Abstract: An adjustment of the amount of energy in at least one specific applying unit is executed when energy is applied to a cylindrical member pair in which another cylindrical member is inserted inside a cylindrical member to melt and weld the cylindrical member pair in a circumferential direction. The adjustment is executed in association with a rotation angle to satisfy a relationship of Pd+Pw>?, wherein Pd is an output decease rotation angle that decreases the energy amount from a steady energy amount HP applied from the specific applying unit in a welding end process, Pw is an overlap rotation angle at which the irradiation parts around the cylindrical member pair overlap with the steady energy amount HP, and ? is a separation angle between the specific applying unit and another applying unit adjacent to each other in a rotation direction around the axis.

Abstract: A nozzle body has an injection hole configured to inject fuel and a fuel passage connecting to the injection hole. A needle is configured to open and close the fuel passage to switch between fuel injection from the injection hole and stop of the fuel injection. An injection hole axis is an imaginary line extending along a center of the injection hole. An injection hole perpendicular cross section is a cross section of the injection hole perpendicular to the injection hole axis. The injection hole perpendicular cross section has a flat shape. The injection hole perpendicular cross section has an area that gradually expands from an inlet of the injection hole to an outlet of the injection hole while maintaining a similar shape.

Abstract: A martensitic stainless steel contains 0.20 mass %?C?0.60 mass %, 0.10 mass %?N?0.50 mass %, 14.00 mass %?Cr?17.00 mass %, 1.00 mass %?Mo?3.00 mass %, 0.20 mass %?V?0.40 mass %, Si?0.30 mass %, Mn?0.80 mass %, P?0.040 mass %, S?0.040 mass %, Cu?0.25 mass %, Ni?0.20 mass %, and the balance Fe with inevitable impurities.

Abstract: A fuel injection valve including: an injection hole body formed of metal and having an injection hole configured to inject fuel; and a metal holder that has a cylindrical shape having an insertion port in which the injection hole body is inserted, and is fusion welded to a portion of the injection hole body located inside the insertion port. The injection hole body includes a body-side fused portion formed by fusion welding, a heat-affected portion which is located on a side of the insertion port with respect to the body-side fused portion, and of which a tissue structure is changed due to heat of the fusion welding, and a seal portion located on an opposite side of the heat-affected portion from the body-side fused portion and extending in an annular shape around a cylinder center line of the holder to come into close contact with the holder.

Abstract: A nozzle body has an injection hole configured to inject fuel and a fuel passage connecting to the injection hole. A needle is configured to open and close the fuel passage to switch between fuel injection from the injection hole and stop of the fuel injection. An injection hole axis is an imaginary line extending along a center of the injection hole. An injection hole perpendicular cross section is a cross section of the injection hole perpendicular to the injection hole axis. The injection hole perpendicular cross section has a flat shape. The injection hole perpendicular cross section has an area that gradually expands from an inlet of the injection hole to an outlet of the injection hole while maintaining a similar shape.

Abstract: An adjustment of the amount of energy in at least one specific applying unit is executed when energy is applied to a cylindrical member pair in which another cylindrical member is inserted inside a cylindrical member to melt and weld the cylindrical member pair in a circumferential direction. The adjustment is executed in association with a rotation angle to satisfy a relationship of Pd+Pw>?, wherein Pd is an output decease rotation angle that decreases the energy amount from a steady energy amount HP applied from the specific applying unit in a welding end process, Pw is an overlap rotation angle at which the irradiation parts around the cylindrical member pair overlap with the steady energy amount HP, and ? is a separation angle between the specific applying unit and another applying unit adjacent to each other in a rotation direction around the axis.

Abstract: A martensitic stainless steel contains 0.20 mass %?C?0.60 mass %, 0.10 mass %?N?0.50 mass %, 14.00 mass %?Cr?17.00 mass %, 1.00 mass %?Mo?3.00 mass %, 0.20 mass %?V?0.40 mass %, Si?0.30 mass %, Mn?0.80 mass %, P?0.040 mass %, S?0.040 mass %, Cu?0.25 mass %, Ni?0.20 mass %, and the balance Fe with inevitable impurities.

