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: 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: 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: 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: A pallet exchange apparatus for a machine tool includes a horizontal rotary support for rotation about a vertical axis. A drive unit vertically moves and rotates the rotary support. The rotary support is flanked by a setup stand which is pivotable between a lying position for receiving a pallet and an upright position for transferring the received pallet onto the rotary support. Further, the rotary support has a plurality of pallet receivers each provided on the rotary support for receiving the pallet in an erect posture from the setup stand which has been pivoted to the upright position.