摘要:
There is disclosed a method of controlling a wire-cut electric discharge machine to correct cutting errors due to flexing of a wire electrode caused by electric discharge. A processing unit processes data (x.sub.1, y.sub.1, r.sub.1, x.sub.2, y.sub.2) on a corner shape which is given by a paper tape and data on an amount of flexing (D.sub.0) upon rectilinear cutting for calculating a corrected radius of curvature r.sub.1 ' of the corner, and determines the center Pc of an arc having the radius of curvature r.sub.1 ' and contacting straight lines (l.sub.1, l.sub.2) and points of contact Pt, Pt' to move the wire electrode along a straight line P.sub.1 Pt, an arc PtPt', and a straight line Pt'P.sub.3 to thereby correct the cutting error at the corner.
摘要:
A method of controlling a wire-cut electric discharge machine to prevent cutting errors when cutting a corner CN which are caused by flexing of a wire electrode 1 during electric discharge cutting of a workpiece. Electric discharge is stopped when a rectilinear slot is cut to measure an amount of flexing of the wire electrode 1, and then the measured amount of flexing is used to effect an arithmetic operation to calculate a commanded speed or an interval of time in which relative movement between the wire electrode and the workpiece is arrested at the corner CN. The corner CN is cut under the control of the calculated commanded speed or interval of time in which the relative movement is arrested.
摘要:
A cutting control method for reducing cutting errors at a corner due to flexing of a wire electrode in a wire-cut electric discharge machine in which a voltage is applied between the wire electrode and a workpiece to cut the latter with electric discharge energy while moving the workpiece relatively to the wire electrode based on cutting command data for cutting the workpiece to a predetermined shape. An amount of override (K) is determined by an override arithmetic unit (103b) using data (r) on the radius of curvature of a corner angle (.theta.) data which are given as the cutting command data from a paper tape (101). A relative speed (F) is derived by a relative speed arithmetic unit (103f) from the amount of override (K) and a commanded feeding speed (F.sub.0). Motors (MX, MY) are rotated by pulse distributors (105X, 105Y) and servo circuits (SVX, SVY), respectively, based on the relative speed (F) which is lower than the commanded feeding speed (F.sub.0) to move the workpiece with respect to the wire electrode for electric discharge cutting of the corner.
摘要:
A wire cut electric discharge machining condition setting system including cursor shift push button switches for selecting with a cursor one of the machining conditions displayed on a screen at a CRT display unit, numerical push button switches for setting values of the selected machining conditions, and increment and decrement push button switches for continuously updating the preset values of the machining conditions all arranged in a wire cut electric discharge machine. The value of the machining condition selected with the cursor is set by the numerical push button switches and is updated by the increment and decrement push button switches.
摘要:
A method of automatically measuring the flexure value of a wire electrode 1 in a wire-cut electric discharge machine, such that at a measurement point in the course of electric discharge machining, the electric discharge is temporarily stopped, and whether or not a wire electrode 1 and a workpiece 2 come into contact is sensed by a contact sensing device 107a. The wire electrode 1 and the workpiece 2 are moved relatively to advance or retreat in accordance with a sensed touch signal TS, and a distance .epsilon..sub.1 of movement until the contact state changes is measured. The flexure value .epsilon. is calculated from the measured movement distance .epsilon..sub.1 and the size of the discharge gap.
摘要:
A method of automatically measuring the flexure value of a wire electrode 1 in a wire-cut electric discharge machine is disclosed.At a measurement point in the course of electric discharge machining, the electric discharge is temporarily stopped, and whether or not the wire electrode 1 and a workpiece 2 come into contact is sensed by a contact sensing device 107a. The wire electrode 1 and the workpiece 2 are moved relatively to advance or retreat in accordance with the sensed touch signal TS, and the distance .epsilon..sub.1 of movement until the contact state changes, is measured. The flexure value .epsilon. is obtained calculatively from the measured movement distance .epsilon..sub.1.
摘要:
An electric discharge machining power source is provided which charges a capacitor connected in parallel with an electrode and a work, and applies a charge voltage between the electrode and the work to cause electric discharge, thereby performing electric discharge machining. The machining power source allows rapid charging of the capacitor and is inexpensive while the power source efficiency is improved. A switching element is arranged in the charge circuit of the capacitor which is capable of being turned on and off. The switching element connects the capacitor to a direct current power source and charges the capacitor. A flywheel circuit including an inductance and a diode is provided in the charge circuit. A reverse voltage that is caused by a stray inductance in the electric discharge circuit during electric discharge is applied to the capacitor as a positive voltage through the flywheel circuit.
摘要:
A wire electrode type electrical discharge machining apparatus is provided with a taper-machining controller which is capable of conducting taper-machining with high accuracy, even in the case where the rigidity of the electrode varies due to the variation of the temperature thereof following the variation of the electric current flowing therein. The information representing the relations between a machining current and a taper-angle in the entire controllable range of a taper-angle to be controlled is prepared in advance and stored in a memory. A means for setting a machining current, a means for program-inputting a machining current, or a means for sensing a machining current is provided. The above information is read by a correction means, in response to the machining current which was set, program-input, or sensed by one of the above presented means, before it is input to the taper-machining controller, which corrects the taper-angle. In one embodiment, the taper machining controller computes the correct taper angle. With this corrected taper angle, tapper-machining can be conducted with high accuracy.
摘要:
The electric discharge machining apparatus of the wire-cutting type comprises a wire-treating unit (48) movable in the horizonal direction relative to an upper wire guide member (12) between the upper wire guide member and a work table (10) to traverse a wire electrode (W) extending downward from a wire passage (13) of the upper wire guide member. The wire-treating unit has a base block (55) and a movable block (56) that can approach to and separate from the base block to define a slit (60) and a nozzle hole (61) that can be opened and closed between the two blocks. The slit extends in the horizontal moving direction of the wire-treating unit to receive the wire electrode therein. The nozzle hole can be connected to the lower end of the wire passage of the upper wire guide member, and the nozzle hole is constructed so that a spray liquid supplied into the wire passage of the upper wire guide member can be injected into a wire passage (15) of a lower wire guide member (14). The wire-treating unit comprises a wire-detecting device (66) for detecting the end of the wire electrode between the base block and the movable block and wire-cutting means (62) for cutting the wire electrode between the base block and the movable block.
摘要:
A wire discharge machining power source controls an average machining voltage value applied between a wire electrode (P) and a workpiece (W) to be zero to prevent galvanic corrosion of the workpiece (W). A reverse voltage application time control circuit (2) detects the average machining voltage value and generates a pulse (S5) having a pulse width corresponding to a detected value. A reverse voltage regulating circuit (1) detects a difference between a reference voltage and a voltage applied between a transistor (T2) and a resistor (R2) upon application of the reverse voltage through the transistor (T2) and the resistor (R2), and supplies a difference signal, which corresponds to the detected difference, as an ON control signal to the transistor (T2) for a period corresponding to the width of the pulse (S5), thereby controlling the reverse voltage value and setting the average machining voltage value to zero.