JP2009178781A - Radiation oscillation working method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation oscillation working method which makes angle transfer precision of working shape even by reducing one-sided consumption of each of angular parts of a pyramidal electrode during the time until an electrode reaches an instructed working position. <P>SOLUTION: In the radiation oscillation working method, the electrode with a reduced size of an angular hole is relatively moved from the radiation oscillation center toward the bottoms of a plurality of angular parts so as to go along the ridge lines of the pyramids while controlling the gap between the electrode and a workpiece, to thereby perform an electric discharge machining. The method includes: a small cyclic oscillation working step of circulatingly and oscillatingly working respective parts of the plurality of angular parts in a prescribed order until the electrode reaches a prescribed working progress amount smaller than an instructed working depth and an instructed radiation oscillation amount; and a step of repeating the small cyclic oscillation working step until the electrode reaches the instructed working depth and the instructed radiation oscillation amount or until the instructed working time comes. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In order to finish a square hole having a plurality of corners on a workpiece by a numerically controlled electric discharge machine, a reduction electrode having a shape similar to that of a square hole is provided at the bottom of a plurality of corners from a radial oscillation center. The present invention relates to a radial oscillating machining method in which an electric discharge machining is performed by relatively moving the gap between an electrode and a workpiece along a ridge line of a pyramid toward the surface.

  2. Description of the Related Art Conventionally, in a numerically controlled electric discharge machine having an oscillating function, oscillating means that performs an orbiting motion or a radiating motion at a predetermined speed within a fixed oscillating surface, and the orbiting or radiating motion within the oscillating surface. Independently, there is provided a swinging gap control means for controlling the gap between the electrode and the workpiece.

  The numerically controlled electric discharge machine includes a swing shape dividing unit that divides a swing final target shape into a plurality of pieces, an individual arrival determination unit that determines whether or not the final target shape has been reached for each divided shape, Rocking determination means for ending rocking when it is determined that all the divided shapes have reached the final target shape.

  The swing machining method by the electric discharge machine described above is such that, after the constant speed swing at the rough machining electrode + the gap control feed in the depth direction, the finish electrode performs the truncated cone swing, Promotion of sludge discharge by agitation, prevention of concentrated discharge, and improvement of the surface roughness of the side surfaces (for example, see Patent Document 1).

JP-A-10-166224

  However, according to the above-described conventional technique, in finishing processing, when the processing end is determined after reaching the command processing position, the end determination for each divided swing region and the determination of whether to move to the next divided shape are performed. However, no processing is performed to make the wear of each corner and each side of the electrode uniform until the command machining position is reached. Therefore, by repeating the same swinging, there is a problem that the electrode wear bias is generated at the corner, the electrode wear bias is transferred to the final processed shape, and the shape accuracy of the corner of the final processed shape is deteriorated. In addition, there is a similar problem in time cutting for ensuring surface roughness.

  The present invention has been made in view of the above, and reduces the uneven consumption of each corner of the prismatic electrode until the command machining position is reached, and radiation that makes the angular transfer accuracy of the machined shape uniform. The object is to obtain a swing machining method.

  In order to solve the above-described problems and achieve the object, the present invention provides a method for finishing a square hole having a plurality of corners on a workpiece, and reducing the reduction electrode of the square hole from the radial oscillation center. In the radial rocking machining method in which electric discharge machining is performed by controlling the gap between the electrode and the workpiece along the pyramid ridge line toward the bottom of a plurality of corners, and performing electric discharge machining, from the command machining depth and the commanded radiation fluctuation amount A small orbital oscillating machining step in which each of the plurality of corners is orbitally oscillated in a predetermined order until a small predetermined machining progress amount is achieved, and the small orbital oscillating machining step includes the command machining depth and the command And a step of repeating a plurality of times until the amount of radiation fluctuation is reached or the command processing time comes.

  According to this invention, until reaching the command machining position, there is an effect that it is possible to reduce uneven wear of each corner of the prismatic electrode and make the angular transfer accuracy of the machined shape uniform. In addition, it is possible to reduce unevenness of wear at each corner at an arbitrary time during processing, and to make the processing progress uniform, so that the corner transfer accuracy can also be achieved in time cut processing to ensure surface roughness. Can be secured.

  Embodiments of a radial rocking machining method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1-1 is a cross-sectional view showing a state in the process of finishing a square hole in a workpiece with a square columnar reduction electrode by the radial oscillation processing method according to the present invention, and FIG. FIG. 2 is a longitudinal sectional view showing the same state as FIG. 1-1, FIG. 2 is a perspective view conceptually showing a radial rocking machining method according to the present invention, and FIG. FIG. 3-2 to FIG. 3-5 are diagrams illustrating the order of the small radial oscillation processing of the first round to the 4th (0) round, respectively. 4 is a functional block diagram of the numerically controlled electric discharge machine according to the first embodiment for carrying out the radial rocking machining method according to the present invention, and FIG. 5 is a numerically controlled electric discharge machine according to the first embodiment. It is a flowchart which shows small radiation fluctuation control operation | movement.

