A machine tool includes: a spindle unit for rotatably supporting a spindle; a moving mechanism for moving the spindle unit; a motor for driving the moving mechanism; a motor control unit for controlling the motor; and an estimation unit for estimating that abnormal vibration is likely to have occurred in the spindle when the amplitude of a signal indicating the driving state of the motor falls out of a predetermined allowable range.

The present invention is directed to a system for determining the structural characteristics of a machine tool. The system comprises an excitation device configured to induce a dynamic excitation in a tool of the machine tool, a preloading device configured to generate a static force on the tool, and a sensing device for acquiring a set of data based on which the structural characteristics of the tool can be determined.

The present invention is directed to a system for determining the structural characteristics of a machine tool. The system comprises an excitation device configured to induce a dynamic excitation in a tool of the machine tool, a preloading device configured to generate a static force on the tool, and a sensing device for acquiring a set of data based on which the structural characteristics of the tool can be determined.

A machining center for machining a center groove on a pulley and a flange formed at opposite ends of a crankshaft of a vehicle includes a measurement unit configured to measure a moment of the crankshaft when the crankshaft is loaded and actuated, a control unit configured to calculate an imbalance amount of the crankshaft and to derive center drill coordinates for removing the imbalance amount, a compensation unit mounted in a base frame and configured to compensate a position of the crankshaft by rotating first and second rotating elements based on the center drill coordinates inputted from the control unit when the crankshaft is transported and clamped by a clamping system, and a machining unit configured to machine the center groove in the pulley and the flange of the crankshaft.

A machining state display apparatus includes an achievement degree data storage (9) storing machining condition data relating to each of sets of machining conditions and achievement degree data relating to degrees of achievement of evaluation items to be obtained in machining under each of the sets of machining conditions, with the machining condition data and the achievement degree data being associated with each other, a display part (2) displaying a set of machining conditions and degrees of achievement of the evaluation items corresponding thereto on a display (5), and an input part (6) inputting a signal for selecting one from the evaluation items and a required degree of achievement for the selected evaluation item. The display part (2) recognizes, based on the selected evaluation item and the required degree of achievement, a set of machining conditions corresponding to the required degree of achievement for the selected evaluation item as well as the degrees of achievement of other evaluation items to be obtained under the set of machining conditions by referring to the achievement degree data storage (9), and displays the recognized degrees of achievement on evaluation-item basis and displays the recognized set of machining conditions.

A machining state display apparatus includes an achievement degree data storage (9) storing machining condition data relating to each of sets of machining conditions and achievement degree data relating to degrees of achievement of evaluation items to be obtained in machining under each of the sets of machining conditions, with the machining condition data and the achievement degree data being associated with each other, a display part (2) displaying a set of machining conditions and degrees of achievement of the evaluation items corresponding thereto on a display (5), and an input part (6) inputting a signal for selecting one from the evaluation items and a required degree of achievement for the selected evaluation item. The display part (2) recognizes, based on the selected evaluation item and the required degree of achievement, a set of machining conditions corresponding to the required degree of achievement for the selected evaluation item as well as the degrees of achievement of other evaluation items to be obtained under the set of machining conditions by referring to the achievement degree data storage (9), and displays the recognized degrees of achievement on evaluation-item basis and displays the recognized set of machining conditions.

A vibration state detection device includes an imaging device configured to image at least one driven element to be driven by a drive unit of a machine tool; and a vibration state analysis unit configured to calculate a parameter corresponding to vibration of the driven element, based on image data for each predetermined period of elapsed time acquired by the imaging device. The parameter includes at least a vibration frequency and a machine tool including the vibration state detection device. Accordingly, it is possible to reliably obtain a parameter corresponding to vibration caused by cutting, even if cutting oil, chips, or the like adheres to a tool of a machine tool, and it is possible to suppress vibration caused by cutting.

A vibration state detection device includes an imaging device configured to image at least one driven element to be driven by a drive unit of a machine tool; and a vibration state analysis unit configured to calculate a parameter corresponding to vibration of the driven element, based on image data for each predetermined period of elapsed time acquired by the imaging device. The parameter includes at least a vibration frequency and a machine tool including the vibration state detection device. Accordingly, it is possible to reliably obtain a parameter corresponding to vibration caused by cutting, even if cutting oil, chips, or the like adheres to a tool of a machine tool, and it is possible to suppress vibration caused by cutting.

A machine tool includes: a main spindle that holds a work piece; a tool holding unit that holds a tool for processing the work piece; a detection unit that detects vibration generated during processing of the work piece; and a processor that controls machining of the work piece performed by the tool, in which the processor compares a detected value detected by the detection unit with a predefined threshold value, interrupts the machining by releasing contact between the work piece and the tool at time of generation of chatter vibration or when there is a sign of the generation of the chatter vibration in which the detected value exceeds the threshold value, and analyzes the chatter vibration while the machining is being interrupted on basis of the detected value detected by the detection unit before the interruption.

A machine tool includes: a main spindle that holds a work piece; a tool holding unit that holds a tool for processing the work piece; a detection unit that detects vibration generated during processing of the work piece; and a processor that controls machining of the work piece performed by the tool, in which the processor compares a detected value detected by the detection unit with a predefined threshold value, interrupts the machining by releasing contact between the work piece and the tool at time of generation of chatter vibration or when there is a sign of the generation of the chatter vibration in which the detected value exceeds the threshold value, and analyzes the chatter vibration while the machining is being interrupted on basis of the detected value detected by the detection unit before the interruption.