The invention relates to a design method of high-temperature nickel-based bolts based on damage tolerance theory, comprising the following steps: S.sub.1: acquiring operating parameters for the design; S.sub.2: selecting a material for bolts; S.sub.3: acquiring mechanical properties of the materials; S.sub.4: determining a pretension stress σ.sub.p of a single bolt; S.sub.5: determining the service stress σ.sub.s under the steady state; S.sub.6: determining the number n, the effective cross-section area A and the distribution of bolts; S.sub.7: determining a maximum allowable crack dimension; S.sub.8: calculating the maximum allowable service stress σ.sub.th using the crack propagation threshold K.sub.th at the design temperature; S.sub.9: comparing the service stress σ.sub.s and the maximum allowable service stress σ.sub.th, if σ.sub.s is smaller than σ.sub.th, then the bolts are safe in the design life; otherwise, return to step S.sub.4 and reduce the pretension stress σ.sub.p.

A spinning forming method includes: preparing a plate including a back surface at which a ring-shaped projection is formed along an outer peripheral edge of the plate, a ratio of a thickness at a reference position of the plate to a thickness at a tip end of the projection being 0.7 or less, the reference position being a position where an inclination of a portion of the back surface which portion extends toward the tip end of the projection is 45° or more; rotating the plate; moving a processing tool outward in a radial direction from an inner side of the projection to a position above the projection while pressing the processing tool against a front surface of the plate that is rotating; and locally heating a portion of the plate against which portion the processing tool is pressed.

This disc rotor has a hat portion having a cylindrical portion and a sliding plate portion having an insertion hole into which the cylindrical portion is inserted, being connected together with the hat portion in a state in which the cylindrical portion protrudes from the insertion hole. The coupling is achieved by pinching an inner peripheral edge of the sliding plate portion between a first portion and a second portion that are formed in the cylindrical portion. The second portion is formed by plastically deforming an outer peripheral side of the cylindrical portion toward the first portion.

This disc rotor has a hat portion having a cylindrical portion and a sliding plate portion having an insertion hole into which the cylindrical portion is inserted, being connected together with the hat portion in a state in which the cylindrical portion protrudes from the insertion hole. The coupling is achieved by pinching an inner peripheral edge of the sliding plate portion between a first portion and a second portion that are formed in the cylindrical portion. The second portion is formed by plastically deforming an outer peripheral side of the cylindrical portion toward the first portion.

The present application discloses wheel engraving equipment, which includes a lower lifting system, lower flange engraving systems, inner rim engraving systems, a wheel positioning and clamping system, an upper lifting and rotating system, a synchronous clamping and rotating system and the like.

The present application discloses wheel engraving equipment, which includes a lower lifting system, lower flange engraving systems, inner rim engraving systems, a wheel positioning and clamping system, an upper lifting and rotating system, a synchronous clamping and rotating system and the like.

A spinning forming method includes: preparing a plate including a back surface at which a ring-shaped projection is formed along an outer peripheral edge of the plate, a ratio of a thickness at a reference position of the plate to a thickness at a tip end of the projection being 0.7 or less, the reference position being a position where an inclination of a portion of the back surface which portion extends toward the tip end of the projection is 45 or more; rotating the plate; moving a processing tool outward in a radial direction from an inner side of the projection to a position above the projection while pressing the processing tool against a front surface of the plate that is rotating; and locally heating a portion of the plate against which portion the processing tool is pressed.

A method of manufacturing a preliminary formed body includes an ironing step and a thickening step. In the ironing step, a predetermined range of a plate is formed into a tapered shape in such a manner that while rotating the plate, a transform target portion of the plate is locally heated by induction heating, and a processing tool is pressed against the transform target portion. In the thickening step, a peripheral portion that is a distal end of the tapered shape of the plate is expanded inward in such a manner that while rotating the plate, the peripheral portion is locally heated, and a forming roller is pressed against the peripheral portion to push the peripheral portion in a direction orthogonal to a thickness direction of the peripheral portion.

A method of manufacturing a preliminary formed body includes an ironing step and a thickening step. In the ironing step, a predetermined range of a plate is formed into a tapered shape in such a manner that while rotating the plate, a transform target portion of the plate is locally heated by induction heating, and a processing tool is pressed against the transform target portion. In the thickening step, a peripheral portion that is a distal end of the tapered shape of the plate is expanded inward in such a manner that while rotating the plate, the peripheral portion is locally heated, and a forming roller is pressed against the peripheral portion to push the peripheral portion in a direction orthogonal to a thickness direction of the peripheral portion.

Mandrels for rolling a ring include recesses for receiving the ring, which have rounded parts at the connection between the various faces, so as to avoid the formation of sharp angles on the rolled ring and the accidental formation of cracks.