  As shown in FIGS. 1-1 and 1-2, the radial rocking machining method of the present invention is a square hole (in this embodiment, a square hole) 15 having a plurality of corner portions 11, 12, 13, 14. In order to finish the workpiece 10 into a workpiece 10, a prismatic (square prism) -shaped reduction electrode 20 similar to the square hole 15 is provided from the radial oscillation center 25 to the bottom of the plurality of corner portions 11 to 14 (command processing depth). This is a machining method in which electric discharge machining is performed by relatively moving the pyramids (quadrangular pyramids) 30 shown in FIG. 2 along the respective ridgelines 31 to 34 toward the bottoms 11A to 14A.

  In this case, as a characteristic processing method of the present invention, the reduction electrode 20 is relatively moved along the ridgeline of the quadrangular pyramid from the radial oscillation center 25 toward the bottoms 11A to 14A of the respective corners 11 to 14. Rather than having the bottoms 11A to 14A reached and finishing the square holes by a total of four continuous electrical discharge machinings, a plurality of machinings to the bottoms 11A to 14A of the respective corners 11 to 14 are performed. Divide it into times.

  Further, a predetermined machining progress amount (vector value) smaller than each of the combined vectors of the command machining depth 36 and the command radiation fluctuation amounts 31A, 32A, 33A, and 34A for performing the finishing machining for removing the finishing machining allowance 1A is reached. Each of the plurality of corner portions 11 to 14 is circularly processed in a predetermined order (small circular oscillation processing step).

  That is, as shown in FIGS. 2 and 3-1 to 3-5, in the first round small-turn swing machining step, in the order of radial direction 1 → radial direction 3 → radial direction 2 → radial direction 4, Each of them is rounded until the amount of progress is reached. In the first round small-swing oscillating machining step, the machining in the radial directions 2 and 4 is the machining of the surfaces already removed except for the vicinity of the corner portions 12 and 14 by the machining in the radial directions 1 and 3. There is a tendency that the machining advance amount becomes larger than those in the radial directions 1 and 3.

  Next, in the small-round swing machining step of the second round, the round machining is performed in the order of the radial direction 2 → radial direction 4 → radial direction 3 → radial direction 1 until the machining progress amount is reached. In the second round small orbital oscillating machining step, the machining in the radial directions 3 and 1 is the machining of the surfaces already removed except for the vicinity of the corners 11 and 13 by the machining in the radial directions 2 and 4. There is a tendency that the machining advance amount becomes larger than the radial directions 2 and 4, and the unbalance of the machining advance amount generated in the small-turn swing machining step in the first round is eliminated in the small-turn swing machining step in the second week. be able to. In addition, it is possible to eliminate unevenness of wear at each corner of the prismatic reduction electrode 20 and make the angular transfer accuracy of the processed shape uniform. In the third and fourth laps, the circular machining is performed in the order shown in FIGS. 3-1, 3-4, and 3-5, and the small circular oscillation machining step is performed with the command machining depth 36 and the command radial oscillation. Repeat several times until the amount of movement 31A, 32A, 33A, 34A is reached or the command machining time is reached.

  Thus, in the radial rocking machining method of the present invention, each of the plurality of corner portions 11 to 14 of the square hole 15 reaches the predetermined machining progress amount smaller than the command machining depth 36 and the commanded radiation rocking amounts 31A to 34A. A small orbital oscillating machining step in which the oscillating machining is performed in a predetermined order, and this small orbital oscillating machining step reaches the command machining depth 36 and the command radial oscillation amounts 31A to 34A or the command machining time comes. Until the command machining position 36, 31A to 34A is reached, the uneven consumption of each corner of the prismatic reduction electrode 20 is eliminated, and the angular transfer accuracy of the machining shape is improved. It can be made uniform.

  Next, with reference to FIG. 4, the numerically controlled electric discharge machine according to the first embodiment for carrying out the radial rocking machining method according to the present invention will be described. As shown in FIG. 4, the NC program interpretation unit 41 includes an NC program memory in which an NC program used for machining is stored. The NC program interpretation unit 41 reads and interprets the NC program from the NC program memory, and the radiation fluctuation pattern such as a triangular hole, a square hole, and a hexagonal hole selected and commanded by the operator from the radiation fluctuation pattern memory 42, and Then, the command machining depth 36 selected by the operator from the machining command position memory 43 and the commanded radiation fluctuation amounts 31A, 32A, 33A, 34A in the respective radial directions are sent to the interpolation processing unit 44, and further, the radiation fluctuations are transmitted. A pattern, a swing speed, and the like are sent to the swing control unit 51, and processing conditions are sent to the discharge control unit 46.

