9 results about "Chatter vibration" patented technology

Provided is a cutting insert that allows for a large degree of cutting flexibility while making it easier to avoid large chatter vibrations. A land surface has, in a cross section orthogonal to the cutting edge, a convex-curved first land surface, a convex-curved second land surface, and a concave-curved third land surface. In the cross section orthogonal to the cutting edge, the radius of curvature of the first land surface is smaller than the radius of curvature of the second land surface.

Provided is a rotary tool capable of performing stable cutting while not readily generating chatter vibration. According to the present invention, a second twist angle and a fourth twist angle are each constant, the fourth twist angle is greater than the second twist angle, a third twist angle increases with proximity to a rear end, and the length of a third region in a direction following a rotary axis is greater than the length of a second region and greater than the length of a fourth region.

In an end mill having three or more odd-numbered gashes provided at the tip of a tool body to form three or more odd-numbered bottom edges, when performing cutting by rotating the tool body at high speed, chatter vibration of the tool body is prevented, the finish of the machined surface of the workpiece is improved, and the chip evacuation property is enhanced. 【Solution means】 In an end mill in which three gashes 11a to 11c are provided at the tip of a tool body 10 to form three bottom edges 13a to 13c, while one bottom edge 13a is formed so as to reach the rotation center o, and the other bottom edges 13b and 13c are formed so as not to reach the rotation center, the size of the gashes provided corresponding to each bottom edge is adjusted to bring the center of gravity of the tool body closer to the rotation axis L.

Provided is a control device for a machine tool capable of reducing adverse effects due to rapid changes in periodic fluctuations in the rotation speed of a main spindle while maintaining an effect of suppressing regenerative self-excited chatter vibration. This control device for a machine tool includes a fluctuation command calculation unit configured to calculate a fluctuation command based on a speed command for a main spindle motor of the machine tool and a fluctuation condition for causing a rotation speed of the main spindle motor to periodically fluctuate, and a speed control unit configured to control the rotation speed of the main spindle motor based on the speed command and the fluctuation command. The fluctuation command calculation unit is configured to calculate, when the fluctuation condition is changed, the fluctuation command in which an amplitude of the rotation speed that periodically fluctuates and / or a frequency of the rotation speed that periodically fluctuates gradually changes.

This invention provides a technology for identifying the type of chatter vibration occurring when chatter vibration is present. [Solution] The method for analyzing self-excited chatter vibration includes a first step (S10) of acquiring vibration data in two directions different from the tool rotation axis direction, a second step (S12) of acquiring the frequency components of the self-excited chatter vibration in two directions from the vibration data in two directions, and a third step (S14) of determining whether or not mode-coupling type chatter vibration is occurring based on the frequency components of the self-excited chatter vibration in two directions.

Vibration information display device (10) for a machine tool in which a tool or a workpiece is rotated to machine the workpiece, wherein the vibration information display device (10) is arranged in the machine tool which has a vibration detection system configured to detect chatter vibrations occurring during machining, wherein the vibration information display device (10) comprises: a monitor (19) configured to display information about the chatter vibrations; a vibration information acquisition unit configured to acquire vibration information when chatter vibrations are detected; a work information acquisition unit that is configured to acquire work information from the machine tool when chatter vibrations are detected; a storage unit (15) that stores the acquired vibration information and work information; a display control unit (18) configured to display the vibration information and work information stored in the memory unit (15) on the monitor (19), or alternatively, the display control unit (18) configured to display the vibration information stored in the memory unit (15) together with trajectory information of a cutting edge of the tool contained in the work information on the monitor (19); a vibration limitation function that is configured to ensure a limitation of the detected chatter vibrations, wherein the display control unit (18) is configured to display the vibration information together with an achieved state of the vibration limitation function on the monitor (19); and an input unit to the monitor (19), wherein When the input unit is operated, the display control unit (18) is configured to display a screen regarding countermeasures to limit the chatter vibrations, wherein In order to display the vibration information together with the trajectory information of the cutting edge of the tool on the monitor (19), the display control unit (18) is configured to display a position of the chatter vibrations on a trajectory of the cutting edge of the tool, and, when the position is selected with the input unit, the display control unit (18) is configured to display the screen regarding countermeasures to limit the chatter vibrations at the position selected on the monitor (19), wherein the display control unit (18) is configured to ensure change information required to generate the screen with the input unit.

To accurately detect chatter sound generated from a workpiece and reliably detect the occurrence of chatter vibration even when the background noise level is high, such as when cutting sound generated from another machine tool and environmental noise are both high.SOLUTION: There is provided an abnormality detection method during cutting machining. In order to separate an abnormal sound caused by a cutting abnormality from background noise, sound in a band of 10 kHz or higher is detected and an acoustic signal is subjected to Fourier transformation, and Fourier-transformation data during abnormal cutting machining is obtained by comparison with Fourier-transformation data during normal cutting machining, thereby performing abnormality detection. In this process, a cutting instrument that moves between a cutting machining position and an initial position away from the cutting machining position is used as a cutting instrument for cutting machining. A movement state of the cutting instrument is detected by a sensor, and abnormality detection is performed using Fourier-transformation data at the time when the cutting instrument is present at the cutting machining position.SELECTED DRAWING: Figure 5

A chatter vibration damping method for damping chatter vibrations of a machine tool that performs cutting work by rotating a rotating body containing a workpiece (4) or a tool according to a machining program stored in a storage unit (11), comprising: - an inertia detection step (S3) to detect the moment of inertia of the rotating body; - a recording step (S4) to record the value of the detected moment of inertia in the machining program; and - a calculation step (S5) to calculate the variable amplitude and the variable period from the value for the moment of inertia recorded in the machining program and the maximum power consumption of a motor (6) for rotating the rotating body when the speed of the rotating body is varied in order to dampen the chatter vibrations.

The present invention provides a machine tool and control device that can obtain modal parameters without performing a hammering test. [Solution] A machine tool 10 comprising a spindle 110, a rotating mechanism 120, a tool 210, a moving mechanism for relatively moving the spindle 110 and the tool 210, a displacement detection unit 210X for detecting the displacement of the tool 210, and a cutting force detection unit 210Y, further comprising a control unit C having an acquisition unit C1 for acquiring detected machining data, a storage unit C2 for storing the machining data, and a calculation unit C3 for calculating the machining data, wherein the control unit C uses the machining data stored in the storage unit C2 under multiple machining conditions when chatter vibration occurs to cause the calculation unit C3 to identify the equivalent mass m, damping coefficient c, and spring constant k when the structure involved in holding the tool 210 is treated as a 1-degree-of-freedom vibration model.