19 to switch to a machining condition with large energy.
- the machining condition switching means 19 sends a machining condition switching command for switching to a machining condition having a large machining energy by a predetermined value determined by the notch to the control means 11 (step S12).
- the control unit 11 controls the oscillator and the servo amplifier so as to achieve a processing condition with a large processing energy
- the disconnection detection unit 18 confirms whether the wire electrode 1 is disconnected (step S13). If the wire electrode 1 is not disconnected, the process proceeds to step S16.
- step S14 the machining condition switching means 19 sends to the control means 11 a machining condition switching command for switching to a condition where the machining energy is smaller than the condition changed in step S12 (step S14).
- the condition to be switched in step S14 the energy of the condition before and after switching in step S12 or the energy at which the notch has an intermediate value is selected.
- the machining is resumed (step S15), and the process proceeds to step S16.
- step S16 the set disconnection threshold value and the processing condition are stored in the disconnection threshold value storage unit 21 and the processing condition storage unit 20 for each plate thickness calculated by the plate thickness calculation unit 14 (step S16).
- the processing from step S6 to step S16 is repeated until the trial machining is completed (step S17).
- step S6 to step S17 when the number of repetitions of step S6 to step S17 is small in the calculated plate thickness, the processing conditions switched in step S8 are not necessarily appropriate processing conditions. While the procedure from step S6 to step S16 is repeatedly performed, the processing conditions are gradually approached with respect to the calculated plate thickness.
- the plate thickness and the disconnection predictive signal can be obtained on the premise that processing is performed. Therefore, even if it is not a step that is explicitly described as determining the disconnection of the wire electrode 1, the disconnection detecting means 18 always detects the disconnection of the wire electrode 1 during processing. Then, when the wire electrode 1 is disconnected, a processing resumption process is performed.
- FIG. 5 is a block diagram showing a configuration of a wire electric discharge machining apparatus in the present machining.
- the same components as those in FIG. 1 The difference from FIG. 1 is that the machining condition input means 10 and the disconnection threshold value setting means 16 are not provided, and the paths of some block diagrams are different.
- FIG. 6 is a flowchart showing a procedure for performing the main processing using the disconnection threshold value for each plate thickness acquired by the trial processing and appropriate processing conditions.
- the user selects the main processing by a processing mode selection means (not shown).
- the control means 11 reads the initial machining conditions with reference to the machining conditions stored in the machining condition storage means 20 (step S21), and starts machining (step S22).
- the machining condition storage means 20 stores the machining conditions for each plate thickness. However, since the plate thickness is not calculated at the start of machining, the machining condition with the smallest machining energy is selected to avoid disconnection.
- the plate thickness calculating means 14 calculates the plate thickness based on the formula (2) using the machining energy output by the machining energy calculating means 12 and the machining feed amount output by the machining speed measuring means 13 ( Step S23).
- the calculated plate thickness is sent to the processing condition storage means 20. Since the processing condition storage unit 20 stores appropriate processing conditions for each plate thickness, the appropriate processing conditions are read according to the plate thickness sent from the plate thickness calculation unit 14 (step S24), and are sent to the control unit 11. Send it out.
- the control means 11 switches to the machining conditions read from the machining condition storage means 20 (step S25).
- the plate thickness calculated by the plate thickness calculation means 14 is also sent to the disconnection threshold value storage means 21.
- the disconnection threshold storage unit 21 stores a disconnection threshold for each plate thickness, reads the disconnection threshold according to the plate thickness sent from the plate thickness calculation unit 14 (step S26), and sends it to the disconnection sign detection unit 17.
- the disconnection sign signal calculation means 15 calculates a disconnection sign signal based on the machining state quantity input from the oscillator 4 (step S27) and sends it to the disconnection sign detection means 17.
- the disconnection sign detection means 17 compares the disconnection sign signal with the disconnection threshold (step S28).
- the disconnection sign detection means 17 determines that there is a possibility of disconnection, and sends a disconnection sign detection signal to the machining condition switching means 19.