  The NC program interpretation unit 11 also includes the material of the workpiece 10 and the electrode 20 selected and input by the operator, along with the radiation fluctuation pattern, the command machining depth 36, and the command radiation fluctuation amounts 31A, 32A, 33A, 34A in the respective radial directions. Are sent to the processing progress amount management unit 52.

  The discharge control unit 46 applies a discharge voltage to the discharge gap between the electrode 20 and the workpiece 10 based on the machining conditions sent from the NC program interpretation unit 41 to generate a discharge (not shown). Command.

  The machining progress amount management unit 52 is a machining progress amount parameter of small-circulation swing machining smaller than the command machining depth 36 and the command radial swing amounts 31A, 32A, 33A, 34A of the respective corner portions 11 to 14 of the square hole 15. Is stored. As the machining progress amount parameters, the machining advance amount (vector amount) in each radial direction toward the bottom 11A to 14A of each corner 11 to 14, the machining time (time during which the machining advance amount can be substantially achieved), the number of effective discharge pulses Any one of (the number of effective discharge pulses that can substantially achieve the machining progress amount) is selected and used by the operator.

  This machining progress parameter is determined by the electric discharge machine manufacturer on the basis of various machining conditions, workpiece and electrode materials, electrode shape, machining area, etc. The amount of processing progress is possible. For example, as the machining time parameter, a plurality of appropriate machining progress amounts of about 1 second to 3 minutes are stored in the parameter table in accordance with the above-described conditions. Based on the machining information sent from the NC program interpretation unit 11, an appropriate machining progress amount (for example, time 1 minute) is selected and determined and sent to the radial direction switching determination unit 54.

  The machining progress amount monitor unit 53 monitors the actual machining progress amount by the electrode, and sends the monitored machining progress amount (for example, the elapsed machining time) to the radial direction switching determination unit 54. The radial direction switching determination unit 54 compares the appropriate processing progress amount sent from the processing progress amount management unit 52 with the actual processing progress amount sent from the processing progress amount monitor unit 53, and the actual processing progress amount is determined. When an appropriate machining progress amount is reached, an arrival determination signal is sent to the next radiation direction determination unit 56.

  The machining progress amount monitoring unit 53 monitors the machining progress amount if the machining progress amount is the machining advance amount, monitors the machining time if the machining time is the machining time, and monitors the pulse number if the number of effective discharge pulses. Usually, the processing time is used as the processing progress amount.

  The radiation order management unit 55 stores a management table of the order of the radial oscillation direction in each small-round oscillation processing of a square hole as shown in FIG. As an example, in the small round swing machining of a square hole, as shown in FIG. 3-2, in the first round, 1, 3, 2, 4 so as to protrude diagonally toward the bottom of each corner. Commands to perform radial rocking in order. In the 2nd to 4th laps, a command is given to perform the radial rocking process in the order shown in FIGS. 3-3 to 3-5.

  When the arrival determination signal described above is input, the next radiation direction determination unit 56 reads the next radiation fluctuation direction in the small-circulation rocking process from the radiation order management unit 55 and determines the next radiation fluctuation direction. To the swing control unit 51. The swing control unit 51 sends a predetermined small radiation swing command to the servo control unit 15 based on the radiation swing direction signal from the next radiation direction determination unit 56 and the processing progress amount signal from the processing progress amount management unit 52. To send.

  The interpolation processing unit 44 uses the command processing depth 36 from the NC program interpretation unit 41, the command radial fluctuation amounts 31A, 32A, 33A, 34A in each radial direction, and the processing progress amount signal from the processing progress amount management unit 52. Based on this, a predetermined small machining depth command is sent to the servo control unit 45.

  The servo control unit 45 controls the X, Y, and Z axis servo motors (not shown) based on the small radiation swing command from the swing control unit 51 and the small machining depth command from the interpolation processing unit 44, A reduction electrode 20 similar in shape to the square hole 15 is subjected to electrical discharge finishing until a predetermined amount of machining progresses along the ridge line of the pyramid from the radial oscillation center 25 toward the bottom of one corner of the square hole 15. When the amount of progress is reached, the electrode is returned to the radial oscillation center 25.

