Abstract: In a workpiece fixing jig, at least a top surface and a bottom surface of a base plate is made of fiber reinforced plastic. The base plate has an attachment hole that extends through the base plate in a thickness direction, and an insert member made of a metal is attached to the base plate such that the insert member is inserted in the attachment hole. The insert member has a flow path hole that functions as a fluid channel for enabling fluid to through the base plate.

Abstract: A main shaft drive includes a supply groove that opens to a friction surface, that extends so as to surround a main shaft within a contact range where the friction surface and a pressing surface oppose each other, and that includes an intersecting groove and a discharge opening. The intersecting groove extends in a direction of intersection with a circumference in which a rotational center of the main shaft is a center. The discharge opening is connected to a location that is outside the contact range. By opening a nozzle hole, used for supplying lubricant, towards the supply groove, as the main shaft rotates, four intersecting grooves move relative to the contact range, so that the lubricant is supplied to the four moved intersecting grooves. Therefore, the lubricant easily reaches a location within the contact range where the friction surface and the pressing surface oppose each other.

Abstract: In a spindle head for a machine tool in which a spindle (10) to which a tool is mounted is rotated around an axial line of a support shaft (58, 59), two rotating members (9, 58) that form a rotation transmission mechanism for rotating the spindle (10) and that transmit drive force of the rotation driving device (56) are fastened to each other at respective connection sections thereof by a bolt group (301) and are connected to each other so as to be prevented from rotating relative to each other by friction force resulting from the fastening. Rotation prevention torque based on the friction force is a value greater than torque applied to the connection sections during processing and smaller than torque applied to the connection sections when external force that causes the spindle (10) to deform beyond a permissible range is applied to the spindle (10).

Abstract: An index device for a machine tool includes a rotary shaft (40) to which a drive object is attached, a housing (30) surrounding the rotary shaft (40), a bearing (BI, B2) secured between the housing (30) and the rotary shaft (40) by a securing member (30b), and a drive (M) provided around the rotary shaft (40) and including a rotor (M1a, M2a) and a stator (M1b, M2b). The stator (M1b, M2b) is attached to the housing (30) and the rotor (M1a, M2a) is attached to the rotary shaft (40). The rotary shaft (40), the bearing (BI, B2), the rotor (M1a, M2a), and the securing member (30b) are connected together to form a built-in unit (22) that can be inserted into and extracted from an enclosure unit including a casing member (30a, 31a) of the housing (30) and the stator (M1b, M2b), thus facilitating connection and disconnection of wiring between the stator of a DD motor mounted in a spindle head of a machine tool and a main body of the machine tool.

Abstract: Intended is to unitize a clamp device for a rotation indexing apparatus for a machine tool, thereby facilitating the maintenance of the clamp device and the assembly of the indexing apparatus including the clamp device. The rotation indexing apparatus (1) for the machine tool comprises the clamp device (2) for clamping a clamp disc (11) by causing a clamp element (6) to exert a pressing force on the clamp disc (11), thereby to bring a rotary drive target member (4) such as a circular table into a clamped state. Of the individual members constituting the clamp device (2), the individual major members excepting the clamp device (11) to be mounted on a rotating shaft (5) are unitized.

Abstract: In an unbalance torque compensating device, the supporting member has an engagement surface that receives, through the engaging portion, a first rotary torque T1 applied to the rotating shaft. The urging member causes a second rotary torque T2 in a direction opposite to the first rotary torque T1 to be generated at the rotating shaft through the engaging portion.

Abstract: An angular indexing apparatus for a machine tool includes a rotating shaft to which a rotationally driven member is secured; a housing, surrounding the outer periphery of the rotating shaft and mounted to and removed from the body of the machine tool; bearings disposed between the housing and the rotating shaft, and driving means disposed between the housing and the rotating shaft and rotating the rotating shaft to index an angular position. The driving means includes drive motors, each including a motor rotor and a motor stator concentrically disposed around the rotating shaft in the housing. The housing has wiring holes in a thick-walled internal portion of an outer cylinder surrounding the outer periphery of the rotating shaft. The wiring holes are provided along an axial direction of the rotating shaft. The wiring holes receive at least upstream portions in entire lengths in a drawing-out direction of cables connected to the driving motors.