- the machining condition switching means 19 sends a switching command to the control device 11 so as to switch to a machining condition whose energy is smaller than the machining conditions stored in the machining condition storage means 20 (step S29), and proceeds to step S30.
- step S30 the disconnection sign detection means 17 determines that there is no possibility of disconnection, and proceeds to step S30.
- the processing can be performed using an appropriate processing condition according to the calculated plate thickness. Furthermore, when there is a possibility of disconnection, the processing can be continued while avoiding disconnection of the wire electrode 1 by switching to a processing condition with low energy.
- processing is performed under appropriate processing conditions for each plate thickness acquired at the time of trial processing, and further control for avoiding disconnection of the wire electrode 1 is performed by detecting disconnection signs.
- the disconnection detecting means 18 detects the disconnection.
- the disconnection cause investigation means investigates whether or not the disconnection sign signal has exceeded the disconnection threshold.
- the disconnection detection means 18 sends a disconnection detection signal to the processing condition storage means 20.
- the machining condition storage means 20 again stores a machining condition having a machining energy smaller than the stored condition as a machining condition for the plate thickness.
- the disconnection detection unit 18 sends a disconnection detection signal to the disconnection threshold value storage unit 21.
- the disconnection threshold value storage means 21 again stores a threshold value smaller than the disconnection sign signal at the time of disconnection as the disconnection threshold value of the plate thickness.
- the first embodiment it is possible to automatically acquire the disconnection threshold value and the appropriate processing condition for each plate thickness in the trial processing, so that the processing condition setting can be automated. Play. Furthermore, since the processing is performed using the disconnection threshold value for each plate thickness obtained in the trial processing and an appropriate processing condition in the main processing, the processing productivity can be improved.
- the wire electrode 1 is described as being moved at a predetermined speed relative to the workpiece 5 by the servo motor 8, but this is not always necessary.
- the servo motor 8 may be configured to drive the workpiece table 6 on which the workpiece 5 is placed. That is, any means may be used as long as the wire electrode 1 and the workpiece 5 are moved relative to each other.
- the user or the manufacturer inputs the machining conditions by the machining condition input means 10, but this is not always necessary.
- a predetermined machining condition may be selected as an initial value.
- the processing condition input means 10 can be reduced.
- the plate thickness calculation means 14 calculates the plate thickness, but this is not always necessary.
- the plate thickness of the workpiece may be recognized by using a plate thickness input unit (not shown) instead of the plate thickness calculation unit 14 and reading the plate thickness from, for example, a 3D drawing created by CAD or the like.
- the plate thickness input means is not limited to the 3D drawing, and any means may be used as long as the plate thickness can be recognized. Thereby, even if it does not have the plate
- the number of normal discharge pulses and the number of short-circuit discharge pulses are counted by the machining state quantity measuring means 43 provided in the oscillator 4, and the short-circuit discharge pulse ratio is calculated by the disconnection predictor signal calculating means 15 as the disconnection predictor signal.
- the machining state quantity may be measured based on the value of the discharge voltage or the value of the discharge current. In such a case, the machining state quantity measuring means need not be provided in the oscillator 4. By adopting such a configuration, the same effect can be obtained while reducing the operation load on the oscillator 4.
- the thickness of the workpiece 5 does not change during processing, but the thickness may actually change during processing. Since the disconnection threshold value and the corresponding appropriate processing conditions differ for each plate thickness, if the plate thickness changes during processing, the appropriate processing conditions also change, and appropriate processing cannot be performed. Therefore, in the first embodiment, it is sufficient to always detect the plate thickness both during the trial processing and during the main processing. When different plate thicknesses are calculated, the same processing as shown in FIG. 3 or FIG. 6 is performed again to acquire or set the disconnection threshold value and appropriate processing conditions for the different plate thicknesses. By setting it as such a structure, even if it is a case where the plate
- the present invention can be used in a wire electric discharge machining apparatus having a function of preventing wire electrodes from being disconnected in the field of machine tools and the like.