  The machining progress amount monitoring unit 53 monitors the above-described machining progress amount, sends the monitored machining progress amount to the radial direction switching determination unit 54, and the radial direction switching determination unit 54 includes the machining progress amount management unit. The appropriate machining progress amount sent from 52 and the actual machining progress amount sent from the machining progress monitor unit 53 are compared, and the actual machining progress amount has reached the appropriate machining progress amount. The determination signal is sent to the next radiation direction determination unit 56, and when the arrival determination signal is input, the next radiation direction determination unit 56 determines the next radiation fluctuation direction in the small-turn oscillation processing from the radiation order management unit 55. Read, determine the next oscillating direction of radiation, and send to the oscillating control unit 51. In this way, the small-round swing machining step is repeated until the command machining depth 36 and the commanded radiation swing amounts 31A to 34A are reached.

  On the other hand, when the operator selects and inputs a command machining time (for example, 10 minutes) from the machining time management unit 57, the time-out determining unit 58 counts the machining time from the start of machining, and when the command machining time has elapsed, A stop command is sent to the swing control unit 51, and the electric discharge machining is stopped even if the command machining depth 36 and the command radiation swing amounts 31A to 34A have not been reached. At this time, when one small-turn swing machining step is in the middle of the process, if one small-turn step is completed and then stopped, a square hole with a small unbalanced machining residue can be obtained.

  Oscillation control unit 51, processing progress amount management unit 52, processing progress amount monitor unit 53, radial direction switching determination unit 54, radial order management unit 55, next radial direction determination unit 56, processing time management unit 57, and time cut determination unit 58 constitutes the small-turn swing control unit 50.

  Next, with reference to FIG. 5, the small-turn swing control operation by the small-turn swing control unit 50 will be described. When the radial oscillating machining is started, a machining progress amount (for example, a machining time of 1 minute) in which the deviation of the consumption amount of the electrode can be substantially ignored is determined in step S11. Next, it progresses to step S12 and the radial rocking | swiveling direction n = 1 is set.

  Next, the process proceeds to step S13, and the order of the radial rocking direction in the current small-turn rocking process is determined. Next, it progresses to step S14 and performs the electric discharge machining to the nth radial rocking | fluctuation direction of this small circumference rocking | fluctuation machining. Next, it progresses to step S15 and it is determined whether it reached | attained the command processing position in the radial rocking direction currently processed. If step S15 is affirmed, the machining is stopped, the process proceeds to step S17, the radial rocking direction n = n + 1 is set, the process returns to step S14, and this time the small-round rocking machining is performed in the (n + 1) th radial rocking direction. Perform electrical discharge machining.

  When step S15 is denied, it progresses to step S16 and it is determined whether the predetermined process progress amount was processed in the radial direction currently processed. If not, it returns to step S14 and continues electric discharge machining.

  If step S16 is affirmed, the process proceeds to step S18, where it is determined whether or not a predetermined machining progress amount of machining has been completed in all radial rocking directions of the current small-turn rocking machining. If not, the process proceeds to step S17, the radial rocking direction n = n + 1 is set, and the process returns to step S14 to perform electric discharge machining in the n + 1th radial rocking direction of the current small-turn rocking process.

  Steps S14 to S18 are repeated, and when processing of a predetermined machining progress amount is completed in all the radial swing directions of the small-turn swing processing this time and step S18 is affirmed, the process proceeds to step S19, and the command processing time has elapsed. Determine whether or not.

  If step S19 is affirmed, the processing is terminated. If step S19 is negative, the process proceeds to step S20, and it is determined whether or not the command machining position has been reached in all radial swing directions. If not, the process proceeds to step S21, the number of small turns +1 is set, the process returns to step S12, and the process proceeds to the next small turn swing machining step.

  Steps S12 to S21 are repeated, and when the command processing position is reached in all radial swing directions, and step S20 is affirmed, the processing ends.

  As described above, the radial rocking machining method according to the first embodiment is configured so that a square hole 15 such as a triangle, a quadrangle, or a hexagon having a plurality of corner portions 11 to 14 is finished on the workpiece 10. The prismatic reduction electrode 20 having a shape similar to that of the hole 15 is arranged along the ridge lines 31 to 34 of the pyramid 30 from the radial oscillation center 25 toward the bottoms 11A to 14A of the plurality of corners 11 to 14 of the square hole 15. In the radial rocking machining method in which electrical discharge machining is performed relative to the plurality of corner portions 11 to 14 until reaching a predetermined machining progress amount smaller than the final finishing command machining depth 36 and the final finishing command radial rocking amounts 31A to 34A. A small orbital oscillating machining step that circulates orbits each in a predetermined order, and whether this small orbital oscillating machining step reaches the final finishing command machining depth 36 and the final finishing command radiation oscillating amounts 31A to 34A. Or command processing time Repeating steps a plurality of times until, characterized in that it comprises a.