Abstract: A clamping device in a main shaft driving device for a machine tool, in which the main shaft driving device rotationally driving a main shaft by a driving device, the clamping device includes: a braking member provided at a side of the frame and including a pressure-receiving surface and a braking portion; a pressure chamber formed by the pressure-receiving surface and the frame; and an operating fluid supplying mechanism provided for supplying the operating fluid from an operating fluid supply source to the pressure chamber. The press-contact force is caused to act upon the main shaft. The operating fluid supplying mechanism includes a switching portion that selectively supplies the operating fluid. The braking member is formed so that the braking portion causes the press-contact forces that differ from each other.

Abstract: In a rotary index device for a machine tool, in which the index position of, for example, a circular table is maintained by normally clamping a clamp disc with a clamping mechanism and in which, for example, the circular table is unclamped by an unclamping mechanism when an indexing operation is performed, the clamping mechanism includes a fixing portion, a resiliently deformable supporting portion, and an urging mechanism. The fixing portion is fixed to a housing of the rotary index device for the machine tool. One end of the supporting portion is secured to the fixing portion, and a pressing portion having a face that opposes the clamp disc is secured to the other end of the supporting member. The urging mechanism normally urges the supporting portion towards the clamp disc to realize a state in which the clamp disc is pressed by the pressing portion.

Abstract: A clamp sleeve for an indexing device is provided, the clamp sleeve being capable of providing a desirable clamping force without greatly increasing a fluid pressure, and having a long life. A clamp sleeve 34a has a through hole 34a7 and an annular groove 34a1 continuously provided around an outer periphery of the clamp sleeve 34a and defining a part of a pressure chamber 34d. The annular groove 34a1 includes a pair of inner end surfaces 34e6, 34e6?, a groove bottom surface 34e0 extending in parallel to the through hole 34a7, and arcuate first transition surfaces 34e1, 34e1? provided between the inner end surfaces 34e6, 34e6? and the groove bottom surface 34e0. The annular groove 34a1 is provided such that a thickness t1 in a region provided with the groove bottom surface 34e0 is a thickness to allow the region to be deformable.

Abstract: A cylindrical pressure-receiving member 34b is arranged in a space between a ring-shaped clamp sleeve 34a and a frame 31b such that the clamp sleeve 34a is fitted around a shaft 38b being integral with a rotary shaft 39. In an outer peripheral portion 34a2 of the clamp sleeve 34a, an annular groove 34a1 provided continuously over the entire circumference within an axial area of the outer peripheral portion 34a2 fitted into an inner peripheral portion 34b3 of the pressure-receiving member 34b provides a thin-wall portion 34a5. Also, a space surrounded by the annular groove 34a5 and the pressure-receiving member 34b provides a pressure chamber 34d communicating with a fluid control circuit. A predetermined gap 34d2 is provided between an inner peripheral surface 31b4 of the through hole 31b1 of the frame and an outer peripheral surface 34b2 of the pressure-receiving member 34b.

Abstract: A clamping device in a main shaft driving device for a machine tool, which rotationally drives a main shaft, wherein the main shaft is rotatably supported by a frame. The clamping device includes a clamp piston, a pressure chamber and an operating fluid supplying mechanism, wherein the clamp piston has a first pressure-receiving surface and a second pressure-receiving surface, the first pressure-receiving surface receiving the spring force of a spring member, the second pressure-receiving surface receiving pressure of an operating fluid, wherein the operating fluid supplying mechanism includes a switching portion that selectively supplies the corresponding operating fluid from a common operating fluid supply source to at least one of a first pressure chamber and a second pressure chamber.

Abstract: A clamping device in a main shaft driving device for a machine tool, which rotationally drives a main shaft, wherein the main shaft is rotatably supported by a frame. The clamping device includes a clamp piston, a pressure chamber and an operating fluid supplying mechanism, wherein the clamp piston has a first pressure-receiving surface and a second pressure-receiving surface, the first pressure-receiving surface receiving the spring force of a spring member, the second pressure-receiving surface receiving pressure of an operating fluid, wherein the operating fluid supplying mechanism includes a switching portion that selectively supplies the corresponding operating fluid from a common operating fluid supply source to at least one of a first pressure chamber and a second pressure chamber, the first pressure chamber being formed by the first pressure-receiving surface and the frame, the second pressure chamber being formed by the second pressure-receiving surface and the frame.

