Patent Application
20170266744
The present invention relates to a wire electric discharge machine that applies a machining voltage between a wire electrode and a work and applies electric discharge machining to the work, a control method of a control device of the wire electric discharge machine, and a positioning method.
In wire electric discharge machining, it is necessary to accurately grasp a positional relation between electrodes, that is, between a wire electrode and a work prior to machining and execute positioning between electrodes. A conventional positioning method between electrodes in the wire electric discharge machining is generally a method of detecting electric contact between a wire electrode and a work as described in Patent Literature 1 and Patent Literature 2.
Patent Literature 1: Japanese Patent Application Laid-Open No. H4-171120
Patent Literature 2: Japanese Patent Application Laid-Open No. S60-135127
In the positioning method described in Patent Literature 1 and Patent Literature 2, the wire electrode vibrates during movement of the wire electrode. Therefore, electric contact is detected when the work approaches a range of the vibration of the wire electrode. At this point, the amplitude and the frequency of the vibration of the wire electrode are not fixed because of differences in the strength and the direction of tension applied to wire electrodes between wire electric discharge machines. Therefore, in the positioning method described in Patent Literature 1 and Patent Literature 2, it is difficult to accurately detect a positional relation between electrodes on the basis of only the detection of the electric contact. Therefore, in the positioning method described in Patent Literature 1 and Patent Literature 2, even when positioning of the wire electrode is performed on the same work, the position between electrodes fluctuates by a vibration width of the wire electrode.
When the movement of the wire electrode is stopped and the positioning is performed, fluctuation in the position of the wire electrode occurs in a range of a clearance, which is a gap of a wire piercing-through portion in a die that holds the wire electrode. Therefore, it is difficult to accurately grasp the positional relation between electrodes.
In the positioning method described in Patent Literature 1 and Patent Literature 2, when a wire electrode, which is an extra fine wire having an outer diameter of 70 micrometers or less, is positioned, electric resistance between the wire electrode and a work increases because the wire electrode is thin. It is sometimes difficult to accurately detect a position where the wire electrode and the work are in contact. In this way, in the positioning method described in Patent Literature 1 and Patent Literature 2, it is sometimes difficult to accurately position the wire electrode and the work.
The present invention has been devised in view of the above and an object of the present invention is to obtain a wire electric discharge machine capable of accurately positioning a wire electrode and a work.
To solve the problems and achieve the object, the present invention includes: a wire electrode that is applied with a machining voltage and causes electric discharge between the wire electrode and a work; a driving section that relatively moves the wire electrode and the work in a direction crossing a longitudinal direction of the wire electrode; a wire moving section that moves the wire electrode in the longitudinal direction; and a capacitance measuring section that measures capacitance between the wire electrode and the work. The present invention includes a control device that causes, in a state in which the movement of the wire electrode in the longitudinal direction is stopped, the capacitance measuring section to measure the capacitance while causing the driving section to relatively move the wire electrode and the work, thereafter, causes, in a state in which the control device causes the wire moving section to move the wire electrode in the longitudinal direction, the capacitance measuring section to measure the capacitance, and causes the driving section to adjust relative positions of the wire electrode and the work on the basis of a measurement result of the capacitance measuring section.
The wire electric discharge machine according to the present invention has an effect that it is possible to accurately position the wire electrode and the work.
Wire electric discharge machines, control methods of control devices of the wire electric discharge machines, and positioning methods according to embodiments of the present invention are explained in detail below with reference to the drawings. Note that the present invention is not limited by the embodiments.
A wire electric discharge machine 1 is an apparatus that applies wire electric discharge machining to a work W. The wire electric discharge machine 1 includes, as shown in
The wire electrode 10 is applied with a machining voltage and causes electric discharge between the wire electrode 10 and the work W. The wire electrode 10 is configured by metal having electric conductivity and is formed in a long shape. The sectional shape of the wire electrode 10 is formed in a circular shape. In the first embodiment, the outer diameter of the wire electrode 10 is 20 micrometers or more and 300 micrometers or less.