  According to the above-described radial rocking machining method, in the radial rocking machining for improving the shape accuracy of the corner portions 11 to 14 of the square hole 15, the radial rocking direction is determined while switching the radial rocking direction for each predetermined amount of machining progress. By proceeding with the small-circulation swinging process in the same order, the consumption amount of each corner of the prismatic electrode 20 can be minimized and uniform in the same small-circulation. Therefore, it is possible to make the transfer accuracy of the corner portions 11 to 14 existing in the square hole 15 to be finished uniform.

  Further, even when the machining is stopped at an arbitrary time during the finishing of the square hole 15, the consumption amount of each corner portion of the prismatic electrode 20 in each radial oscillation direction is uniform, so that the electrode consumption is particularly significant. In the time cut processing for securing the surface roughness in the finishing process with a large amount, both the surface roughness and the shape accuracy of the corners can be ensured.

Embodiment 2. FIG.
FIG. 6 is a functional block diagram of the numerically controlled electric discharge machine according to the second embodiment that implements the radial oscillating machining method according to the present invention, and FIG. 7 shows the small radiation of the numerically controlled electric discharge machine according to the second embodiment. FIG. 8 is a flowchart showing a swing control operation, and FIG. 8 is a cross-sectional view showing a state in the middle of finishing a triangular hole in a workpiece with a triangular prism-shaped reduction electrode by the radial swing machining method of the second embodiment. FIG. 9 is a diagram showing the machining progress amount in each radial rocking direction in the small round rocking machining step of the triangular hole.

  With reference to FIG. 6, a numerically controlled electric discharge machine according to a second embodiment for carrying out the radial rocking machining method according to the present invention will be described. As shown in FIG. 6, the NC program interpretation unit 41 includes an NC program memory in which an NC program used for machining is stored. The NC program interpreting unit 41 reads and interprets the NC program from the NC program memory, and the operator selects and commands the radial rocking pattern memory 42, and the triangular rocking radial rocking pattern shown in FIG. The command processing depth 36 selected by the operator from the position memory 43 and the commanded radiation swing amounts 31A, 32A, 33A, etc. in the respective radial directions are sent to the interpolation processing unit 44, and the radiation swing pattern and swing speed are further transmitted. And the like are sent to the swing control unit 51, and the machining conditions are sent to the discharge control unit 46.

  The NC program interpretation unit 11 also includes the material of the workpiece 10 and the material of the electrode 20 selected and input by the operator, along with the radiation oscillation pattern, the command machining depth 36, and the command radiation oscillation amounts 31A, 32A, 33A in the respective radial directions. The electrode consumption amount and the like of the electric discharge machining conditions are sent to the machining progress amount calculation unit 52A.

  The discharge control unit 46 applies a discharge voltage to the discharge gap between the electrode 20 and the workpiece 10 based on the machining conditions sent from the NC program interpretation unit 41 to generate a discharge (not shown). Command.

  The machining progress amount calculation unit 52A stores the machining progress amount parameters of the small-round swing machining smaller than the command machining depth 36 and the command radial swing amounts 31A, 32A, and 33A of the respective corner portions 11 to 13 of the square hole 15. is doing. As the machining progress parameter, the operator selects and uses either the machining time in each radial direction toward the bottom 11A to 13A of each corner 11 to 13 or the number of effective discharge pulses.

  This machining progress parameter is determined by the electric discharge machine manufacturer on the basis of various machining conditions, workpiece and electrode materials, electrode shape, machining area, etc. The amount of processing progress is possible. For example, as the machining time parameter, a plurality of appropriate machining progress amounts of about 1 second to 3 minutes are stored in the parameter table in accordance with the above-described conditions. Based on the machining information sent from the NC program interpretation unit 11, an appropriate machining progress amount (for example, time 1 minute) is selected and determined and sent to the radial direction switching determination unit 54.

  The processing progress amount monitoring unit 53 monitors the actual processing progress amount by the electrode and sends the monitored processing progress amount to the radial direction switching determination unit 54. The radial direction switching determination unit 54 compares the appropriate machining progress amount sent from the machining progress amount calculation unit 52A with the actual machining progress amount sent from the machining progress amount monitor unit 53, and the actual machining progress amount is determined. When an appropriate machining progress amount is reached, an arrival determination signal is sent to the next radiation direction determination unit 56.

  The machining progress amount monitoring unit 53 monitors the machining time if the machining progress amount is the machining time, monitors the number of pulses if the machining progress amount is the number of effective discharge pulses, and also monitors the machining progress amount. Usually, the processing time is used as the processing progress amount.

