A mold machining method using an endmill, the contour of a cross section of the mold being concave and continuous in an area, a ratio of the maximum to the minimum of radius of curvature of the contour of a portion of the area (a first area) being 2 or greater, and a blade of the endmill having a second area where the contour of a cross section is similar to the contour of the first area, the method comprising the steps of determining a spiral path of the endmill such that each point of the first area is machined by a portion of the second area, corresponding to said each point in the similarity, and a radial interval between the spiral tool path is maximized while keeping surface roughness of the machined mold at or below a predetermined value; and machining the mold along the path.

A tool (T) is provided with: a shaft-like tool body (11) having a first end portion (11a) extending along a central axis line (Ot) and attached to a main shaft, and a second end portion (11b) on an opposite side to the first end portion (11a); and a fore end portion (12) connected to the second end portion (11b) of the shaft-like tool body (11). The fore-end portion (12) includes a central portion (13) including a fore-end face (17) of the tool (T), and a plurality of blade portions (14) protruding radially outward from the central portion (13). A cutting blade of each blade portion (14) includes a main cutting blade (15) adjacent to the fore-end face (17). The main cutting blade (15) includes an outline that forms an angle of 30-150 degrees with respect to the central axis line (Ot) in a cross-sectional view including the central axis line (Ot).

Certain embodiments of the present disclosure provide an acoustic inlet barrel of an engine. The acoustic inlet barrel may include an inner barrel configured to provide a boundary for directing airflow through the engine. The inner barrel may include an inner face sheet separated from an outer face sheet by an acoustic core. The inner barrel may include a plurality of elongated, non-circular perforations formed through the inner face sheet.

A manufacturing method of a casing includes a step of preparing a casing forming member that includes a casing body forming portion which is formed in a tubular shape and a protruding portion forming portion which protrudes from the casing body forming portion toward an outer side in a radial direction, a step of placing the casing forming member on a table which is rotatable about a table axis which extends in a vertical direction and disposing a tool which is rotatable about a tool axis on an inner side of the casing forming member in the radial direction, and a step of forming the casing by performing cutting an inner circumferential surface of the casing forming member with the tool while rotating the table about the table axis together with the casing forming member and rotating the tool about the tool axis.

A milling device for machining a slot into an inner surface of a casing for a gas turbine engine. The milling device includes a frame assembly including multiple structural guides configured to engage structural features on the inner surface of the casing to maintain an axial position of the milling device relative to a longitudinal axis of the casing. The milling device also includes a milling cutter coupled to the frame assembly. The milling device is configured to be displaced in a circumferential direction relative to the longitudinal axis to machine the slot, via the milling cutter, along the inner surface of the casing in the circumferential direction.

A system for machining an abradable material of a gas turbine engine and associated methods. The system includes a frame including a first arm extending from a central location. The system further includes an attachment structure coupled to the frame at the central location. Moreover, the attachment structure is configured to couple to at least a fan rotor of the gas turbine engine. Additionally, the system includes a cutting apparatus coupled to a first distal end of the first arm opposite the central location. The cutting apparatus includes a rotating shaft and plurality of cutting disks coupled to the rotating shaft. Further, the plurality of cutting disks define a helical cutting profile configured to machine a contour within the abradable material complementary to at least one fan blade of the gas turbine engine.

A milling device for machining a slot into an inner surface of a casing for a gas turbine engine. The milling device includes a frame assembly including multiple structural guides configured to engage structural features on the inner surface of the casing to maintain an axial position of the milling device relative to a longitudinal axis of the casing. The milling device also includes a milling cutter coupled to the frame assembly. The milling device is configured to be displaced in a circumferential direction relative to the longitudinal axis to machine the slot, via the milling cutter, along the inner surface of the casing in the circumferential direction.

A manufacturing method of a casing includes a step of preparing a casing forming member that includes a casing body forming portion which is formed in a tubular shape and a protruding portion forming portion which protrudes from the casing body forming portion toward an outer side in a radial direction, a step of placing the casing forming member on a table which is rotatable about a table axis which extends in a vertical direction and disposing a tool which is rotatable about a tool axis on an inner side of the casing forming member in the radial direction, and a step of forming the casing by performing cutting an inner circumferential surface of the casing forming member with the tool while rotating the table about the table axis together with the casing forming member and rotating the tool about the tool axis.

A milling device for machining a slot into an inner surface of a casing for a gas turbine engine. The milling device includes a frame assembly including multiple structural guides configured to engage structural features on the inner surface of the casing to maintain an axial position of the milling device relative to a longitudinal axis of the casing. The milling device also includes a milling cutter coupled to the frame assembly. The milling device is configured to be displaced in a circumferential direction relative to the longitudinal axis to machine the slot, via the milling cutter, along the inner surface of the casing in the circumferential direction.

A chamfering device includes: a main body including, at a proximal end side thereof, a shank to be attached to a main shaft of a machine tool, the main body including, at a distal end side thereof, a shaft portion extending in a rotational axis direction; a movable body whose proximal end portion is mounted to the shaft portion, the movable body being configured to rotate together with the shaft portion and be movable in the rotational axis direction; an urging member configured to urge the movable body in a direction toward the distal end of the main body; a chamfering tool mounted to a distal end portion of the movable body and configured to rotate together with the movable body to perform chamfering on an edge portion of a workpiece; and a following member mounted to the movable body such that a position of the following member relative to the movable body in the rotational axis direction is invariable and the following member is rotatable relative to the movable body, the following member being configured such that a distal end thereof comes into contact with a surface of the workpiece.