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Abstract
Description
加工体積は加工エネルギに比例する。また通常、加工取り代はサーボ制御により一定となるよう制御される。従って式(1)を変形すれば式(2)を得ることができる。
式(2)において係数は、板厚が既知の被加工物で加工を行えば予め求めることができる。すなわち、加工エネルギと加工速度を算出すれば、式(2)の係数以外の値が既知となるので、係数を算出できる。係数を決定できれば、加工エネルギと加工速度を求めることで、式(2)から板厚を算出できる。特許文献1は、算出した板厚に応じ予め定められた適切な加工条件を切り替えるものである。
実施の形態1.
まず本実施の形態1におけるワイヤ放電加工装置の構成を図を用いて説明する。図1は本発明の実施の形態1に係るワイヤ放電加工装置の装置全体を示すブロック図であり、試し加工時の動作を説明するためのブロック図である。図2は図1における発振器の構成を示すブロック図である。ワイヤ電極1には加工電源2に接続する一対の給電子3が接触する。加工電源2は発振器4の発振手段41の発振出力に応じて給電子3にパルス電圧を印加する。被加工物5は被加工物テーブル6に載置され、ワイヤ電極1との間の加工間隙に放電を発生させることで加工が行われる。加工中、ワイヤ電極1はサーボアンプ7で駆動されるサーボモータ8により、被加工物5に対して所定の速度で移動する。
2 加工電源
3 給電子
4 発振器
5 被加工物
6 被加工物テーブル
7 サーボアンプ
8 サーボモータ
9 NC装置
10 加工条件入力手段
11 制御手段
12 加工エネルギ算出手段
13 加工速度計測手段
14 板厚算出手段
15 断線予兆信号算出手段
16 断線閾値設定手段
17 断線予兆検出手段
18 断線検出手段
19 加工条件切替手段
20 加工条件記憶手段
21 断線閾値記憶手段
41 発振手段
42 放電パルス数計数手段
43 加工状態量計測手段
Claims (9)
- ワイヤ放電加工装置の放電パルスを出力する発振器とワイヤ電極または被加工物を駆動して互いに相対移動させるサーボモータを制御するサーボアンプとを制御するワイヤ放電加工装置の数値制御装置において、
前記発振器から入力される加工状態量に基づき断線予兆信号を生成する断線予兆信号生成手段と、
前記断線予兆信号と断線閾値とに基づき加工条件再設定指令及び断線閾値再設定指令を出力する断線予兆検出手段と、
前記断線閾値再設定指令と入力される断線信号とに基づき前記断線閾値を設定する断線閾値設定手段と、
前記発振器から入力される放電パルス数に基づき加工エネルギを算出する加工エネルギ算出手段と、
前記サーボアンプから入力される位置情報に基づき加工速度を計測する加工速度計測手段と、
前記加工エネルギと前記加工速度とに基づき被加工物の板厚を算出する板厚算出手段と、
前記板厚、前記加工条件再設定指令、および前記断線信号に基づき所定のアルゴリズムに従い加工条件切替え指令を出力する加工条件切替手段と、
前記加工条件切替え指令により定まる加工条件となるよう前記発振器に発振指令を送るとともに前記サーボアンプに軸送り指令を送る制御手段と、
前記板厚に対応する前記加工条件を記憶する加工条件記憶手段と、
前記板厚に対応する断線閾値を記憶する断線閾値記憶手段と、
を備えたことを特徴とするワイヤ放電加工装置の数値制御装置。 - 前記加工状態量は正常放電パルス数及び短絡放電パルス数であり、前記断線予兆信号は短絡放電パルス比率であることを特徴とする、請求項1に記載の数値制御装置。
- 前記断線予兆検出手段は、前記断線閾値と前記断線予兆信号とを比較し、試し加工中に断線予兆信号が断線閾値を超える場合に断線閾値再設定指令を出力し、
前記断線閾値設定手段は、前記断線閾値再設定指令が入力され、かつ前記断線信号が入力されない場合に、所定量だけ大きな断線閾値を再設定することを特徴とする、請求項1に記載の数値制御装置。 - 前記断線閾値設定手段は、断線閾値再設定指令が入力されず、かつ前記断線信号が入力される場合に、所定量だけ小さな断線閾値を再設定することを特徴とする、請求項1に記載の数値制御装置。
- 前記断線予兆検出手段は、前記断線閾値と前記断線予兆信号とを比較し、試し加工中に断線予兆信号が断線閾値以内の場合に加工条件再設定指令を出力し、
前記加工条件切替手段は、前記加工条件再設定指令が入力されると所定量だけ大きな加工条件となるよう加工条件切替え指令を出力することを特徴とする、請求項1に記載の数値制御装置。 - 前記加工条件切替手段は、試し加工中に前記断線信号が入力されると、所定量だけ小さな加工条件となるよう加工条件切替え指令を出力することを特徴とする、請求項1に記載の数値制御装置。
- ワイヤ電極または被加工物を駆動して互いに相対移動させるサーボモータを制御するサーボアンプと、
前記ワイヤ電極と前記被加工物との加工間隙に電圧を印加して被加工物を加工するための加工電源に放電パルスを出力する発振器と、
所望の加工条件となるよう前記発振器及び前記サーボアンプを制御する数値制御装置と、
