Abstract: A spark plug includes: a mounting bracket; a center electrode having a first end portion exposed and extended from first end portion of the mounting bracket; a slant-shape ground electrode that has first end side joined to the first end portion of the mounting bracket, has a surface of the second end side extended to be opposed to the first end portion of the center electrode, and has an extension direction inclined with respect to the center electrode; a convex portion protruding from a base material of the ground electrode on the surface thereof toward the center electrode, inclines toward the center electrode with respect to a protrusion direction, and has a convex portion opposed surface opposed to an end surface of the center electrode; and a precious metal layer formed on at least the convex portion opposed surface out of surfaces of the convex portion.

Abstract: A spark plug includes: a cylindrical mounting bracket attachable to an internal combustion engine; a center electrode that is held by the mounting bracket in an insulated manner and has a first end portion exposed and extended from a first end portion of the mounting bracket; a ground electrode that has a first end side joined to the first end portion of the mounting bracket and has a surface of the second end side extended to be opposed to the first end portion of the center electrode; a convex portion that protrudes from a base material of the ground electrode on the surface of the ground electrode toward the center electrode, has a surface protruded outward, and has surfaces without corners; and a precious metal layer formed on the surface of the convex portion.

Abstract: A spark plug for an internal combustion engine includes a cylindrical housing, a cylindrical insulator, a center electrode, and a ground electrode. The ground electrode includes an upright part and an inclined part. The upright part is a portion vertically provided on a tip end part of the housing to a tip end side. The inclined part is a portion that is bent from the tip of the upright part toward the center electrode side, and is extended toward an oblique tip end side. The inclined part has a ground end face, an opposed face, and a corner curved face. The corner curved face is a face that smoothly connects the ground end face and the opposed face. The corner curved face has a curved shape. The curvature radius R of the corner curved face satisfies 0.3 mm?R?0.7 mm. The inclination angle ? of the inclined part with respect to a plug axial direction (Z) satisfies 30°???60°.

Abstract: A spark plug includes: a mounting bracket; a center electrode having a first end portion exposed and extended from first end portion of the mounting bracket; a slant-shape ground electrode that has first end side joined to the first end portion of the mounting bracket, has a surface of the second end side extended to be opposed to the first end portion of the center electrode, and has an extension direction inclined with respect to the center electrode; a convex portion protruding from a base material of the ground electrode on the surface thereof toward the center electrode, inclines toward the center electrode with respect to a protrusion direction, and has a convex portion opposed surface opposed to an end surface of the center electrode; and a precious metal layer formed on at least the convex portion opposed surface out of surfaces of the convex portion.

Abstract: A spark plug includes: a cylindrical mounting bracket attachable to an internal combustion engine; a center electrode that is held by the mounting bracket in an insulated manner and has a first end portion exposed and extended from a first end portion of the mounting bracket; a ground electrode that has a first end side joined to the first end portion of the mounting bracket and has a surface of the second end side extended to be opposed to the first end portion of the center electrode; a convex portion that protrudes from a base material of the ground electrode on the surface of the ground electrode toward the center electrode, has a surface protruded outward, and has surfaces without corners; and a precious metal layer formed on the surface of the convex portion.

Abstract: A spark plug for an internal combustion engine includes a cylindrical housing, a cylindrical insulator, a center electrode, and a ground electrode. The ground electrode includes an upright part and an inclined part. The upright part is a portion vertically provided on a tip end part of the housing to a tip end side. The inclined part is a portion that is bent from the tip of the upright part toward the center electrode side, and is extended toward an oblique tip end side. The inclined part has a ground end face, an opposed face, and a corner curved face. The corner curved face is a face that smoothly connects the ground end face and the opposed face. The corner curved face has a curved shape. The curvature radius R of the corner curved face satisfies 0.3 mm?R?0.7 mm. The inclination angle ? of the inclined part with respect to a plug axial direction (Z) satisfies 30°???60°.

Abstract: When one of a center chip and a ground chip of a spark plug is defined as a first chip and another one is defined as a second chip, a discharge starting ridge line, which is a straight ridge line that forms a boundary between two surfaces having different normal line directions, is formed in a portion closest to the second chip in the first chips, and a distance from the discharge starting ridge line to the second chip is configured to be equal at a portion where the first chip and the second chip are opposed to each other.