The wire moving section 20 includes a wire bobbin 21 on which the wire electrode 10 is wound to supply the wire electrode 10, a plurality of wire feeding rollers 22, a machining head 24 including an upper nozzle 23 that delivers the wire electrode 10 toward the work W, a lower nozzle 25 through which the wire electrode 10 is inserted, and a collection roller 26 that collects the wire electrode 10. The wire feeding rollers 22 are supported rotatably around axes. At least one wire feeding roller 22 is provided between the wire bobbin 21 and the machining head 24. The wire electrode 10 is wound on the wire feeding roller 22. The wire feeding roller 22 guides the wire electrode 10 from the wire bobbin 21 to the machining head 24. At least one wire feeding roller 22 is provided between the lower nozzle 25 and the collection roller 26. The wire electrode 10 is wound on the wire feeding roller 22. The wire feeding roller 22 guides the wire electrode 10 from the lower nozzle 25 to the collection roller 26. The wire feeding roller 22 rotates according to the movement of the wire electrode 10.
The machining head 24 includes a head main body 24a, through the inner side of which the wire electrode 10 is inserted, a contactor 24b provided in the head main body 24a and in contact with the wire electrode 10, and the upper nozzle 23 attached to the lower surface of the head main body 24a opposed to the work W. The upper nozzle 23 includes, as shown in
The lower nozzle 25 is disposed below the upper nozzle 23 of the machining head 24. The lower nozzle 25 includes, as shown in
The collection roller 26 holds the wire electrode 10 between the collection roller 26 and the wire feeding roller 22 and is rotated by a not-shown motor. When electric discharge machining is applied to the work W, the collection roller 26 is rotated by the motor to collect the wire electrode 10 inserted through the guide hole 23a of the upper nozzle 23 and the guide hole 25a of the lower nozzle 25. When rotating speed by the motor is changed, the collection roller 26 can change the moving speed of the wire electrode 10.
The work holding section 30 is configured by metal having electric conductivity. The plane shape of the outer edge of the work holding section 30 is formed in a square frame shape. The surface of the work holding section 30 is formed flat. The work holding section 30 is disposed in parallel to the horizontal direction. The wire electrode 10 present between the upper nozzle 23 and the lower nozzle 25 is inserted through the inner side of the work holding section 30.
The driving section 40 relatively moves the wire electrode 10 and the work W in a direction crossing the longitudinal direction of the wire electrode 10 present between the nozzles 23 and 25. The driving section 40 includes a motor 41 incorporating an encoder, a not-shown ball screw rotated around an axis by the motor 41, and a not-shown nut into which the ball screw is screwed, the nut being attached to the work holding section 30. The motor 41 is connected to the control device 100 via an amplifier 42. The motor 41 rotates the ball screw around the axis. The encoder incorporated in the motor 41 measures a rotation angle of the ball screw and outputs a measurement result to the control device 100. When the motor 41 rotates the ball screw around the axis, the driving section 40 moves, with respect to the wire electrode 10, the work W held by the work holding section 30. The driving section 40 moves the work W to move the work W in directions in which the work W approaches the wire electrode 10 present between the nozzles 23 and 25 and moves away from the wire electrode 10 present between the nozzles 23 and 25.
In the first embodiment, the driving section 40 moves the work W in the direction orthogonal to the longitudinal direction of the wire electrode 10 present between the nozzles 23 and 25. However, the driving section 40 can move the work W in a direction not orthogonal to the longitudinal direction of the wire electrode 10 present between the nozzles 23 and 25. The driving section 40 can move both of the wire electrode 10 present between the nozzles 23 and 25 and the work W or can move, with respect to the work W, the wire electrode 10 present between the nozzles 23 and 25 without moving the work W.
A machining voltage is applied between the wire electrode 10 and the work W from a power supply 80. The power supply 80 is electrically connected to the wire electrode 10 via the contactor 24b and connected to the work W via the work holding section 30. The power supply 80 applies the machining voltage between the contactor 24b and the work holding section 30 to apply the machining voltage between the wire electrode 10 and the work W. The machining voltage applied by the power supply 80 is a voltage for breaking insulation between the wire electrode 10 present between the nozzles 23 and 25 and the work W, causing electric discharge, and removing a part of the work W with the electric discharge. In the first embodiment, when an inter-electrode distance, which is the distance between the wire electrode 10 present between the nozzles 23 and 25 and the work W, is 10 micrometers or more and 20 micrometers or less, the machining voltage is a voltage for causing electric discharge between the wire electrode 10 and the work W. However, the inter-electrode distance between the wire electrode 10 and the work W is not limited to be 10 micrometers or more and 20 micrometers or less.