前記ワイヤ電極の断線を検出して断線信号を前記数値制御装置へ出力する断線検出器と
を備えるワイヤ放電加工装置において、
前記数値制御装置は、
前記発振器から入力される加工状態量に基づき断線予兆信号を生成する断線予兆信号生成手段と、
前記断線予兆信号と断線閾値とに基づき加工条件再設定指令及び断線閾値再設定指令を出力する断線予兆検出手段と、
前記断線閾値再設定指令と前記断線信号とに基づき前記断線閾値を設定する断線閾値設定手段と、
前記発振器から入力される放電パルス数に基づき加工エネルギを算出する加工エネルギ算出手段と、
前記サーボアンプから入力される位置情報に基づき加工速度を計測する加工速度計測手段と、
前記加工エネルギと前記加工速度とに基づき被加工物の板厚を算出する板厚算出手段と、
前記板厚、前記加工条件再設定指令、および前記断線信号に基づき所定のアルゴリズムに従い加工条件切替え指令を出力する加工条件切替手段と、
前記加工条件切替え指令により定まる加工条件となるよう前記発振器に発振指令を送るとともに前記サーボアンプに軸送り指令を送る制御手段と、
前記板厚に対応する前記加工条件を記憶する加工条件記憶手段と、
前記板厚に対応する断線閾値を記憶する断線閾値記憶手段と、
を備えたことを特徴とするワイヤ放電加工装置。 - 数値制御装置が所望の加工条件となるよう発振器及びサーボアンプを制御し、
前記サーボアンプはワイヤ電極又は被加工物を駆動して互いに相対移動させるサーボモータを制御し、
前記発振器は加工電源に放電パルスを出力して前記ワイヤ電極と前記被加工物との加工間隙に電圧を印加することで被加工物を加工し、
前記ワイヤ電極の断線を検出して断線信号を前記数値制御装置へ出力するワイヤ放電加工方法において、
ワイヤ電極の断線を検出すると所定量だけ小さな加工条件となるよう加工条件切替え指令を出力するステップと、
加工エネルギと加工速度とに基づき板厚を算出するステップと、
前記板厚が変化した場合は変化した板厚に応じて設定された加工条件となるよう加工条件切替え指令を出力するステップと、
加工状態量に基づき断線予兆信号を生成するステップと、
前記断線予兆信号が断線閾値より大きい場合、所定量だけ大きな断線閾値を再設定して断線閾値と加工条件を記憶するステップと、
前記断線予兆信号が断線閾値より小さい場合、所定量だけ大きな加工条件となるよう加工条件切替え指令を出力して断線閾値と加工条件を記憶するステップと、
前記加工条件切替え指令に基づき加工条件を切替えて発振器及びサーボアンプを制御するステップと、
を備えたことを特徴とするワイヤ放電加工方法。 - 数値制御装置が所望の加工条件となるよう発振器及びサーボアンプを制御し、
前記サーボアンプはワイヤ電極又は被加工物を駆動して互いに相対移動させるサーボモータを制御し、
前記発振器は加工電源に放電パルスを出力して前記ワイヤ電極と前記被加工物との加工間隙に電圧を印加することで被加工物を加工し、
前記ワイヤ電極の断線を検出して断線信号を前記数値制御装置へ出力するワイヤ放電加工方法において、
加工エネルギと加工速度とに基づき板厚を算出するステップと、
前記板厚に応じて設定された加工条件を読み出して加工条件の切替え指令を出力するステップと、
前記板厚に応じて設定された断線閾値を読み出すとともに加工状態量に基づき断線予兆信号を生成するステップと、
前記断線予兆信号が断線閾値より大きい場合、所定量だけ小さな加工条件となるよう加工条件切替え指令を出力するステップと、
前記加工条件切替え指令に基づき加工条件を切替えて発振器及びサーボアンプを制御するステップと、
を備えたことを特徴とするワイヤ放電加工方法。
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CN201080062003.8A CN102712056B (zh) | 2010-01-22 | 2010-01-22 | 数控装置、使用该装置的线电极放电加工装置以及线电极放电加工方法 |
US13/574,521 US9272349B2 (en) | 2010-01-22 | 2010-01-22 | Numerical control device, wire electric discharge machining apparatus using the same, and wire electric discharge machining method using the same |
JP2011550717A JP5460739B2 (ja) | 2010-01-22 | 2010-01-22 | 数値制御装置、これを用いたワイヤ放電加工装置、及びこれを用いたワイヤ放電加工方法 |
PCT/JP2010/000353 WO2011089648A1 (ja) | 2010-01-22 | 2010-01-22 | 数値制御装置、これを用いたワイヤ放電加工装置、及びこれを用いたワイヤ放電加工方法 |
