Abstract: A machining tool forms a first relief surface, a valve seat surface, and a second relief surface by cutting the inner periphery of a valve seat blank having an opening. The machining tool is provided with: a tool body rotationally driven about an axis; a plurality of cutting tools rotating with the tool body; a cartridge mounted to the tool body so as to be capable of moving forward and backward along the axis; and a cam in contact with the base end surface of the cartridge and moving the cartridge forward and backward. At least one of the plurality of cutting tools is mounted to the cartridge.

Abstract: In a tool holding portion of a machining tool, a cartridge is provided so as to be movable forward and backward. A cam accommodated inside a cam accommodation portion rotates while the cam is in abutment against the cartridge to thereby move the cartridge forward and backward. A rod which moves forward and backward inside a tool body along an axis is provided with an abutment portion. The abutment portion abuts against an abutment position of the cam according to the forward and backward movement of the rod to thereby rotate the cam. A restriction mechanism is capable of adjusting the phase of the cam when the abutment portion is apart from the abutment position so that a reference position is reached where the abutment position faces the abutment portion.

Abstract: A machining tool forms a first relief surface, a valve seat surface, and a second relief surface by cutting the inner periphery of a valve seat blank having an opening. The machining tool is provided with: a tool body rotationally driven about an axis; a plurality of cutting tools rotating with the tool body; a cartridge mounted to the tool body so as to be capable of moving forward and backward along the axis; and a cam in contact with the base end surface of the cartridge and moving the cartridge forward and backward. At least one of the plurality of cutting tools is mounted to the cartridge.

Abstract: Actuator of a connecting-rod fracture splitting apparatus includes: a piston rod having one end portion extending through a lid of the cylinder and connected to a wedge; and a free piston slidably mounted on the piston rod and abuttable against the upper surface of the piston. By pressure fluid being supplied to act on the upper surface of the piston, the free piston imparts a preload to a hole of a big end section of the connecting rod. By pressure fluid being supplied to act on a region upward of the free piston, the free piston is driven downward to collide against the upper surface of the piston, so that divided mandrel members are moved apart from each other, via the piston rod and the wedge, to fracture a large end section of the connecting rod.

Abstract: A disc-shaped grindstone 1 includes a plurality of split grindstones provided in an outer circumferential surface of a disc-shaped base 3. At least a part of the split grindstones include a moving grindstone 6 which is movable in the axial direction of the disc-shaped base 3. Since a part of the split grindstones 4 is the moving grindstone 6 which is movable in the axial direction, the width of the disc-shaped grindstone 1 may be changed in a manner such that the moving grindstone 6 is moved in the axial direction. Accordingly, it is possible to promptly handle a plurality of kinds of grinding targets without replacing the disc-shaped grindstone 1.

Abstract: Actuator of a connecting-rod fracture splitting apparatus includes: a piston rod having one end portion extending through a lid of the cylinder and connected to a wedge; and a free piston slidably mounted on the piston rod and abuttable against the upper surface of the piston. By pressure fluid being supplied to act on the upper surface of the piston, the free piston imparts a preload to a hole of a big end section of the connecting rod. By pressure fluid being supplied to act on a region upward of the free piston, the free piston is driven downward to collide against the upper surface of the piston, so that divided mandrel members are moved apart from each other, via the piston rod and the wedge, to fracture a large end section of the connecting rod.

Abstract: A disc-shaped grindstone 1 includes a plurality of split grindstones provided in an outer circumferential surface of a disc-shaped base 3. At least a part of the split grindstones include a moving grindstone 6 which is movable in the axial direction of the disc-shaped base 3. Since a part of the split grindstones 4 is the moving grindstone 6 which is movable in the axial direction, the width of the disc-shaped grindstone 1 may be changed in a manner such that the moving grindstone 6 is moved in the axial direction. Accordingly, it is possible to promptly handle a plurality of kinds of grinding targets without replacing the disc-shaped grindstone 1.

Abstract: A connecting rod is formed by cold forging in a single pressing cycle at a good accuracy without separately preparing a large-end cap, to thereby reduce the manufacturing cost. A double-action type of forging apparatus is made up of an upper die, a lower die, and a large-end portion punch and a small-end portion punch, both being movably provided in each of the dies. The upper die is closed to the lower die while forging a preform, to thereby roughly form a connecting rod. Then, the large-end portion punch and the small-end portion punch are protruded into a forming space between both the upper and lower dies to forge the parts to be pierced, thereby filling underfilled parts with material. Then, the large-end portion punch and the small-end portion punch on the side of the upper die are pushed out of the forming space to reach the lower die. The underfills left in the parts to be pierced are blanked or punched away to form a large-end hole and a small-end hole.

Abstract: A slotting apparatus has a slotting tool for producing a slot of a substantially arcuate cross section axially in an inner circumferential surface of a tubular workpiece held in position. When the slotting tool moves in one direction axially in the tubular workpiece, it follows an arcuate path by moving progressively toward and away from the inner circumferential surface of the tubular workpiece. The slotting tool cuts off the inner circumferential surface of the tubular workpiece, forming an arcuate slot therein. When the slotting tool moves back, it is spaced from the slotted surface region of the workpiece, and travels along a straight path back to its starting position. The slotting tool is supported on a tool support angularly movably supported by first and second link arms in a casing.