The tension applying section 50 applies tension to the wire electrode 10 when the machining voltage is applied to the wire electrode 10 and electric discharge machining of the work W is performed. The tension applying section 50 includes a tension applying roller 51 and a not-shown motor capable of rotating the tension applying roller 51. The tension applying roller 51 is provided between the wire bobbin 21 and the machining head 24 and holds the wire electrode 10 between the tension applying roller 51 and the wire feeding roller 22. The motor of the tension applying section 50 rotates the tension applying roller 51 in a direction in which the wire electrode 10 is wound by the wire bobbin 21. The driving torque of the motor of the tension applying section 50 is weaker than the driving torque of the motor that rotates the collection roller 26. When the electric discharge machining is applied to the work W, because the motor is about to rotate the tension applying roller 51 with the driving torque weaker than the driving torque of the motor that rotates the collection roller 26, the tension applying section 50 applies tension to the wire electrode 10 along the longitudinal direction of the wire electrode 10 present between the nozzles 23 and 25.
The linear scale 60 includes a scale and a detector movably provided in the scale and fixed to the work holding section 30. The linear scale 60 measures a movement amount of the detector with respect to the scale to measure a movement amount of the work and outputs a measurement result to the control device 100. The measuring means can be, instead of the linear scale 60, means for measuring a movement amount of the work W on the basis of a driving signal of the motor 41 or a measurement result of the encoder of the motor 41.
One end of the capacitance measuring section 70 is electrically connected to the wire electrode 10 via the contactor 24b. The other end is connected to the work W via the work holding section 30. The capacitance measuring section 70 includes, as shown in
The control device 100 is a numerical control device and configured by, as shown in
In the first embodiment, information necessary for generating machining conditions is input to the control device 100 from an input device 104 connected to an input/output unit 103. The input device 104 is configured by a touch panel, a keyboard, a mouse, a track ball, or a combination of these devices.
A machining operation of the wire electric discharge machine 1, a control method of the control device 100, and a positioning method according to the first embodiment are explained with reference to the drawings.
The wire electric discharge machine 1 starts a machining operation when information necessary for generating machining conditions is input and a machining start command is input to the control device 100 from the input device 104. In the machining operation, the control device 100 of the wire electric discharge machine 1 positions the wire electrode 10 and the work W on the basis of the input information. After positioning the wire electrode 10 and the work W, the control device 100 generates machining conditions on the basis of the input information and outputs the generated machining conditions to the driving section 40, the wire moving section 20, the driving section 40, and the power supply 80. Then, the power supply 80 applies a machining voltage between the wire electrode 10 and the work W. The wire electric discharge machine 1 causes electric discharge between the wire electrode 10 and the work W and applies the electric discharge machining to the work W.
In the wire electric discharge machine 1, after the work W is held by the work holding section 30, when receiving the machining start command input from the input device 104, the control device 100 executes positioning of the wire electrode 10 and the work W (step ST1). When positioning the wire electrode 10 and the work W, first, the control device 100 causes the wire moving section 20 to stop the movement of the wire electrode 10 (step ST2). The control device 100 causes the driving section 40 to move the work W in a direction approaching the wire electrode 10 (step ST3). The control device 100 determines on the basis of a measurement result of the capacitance measuring section 70 whether the work W has come into contact with the wire electrode 10 (step ST4). When the capacitance between the wire electrode 10 and the work W detected by the capacitance measuring section 70 decreases to zero, the control device 100 determines that the work W has come into contact with the wire electrode 10. When the capacitance between the wire electrode 10 and the work W detected by the capacitance measuring section 70 is not zero, the control device 100 determines that the work W has not come into contact with the wire electrode 10.
