Abstract: A process planning apparatus extracts a region to be machined based on the difference of the shape data before and after machining of the workpiece, replaces the extracted region into combinations of the predetermined machining features, allocates a predetermined fixed cycle to each of the replaced machining features, and applies an assessment function relating to a machining time and a life of the end mill to each of the combinations of the machining features to which the fixed cycles are respectively allocated, thereby selecting a group of the fixed cycles which makes an assessment value obtained by the assessment function optimum as the optimal process. By these steps, it becomes possible to design the process for causing the NC machine employing end mills as a cutting tool to perform a predetermined machining of a workpiece without relying on the experience of the designer, and without necessitating complicated work.

Abstract: End-mill machining control method and apparatus in which cutting forces tangential and normal to tool motion are detected and machining is controlled based on the detected cutting force values. A primary component Ft and motion axis components Fx, Fy of a cutting force are determined from current values of a spindle motor and motion axis motors for tool feed. A cutting-engaged angle ?en is determined from a radius R of a tool and a depth of cut I into a workpiece. A motion direction angle ? is determined from distribution motion amounts ?X, ?Y to the axes. The cutting forces Fm, Fs tangential and normal to tool motion are determined from the primary component Ft and a motion axis component Fx or Fy whichever is the largest, the cutting-engaged angle ?en, the motion direction angle ?. The accuracy of the determined cutting forces Fm, Fs is high since they are determined from the primary component Ft less affected by disturbance and the largest axis component of the cutting force.

Abstract: A process planning apparatus extracts a region to be machined based on the difference of the shape data before and after machining of the workpiece, replaces the extracted region into combinations of the predetermined machining features, allocates a predetermined fixed cycle to each of the replaced machining features, and applies an assessment function relating to a machining time and a life of the end mill to each of the combinations of the machining features to which the fixed cycles are respectively allocated, thereby selecting a group of the fixed cycles which makes an assessment value obtained by the assessment function optimum as the optimal process. By these steps, it becomes possible to design the process for causing the NC machine employing end mills as a cutting tool to perform a predetermined machining of a workpiece without relying on the experience of the designer, and without necessitating complicated work.

Abstract: An NC apparatus 1 replaces a required machining shape of a workpiece 5 with a predetermined canned machining cycle depending on a specification of machining conditions including a machining start point, a machining end point, and the size of an end mill E to be used. Calculation of an estimated value of cutting force exerted on the end mill E fed along the assumed tool path during the replaced canned machining cycle is repeated until a predetermined comparison and evaluation result is obtained in comparison with a predetermined appropriate value. Accordingly, the tool path of the end mill E together with the feed rate in each portion of the tool path is determined. This permits generation of an NC program which is used in a NC machine equipped with an end mill serve as a cutting tool, and which optimizes the tool path of the end mill together with the feed rate in each portion of the tool path such as to achieve high machining efficiency and accuracy.

Abstract: End-mill machining control method and apparatus in which cutting forces tangential and normal to tool motion are detected and machining is controlled based on the detected cutting force values. A primary component Ft and motion axis components Fx, Fy of a cutting force are determined from current values of a spindle motor and motion axis motors for tool feed. A cutting-engaged angle &agr;en is determined from a radius R of a tool and a depth of cut I into a workpiece. A motion direction angle &bgr; is determined from distribution motion amounts &Dgr;X, &Dgr;Y to the axes. The cutting forces Fm, Fs tangential and normal to tool motion are determined from the primary component Ft and a motion axis component Fx or Fy whichever is the largest, the cutting-engaged angle &agr;en, the motion direction angle &bgr;. The accuracy of the determined cutting forces Fm, Fs is high since they are determined from the primary component Ft less affected by disturbance and the largest axis component of the cutting force.

Abstract: A maximum undeformed chip thickness, a cutting arc length or an engage angle, and an active angle for each tooth of the end mill are calculated when a ball end mill is used in machining, or the maximum undeformed chip thickness, the cutting arc length or the engage angle, and an axial depth of cut for each tooth of the end mill are calculated when a straight end mill is used in machining. Then, the estimated value of the cutting force Fxy or Fxyz in each portion of the tool path is calculated on the basis of a response surface whose explanation variables are composed of the above-mentioned calculated values, whereby the feed rate contained in an equation for the maximum undeformed chip thickness tm is determined to maintain the obtained estimated value of the cutting force Fxy or Fxyz at an appropriate value.

Abstract: A machining control system maintaining optimum machining states and enhancing efficiency and reliability even when an actual machining environment fluctuates. The machining control system includes a machining information determination portion for determining initial machining conditions on the basis of information stored in a machining data base and in accordance with adaptive control characteristics defined by adaptive control modes and adaptive control parameters, and an adaptive control portion for controlling machining by changing the machining conditions in accordance with the machining states observed during machining with the initial machining conditions as an initial value of the machining conditions.

Abstract: An NC apparatus 1 replaces a required machining shape of a workpiece 5 with a predetermined canned machining cycle depending on a specification of machining conditions including a machining start point, a machining end point, and the size of an end mill E to be used. Calculation of an estimated value of cutting force exerted on the end mill E fed along the assumed tool path during the replaced canned machining cycle is repeated until a predetermined comparison and evaluation result is obtained in comparison with a predetermined appropriate value. Accordingly, the tool path of the end mill E together with the feed rate in each portion of the tool path is determined. This permits generation of an NC program which is used in a NC machine equipped with an end mill serve as a cutting tool, and which optimizes the tool path of the end mill together with the feed rate in each portion of the tool path such as to achieve high machining efficiency and accuracy.