  The radiation order calculation unit 55A stores a management table for the order of the radiation swing direction in each small-turn swing processing of a square hole as shown in FIG. In the small round swing machining of the triangular hole, in the first round, for example, a command is given to perform the radial swing machining in the order of the corner portions 11, 13, and 12 shown in FIG. In the second round, a command is given to perform radial rocking processing in the order of corners 12, 13, and 11 shown in FIG. In the third and fourth laps, a command is given to perform radial rocking in the same order as in the first and second laps.

  When the arrival determination signal described above is input, the next radiation direction determination unit 56 reads out the next radiation fluctuation direction in the small turn oscillation processing from the radiation order calculation unit 55A, and determines the next radiation fluctuation direction. To the swing control unit 51. The swing control unit 51 sends a predetermined small radial swing command to the servo control unit 15 based on the radiation swing direction signal from the next radiation direction determination unit 56 and the processing progress amount signal from the processing progress amount calculation unit 52A. To send.

  The interpolation processing unit 44 is based on the command processing depth 36 from the NC program interpreting unit 41, the command radiation fluctuation amounts 31A, 32A, 33A in the respective radial directions, and the processing progress amount signal from the processing progress amount calculating unit 52. A predetermined small machining depth command is sent to the servo control unit 45.

  The servo control unit 45 controls the X, Y, and Z axis servo motors (not shown) based on the small radiation swing command from the swing control unit 51 and the small machining depth command from the interpolation processing unit 44, A reduction electrode 20 having a shape similar to that of the square hole 15 is subjected to an electric discharge finishing process up to a predetermined machining progress amount along the ridgeline of the pyramid from the radial oscillation center 25 toward the bottom of one corner of the triangular hole 15. When the amount of progress is reached, the electrode is returned to the radial oscillation center 25.

  The machining progress amount monitor unit 53 monitors the above-described machining progress amount, sends the monitored machining progress amount to the radial direction switching determination unit 54, and the radial direction switching determination unit 54 starts from the machining progress amount calculation unit 52A. The appropriate machining progress amount sent and the actual machining progress amount sent from the machining progress amount monitor unit 53 are compared, and the actual machining progress amount has reached the appropriate machining progress amount, so an arrival determination signal Is transmitted to the next radiation direction determination unit 56, and when the arrival determination signal is input, the next radiation direction determination unit 56 reads the next radiation oscillation direction in the small-circulation oscillation processing from the radiation sequence calculation unit 55A, The next radiation swing direction is determined and sent to the swing control unit 51.

  In this way, when the current small-turn swing machining step is completed and the processing in all the radial swing directions is finished, as shown in an exaggerated manner in FIG. 9, the processing proceeds at each of the corner portions 11 to 13. The amount is different. The difference in machining advance amount in the processing of the unequal side triangle in the second embodiment is mainly due to the difference in the amount of radial oscillation in each radial direction of the unequal side triangle and the machining amount (take amount) of the workpiece per machining advance amount. It is. That is, since the corner portion 11 which is an acute angle has a large amount of machining (amount of machining) of the workpiece per the amount of radial oscillation and the amount of machining advance, the amount of machining advance becomes small.

  The machining progress amount monitoring unit 53 monitors the above-described machining progress amount and also monitors the machining progress amount, and when the current small-turn swing machining step is completed, the machining progress amount in each radial direction is It is sent to the processing progress amount storage unit 59 at the time of switching the radial direction, and the processing progress amount in each radial direction is stored.

  When proceeding to the next small-round swing machining step, the machining progress amount storage unit 59 sends the stored machining progress amounts in the respective radial directions to the radiation sequence calculation unit 55A and the machining progress amount calculation unit 52A, so that the radiation sequence calculation is performed. In the section 55A, the order of the radial oscillation direction is determined based on the difference in the machining progress amount in each radial direction. That is, in the next small orbital oscillating machining step, the machining is performed first from the radial direction in which the machining advance amount is large (for the same reason as in the first embodiment). If the processing amount per processing direction in each radial direction differs depending on the shape of the electrode, for example, if the processing progress amount is non-uniform during processing, by appropriately switching the radial oscillation direction sequence, The amount of processing advance can be made uniform.

  The processing progress amount calculation unit 52A also determines the processing progress amount in each radial direction based on the difference in the processing progress amount in each radial direction. That is, in the next small-round swing machining step, the machining progress amount in the radial direction with a small machining advance amount is increased. When unevenness occurs in the processing progress amount during processing, the processing progress amount can be made uniform by appropriately increasing or decreasing the processing progress amount in each radial oscillation direction. In this way, the small-round swing machining step is repeated until the command machining depth 36 and the commanded radiation swing amounts 31A to 34A are reached.

