Abstract: A spark plug includes: a cylindrical insulator; a center electrode that is held on an inner circumferential side of the insulator and includes a tip-end protruding portion that protrudes from the insulator toward a tip end side; a cylindrical housing that holds the insulator on an inner circumferential side; and a plug cover that is provided in a tip end portion of the housing so as to cover a pre-combustion chamber in which the tip-end protruding portion is arranged. The plug cover is provided with an injection hole that communicates the pre-combustion chamber to the outside. A positioning portion that performs positioning of the housing and the plug cover in a plug circumferential direction is provided in the housing and the plug cover.

Abstract: A spark plug for an internal combustion engine includes a housing, an insulator, a center electrode, a ground electrode, and an auxiliary chamber forming portion. The ground electrode faces the center electrode from an outer peripheral side and forms a discharge gap between the ground electrode and the center electrode. An auxiliary chamber is formed inside the auxiliary chamber forming portion. A distance in an axial direction between the discharge gap and a distal end of the auxiliary chamber is equal to or greater than a maximum wall thickness of the auxiliary chamber forming portion. The auxiliary chamber forming portion includes injection holes. The injection holes are formed in a state where openings on an outer side are located closer to a distal end than openings on the auxiliary chamber side. At least one of the injection holes is an injection hole in the axial direction formed along an axial direction of a plug.

Abstract: A spark plug includes a housing, a porcelain insulator, a center electrode, a ground electrode, and a prechamber-defining portion. The prechamber-defining portion has a prechamber formed therein. The prechamber-defining portion has a plurality of spray holes. At least one of the spray holes is an upstream spray hole which is arranged upstream of a plug center axis in a gas flow within a main combustion chamber and designed such that and an angle which an extension in an opening direction makes with an inner wall surface of the prechamber is selected to be larger than 90°. A spark gap is formed upstream of a plug center axis in the gas flow within the main combustion chamber.

Abstract: A spark plug includes: a cylindrical insulator; a center electrode that is held on an inner circumferential side of the insulator and includes a tip-end protruding portion that protrudes from the insulator toward a tip end side; a cylindrical housing that holds the insulator on an inner circumferential side; and a plug cover that is provided in a tip end portion of the housing so as to cover a pre-combustion chamber in which the tip-end protruding portion is arranged. The plug cover is provided with an injection hole that communicates the pre-combustion chamber to the outside. A positioning portion that performs positioning of the housing and the plug cover in a plug circumferential direction is provided in the housing and the plug cover.

Abstract: A spark plug for an internal combustion engine includes a housing, an insulator, a center electrode, a ground electrode, and an auxiliary chamber forming portion. The ground electrode faces the center electrode from an outer peripheral side and forms a discharge gap between the ground electrode and the center electrode. An auxiliary chamber is formed inside the auxiliary chamber forming portion. A distance in an axial direction between the discharge gap and a distal end of the auxiliary chamber is equal to or greater than a maximum wall thickness of the auxiliary chamber forming portion. The auxiliary chamber forming portion includes injection holes. The injection holes are formed in a state where openings on an outer side are located closer to a distal end than openings on the auxiliary chamber side. At least one of the injection holes is an injection hole in the axial direction formed along an axial direction of a plug.

Abstract: A method for measuring a fiber orientation degree includes: irradiating a sample formed of a composite material containing discontinuous carbon fibers with an X-ray to acquire an X-ray diffraction image; calculating an angle (2?)A of a peak originating from a crystal face of graphite; calculating a correction coefficient ? of a thickness of the sample; calculating an upper limit (2?)B of the peak of the crystal face of graphite; calculating a diffraction sensitivity IC(?) of the peak originating from the crystal face of graphite by correcting an integrating range with the correction coefficient ? and integrating the X-ray diffraction image with respect to a diffraction angle (2?); and calculating a fiber orientation degree Sd(?) by the method of Hermans from the diffraction sensitivity IC(?).

Abstract: A spark plug includes a housing, a porcelain insulator, a center electrode, a ground electrode, and a prechamber-defining portion. The prechamber-defining portion has a prechamber formed therein. The prechamber-defining portion has a plurality of spray holes. At least one of the spray holes is an upstream spray hole which is arranged upstream of a plug center axis in a gas flow within a main combustion chamber and designed such that and an angle which an extension in an opening direction makes with an inner wall surface of the prechamber is selected to be larger than 90°. A spark gap is formed upstream of a plug center axis in the gas flow within the main combustion chamber.

