Abstract: A grinding machine includes a pair of workpiece support devices (12, 13), which clamp and rotate a workpiece (W), on a bed (11). A pair of saddles (14) is provided on the bed (11) in such a way as to be movable along the rotational axis of the workpiece (W). Grindstone heads (16) provided with rotating grindstones (16c) and drive mechanisms (16d) are supported on the saddles (14) in such a way as to be movable in a direction that perpendicularly intersects the movement direction of the saddles (14).

Abstract: A center hole machining method includes first to fifth steps. The first step includes obtaining outer peripheral shape data of a plurality of portions of the shaft blank in an axial direction. The second step includes obtaining a center axis by comparing measured data of the portions of the shaft blank with design data. The third step includes calculating a minimum distance from the center axis to the outer periphery in each of the portions of the shaft blank. The fourth step includes shifting the center axis in a direction of making the minimum distance greater than the machining dimension and repeatedly executing the third step when the minimum distance is less than or equal to the machining dimension. The fifth step includes boring the center hole in an end surface of the shaft blank at a position arranged on a line extended from the center axis.

Abstract: A vertical outer circumferential cutter tip, which has an approximate hourglass shape that is narrower at its middle than at its ends, and all of its eight corners are acute angles. Both sides of the vertical outer circumferential cutter tip are relieved at an angle ?. When performing cutting processing upon the side surface of a counter weight with the vertical outer circumferential cutter tip, excessive friction is prevented. The shapes of the upper end portion and the lower end portion of the vertical outer circumferential cutter tip are formed so as to be very gently convexed, and with a relief of an angle ?. Abrasion of the upper end portion and the lower end portion of the vertical outer circumferential cutter tip is prevented before the acute angled corner used for cutting is damaged.

Abstract: A horizontal machine tool (1) includes a base frame (10) where workpiece support faces (11c) for supporting a workpiece are formed at front portions; an X-axis saddle (20) attached to a back-face portion (12b) of the base frame (10) through an X-axis movement mechanism (50) universally slidably in a left-right direction; a Y-axis saddle (30) attached to the X-axis saddle (20) through a Y-axis movement mechanism (60) universally slidably in an up-down direction; and a spindle device (40) attached to the Y-axis saddle (30) through a Z-axis movement mechanism (70) universally slidably in a front-rear direction. According to this configuration, it is possible to make a whole of the horizontal machine tool a small size and lightweight and to enhance machining accuracy of the workpiece.

Abstract: A processing apparatus includes a three-dimensional shape data acquiring section, a tentative center-hole position determining section, a shape simulating section, a balance deciding section, and a center-hole deciding section. The tentative center-hole position determining section is configured to determine a tentative position of the center holes based on the three-dimensional shape data. The shape simulating section is configured to obtain a simulated shape of the material crankshaft after a working is simulated for the material crankshaft based on the tentative position of the center holes as a reference. The balance deciding section is configured to decide whether a rotational imbalance amount in the simulated shape is within a predetermined allowable range. The center-hole deciding section is configured to decide the tentative position as an actual boring position of the center holes when the rotational imbalance amount is within the predetermined allowable range.

Abstract: A first grinding head is provided on a base frame via a first movable body and a first grinding base. The proximal portion of the tilt arm is tiltably fitted in the housing of the grinding head. A measuring device is rotatably coupled to a distal portion of the tilt arm. A gauge and a measuring pin are coupled to the lower end of the measuring device, and the gauge is engaged with a crankpin of a crankshaft. A tilt center of the tilt arm is arranged on the same axis as the rotation center of the first grindstone ISA. When the tilt arm is tilted, the position of the measuring device is changed, accordingly. However, since the relational relationship between the first grindstone ISA and the gauge is not changed, the position of the gauge is easily adjusted in accordance with the diameter of the crankpin. Accordingly, a grinding machine is provided that simplifies the movement path of the gauge of the measuring device, thereby allowing the outer diameter of the workpiece to be quickly measured.

Abstract: A reference block 30 attached to a housing 20a is moved together with a main spindle 20 to a measurement start position A1, and the reference block 30 is so moved in a Z-axis direction as to across air injected from an air injection nozzle 25, so that a thermal displacement of the main spindle 20 is calculated based on change in pressure measured in the movement. The outer circumference of a tool mounted on the main spindle 20 is brought close to a leading end face of the air injection nozzle 25, and the air is injected to the outer circumference of the tool while rotating the tool at a predetermined position, and the air pressure is measured so that the rotational deflection of the tool is calculated based on the change in the measured pressure.

Abstract: A machine tool including a base frame, a workpiece table, a machining unit, and a connection portion is disclosed. The base frame has a machining area. The base frame includes two left and right side frames and a connection frame connecting the two side frames. The workpiece table is arranged on the base frame in the machining area. The machining unit is arranged on an upper portion of the base frame and includes a spindle device. A connection portion connects the machining unit and the base frame in a detachable manner.