Abstract: A machining head has a support head component, which includes first and second support segments and a base segment supporting both the first and second support segments, the support segments being disposed opposite to each other across the spindle unit to hold the spindle unit therebetween such that a center of axle thereof is aligned with a rotary axis line thereof, the first and second support segments respectively including support shafts whose opposing end surfaces have the spindle unit secured thereto. The support segments respectively include housings as main bodies that are independent of the base segment. The housings accommodate the support shafts. Each housing is attached to the base segment by means of a plurality of first screw members that are screwed to the base segment and are manipulatable from the outside. The spindle unit is attached to the support shafts by means of a plurality of second screw members that are screwed to the support shafts and are manipulatable from the outside.

Abstract: A machining head (10) for a machine tool includes a spindle unit (20) to which a tool is attachable and a support head component (30, 60) that includes an index mechanism for indexing an angular position of a spindle (21). The index mechanism includes a drive motor (33, 63) supported by a bearing (35, 65) within the housing (31a, 61) of the support head component (30, 60) and a rotary joint (37, 67) disposed concentrically with the bearing (35, 65) and the drive motor (33, 63). The bearing (35, 65) is disposed within a range occupied by the drive motor (33, 63) in an axial direction of a support shaft (32, 37b, 62, 67c), and the rotary joint (37, 67) is disposed within the drive motor (33, 63) in a radial direction thereof.

Abstract: A main shaft drive includes a supply groove that opens to a friction surface, that extends so as to surround a main shaft within a contact range where the friction surface and a pressing surface oppose each other, and that includes an intersecting groove and a discharge opening. The intersecting groove extends in a direction of intersection with a circumference in which a rotational center of the main shaft is a center. The discharge opening is connected to a location that is outside the contact range. By opening a nozzle hole, used for supplying lubricant, towards the supply groove, as the main shaft rotates, four intersecting grooves move relative to the contact range, so that the lubricant is supplied to the four moved intersecting grooves. Therefore, the lubricant easily reaches a location within the contact range where the friction surface and the pressing surface oppose each other.

Abstract: A slide disk that is displaceable when the slide disk is bent toward a base section of a frame is provided at a main shaft, and a friction surface that can contact a pressing portion of the slide disk is provided at the base section. The pressing portion of the slide disk normally presses the friction surface to cause the pressing portion of the slide disk to normally press the friction surface, and hence a pressing force for applying to the main shaft a rotational resistance that permits rotation of the main shaft normally acts on the main shaft. Accordingly, even if the position of the center of gravity of a member to be rotated is deviated from a rotation axis of the main shaft, the rotational resistance can be applied to the main shaft.

Abstract: A support shaft of a spindle unit having a through hole in which wires are laid has a structure that can obtain much spatial room so as to prevent a break in cables and to be compatible with a high-output spindle motor. A machine-tool spindle head 1 includes a support head 6 that drives a spindle unit 4 for indexing around a turn axis (A-axis) of the spindle unit 4 by rotatably supporting a pair of support shafts 9 coupled to the spindle unit 4 on the A-axis by a pair of fork arms 7 and bearings 13. The pair of support shafts 9 have through holes 12 in which a plurality of wires 22 extending from the spindle unit 4 are laid, the plurality of wires 22 are divided into two wire groups, and the wire groups are separately laid in the pair of support shafts 9.

Abstract: A rotational resistance applying device in which a hollow roller is provided between a first surface of a clamp piston (pressing member) and a second surface of a sliding disc (a press member), and in which a pressing force applied to the clamp piston acts upon the sliding disc through the hollow roller that press-contacts the first and second surfaces by displacement of the clamp piston. By this, rolling resistance of the hollow roller resiliently deformed by the pressing force causes a rotational resistance to be applied to a main shaft within a range allowing rotation. This makes it possible to prevent pulsation from being generated in the rotation of the main shaft. In addition, even if the pressing force is applied to the clamp piston, the hollow roller rolls, so that wear of the clamp piston and wear of the sliding disc can be restricted.

Abstract: To provide a spindle device and a machining center, in which spindle replacement can be carried out in an extremely short time, downtime during maintenance is short, and productivity is high. In a spindle device 20, there are provided wirings 41, 42 extended from a spindle 30 and wired to support arms via a bracket 21, and joint components 74, each provided at a position a predetermined length extended from extended parts for the wirings 41, 42, are accommodated within the bracket 21.