Abstract: A method for producing a preparation for fiber length measurement includes: a preliminary dispersion process of adding fibers and a dispersion medium with a viscosity of 500 Pa·s to 10,000 Pa·s to a sealable container so as to give a concentration of the fibers of 0.1% by mass or less and shaking the container to prepare a preliminary dispersion liquid; a dispensing process of dispensing part of the preliminary dispersion liquid to another sealable container; a dilution process of adding the dispersion medium to the dispensed preliminary dispersion liquid so as to give a concentration of the fibers of 0.005% by mass or less and shaking the container to prepare a dispersion liquid for measuring fiber length; and a casting process of spreading part of the dispersion liquid for measuring fiber length onto a base having light transparency.

Abstract: A spark plug includes a housing, an insulator, a center electrode, and an earth electrode. The earth electrode has a gap-forming surface which forms a discharge gap between the gap-forming surface and a tip surface of the center electrode. The insulator includes an insulator protrusion protruding on the tip side of the housing in a plug axial direction. At least one of cross-sections passing through a plug center axis and parallel to the plug axial direction is referred to as an axial parallel cross-section. The outer peripheral surface of the insulator protrusion includes an insulator inclined surface extending inward toward the tip in the plug axial direction, in a straight line or a curve that is convex inward, in the axial parallel cross-section. In the axial parallel cross-section, a virtual straight line passing through both ends of the insulator inclined surface passes through the gap-forming surface.

Abstract: A spark plug includes a ground electrode facing a distal end surface of a center electrode. In a main body of the ground electrode, a first slanted surface is formed at a portion on a side facing the distal end surface and upstream of the center electrode relative to the airflow, a facing portion, a second slanted surface is formed at a portion on a side opposite to the side facing the distal end surface and upstream of the center electrode relative to the airflow, and when T represents a thickness of the main body of the ground electrode and Su represents a distance from a connection between the first slanted surface and the second slanted surface to the facing portion, 2T/16?Su?8T/16.

Abstract: An ignition apparatus for an internal combustion engine includes a center electrode, a ground electrode, an insulator, a housing, and an insulator protective wall portion. The ground electrode is disposed such that a discharge gap is formed between the ground electrode and the center electrode. The insulator holds the center electrode on an inner side of the insulator. The housing holds the insulator on an inner side of the housing. The insulator protective wall portion is arranged to surround an outer circumference side of a distal end portion of the insulator. A distal end of the insulator protective wall portion is positioned further towards a distal end side than a distal end of the insulator is and further towards a proximal end side than a distal end of the center electrode is. The insulator protective wall portion includes an inward protruding portion that protrudes towards a side surface of the center electrode.

Abstract: A spark plug includes a ground electrode facing a distal end surface of a center electrode. In a main body of the ground electrode, a first slanted surface is formed at a portion on a side facing the distal end surface and upstream of the center electrode relative to the airflow, a facing portion, a second slanted surface is formed at a portion on a side opposite to the side facing the distal end surface and upstream of the center electrode relative to the airflow, and when T represents a thickness of the main body of the ground electrode and Su represents a distance from a connection between the first slanted surface and the second slanted surface to the facing portion, 2T/16?Su?8T/16.

Abstract: A spark plug includes a housing, an insulator, a center electrode, and an earth electrode. The earth electrode has a gap-forming surface which forms a discharge gap between the gap-forming surface and a tip surface of the center electrode. The insulator includes an insulator protrusion protruding on the tip side of the housing in a plug axial direction. At least one of cross-sections passing through a plug center axis and parallel to the plug axial direction is referred to as an axial parallel cross-section. The outer peripheral surface of the insulator protrusion includes an insulator inclined surface extending inward toward the tip in the plug axial direction, in a straight line or a curve that is convex inward, in the axial parallel cross-section. In the axial parallel cross-section, a virtual straight line passing through both ends of the insulator inclined surface passes through the gap-forming surface.