  On the other hand, when the operator selects and inputs a command machining time (for example, 10 minutes) from the machining time management unit 57, the time-out determining unit 58 counts the machining time from the start of machining, and when the command machining time has elapsed, A stop command is sent to the swing control unit 51, and the electric discharge machining is stopped even if the command machining depth 36 and the command radiation swing amounts 31A to 34A have not been reached. At this time, when one small-turn swing machining step is in the middle of the process, if one small-turn step is completed and then stopped, a square hole with a small unbalanced machining residue can be obtained.

  Oscillation control unit 51, processing progress amount calculation unit 52A, processing progress amount monitor unit 53, radial direction switching determination unit 54, radial order calculation unit 55A, next radial direction determination unit 56, processing time management unit 57, and time cut determination unit 58 constitutes the small orbital swing controller 50A of the second embodiment.

  Next, with reference to FIG. 7, the small-turn swing control operation by the small-turn swing control unit 50A according to the second embodiment will be described. When the radial rocking process is started, first, the radial rocking direction n = 1 is set in step S31. Next, the process proceeds to step S32, and the order of the radial rocking direction in the current small-turn rocking process is determined.

  Next, the process proceeds to step S33, and the amount of machining progress in each radial direction (for example, each machining direction is 1 minute in each radial direction) in which the deviation of the consumption amount of the electrode in the current small-turn swing machining can be ignored is determined. . Next, it progresses to step S34 and performs the electrical discharge machining to the nth radial rocking | fluctuation direction of this small-circle rocking | fluctuation machining.

  Next, it progresses to step S35 and it is determined whether it reached | attained the command processing position in the radial rocking direction currently processed. When step S35 is affirmed, the machining is stopped, the process proceeds to step S37, the radial rocking direction n = n + 1 is set, the process returns to step S34, and the process proceeds to the (n + 1) th radial rocking direction of the current small-turn rocking process. EDM is performed.

  If step S35 is negative, the process proceeds to step S36, in which it is determined whether or not a predetermined machining progress amount (machining time of 1 minute) has been machined in the currently processed radial direction. If not, the process returns to step S34 to continue the electric discharge machining.

  If step S36 is affirmed, the process proceeds to step S38, and it is determined whether or not the machining of a predetermined machining progress amount has been completed in all the radial rocking directions of the current small-turn rocking machining. If not, the process proceeds to step S37, the radial rocking direction n = n + 1 is set, and the process returns to step S34 to perform electric discharge machining in the n + 1th radial rocking direction of the current small-turn rocking process.

  Steps S34 to S38 are repeated, and when processing of a predetermined processing progress amount is completed in all the radial swing directions of the current small-turn swing processing, and step S38 is affirmed, the process proceeds to step S39, and this small-turn swing is performed. The machining advance amount (actual machining distance) in each radial oscillation direction of the oscillation processing is stored. Next, it progresses to step S40 and it is determined whether the command processing time passed.

  If step S40 is affirmed, the processing is terminated. If step S40 is negative, the process proceeds to step S41, where it is determined whether or not the command machining position has been reached in all radial swing directions. If not, the process proceeds to step S42, sets the number of small turns + 1, returns to step S31, and proceeds to the next small turn swing machining step.

  In step S31, the radial oscillation direction n = 1 is set. Next, the process proceeds to step S32, and the order of the radial rocking direction in the current small-turn rocking process is determined. In the order of the radial oscillation direction, the processing is performed first from the radial direction in which the processing progress amount (processing distance) is large. When the processing progress amount becomes non-uniform during processing, the processing progress amount can be made uniform by appropriately switching the radial swing processing sequence.

  Next, the process proceeds to step S33, and the amount of machining progress in each radial oscillation direction in the current small-turn oscillation processing is determined. As this processing progress amount, the current processing progress amount in each radial oscillation direction is determined based on the difference in the processing advance amount (processing distance) in each radial direction in the previous small-round oscillation processing. That is, in the current small orbital oscillating machining step, the machining progress amount in the radial oscillating direction with a small machining advance amount is increased in the previous small orbital oscillating machining. When unevenness occurs in the processing progress amount during processing, the processing progress amount can be made uniform by appropriately increasing or decreasing the processing progress amount in each radial oscillation direction.

  The steps after step S34 are the same as the previous small-turn swing machining step. In this way, the small-round swing machining steps of steps S31 to S42 are repeated until the command machining depth 36 and the commanded radiation swing amounts 31A to 33A are reached.

  As described above, the radial rocking machining method of the second embodiment stores the machining advance amounts (machining distances) of the plurality of corners in the small round rocking machining step, and the next small round rocking process. At the time of the machining step, the order of small-round swing machining of each corner is changed on the basis of the difference in machining advance of each corner, so that the machining advance of each corner can be made uniform.