When determining that the work W has not come into contact with the wire electrode 10 (No at step ST4), the control device 100 returns to step ST3. When determining that the work W has come into contact with the wire electrode 10 (Yes at step ST4), after causing the driving section 40 to stop the movement of the work W, the control device 100 acquires a relation between the position of the work W and the capacitance between the wire electrode 10 and the work W while causing the driving section 40 to move the work W in a direction away from the wire electrode 10 (step ST5). The control device 100 associates a detection result of the linear scale 60 and the capacitance between the wire electrode 10 and the work W, which is a measurement result of the capacitance measuring section 70, in a one-to-one relation and acquires a relation between the capacitance between the wire electrode 10 and the work W and a moving distance of the work W as shown in
In the wire electric discharge machine 1, the control device 100 executes processing at step ST1 to step ST5 to cause, in a state in which the movement of the wire electrode 10 in the longitudinal direction is stopped, the capacitance measuring section 70 to measure capacitance while causing the driving section 40 to relatively move the wire electrode 10 and the work W. When executing the processing at step ST5 to cause the capacitance measuring section 70 to measure capacitance, the control device 100 acquires the calibration data K from the measurement result of the measurement by the capacitance measuring section 70. When executing the processing at step ST4 to cause the capacitance measuring section 70 to measure capacitance, the control device 100 brings the work W into contact with the wire electrode 10. The processing at step ST1 to step ST5 configures a calibration-data acquiring step S1 for causing, in the state in which the movement of the wire electrode 10 in the longitudinal direction is stopped, the capacitance measuring section 70 to measure capacitance while causing the driving section 40 to relatively move the wire electrode 10 and the work W.
The control device 100 determines whether the work W has retracted from the wire electrode 10 by a designated distance (step ST6). Note that, when the wire electrode 10 is moved by the wire moving section 20, the wire electrode 10 comes into contact with the inner surfaces of the guide holes 23a and 25a of the nozzles 23 and 25 and, as indicated by a solid line in
When determining that the work W has retracted from the wire electrode 10 by the designated distance (Yes at step ST6), the control device 100 causes the driving section 40 to stop the movement of the work W, causes the tension applying section 50 to apply tension having intensity same as the intensity during the discharge machining to the wire electrode 10, and causes the wire moving section 20 to move the wire electrode 10 at speed same as the speed during the discharge machining (step ST7). In the first embodiment, when tension same as the tension during the electric discharge machining is applied to the wire electrode 10 by the tension applying section 50 from a position indicated by a solid line in
The control device 100 brings the work W close to the wire electrode 10 on the basis of the measurement result of the capacitance measuring section 70 such that the work W does not come into contact with the wire electrode 10 and the work W is located within a range H shown in
The control device 100 causes the capacitance measuring section 70 to measure the capacitance between the wire electrode 10 and the work W. At this point, as indicated by a solid line in
The control device 100 calculates an inter-electrode distance between the wire electrode 10 moving in the longitudinal direction and the work W on the basis of the value Cx of the capacitance, which is the measurement result of the capacitance measuring section 70, and the calibration data K shown in
In the wire electric discharge machine 1, the control device 100 executes the processing at step ST6 to step ST10 to cause the capacitance measuring section 70 to measure capacitance while causing the wire moving section 20 to move the wire electrode 10 in the longitudinal direction and cause the driving section 40 to adjust the relative positions of the wire electrode 10 and the work W on the basis of the measurement result of the capacitance measuring section 70. The control device 100 executes the processing at step ST7 to, when causing the driving section 40 to adjust the relative positions of the wire electrode 10 and the work W, cause the tension applying section 50 to apply tension having intensity same as the intensity in applying the electric discharge machining to the wire electrode 10. The control device 100 executes the processing ate step ST9 to, when causing the driving section 40 to adjust the relative positions of the wire electrode 10 and the work W, calculate the inter-electrode distance between the wire electrode 10 moving in the longitudinal direction and the work W on the basis of the value Cx of the capacitance, which is the measurement result of the capacitance measuring section 70, and the calibration data K. The processing at step ST6 to step ST10 configures an adjusting step S2 for causing, in a state in which the control device 100 causes the wire moving section 20 to move the wire electrode 10 in the longitudinal direction, the capacitance measuring section 70 to measure capacitance and causing the driving section 40 to adjust the relative positions of the wire electrode 10 and the work W.