Abstract: Among all combinations of two injection holes, in a combination in which when the injection holes are offset such that their central axes are coincident with each other in inlet openings, an inter-injection hole angle formed by the central axes is minimized, the inter-injection hole angle between the two injection holes is represented as yamin[deg], taper angles, which are formed by the respective contours of the injection hole inner walls in the cross sections along the virtual planes including the central axes of the two injection holes that allow the inter-injection hole angle to be minimized, are represented as ?a1 and ?a2[deg], and when fuel is injected from the injection holes, average pressure of the fuel in the fuel passage is represented as P[Mpa], and the injection holes are formed so as to satisfy a relationship: ?amin??a1+?a2+0.5×P0.6.

Abstract: An injection hole has an injection hole passage communicating an inner opening with an outer opening. The inner opening is smaller than the outer opening in cross-sectional area. The needle moves in a valve closing direction to abut against a valve seat to restrict a flow of fuel through the injection hole. A first inner wall of the injection hole is located on a valve closing direction side relative to an injection hole axis. A second inner wall of the injection hole is located on an opposite side of the injection hole axis from the valve closing direction side. The injection hole passage is defined by the first inner wall and the second inner wall.

Abstract: In an injection hole set, primary and secondary injection holes are formed to satisfy the following relationship: ???t1+?t2?0.87×P{circumflex over (?)}0.52, where ? (deg) is an injection-hole-to-injection-hole angle, which is an angle formed between a primary central axis of the primary injection hole and a secondary central axis of the secondary injection hole; ?t1 (deg) is a primary taper angle, which is an angle formed between outlines of a primary injection hole inner wall of the primary injection hole in a cross section of the primary injection hole inner wall; ?t2 (deg) is a secondary taper angle, which is an angle formed between outlines of a secondary injection hole inner wall of the secondary injection hole in a cross section of the secondary injection hole inner wall; and P (MPa) is an average pressure of the fuel in a fuel passage at a time of injecting the fuel from the injection holes.

Abstract: A needle has a seal portion that contacts a valve seat, and is provided so as to be able to reciprocate inside a valve body. A sack chamber is formed between the seal portion and a recess. A seal portion is formed in a curved shape protruding in the axial direction of the needle. A distance between an inlet intersection and a needle intersection on a same virtual straight line is defined as a distance Dh, and a distance between the recess and the seal portion on an axis of the valve body is defined as a distance Ds. When the seal portion is in contact with the valve seat, the distance Dh is larger than the distance Ds (Dh>Ds).

Abstract: Among all combinations of two injection holes, in a combination in which when the injection holes are offset such that their central axes are coincident with each other in inlet openings, an inter-injection hole angle formed by the central axes is minimized, the inter-injection hole angle between the two injection holes is represented as yamin[deg], taper angles, which are formed by the respective contours of the injection hole inner walls in the cross sections along the virtual planes including the central axes of the two injection holes that allow the inter-injection hole angle to be minimized, are represented as ?a1 and ?a2[deg], and when fuel is injected from the injection holes, average pressure of the fuel in the fuel passage is represented as P[Mpa], and the injection holes are formed so as to satisfy a relationship: ?amin??a1+?a2+0.5×P0.6.

Abstract: Among all combinations of two injection holes, in a combination in which when the injection holes are offset such that their central axes are coincident with each other in inlet openings, an inter-injection hole angle formed by the central axes is minimized, the inter-injection hole angle between the two injection holes is represented as ?a min[deg], taper angles, which are formed by the respective contours of the injection hole inner walls in the cross sections along the virtual planes including the central axes of the two injection holes that allow the inter-injection hole angle to be minimized, are represented as ?a1 and ?a2[deg], and when fuel is injected from the injection holes, average pressure of the fuel in the fuel passage is represented as P[Mpa], and the injection holes are formed so as to satisfy a relationship: ?a min??a1+?a2+0.5×P0.6.