  In addition, the respective machining advance amounts of a plurality of corners in the small-circulation swing machining step are stored, and the respective corners are stored based on the difference in the machining advance amounts of the respective corner portions in the next small-turn swing machining step. Since the amount of machining progress of the part is changed, the amount of machining progress of each corner can be made uniform.

  As described above, the radial rocking machining method according to the present invention is useful for finishing a square hole having a plurality of corners into a workpiece.

It is a cross-sectional view showing a state in the middle of finishing a square hole in a workpiece with a rectangular columnar reduction electrode by the radial rocking machining method according to the present invention. It is a longitudinal cross-sectional view which shows the same state as FIGS. 1-1. It is a perspective view which shows notionally the radial rocking processing method concerning this invention. It is a table which instruct | indicates the rotation order of the small radiation rocking | fluctuation process of each corner | angular part of a square hole. It is a figure which shows the small radiation rocking | fluctuation processing order of the 1st round. It is a figure which shows the small radiation rocking | fluctuation processing order of the 2nd round. It is a figure which shows the small radiation rocking | fluctuation machining order of the 3rd round. It is a figure which shows the small radiation rocking | fluctuation processing order of 4th (0) circumference. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional block diagram of a numerically controlled electric discharge machine according to a first embodiment that implements a radial rocking machining method according to the present invention. 3 is a flowchart showing a small radiation fluctuation control operation of the numerically controlled electric discharge machine according to the first embodiment. It is a functional block diagram of the numerical control electric discharge machine of Embodiment 2 which implements the radial rocking machining method concerning the present invention. 6 is a flowchart showing a small radiation fluctuation control operation of the numerically controlled electric discharge machine according to the second embodiment. It is a cross-sectional view which shows the state in the middle of finishing a triangular hole in a workpiece | work with a triangular prism-shaped reduction electrode by the radial oscillation processing method of Embodiment 2. FIG. It is a figure which shows the process advance amount of each radial rocking | fluctuation direction in the small circumference rocking | fluctuation machining step of a triangular hole.

Explanation of symbols

1A Finishing machining allowance 10 Work 11, 12, 13, 14 Corner 11A, 12A, 13A, 14A Corner bottom (command processing depth bottom)
15 square hole (square hole)
20 Reduction electrode 25 Radial oscillation center 30 Pyramid (square pyramid)
31, 32, 33, 34 Ridge 31A, 32A, 33A, 34A Command Radiation Fluctuation 36 Command Machining Depth 41 NC Program Interpretation Unit 42 Radiation Fluctuation Pattern Memory 43 Machining Command Position Memory 44 Interpolation Processing Unit 45 Servo Control Unit 46 Discharge Control unit 50, 50A Small-circulation oscillation control unit 51 Oscillation control unit 52 Processing progress amount management unit 52A Processing progress amount calculation unit 53 Processing progress amount monitor unit 54 Radiation direction switching determination unit 55 Radiation order management unit 55A Radiation order calculation unit 56 Next Radiation Direction Determination Unit 57 Machining Time Management Unit 58 Time Cutout Determination Unit

Claims (4)

In order to finish a square hole having a plurality of corners into a workpiece, the electrode for reducing the size of the square hole is formed so as to be along the ridge line of the pyramid from the radial oscillation center toward the bottom of the plurality of corners. In the radial rocking machining method that performs electrical discharge machining by relative movement while controlling the gap of the workpiece,
A small orbital oscillating machining step for orbiting and oscillating each of the plurality of corners in a predetermined order until a predetermined machining progress amount smaller than the command machining depth and the commanded radial oscillation amount;
Repeating the small orbital oscillating machining step a plurality of times until the command machining depth and the command radial oscillation amount are reached or the command machining time comes;
A radial rocking machining method comprising:   2. The radial rocking machining method according to claim 1, wherein the machining progress amount is one of a machining advance amount, a machining time, and an effective discharge pulse number in each radial direction toward the bottom of each corner. .   The respective machining advance amounts of the plurality of corner portions in the small-circular swing machining step are stored, and the respective progress amounts of the corner portions are stored based on the difference in the machining advance amounts of the respective corner portions in the next small-circular swing machining step. 3. The radial oscillating machining method according to claim 1, wherein the order of the small oscillating machining of the corners is changed.   The respective machining advance amounts of the plurality of corner portions in the small-circular swing machining step are stored, and the respective progress amounts of the corner portions are stored based on the difference in the machining advance amounts of the respective corner portions in the next small-circular swing machining step. The radial rocking machining method according to claim 1, wherein a machining progress amount of the corner portion is changed.

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