As explained above, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, the control device 100 calculates the inter-electrode distance between the wire electrode 10 and the work W on the basis of the capacitance between the wire electrode 10 and the work W. Therefore, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, the capacitance changes according to a change in the inter-electrode distance between the wire electrode 10 and the work W. The capacitance decreases to zero when the wire electrode 10 and the work W come into contact. Therefore, it is possible to more accurately measure the inter-electrode distance between the wire electrode 10 and the work W than the comparative example shown in
In the comparative example shown in
When the work W is brought close to the extra fine wire 10S as shown in
In the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, the control device 100 calculates the inter-electrode distance between the wire electrode 10 and the work W on the basis of the capacitance between the wire electrode 10 and the work W. As a result, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, even when the machining oil is used as the machining fluid, it is possible to accurately grasp the inter-electrode distance between the wire electrode 10 and the work W and accurately position the wire electrode 10 and the work W.
In the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, in the state in which the movement of the wire electrode 10 in the longitudinal direction is stopped, the control device 100 causes the capacitance measuring section 70 to measure the capacitance between the wire electrode 10 and the work W while relatively moving the wire electrode 10 and the work W in the direction crossing the longitudinal direction of the wire electrode 10. Therefore, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, even if the wire electrode 10 vibrates when the wire electrode 10 is moved in the longitudinal direction, the capacitance is measured in the state in which the wire electrode 10 is stopped. Therefore, it is possible to acquire an accurate relation between the inter-electrode distance between the wire electrode 10 and the work W and the capacitance between the wire electrode 10 and the work W.
In the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, in the state in which the movement of the wire electrode 10 in the longitudinal direction is stopped, after causing the capacitance measuring section 70 to measure the capacitance between the wire electrode 10 and the work W, the control device 100 causes the capacitance measuring section 70 to measure capacitance while causing the wire moving section 20 to move the wire electrode 10 in the longitudinal direction and causes the driving section 40 to adjust the relative positions of the wire electrode 10 and the Work W. Therefore, even if the relative positions of the wire electrode 10 and the work W deviate between the state in which the wire electrode 10 is stopped and the state in which the wire electrode 10 is moved, before positioning the wire electrode 10, it is possible to accurately calculate the inter-electrode distance between the wire electrode 10 moving in the longitudinal direction and the work W on the basis of the capacitance acquired in the state in which the wire electrode 10 is stopped. As a result, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, it is possible to accurately position the wire electrode 10 and the work W.
In the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, in the state in which the movement of the wire electrode 10 in the longitudinal direction is stopped, the control device 100 causes the capacitance measuring section 70 to measures the capacitance between the wire electrode 10 and the work W and acquires the calibration data K defining the relation between the inter-electrode distance between the wire electrode 10 and the work W and the capacitance between the wire electrode 10 and the work W. As a result, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, even if the wire electrode 10 vibrates when the wire electrode 10 is moved in the longitudinal direction, the relative positions of the wire electrode 10 and the work W are adjusted on the basis of the calibration data K acquired in the state in which the wire electrode 10 is stopped. Therefore, it is possible to accurately position the wire electrode 10 and the work W.
In the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, the control device 100 positions the wire electrode 10 and the work W on the basis of the calibration data K acquired in the state in which the movement of the wire electrode 10 in the longitudinal direction is stopped. Therefore, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, the calibration data K acquired using the wire electrode 10 and the work W used in actual machining is used. Therefore, even if the shape of at least one of the wire electrode 10 and the work W variously changes, it is possible to accurately position the wire electrode 10 and the work W.