Abstract: A spark plug for an internal combustion engine includes a cylindrical metal shell, a center electrode, and a ground electrode. The center electrode has an end portion which protrudes outside an end of the metal shell. The ground electrode is joined at an end thereof to the metal shell and has an inner surface facing the end portion of the center electrode. The ground electrode has a maximum width W meeting a relation of 1.3?W?2.0. A distance d between the center of an end surface of the center electrode and the inner surface of the ground electrode on a plane extending through the center of the center electrode perpendicular to an axis of the spark plug is selected to meet a relation of W+0.525?d?1.07W+0.66. This ensures the stability of ignitability of the spark plug.

Abstract: A spark plug for an internal combustion engine includes a cylindrical metal shell, a center electrode, and a ground electrode. The center electrode has an end portion which protrudes outside an end of the metal shell. The ground electrode is joined at an end thereof to the metal shell and has an inner surface facing the end portion of the center electrode. The ground electrode has a maximum width W meeting a relation of 1.3?W?2.0. A distance d between the center of an end surface of the center electrode and the inner surface of the ground electrode on a plane extending through the center of the center electrode perpendicular to an axis of the spark plug is selected to meet a relation of W+0.525?d?1.07 W+0.66. This ensures the stability of ignitability of the spark plug.

Abstract: When one of a center chip and a ground chip of a spark plug is defined as a first chip and another one is defined as a second chip, a discharge starting ridge line, which is a straight ridge line that forms a boundary between two surfaces having different normal line directions, is formed in a portion closest to the second chip in the first chips, and a distance from the discharge starting ridge line to the second chip is configured to be equal at a portion where the first chip and the second chip are opposed to each other.

Abstract: Provided is a method for manufacturing a spark plug, wherein at least one of a center electrode and the ground electrode includes an electrode base material and a columnar noble metal tip welded to the electrode base material. The method includes a laser welding step of applying a pulse oscillation laser to form a plurality of unit fusion portions on a peripheral area of a boundary between the electrode base material and the noble metal tip and welding the electrode base material and the noble metal tip. One unit fusion portion is formed by one-time laser irradiation. In the laser welding step, an irradiation axis of the laser is displaced from a central axis of the noble metal tip in a radial direction of the noble metal tip. When a diameter of the noble metal tip is denoted as a diameter A and an amount of displacement of the irradiation axis of the laser is denoted as X, A/20?|X|?A/4 is satisfied.

Abstract: A rotary compressor (100) includes a closed casing (1), a cylinder (15), a piston (28), a lower bearing member (7), a vane (33), a suction port (20), a discharge port (41), and a partition member (10). The partition member (10) is attached to the lower bearing member (7) so as to form a refrigerant discharge space (52) serving as a flow path of a refrigerant discharged from a discharge chamber (26b) through the discharge port (41). The lower bearing member (7) is provided with a first recess (7t) on the same side as the suction port (20) with respect to a reference plane, the reference plane being a plane including a central axis of the cylinder (15) and a center of the vane (33) when the vane (33) protrudes maximally toward the central axis of the cylinder (15). A portion of oil stored in an oil reservoir (22) flows into the first recess (7t), and thereby an oil retaining portion (53) is formed.

Abstract: A rotary compressor (100) includes a closed casing (1), a cylinder (15), a piston (28), a lower bearing member (72), a vane (33), a suction port (20), a discharge port (41), and a partition member (64). The partition member (64) is attached to the lower bearing member (72) so as to form a space enclosed by the partition member (64) and the lower bearing member (72) at a position adjacent to the lower bearing member (72). A portion of an oil stored in the oil reservoir (22) flows into the enclosed space, and thereby an oil retaining portion (53) is formed. The oil retaining portion (53) is located on the same side as the suction port (20) with respect to a reference plane (H1).

Abstract: A compression element includes a substantially spiral oil groove which is provided in inner peripheral surfaces of bearings and of the shaft. One end of the oil groove opens at a bearing base portion, and the other end of the oil groove opens at a bearing end. According to this configuration, oil in a gap between the shaft and inner peripheries of the bearings and forcibly discharges, into the hermetic container, gas bubbles generated in a sliding gap between the shaft and the bearings and by action of a viscosity pump generated by the substantially spiral oil groove, and it is possible to provide a rotary compressor capable of preventing seizing and wearing caused by gas-involvement at a bearing sliding portion, and capable of securing reliability when refrigerant including R32 is used.

