摘要:
A numerical control apparatus according to the invention for interpolatory control of a tool along the shape of a workpiece to be machined. In order to perform offsetting of a cutting tool by an amount equivalent to the tool diameter when involute interpolation is carried out, an involute curve is approximated by a circular which is set in dependence upon the intersection angle of a machining trajectory at a command point commanding the start of machining.
摘要:
An involute interpolation method for use in machining by a numerical control apparatus.A rotational direction (G03.1) of an involute curve, coordinates of an end point (Xe, Ye), a center position (I, J) of a base circle as viewed from a start point, and a radius (R) of the base circle are instructed, from two equations representing the involute curve sequence of points are obtained, and interpolation of the involute curve is performed while interpolating those points in a range of the angle .theta. corresponding to the start point on the involute curve to the end point thereon.The increment of .theta. is decremented in proportion to the increment of the angle owing to the factor K/ (R.multidot..theta.), so that the interpolation is performed in such a manner that the speed in the tangential direction is made at constant, whereby a machining speed of the involute curve is maintained at constant.
摘要:
An involute interpolation method for machining operations is used in a numerical control apparatus.A rotational direction (G03.1) of an involute curve, an incremental distance along the involute curve or an incremental angle, a center position (X.sub.0, Y.sub.0) of a base circle and a radius (R) of the base circle are obtained per the instruction. The involute curve is interpolated using a predetermined distance or predetermined angle.The above processing is executed with a numerical control apparatus and pulse distributions are continuously carried out. Therefore, the involute curve can be interpolated without need for a special program producing system.
摘要:
A pitch error compensating system compensates for a pitch error of a ball screw of a numerically controlled machine tool. A pitch error calculating means (4) reads a present value from a present value register (3), reads pitch error corrective quantities (.epsilon.n, .epsilon.pn) in a corresponding period, and outputs pitch error corrective quantities as pitch error corrective pulses (CP) at equal intervals in the period. The pitch error corrective pulses (CP) are added to interpolated pulses (CP) by an adder (5). Since the pitch error corrective quantities are not outputted all at once, the machine tool moves smoothly, and the quality of the machined surface of the workpiece is improved.
摘要:
A gear pitch error correcting system for a numerical control apparatus used for a machine tool including at least one pair of gears provided in a transmission line through which the rotating force of a servomotor is transmitted to a driven member. Gear pitch error correction values for the respective gears, which each correspond to a predetermined gear angle and collectively cover one gear rotation, are stored in a nonvolatile memory. A pitch error computing means (E) refers to a current position register (D), reads out pitch error correction data (14b) corresponding to the current position from the nonvolatile memory, and adds up the data to obtain a superimposed pitch error correction value. The superimposed pitch error correction value and an interpolation pulse from an interpolating means (B) are added together by an adder (C), to obtain a pitch error-corrected output pulse, which is then supplied to an axis control circuit (18). Accordingly, even with a relatively small number of gear pitch error correction values for the individual gears, a gear pitch error correction can be precisely executed in proportion to the superimposing of the gear pitch error correction values.
摘要:
A feed speed control method for a numerical control device in which a feed speed of a tool traveling along an instructed machining path is controlled in accordance with a machining program. The speed of each axis is derived (S2), and the acceleration of each axis is derived from a speed variation between adjacent blocks (S3). When the acceleration (.DELTA.Vx) is larger than a permissible acceleration (.DELTA.Vxmax) (S4), first ratios (K1) of the permissible accelerations to the accelerations are derived for individual axes (S5), and the smallest of the first ratios is selected. The command speed is multiplied by the square root of the smallest first ratio to derive an actual feed speed (S9). In this way, shock to a machine is reduced and an excessive load on a servomotor is reduced even when blocks continue for successive infinitesimal distribution distances, as in the case wherein a curve is approximated by the use of straight lines.
摘要:
Disclosed is a numerical control apparatus for controlling a numerically controlled machine tool such as a hobbing machine and the like. An axis control circuit (14) provided with a synchronization control means (8) controls the rpm of a spindle motor (5) and the rpm of a servo motor (11) based on feedback pulses supplied from a position coder (7) connected to a hob axis (3), so that a ratio of the rpm of the hob axis (3) to the rpm of a C-axis (13) has a given value. A first internal counter (15a) monitors the number of feedback pulses supplied from the position coder (7) and a second internal counter (15b) monitors the number of pulses distributed to the C-axis (13), and when a ratio of the rpm of the hob axis (3) to the rpm of the C-axis (13) is to be changed, a correction pulse calculation means (9) calculates correction pulses based on the number of rotation pulses of the hob axis (3) and the number of the rotation pulses of the C-axis (13) counted by the first and second internal counters (15a, 15b). The correction pulses are supplied to the C-axis (13) to accelerate or decelerate the rpm of the C-axis (13) and thereby achieve a new synchronous relationship between the hob axis (3) and the C-axis (13) during the rotation of the hob axis (3) and C-axis (13).
摘要:
An interface unit simplifies the definition or correction of the contents of conversion from a macro instruction into micro instructions by the machine tool maker, without changing the specifications of the NC processor (3) side in numerical control equipment (NC). A receiving circuit (9, 10) receives a macro instruction delivered from the NC processor (3), and format converting circuitry (6, 8) converts the macro instruction received by the receiving circuit (9, 10) into a series of micro instructions. A transmitting circuit (11, 12) transmits the series of micro instructions obtained by the format converting circuitry (6, 8) to the NC processor (3).
摘要:
An interface unit is connected beween a numerical controller (NC) and an electric power control circuit (PC). The interface unit includes an actual speed memory (50) into which the numerical controller (NC) can write actual speed data and from which the electric power control circuit (PC) can read out the written data, and a corrected speed memory (51) into which the electric power control circuit (PC) can write corrected speed data and from which the numerical controller (NC) can read out the written data. This makes it possible for the electric power control circuit (PC) to detect the actual speed of the numerical controller (NC) by reading out the actual speed memory (50), and to control the actual speed of the numerical controller (NC) by writing the corrected speed data in the corrected speed memory (51).
摘要:
A spline interpolation method of subjecting given points to interpolation by using a cubic spline curve is provided. A first-derivative vector is derived from a preset number of points including a starting point (P.sub.1), and a cubic equation between the starting point and a next point is derived based on the coordinate values of the preset points including the starting point (P.sub.1) and the extreme point condition of the starting point (P.sub.1), to derive a spline curve between the starting point (P.sub.1) and a point (P.sub.2) next to the starting point (P.sub.1). Next, the first-derivative vector at P.sub.2 and a new next point are used instead of the starting point (P.sub.1), to derive a cubic curve between P.sub.2 and P.sub.3. In this way, a cubic equation between points is sequentially derived to obtain a cubic spline curve, and as a result, a spline curve posing no practical problems can be obtained without previously receiving all of the sequential points, while sequentially receiving the sequential points in a forward direction.