Abstract: A maximum undeformed chip thickness, a cutting arc length or an engage angle, and an active angle for each tooth of the end mill are calculated when a ball end mill is used in machining, or the maximum undeformed chip thickness, the cutting arc length or the engage angle, and an axial depth of cut for each tooth of the end mill are calculated when a straight end mill is used in machining. Then, the estimated value of the cutting force Fxy or Fxyz in each portion of the tool path is calculated on the basis of a response surface whose explanation variables are composed of the above-mentioned calculated values, whereby the feed rate contained in an equation for the maximum undeformed chip thickness tm is determined to maintain the obtained estimated value of the cutting force Fxy or Fxyz at an appropriate value.

Abstract: A CNC tapping machine includes a spindle to which a tap is attached and a spindle motor for rotating the spindle. The load torque acting on the spindle motor that is detected when performing a tapping procedure without a workpiece is stored in a memory as referential, torque data. During a tapping procedure, a detection device detects the load torque acting on the spindle motor. A computer computes the difference between the load torque defected by the detection device and the referential load torque and uses the difference as the cutting load acting on the tap. As a result, the cutting load torque acting on the tap is accurately detected.

Abstract: A numerical controlling device and a tooling apparatus having thereof, in which performance required for the machining is greatly improved correspondingly to a degree of importance according to a type of the machining and thus high efficiency and high accuracy in the machining can be obtained, by referring a database based on a type of a specified cutting tool and workpiece, and of a machining mode including an operating path of a movement of the cutting tool and workpiece, and by selecting a control parameter which relates to an adequate operating speed and operating position in the entire operating path during machining and non-machining.

Abstract: A control method for an NC machine tool is provided which ensures a high precision of the contouring control, and allows for extension of the drill life, and reduction in machining time.

Abstract: An abnormality detection apparatus for a tool (11) is described for judging abnormalities of a tool by a uniformly set threshold value in relation to a cutting load even in a machining process wherein a feed rate changes every moment. The abnormalities of the tool can be judged by the uniformly set threshold value on the basis of the tool load wherefrom the feed load that fluctuates upon the feed rate has been removed.

Abstract: A numerical control apparatus (1 or 20) comprising pecking operation controlling means (12) which make a feed drive system (14) retracted when a cutting load detected by cutting load detecting means (7) exceeds a reference value during a drilling process, the cutting load detecting means (7) comprise a bite load detecting section (8) to detect the cutting load at a biting stage wherein a tool bites a work piece, and a stationary load detecting section (10) to detect the cutting load after the biting stage. The numerical control apparatus (1 or 20) comprises pecking judgement means (11) to judge that the feed drive system (14) should be retracted when a fluctuation load exceeds a specified reference value wherein the fluctuation load is obtained by reducing the bite load from the detected stationary load. When it is judged that the feed drive system (14) should be retracted, the pecking operation controlling means (12) make the feed drive system (14) retracted.

Abstract: There is provided a machining control system which is capable of keeping the optimum machining states and enhancing the efficiency and the reliability even in the case where an actual machining environment fluctuates. A machining control system includes a machining information determination portion (102) for determining initial machining conditions (107) on the basis of information (105) stored in a machining data base (101) and in accordance with adaptive control characteristics (106) defined by adaptive control modes and adaptive control parameters, and an adaptive control portion (103) for controlling the machining in appropriate states by changing the machining conditions in accordance with the machining states observed during the machining with the initial machining conditions (107) as an initial value of the machining conditions.

Abstract: A CNC tapping machine includes a spindle to which a tap is attached and a spindle motor for rotating the spindle. The load torque acting on the spindle motor that is detected when performing a tapping procedure without a workpiece is stored in a memory as referential, torque data. During a tapping procedure, a detection device detects the load torque acting on the spindle motor. A computer computes the difference between the load torque defected by the detection device and the referential load torque and uses the difference as the cutting load acting on the tap. As a result, the cutting load torque acting on the tap is accurately detected.

Abstract: A numerical control (NC) device 10 for a machine tool 1 provided with a measurement probe 2b effects measurements of a work 4 on the machine table 5 after a working process. A measurement program, generated by the NC device by modifying a working program, controls the relative movement of the probe 2b with respect to the workpiece 4 such that the probe 2b moves along the contour of the worked portion of the workpiece 4 with a displacement from the neutral position thereof, wherein the displacement of the probe is sampled at a predetermined sampling period. A working error calculation program 17 calculates the working error from the sampled displacements. If the working error is judged correctable, a outside tolerance range and correction re-working is effected so as to reduce the working error. The measurement/re-working cycles are repeated until the working error is within tolerance.

Abstract: A numerical control device comprising a lost motion correction data calculating device having a table/function which represents the motor current of a servo motor, in a servo mechanism for servo-controlling a mechanical movable part. The motor current is detected at a given time instant, and the corresponding amount of lost motion correction is then calculated. The position error caused by the lost motion can be corrected with high accuracy.

Abstract: When a drill is overloaded, while cutting a hole in a workpiece, a torque limiter disconnects the drill from a main spindle. As the drill is disconnected from the main spindle, the torque limiter generates high-level elastic waves. The elastic waves are converted by a transducer into a voltage signal. The level of the voltage signal is compared with a threshold value.

Abstract: For detecting brittle fracture and wear of a tip of a cutting tool an acoustic emission monitoring system has a converter for converting acoustic emission into an electric signal, a filter for rejecting frequency components in the signal below a frequency between 50 kHz and 300 kHz, a detector to detect the amplitude of the signal after the rejection of those frequency components, and a comparator for comparing that amplitude to a predetermined reference amplitude.