Abstract: In a fuel injection device including a body portion that forms an injection hole through which a fuel is injected, the body portion includes an inlet-channel-forming portion that is connected to an inflow port of the fuel in the injection hole and forms an inlet channel which is a fuel flow channel, and an outlet-channel-forming portion that is connected to the inlet channel and an outflow port of the fuel in the injection hole, and forms an outlet channel that is a fuel flow channel. A surface roughness of the outlet-channel-forming portion is larger than a surface roughness of the inlet-channel-forming portion.

Abstract: An injection hole has an injection hole passage communicating an inner opening with an outer opening. The inner opening is smaller than the outer opening in cross-sectional area. The needle moves in a valve closing direction to abut against a valve seat to restrict a flow of fuel through the injection hole. A first inner wall of the injection hole is located on a valve closing direction side relative to an injection hole axis. A second inner wall of the injection hole is located on an opposite side of the injection hole axis from the valve closing direction side. The injection hole passage is defined by the first inner wall and the second inner wall.

Abstract: A first injection hole included by an injection nozzle is formed such that an angle that a first virtual line passing a first inner-wall-side center point away from a center axis by a predetermined first distance, forms with the center axis becomes a first injection angle, and an angle that first injection hole inner walls form becomes a first open angle. A second injection hole included by the injection nozzle is formed such that an angle that a second virtual line passing a second inner-wall-side center point away from the center axis by a predetermined second distance, forms with the center axis becomes a second injection angle that is smaller than the first injection angle, and an angle that second injection hole inner walls form becomes a second open angle that is larger than the first open angle.

Abstract: In an injection hole set, primary and secondary injection holes are formed to satisfy the following relationship: ???t1+?t2?0.87×P?0.52, where ? (deg) is an injection-hole-to-injection-hole angle, which is an angle formed between a primary central axis of the primary injection hole and a secondary central axis of the secondary injection hole; ?t1 (deg) is a primary taper angle, which is an angle formed between outlines of a primary injection hole inner wall of the primary injection hole in a cross section of the primary injection hole inner wall; ?t2 (deg) is a secondary taper angle, which is an angle formed between outlines of a secondary injection hole inner wall of the secondary injection hole in a cross section of the secondary injection hole inner wall; and P (MPa) is an average pressure of the fuel in a fuel passage at a time of injecting the fuel from the injection holes.

Abstract: A fuel injection valve control device controlling a fuel injection valve that injects a fuel into a combustion chamber includes an operation-condition calculation portion that calculates a fuel injection condition of the fuel injection valve based on a crank angle detected by a crank angle sensor that detects the crank angle of an engine, a current-waveform setting portion that sets a current waveform of a current supplied to the fuel injection valve on the basis of the fuel injection condition calculated by the operation-condition calculation portion, and so on. The current-waveform setting portion sets the current waveform so as to set a temporal change of a pickup current of a needle provided in the fuel injection valve to be equal to or less than a predetermined reference value when a fuel injection start timing is equal to or more than 180 degrees BTDC.

Abstract: Among all combinations of two injection holes, in a combination in which when the injection holes are offset such that their central axes are coincident with each other in inlet openings, an inter-injection hole angle formed by the central axes is minimized, the inter-injection hole angle between the two injection holes is represented as ?amin[deg], taper angles, which are formed by the respective contours of the injection hole inner walls in the cross sections along the virtual planes including the central axes of the two injection holes that allow the inter-injection hole angle to be minimized, are represented as ?a1 and ?a2[deg], and when fuel is injected from the injection holes, average pressure of the fuel in the fuel passage is represented as P[Mpa], and the injection holes are formed so as to satisfy a relationship: ?amin??a1+?a2+0.5×P0.

Abstract: In a fuel injection device including a body portion that forms an injection hole through which a fuel is injected, the body portion includes an inlet-channel-forming portion that is connected to an inflow port of the fuel in the injection hole and forms an inlet channel which is a fuel flow channel, and an outlet-channel-forming portion that is connected to the inlet channel and an outflow port of the fuel in the injection hole, and forms an outlet channel that is a fuel flow channel. A surface roughness of the outlet-channel-forming portion is larger than a surface roughness of the inlet-channel-forming portion.