Abstract: A method for measuring a fiber orientation degree includes: irradiating a sample formed of a composite material containing discontinuous carbon fibers with an X-ray to acquire an X-ray diffraction image; calculating an angle (2?)A of a peak originating from a crystal face of graphite; calculating a correction coefficient ? of a thickness of the sample; calculating an upper limit (2?)B of the peak of the crystal face of graphite; calculating a diffraction sensitivity IC(?) of the peak originating from the crystal face of graphite by correcting an integrating range with the correction coefficient ? and integrating the X-ray diffraction image with respect to a diffraction angle (2?); and calculating a fiber orientation degree Sd(?) by the method of Hermans from the diffraction sensitivity IC(?).

Abstract: A method for producing a preparation for fiber length measurement includes: a preliminary dispersion process of adding fibers and a dispersion medium with a viscosity of 500 Pa·s to 10,000 Pa·s to a sealable container so as to give a concentration of the fibers of 0.1% by mass or less and shaking the container to prepare a preliminary dispersion liquid; a dispensing process of dispensing part of the preliminary dispersion liquid to another sealable container; a dilution process of adding the dispersion medium to the dispensed preliminary dispersion liquid so as to give a concentration of the fibers of 0.005% by mass or less and shaking the container to prepare a dispersion liquid for measuring fiber length; and a casting process of spreading part of the dispersion liquid for measuring fiber length onto a base having light transparency.

Abstract: A method of producing a complex of a lamellar inorganic compound and an organic compound includes: heat-treating a particular non-swelling lamellar inorganic compound within a pyrolysis temperature range of the non-swelling lamellar inorganic compound; and intercalating an organic compound into the non-swelling lamellar inorganic compound in a dispersion liquid in which the heat-treated non-swelling lamellar inorganic compound is dispersed in a medium, thereby inserting the organic compound into an interlamellar space of the non-swelling lamellar inorganic compound.

Abstract: In a spark plug, a discharge gap is formed between a ground electrode and a central electrode. The ground electrode has a rod-shaped part and an opposing part. The opposing part faces the central electrode, and has a flat surface part and a slope surface part. The slope surface part is formed on a part of the opposing part in an extending direction of the ground electrode, and formed on the opposing part and gradually separated from the central electrode along a width direction of the opposing part. The spark plug has a ratio V/W within a range of 0.5<V/W<2.0. V indicates a length of the opposing part measured in a gap formation direction in which the central electrode, the discharge gap and the opposing part are arranged in order. W indicates a length of the opposing part in the ground electrode width direction.

Abstract: An air-conditioning apparatus includes a refrigeration cycle that includes an intermediate heat exchanger configured to exchange heat between a heat source side refrigerant and a heat medium different from the heat source side refrigerant. The apparatus further includes a heat medium circuit that includes at least one pump configured to circulate the heat medium in the intermediate heat exchanger. A controller in the apparatus further activates the pump to circulate the heat medium through the heat medium circuit when, during suspension of an air conditioning operation, the detected temperature of outdoor air is at or below a first predetermined temperature and a first predetermined period of time has elapsed since the pump was stopped.

Abstract: An ignition apparatus for an internal combustion engine includes a center electrode, a ground electrode, an insulator, a housing, and an insulator protective wall portion. The ground electrode is disposed such that a discharge gap is formed between the ground electrode and the center electrode. The insulator holds the center electrode on an inner side of the insulator. The housing holds the insulator on an inner side of the housing. The insulator protective wall portion is arranged to surround an outer circumference side of a distal end portion of the insulator. A distal end of the insulator protective wall portion is positioned further towards a distal end side than a distal end of the insulator is and further towards a proximal end side than a distal end of the center electrode is. The insulator protective wall portion includes an inward protruding portion that protrudes towards a side surface of the center electrode.

Abstract: In a spark plug, a discharge gap is formed between a ground electrode and a central electrode. The ground electrode has a rod-shaped part and an opposing part. The opposing part faces the central electrode, and has a flat surface part and a slope surface part. The slope surface part is formed on a part of the opposing part in an extending direction of the ground electrode, and formed on the opposing part and gradually separated from the central electrode along a width direction of the opposing part. The spark plug has a ratio V/W within a range of 0.5<V/W<2.0. V indicates a length of the opposing part measured in a gap formation direction in which the central electrode, the discharge gap and the opposing part are arranged in order. W indicates a length of the opposing part in the ground electrode width direction.