In the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, after acquiring the relation between the inter-electrode distance between the wire electrode 10 and the work W and the capacitance between the wire electrode 10 and the work W, the control device 100 moves the wire electrode 10 in the longitudinal direction and calculates the inter-electrode distance between the wire electrode 10 and the work W. Therefore, even if the relative positions of the wire electrode 10 and the work W deviate between the state in which the wire electrode 10 is stopped and the state in which the wire electrode 10 is moved, before positioning the wire electrode 10, it is possible to calculate the inter-electrode distance between the wire electrode 10 moving in the longitudinal direction and the work W. As a result, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, before positioning the wire electrode 10 and the work W, the control device 100 moves the wire electrode 10 in the same manner as during the electric discharge machining. Therefore, it is possible to measure the inter-electrode distance between the wire electrode 10 and the work W during the electric discharge machining. It is possible to accurately position the wire electrode 10 and the work W.
In the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, the control device 100 calculates the inter-electrode distance between the moving wire electrode 10 and the work W using the value Cx, which is the average of the capacitance that is the measurement result of the capacitance measuring section 70. Therefore, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, even if the moving wire electrode 10 vibrates, it is possible to accurately measure the inter-electrode distance between the wire electrode 10 and the work W. It is possible to accurately position the wire electrode 10 and the work W.
In the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, the control device 100 measures the inter-electrode distance between the moving wire electrode 10 and the work W in a state in which tension same as the tension during the electric discharge machining is applied to the wire electrode 10 by the tension applying section 50. Therefore, even if the relative positions of the wire electrode 10 and the work W deviate between the state in which the tension is applied to the wire electrode 10 and the state in which tension is not applied to the wire electrode 10, before positioning the wire electrode 10, it is possible to accurately calculate the inter-electrode distance between the wire electrode 10 moving in the longitudinal direction and the work W. As a result, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, before positioning the wire electrode 10 and the work W, because the tension same as the tension during the electric discharge machining is applied to the wire electrode 10, it is possible to measure the inter-electrode distance between the wire electrode 10 and the work W during the electric discharge machining. It is possible to accurately position the wire electrode 10 and the work W.
In the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, when acquiring the calibration data K defining a relation between the inter-electrode distance between the wire electrode 10 and the work W and the capacitance between the wire electrode 10 and the work W, the control device 100 once brings the wire electrode 10 and the work W into contact. Therefore, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, it is possible to measure the inter-electrode distance between the wire electrode 10 and the work W on the basis of the position where the wire electrode 10 and the work W are in contact. As a result, in the wire electric discharge machine 1, the control method of the control device 100, and the positioning method according to the first embodiment, it is possible to accurately position the wire electrode 10 and the work W.
The wire electric discharge machine 1 according to a second embodiment of the present invention is explained with reference to the drawings.
The wire electric discharge machine 1 according to the second embodiment has a configuration same as the configuration in the first embodiment. The wire electric discharge machine 1 shown in
The control device 100 of the wire electric discharge machine 1 according to the second embodiment measures a relative position of the wire electrode 10 relative to any position of the work W according to a measurement result of the capacitance measuring section 70 before the first cut and before the second cut. The control device 100 of the wire electric discharge machine 1 according to the second embodiment compares a measurement result before the first cut and a measurement result before the second cut and measures positional deviation between the wire electrode 10 and the work W during the first cut. During the second cut, the control device 100 of the wire electric discharge machine 1 according to the second embodiment corrects, taking into account the positional deviation, a route for relatively moving the wire electrode 10 and the work W. During the second cut, the wire electric discharge machine 1 according to the second embodiment performs an operation same as the operation in the first embodiment except that the wire electric discharge machine 1 corrects the route for relatively moving the wire electrode 10 and the work W.
As in the first embodiment, when positioning the wire electrode 10 and the work W, the wire electric discharge machine 1 according to the second embodiment acquires the calibration data K in the state in which the movement of the wire electrode 10 in the longitudinal direction is stopped. Thereafter, the wire electric discharge machine 1 moves the wire electrode 10 in the longitudinal direction and calculates an inter-electrode distance between the wire electrode 10 and the work W on the basis of the calibration data K. As a result, as in the first embodiment, the wire electric discharge machine 1 according to the second embodiment can accurately position the wire electrode 10 and the work W.
During the second cut, the wire electric discharge machine 1 according to the second embodiment corrects the route for relatively moving the wire electrode 10 and the work W. Therefore, it is possible to suppress the deterioration in the machining accuracy.