Abstract: Provided is a method for manufacturing a spark plug, wherein at least one of a center electrode and the ground electrode includes an electrode base material and a columnar noble metal tip welded to the electrode base material. The method includes a laser welding step of applying a pulse oscillation laser to form a plurality of unit fusion portions on a peripheral area of a boundary between the electrode base material and the noble metal tip and welding the electrode base material and the noble metal tip. One unit fusion portion is formed by one-time laser irradiation. In the laser welding step, an irradiation axis of the laser is displaced from a central axis of the noble metal tip in a radial direction of the noble metal tip. When a diameter of the noble metal tip is denoted as a diameter A and an amount of displacement of the irradiation axis of the laser is denoted as X, A/20?|X|?A/4 is satisfied.

Abstract: A compression element 3 includes a substantially spiral oil groove 23 which is provided in inner peripheral surfaces of bearings 14 and 15 of the shaft 6. One end of the oil groove 23 opens at a bearing base portion 24, and the other end of the oil groove 23 opens at a bearing end 25. According to this configuration, oil in a gap between the shaft 6 and inner peripheries of the bearings 14 and 15 forcibly discharges, into the hermetic container 1, gas bubbles generated in a sliding gap between the shaft 6 and the bearings 14 and 15 by action of a viscosity pump generated by the substantially spiral oil groove 23, and it is possible to provide a rotary compressor capable of preventing seizing and wearing caused by gas-involvement at a bearing sliding portion, and capable of securing reliability when refrigerant including R32 is used.

Abstract: A scroll compressor employs therein a refrigerant having a small global warming potential and a small ozone depletion potential and mainly comprising hydrofluoroolefin having a carbon-carbon double bond. A stationary scroll has and end plate and a discharge port defined in the end plate at a central portion thereof so as to open into a discharge chamber. The stationary scroll also has a bypass hole defined in the end plate to allow a plurality of compression chambers to communicate with the discharge chamber before the compression chambers communicate with the discharge port. A check valve is provided on the bypass hole to allow the refrigerant to flow from the compression chambers to the discharge chamber. This construction can restrain a baneful influence on the global environment, reduce a temperature increase caused by excessive compression, and restrain decomposition of the refrigerant even in long-term use.

Abstract: A rotary compressor (100) includes a closed casing (1), a cylinder (15), a piston (28), a lower bearing member (7), a vane (33), a suction port (20), a discharge port (41), and a partition member (10). The partition member (10) is attached to the lower bearing member (7) so as to form a refrigerant discharge space (52) serving as a flow path of a refrigerant discharged from a discharge chamber (26b) through the discharge port (41). The lower bearing member (7) is provided with a first recess (7t) on the same side as the suction port (20) with respect to a reference plane, the reference plane being a plane including a central axis of the cylinder (15) and a center of the vane (33) when the vane (33) protrudes maximally toward the central axis of the cylinder (15). A portion of oil stored in an oil reservoir (22) flows into the first recess (7t), and thereby an oil retaining portion (53) is formed.

Abstract: A rotary compressor (100) includes a closed casing (1), a cylinder (15), a piston (28), a lower bearing member (72), a vane (33), a suction port (20), a discharge port (41), and a partition member (64). The partition member (64) is attached to the lower bearing member (72) so as to form a space enclosed by the partition member (64) and the lower bearing member (72) at a position adjacent to the lower bearing member (72). A portion of an oil stored in the oil reservoir (22) flows into the enclosed space, and thereby an oil retaining portion (53) is formed. The oil retaining portion (53) is located on the same side as the suction port (20) with respect to a reference plane (H1).

Abstract: A spark plug has a center electrode having an electrode base member and a core material which is disposed in the electrode base member and which predominantly contains copper, and a noble metal tip disposed at a forward end of the center electrode, and a fusion portion formed between the noble metal tip, and the electrode base member and the core material. The fusion portion is in contact with the core material in a cross section which is parallel to the center axis of the center electrode and which passes through the center axis and the fusion portion. The fusion portion contains a component of the noble metal tip, a component of the electrode base member, and a copper component forming the core material.