DE112010005167T DE112010005167T5 (de) | 2010-01-22 | 2010-01-22 | Numerische-Steuerung-Vorrichtung, Drahterosionsvorrichtung, die dieselbe verwendet, und Drahterosionsverfahren, das dieselbe verwendet |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150290733A1 (en) * | 2012-10-30 | 2015-10-15 | Mitsubishi Electric Corporation | Wire electrical discharge machining apparatus, machining control device, and machining control program |
KR20200053414A (ko) * | 2018-11-08 | 2020-05-18 | 화낙 코퍼레이션 | 와이어 단선 예측 장치 |
EP3690571A1 (en) | 2019-01-31 | 2020-08-05 | Fanuc Corporation | Wire disconnection prediction device |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10030465B2 (en) * | 2012-11-15 | 2018-07-24 | Kureha Corporation | Solidification- and extrusion-molded article of polyglycolic acid and method for manufacturing same |
WO2015059875A1 (ja) * | 2013-10-24 | 2015-04-30 | パナソニックIpマネジメント株式会社 | 太陽電池モジュールの製造方法及び太陽電池モジュールの製造装置 |
DE112014006521B4 (de) * | 2014-03-27 | 2019-03-28 | Mitsubishi Electric Corporation | Steuerungsvorrichtung für eine Drahterosionsmaschine |
JP2017024114A (ja) * | 2015-07-21 | 2017-02-02 | ファナック株式会社 | 自動結線装置を備えたワイヤ放電加工機 |
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JP6760997B2 (ja) * | 2018-06-15 | 2020-09-23 | ファナック株式会社 | ワイヤ放電加工機および加工条件調整方法 |
JP6808868B1 (ja) * | 2020-03-31 | 2021-01-06 | 株式会社ソディック | ワイヤ放電加工方法およびワイヤ放電加工装置 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02212023A (ja) * | 1989-02-08 | 1990-08-23 | Makino Milling Mach Co Ltd | 放電加工方法及び装置 |
JPH08118146A (ja) * | 1994-10-25 | 1996-05-14 | Mitsubishi Electric Corp | ワイヤ放電加工機の電源制御装置 |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60255319A (ja) * | 1984-05-30 | 1985-12-17 | Mitsubishi Electric Corp | 放電加工装置におけるワイヤ断線検出方法 |
US5306889A (en) * | 1991-07-05 | 1994-04-26 | Sodick Co., Ltd. | Wire cut electrical discharge machining apparatus |
JPH0732217A (ja) * | 1993-07-20 | 1995-02-03 | Fanuc Ltd | ワイヤ放電加工機における被加工物厚さ測定装置と該測定装置を使用した加工条件変更方法 |
JP3662677B2 (ja) | 1996-07-15 | 2005-06-22 | 三菱電機株式会社 | ワイヤ放電加工機およびワイヤ放電加工方法 |
US6781080B1 (en) * | 2000-10-20 | 2004-08-24 | Mitsubishi Denki Kabushiki Kaisha | Wire electric discharge machine with stored discharge energy threshold function |
DE112006000074T8 (de) * | 2005-09-15 | 2009-03-19 | Mitsubishi Electric Corp. | Elektrische Drahterodier-Bearbeitungsvorrichtung und elektrisches Drahterodier-Bearbeitungsverfahren |