The wire electric discharge machine 1 according to a third embodiment is explained with reference to the drawings.
The wire electric discharge machine 1 according to the third embodiment has a configuration same as the configuration in the first embodiment. The control device 100 of the wire electric discharge machine 1 according to the third embodiment moves the work W in a direction approaching the wire electrode 10 (step ST3) and thereafter acquires and stores the calibration data K while moving the work W in the direction approaching the wire electrode 10 (step ST5).
While acquiring the calibration data K, the control device 100 determines on the basis of a measurement result of the capacitance measuring section 70 whether the work W has come into contact with the wire electrode 10 (step ST4). When determining that the work W has not come into contact with the wire electrode 10 (No at step ST4), the control device 100 returns to step ST3. When determining that the work W has come into contact with the wire electrode 10 (Yes at step ST4), the control device 100 causes the driving section 40 to move the work W in a direction away from the wire electrode 10 and moves the work W until the work W retracts from the wire electrode 10 by a designated distance (step ST6-3). When the work W retracts from the wire electrode 10 by the designated distance, as in the first embodiment, the control device 100 executes the processing at step ST7, step ST8, step ST9, and step ST10.
When positioning the wire electrode 10 and the work W, as in the first embodiment, the wire electric discharge machine 1 according to the third embodiment acquires the calibration data K in the state in which the movement of the wire electrode 10 in the longitudinal direction is stopped. Thereafter, the wire electric discharge machine 1 moves the wire electrode 10 in the longitudinal direction and calculates an inter-electrode distance between the wire electrode 10 and the work W on the basis of the calibration data K. As a result, as in the first embodiment, the wire electric discharge machine 1 according to the third embodiment can accurately position the wire electrode 10 and the work W.
The wire electric discharge machine 1 according to the third embodiment acquires, while bringing the work W close to the wire electrode 10, the calibration data K until the work W comes into contact with the wire electrode 10. As a result, the wire electric discharge machine 1 according to the third embodiment can suppress time required for positioning the wire electrode 10 and the work W.
The wire electric discharge machine 1 according to a fourth embodiment is explained with reference to the drawings.
The wire electric discharge machine 1 according to the fourth embodiment has a configuration same as the configuration in the first embodiment. When calculating the inter-electrode distance between the wire electrode 10 and the work W at step ST9, the control device 100 of the wire electric discharge machine 1 according to the fourth embodiment converts the capacitance between the wire electrode 10 and the work W measured by the capacitance measuring section 70 into the inter-electrode distance between the wire electrode 10 and the work W on the basis of the calibration data K. The control device 100 acquires the inter-electrode distance between the wire electrode 10 and the work W that changes according to the elapse of time as shown in
When positioning the wire electrode 10 and the work W, as in the first embodiment, the wire electric discharge machine 1 according to the fourth embodiment acquires the calibration data K in the state in which the movement of the wire electrode 10 in the longitudinal direction is stopped. Thereafter, the wire electric discharge machine 1 moves the wire electrode 10 in the longitudinal direction and calculates the inter-electrode distance between the wire electrode 10 and the work W on the basis of the calibration data K. As a result, the wire electric discharge machine 1 according to the fourth embodiment can accurately position the wire electrode 10 and the work W as in the first embodiment.
When calculating the inter-electrode distance between the wire electrode 10 and the work W at step ST9, the wire electric discharge machine 1 according to the fourth embodiment converts the capacitance measured by the capacitance measuring section 70 into the inter-electrode distance between the wire electrode 10 and the work W and sets an average of the inter-electrode distance as the inter-electrode distance Dx between the wire electrode 10 and the work W. As a result, the wire electric discharge machine 1 according to the fourth embodiment can accurately calculate the inter-electrode distance between the wire electrode 10 and the work W and can accurately position the wire electrode 10 and the work W.
The configurations explained in the embodiments indicate examples of the contents of the present invention. The configurations can be combined with other publicly-known technologies. A part of the configurations can be omitted and changed in a range not departing from the spirit of the present invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/080852 | 10/30/2015 | WO | 00 |
