Abstract: The table on which a workpiece is put can travel on a guide rail mechanism relative to a working head with a cutting tool mounted thereon. The table is connected through a nut to a ball screw part to move in an axial direction thereof as the ball screw part rotates. One end of the ball screw part is supported by a bearing and the other end is connected to a servomotor to be rotationally driven. A hollow part is provided in the table to receive therein a damper mechanism part, which comprises a spring, a damper, and a weight, the table and the weight being arranged to enable traveling separately on guide rails. Thereby, even when the workpiece is heavy, the weight can move relative to the table to effectively damp vibrations of the table in a feed direction.

Abstract: A cutting state quantity caused by processing, in which a cutting tool is rotated, is measured, cutting force components containing a fundamental and harmonics are extracted from a measured signal, a threshold for abnormality determination is calculated on the basis of harmonic ratios that are ratios between the fundamental and harmonics of the cutting force components, a cutting force is calculated from the extracted cutting force components, and an abnormality is determined on the basis of the calculated cutting force and the calculated threshold.

Abstract: Provided are a device and a method which determine a threshold value for detecting abnormality in a working path in which the cutting condition changes momentarily to thereby enable abnormality determination. Cutting force that becomes an abnormality determination value and threshold value information are previously calculated by cutting simulation, and a threshold value with which a comparison is to be made is determined from the position coordinates of a working machine which have been acquired during cutting and the measurement result of cutting force to thereby enable abnormality determination.

Abstract: The table on which a workpiece is put can travel on a guide rail mechanism relative to a working head with a cutting tool mounted thereon. The table is connected through a nut to a ball screw part to move in an axial direction thereof as the ball screw part rotates. One end of the ball screw part is supported by a bearing and the other end is connected to a servomotor to be rotationally driven. A hollow part is provided in the table to receive therein a damper mechanism part, which comprises a spring, a damper, and a weight, the table and the weight being arranged to enable traveling separately on guide rails. Thereby, even when the workpiece is heavy, the weight can move relative to the table to effectively damp vibrations of the table in a feed direction.

Abstract: In a cutting method of an oblique surface by a rotary tool, for analyzing in advance a stability limit depth of cut with respect to a self-excited cutting vibration in consideration of a pick feed amount and a work oblique angle and reducing the number of steps necessary for preparation and correction of NC data, a tool diameter, the number of cutting teeth and dynamic stiffness of the rotary tool, a cutting force coefficient determined by a combination of the tool and work materials, dynamic stiffness of the work, the pick feed amount, oblique angles between the tool and the work and the like are used as input values, an initial value of the stability limit depth of cut is determined based on the input values, and calculation is performed based on the initial value.

Abstract: A corner portion working tool includes: a main body portion 4 having a space 5 through which a cutting fluid can pass; and a blade portion 8 that is provided in the main body portion 4 and can be displaced outwardly of the main body portion 4, wherein the blade portion 8 is displaced outwardly of the main body portion 4 according to a change in hydrostatic pressure of the cutting fluid having passed through the space 5, and the main body portion 4 is rotated to work a corner portion with the blade portion 8. Thus, the corner portion working tool brings the blade portion for deburring or corner portion shape forming into contact with only a hole end surface, does not reduce quality of an inner wall surface of a hole, does not select a proper rotation condition, and easily performs deburring or corner portion shape forming.

Abstract: Disclosed herein is the structure of a damper that is capable of improving the degree of freedom in design to optimize the damping characteristics of the damper and is capable of allowing the damper to be easily optimized and manufactured for a wide variety of dynamic stiffness characteristics of a tool body, and a manufacturing method using the same. A plurality of ring-shaped elastic members are disposed at opposite ends of a weight part. The weight part is connected to the tool body via the elastic members. Consequently, the weight part is moved relative to the tool body. The plurality of elastic members are mounted while spacers are disposed between the elastic members, and the spacers are moved with respect to the weight part in the axial direction thereof. A viscous fluid is filled in the region surrounded by the outer circumferential surfaces of the spacers, the elastic members, and the inner surface of a hollow part of the tool body.

Abstract: A method for calculating depth of cut without any milling self-excited vibration. An initial value for machining-surface-perpendicular depth of cut is set. A cutting start angle and cutting end angle for a cutting edge is obtained, based on the initial value. A machining-surface-perpendicular depth of cut that causes no self-excited vibration is calculated. The maximum depth of cut that corresponds to the stability limit of a milling self-excited vibration is calculated, by repeating the calculation while modifying the initial value until the difference between the initial value and the calculation result becomes the same as, or smaller than, a given value. As a result, the stability-limit depth of cut is preliminarily analyzed to the milling self-excited vibration in consideration of a pick feed, the gradient angle of a workpiece, and a machining-surface curvature radius, so that man-hours required for creation and modification of NC data can be reduced.

Abstract: In a cutting method of an oblique surface by a rotary tool, for analyzing in advance a stability limit depth of cut with respect to a self-excited cutting vibration in consideration of a pick feed amount and a work oblique angle and reducing the number of steps necessary for preparation and correction of NC data, a tool diameter, the number of cutting teeth and dynamic stiffness of the rotary tool, a cutting force coefficient determined by a combination of the tool and work materials, dynamic stiffness of the work, the pick feed amount, oblique angles between the tool and the work and the like are used as input values, an initial value of the stability limit depth of cut is determined based on the input values, and calculation is performed based on the initial value.

Abstract: There is provided a method for calculating depth of cut without any milling self-excited vibration, in consideration of a machining condition, the rigidity of a machining tool, the machinability of a material, and the like; in the method, an initial value for the machining-surface-perpendicular depth of cut is firstly set, by utilizing as input values the curvature radius of a machining surface, a tool radius, a pick feed, the gradient angle between the machining surface and a rotation axis of the tool, and the number of tool edges; a cutting start angle and a cutting end angle for a cutting edge is obtained, based on the initial value; the machining-surface-perpendicular depth of cut that causes no self-excited vibration is calculated; and the maximum depth of cut that corresponds to the stability limit of a milling self-excited vibration is calculated, by repeating the calculation while modifying the initial value until the difference between the initial value and the calculation result becomes the same as

Abstract: Disclosed herein is the structure of a damper that is capable of improving the degree of freedom in design to optimize the damping characteristics of the damper and is capable of allowing the damper to be easily optimized and manufactured for a wide variety of dynamic stiffness characteristics of a tool body, and a manufacturing method using the same. A plurality of ring-shaped elastic members are disposed at opposite ends of a weight part. The weight part is connected to the tool body via the elastic members. Consequently, the weight part is moved relative to the tool body. The plurality of elastic members are mounted while spacers are disposed between the elastic members, and the spacers are moved with respect to the weight part in the axial direction thereof. A viscous fluid is filled in the region surrounded by the outer circumferential surfaces of the spacers, the elastic members, and the inner surface of a hollow part of the tool body.

Abstract: An electrode comprises an electrode main body having a porosity, and the conductivity of the electrode main body at its part ranging from the arc running face to a stated depth is made higher than the conductivity at the section or the conductivity at the part ranging from the back surface to a stated depth. This brings about an improvement in circuit-break performance of a circuit breaker and also prevents the arc running face of the electrode main body from deteriorating.

Abstract: An electrode comprises an electrode main body having a porosity, and the conductivity of the electrode main body at its part ranging from the arc running face to a stated depth is made higher than the conductivity at the section or the conductivity at the part ranging from the back surface to a stated depth. This brings about an improvement in circuit-break performance of a circuit breaker and also prevents the arc running face of the electrode main body from deteriorating.