JP4294638B2 (ja) * | 2005-11-29 | 2009-07-15 | 株式会社ソディック | ワイヤカット放電加工方法および数値制御ワイヤカット放電加工装置 |
JP4795282B2 (ja) | 2006-07-11 | 2011-10-19 | 三菱電機株式会社 | 加工条件探索装置 |
US7792605B2 (en) * | 2006-07-26 | 2010-09-07 | Mitsubishi Electric Corporation | Numerical control apparatus |
US7928337B2 (en) * | 2006-10-24 | 2011-04-19 | Mitsubishi Electric Corporation | Apparatus for machining a workpiece using wire discharge including an upper and lower power supply unit |
-
2010
- 2010-01-22 CN CN201080062003.8A patent/CN102712056B/zh not_active Expired - Fee Related
- 2010-01-22 US US13/574,521 patent/US9272349B2/en not_active Expired - Fee Related
- 2010-01-22 WO PCT/JP2010/000353 patent/WO2011089648A1/ja active Application Filing
- 2010-01-22 JP JP2011550717A patent/JP5460739B2/ja active Active
- 2010-01-22 DE DE112010005167T patent/DE112010005167T5/de not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH02212023A (ja) * | 1989-02-08 | 1990-08-23 | Makino Milling Mach Co Ltd | 放電加工方法及び装置 |
JPH08118146A (ja) * | 1994-10-25 | 1996-05-14 | Mitsubishi Electric Corp | ワイヤ放電加工機の電源制御装置 |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150290733A1 (en) * | 2012-10-30 | 2015-10-15 | Mitsubishi Electric Corporation | Wire electrical discharge machining apparatus, machining control device, and machining control program |
KR20200053414A (ko) * | 2018-11-08 | 2020-05-18 | 화낙 코퍼레이션 | 와이어 단선 예측 장치 |
EP3653327A1 (en) | 2018-11-08 | 2020-05-20 | Fanuc Corporation | Wire disconnection prediction device |
JP2020075321A (ja) * | 2018-11-08 | 2020-05-21 | ファナック株式会社 | ワイヤ断線予測装置 |
US11630440B2 (en) | 2018-11-08 | 2023-04-18 | Fanuc Corporation | Wire disconnection prediction device |
KR102526225B1 (ko) * | 2018-11-08 | 2023-04-26 | 화낙 코퍼레이션 | 와이어 단선 예측 장치 |
EP3690571A1 (en) | 2019-01-31 | 2020-08-05 | Fanuc Corporation | Wire disconnection prediction device |
KR20200095396A (ko) * | 2019-01-31 | 2020-08-10 | 화낙 코퍼레이션 | 와이어 단선 예측 장치 |
US11471965B2 (en) | 2019-01-31 | 2022-10-18 | Fanuc Corporation | Wire disconnection prediction device |
KR102482512B1 (ko) | 2019-01-31 | 2022-12-28 | 화낙 코퍼레이션 | 와이어 단선 예측 장치 |
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