Abstract: In a forming apparatus, movable journal dies (10U, 10B) and stationary journal dies (9U, 9B) retain rough journal portions (Ja) of a preform blank (4) therebetween, and reference crank pin die (11) and movable crank pin dies (12) contact rough crank pin portions (Pa) thereof, and in this state, the movable journal dies (10U, 10B) and the movable crank pin dies (12) are moved axially toward the reference crank pin die (11) and the reference crank pin die (11) and the movable crank pin dies (12) are moved in a direction perpendicular to an axial direction. With this, weighted rough arm portions (Aa) are axially compressed to reduce their thickness to that of weighted arms of a forged crankshaft, and the rough crank pin portions (Pa) are pressed in the direction perpendicular to the axial direction to increase an amount of eccentricity to that of the crank pins of the forged crankshaft.

Abstract: In a forming apparatus, movable journal dies and stationary journal dies hold and retain rough journal portions of a preform blank therebetween, and movable crank pin dies contact rough crank pin portions thereof, and in this state, the movable journal dies and the movable crank pin dies are moved axially toward the stationary journal dies and the movable crank pin dies are moved in a direction perpendicular to an axial direction. With this, rough arm portions are axially compressed to reduce their thickness to that of arms of a forged crankshaft, and the rough crank pin portions are pressed in the direction perpendicular to the axial direction to increase an amount of eccentricity to that of the crank pins of the forged crankshaft.

Abstract: In a forming apparatus, stationary journal dies (10U, 10B) and movable journal dies (11U, 11B) each hold and retain rough journal portions (J?) of a preform blank (4) therebetween, and crank pin dies (12) contacts rough crank pin portions (P?) thereof, and in this state, the movable journal dies (11U, 11B) are moved axially toward the stationary journal dies (10U, 10B) and the crank pin dies (12) are moved in the same axial direction and in an eccentric direction. Rough crank arm portions (A?) are axially compressed to reduce their thickness to that of crank arms of a forged crankshaft, and the rough crank pin portions (P?) are pressed in the eccentric direction to increase eccentricity to that of the crank pins of the forged crankshaft. Consequently, it is possible to form a blank for finish forging having a shape generally in agreement with the shape of the forged crankshaft.

Abstract: A method for producing a forged crankshaft includes a die forging step, a trimming step, and an excess projecting portion crushing step. The die forging step forms a finish forged blank with flash, the finish forged blank including a shape of the crankshaft, in which crank arms have excess projecting portions at outer peripheries of side portions thereof near a crank pin, the excess projecting portions projecting from the outer peripheries. The trimming step removes the flash from the finish forged blank formed in the die forging step. The excess projecting portion crushing step crushes the excess projecting portions of the crank arms by pressing the crankshaft using a pair of first dies, the crankshaft being obtained by removing the flash in the trimming step.

Abstract: A method for producing a forged crankshaft includes a die forging step, a trimming step, and an excess projecting portion bending step. The die forging step forms a finish forged blank with flash, the finish forged blank including a shape of the crankshaft, in which crank arms have excess projecting portions at outer peripheries of side portions thereof near a crank pin, the excess projecting portions projecting from the outer peripheries. The trimming step removes the flash from the finish forged blank formed in the die forging step. The excess projecting portion bending step bends the excess projecting portions of the crank arms toward a journal-side surface of the crank arm by pressing the crankshaft using a pair of first dies, the crankshaft being obtained by removing the flash in the trimming step.

Abstract: A method for producing a forged crankshaft includes a die forging step, a trimming step, and an excess projecting portion bending step. The die forging step forms a finish forged blank with flash, the finish forged blank including a shape of the crankshaft, in which crank arms have excess projecting portions at outer peripheries of side portions thereof near a crank pin, the excess projecting portions projecting from the outer peripheries. The trimming step removes the flash from the finish forged blank formed in the die forging step. The excess projecting portion bending step bends the excess projecting portions of the crank arms toward a journal-side surface of the crank arm by inserting a first die having a U-shape from a direction of eccentricity of the crank pin to the crankshaft obtained by removing the flash in the trimming step.

Abstract: A forged crankshaft (1) includes a carbon steel containing S, wherein in a portion corresponding to a machined outer circumferential surface of a shaft part such as journals (J), crank pins (P), a front part (Fr), and a flange (Fl), a ratio x/y of an area rate x of sulfide in a position (X) corresponding to a parting surface of a die for finish forging to an area rate y of sulfide in a position (Y) corresponding to a bottom of a die impression of the die for finish forging is equal to or lower than 1.5. The forged crankshaft (1) can avoid an occurrence of machined surface cracks on the journals (J) and the crank pins (P) after the outer circumferential surface is machined.

Abstract: In a forming apparatus, journal dies hold and retain rough journal portions of a preform blank therebetween, and reference crank pin die and movable crank pin dies contact rough crank pin portions thereof. In this state, the journal dies and the movable crank pin dies are moved axially toward the reference crank pin die and the reference crank pin die and the movable crank pin dies are moved perpendicular to an axial direction. With this, rough crank arm portions are axially compressed to reduce their thickness to that of crank arms of a forged crankshaft, and the rough crank pin portions are pressed perpendicular to the axial direction to increase an amount of eccentricity to that of the forged crankshaft crank pins. Consequently, it is possible to form a blank for finish forging having a shape generally in agreement with a shape of the forged crankshaft for a three-cylinder engine.

Abstract: In a forming apparatus, stationary journal dies (10U, 10B) and movable journal dies (11U, 11B) each hold and retain rough journal portions (J?) of a preform blank (4) therebetween, and crank pin dies (12) contacts rough crank pin portions (P?) thereof, and in this state, the movable journal dies (11U, 11B) are moved axially toward the stationary journal dies (10U, 10B) and the crank pin dies (12) are moved in the same axial direction and in an eccentric direction. Rough crank arm portions (A?) are axially compressed to reduce their thickness to that of crank arms of a forged crankshaft, and the rough crank pin portions (P?) are pressed in the eccentric direction to increase eccentricity to that of the crank pins of the forged crankshaft. Consequently, it is possible to form a blank for finish forging having a shape generally in agreement with the shape of the forged crankshaft.

Abstract: A method of manufacturing a die forged crankshaft to be mounted in a two or more cylinder reciprocating apparatus includes: an upsetting step that includes upsetting a billet having a constant cross-sectional area along an entire length thereof to form a blank having an enlarged cross-sectional area at a region between a portion to be formed into a leading crank arm of the crankshaft and a portion to be formed into a trailing crank arm thereof; a die forging step that includes die forging the blank formed in the upsetting step to form a forged blank having a shape of the crankshaft with a flash; and a trimming step that includes trimming the flash from the forged blank formed in the die forging step. This makes it possible to improve the material utilization and to use a billet having a cross-sectional size as small as possible.

Abstract: A fixing method of a temperature sensing element of an air conditioner and its assembling method, including a fixing portion to be fixed to a main body, an opening portion forming an opening surface, a folded portion having a holding portion for holding a temperature sensing element, an accommodating portion installed as being opened at the opening surface, for accommodating a tip of the temperature sensing element, and a foldable thin wall portion installed between the opening portion and the folded portion, in which the fixing portion, opening portion, thin wall portion, and foldable portion are integrally formed, the temperature sensing element is installed in the holding portion, the thin wall portion is folded, and the folded portion is fitted to the opening portion. In this constitution, damage or breakage of the temperature sensing element can be prevented. Further, direct contact by the user is prevented.