Abstract: A vertical machining center includes a table, a tool spindle, an angle tool holder, a tool unclamping operation device, and a tool changer. The angle tool holder includes a shank, a spindle, a housing, a collet, a draw bar, and a spring mechanism. The shank has a shank axis and is rotatable around the shank axis. The spindle has a spindle axis perpendicular to the shank axis and is rotatable around the spindle axis. The tool unclamping operation device includes an angle tool holder rest, a hydraulic piston, and a restrictor. The angle tool holder is to be placed on the angle tool holder rest. The restrictor is disposed on the angle tool holder rest to restrict a portion of the angle tool holder and to receive force in a direction of the spindle axis which is generated in a case where the hydraulic piston presses the draw bar.

Abstract: A vertical machining center includes a table, a tool spindle, an angle tool holder, a tool unclamping operation device, and a tool changer. The angle tool holder includes a shank, a spindle, a housing, a collet, a draw bar, and a spring mechanism. The shank has a shank axis and is rotatable around the shank axis. The spindle has a spindle axis perpendicular to the shank axis and is rotatable around the spindle axis. The tool unclamping operation device includes an angle tool holder rest, a hydraulic piston, and a restrictor. The angle tool holder is to be placed on the angle tool holder rest. The restrictor is disposed on the angle tool holder rest to restrict a portion of the angle tool holder and to receive force in a direction of the spindle axis which is generated in a case where the hydraulic piston presses the draw bar.

Abstract: The invention provides an angle tool holder to be disposed on an attachment attached to a spindle head of a vertical machining center and holding the angle tool holder to enable five-face machining of a workpiece. The angle tool holder denoted as a whole by reference number 500 has a shank 510 inserted to a spindle of the main machine, wherein a rotation of the shank 510 is transmitted via a gear transmission mechanism or the like disposed in a housing 540 so that the direction of a drive shaft thereof is varied orthogonally to thereby drive the angle cutter 520. An arm 550 connected to the housing 540 has three pull stud bolts 570 disposed thereon. The three pull stud bolts 570 are arranged at 90-degree intervals, and are clamped simultaneously by three collet chucks out of the four collet chucks disposed on the attachment unit for five-face machining.

Abstract: The present invention provides an attachment to be attached to a spindle head of a vertical machining center for gripping an angle tool holder and performing five-face machining. An attachment unit 100 for five-face machining comprises a ring-shaped cylinder member 110 fixed to a lower portion of a spindle head, and a clamp unit 130 directly connected to a piston disposed in the interior of a cylinder member. The clamp unit 130 is equipped with four collet chucks 140 for gripping a pull stud bolt 270 disposed on an arm 250 of an angle tool holder 200 attached to a spindle and drives an angle tool 220.

Abstract: The invention provides an angle tool holder to be disposed on an attachment attached to a spindle head of a vertical machining center and holding the angle tool holder to enable five-face machining of a workpiece. The angle tool holder denoted as a whole by reference number 500 has a shank 510 inserted to a spindle of the main machine, wherein a rotation of the shank 510 is transmitted via a gear transmission mechanism or the like disposed in a housing 540 so that the direction of a drive shaft thereof is varied orthogonally to thereby drive the angle cutter 520. An arm 550 connected to the housing 540 has three pull stud bolts 570 disposed thereon. The three pull stud bolts 570 are arranged at 90-degree intervals, and are clamped simultaneously by three collet chucks out of the four collet chucks disposed on the attachment unit for five-face machining.

Abstract: The present invention provides an attachment to be attached to a spindle head of a vertical machining center for gripping an angle tool holder and performing five-face machining. An attachment unit 100 for five-face machining comprises a ring-shaped cylinder member 110 fixed to a lower portion of a spindle head, and a clamp unit 130 directly connected to a piston disposed in the interior of a cylinder member. The clamp unit 130 is equipped with four collet chucks 140 for gripping a pull stud bolt 270 disposed on an arm 250 of an angle tool holder 200 attached to a spindle and drives an angle tool 220.