Abstract: A spark plug including a center electrode; a metallic member forming a tubular shape around an axis of the spark plug, holding the center electrode therein, and having a hole formed in a side wall thereof and extending in a radial direction; and a ground electrode supported in the hole and extending from the hole toward the axis. The ground electrode has a fixing portion formed of metal and fixed to the hole, and an ignition portion containing a noble metal, disposed on a side toward the axis in relation to the fixing portion, and having a discharge surface for forming a gap between the ignition portion and the center electrode. The absolute value of the difference in coefficient of thermal expansion between the metallic member and the fixing portion is smaller than the absolute value of the difference in coefficient of thermal expansion between the metallic member and the ignition portion.

Abstract: A spark plug 100 of the present disclosure includes a center electrode 20; a metallic member provided to form a tubular shape around an axis AX of the spark plug, holding the center electrode 20 therein in an insulated state, and having a hole 55 formed in a side wall thereof and extending in a radial direction; and a ground electrode 30 supported in the hole 55 and extending from the hole 55 toward the axis AX. The ground electrode 30 has a fixing portion formed of a metal and fixed to the hole 55, and an ignition portion 39 containing a noble metal, disposed on a side toward the axis AX in relation to the fixing portion, and having a discharge surface for forming a gap G between the ignition portion and the center electrode 20. The absolute value of the difference in coefficient of thermal expansion between the metallic member and the fixing portion is smaller than the absolute value of the difference in coefficient of thermal expansion between the metallic member and the ignition portion 39.

Abstract: A spark plug includes a tubular metallic shell having an attachment screw portion having an external thread, an insulator disposed inside the metallic shell and having an axial hole, and a center electrode disposed in the axial hole. The attachment screw portion has a pitch diameter local maximum portion at which the external thread has a locally maximum pitch diameter. The pitch diameter local maximum portion is located on the forward end side of a rear end of the center electrode in a direction along an axial line of the metallic shell.

Abstract: A spark plug includes a tubular metallic shell having an attachment screw portion having an external thread. The attachment screw portion has a pitch diameter maximum portion at which the external thread has a maximum pitch diameter, the pitch diameter maximum portion being located on a rear end side of a center of the attachment screw portion in a direction along an axial line of the metallic shell, and a pitch diameter local maximum portion at which the external thread has a locally maximum pitch diameter, the pitch diameter local maximum portion being located on a forward end side of the pitch diameter maximum portion in the direction along the axial line.

Abstract: A spark plug includes a tubular metallic shell having an attachment screw portion having an external thread, an insulator disposed inside the metallic shell and having an axial hole, and a center electrode disposed in the axial hole. The attachment screw portion has a pitch diameter local maximum portion at which the external thread has a locally maximum pitch diameter. The pitch diameter local maximum portion is located on the forward end side of a rear end of the center electrode in a direction along an axial line of the metallic shell.

Abstract: A spark plug includes a tubular metallic shell having an attachment screw portion having an external thread. The attachment screw portion has a pitch diameter maximum portion at which the external thread has a maximum pitch diameter, the pitch diameter maximum portion being located on a rear end side of a center of the attachment screw portion in a direction along an axial line of the metallic shell, and a pitch diameter local maximum portion at which the external thread has a locally maximum pitch diameter, the pitch diameter local maximum portion being located on a forward end side of the pitch diameter maximum portion in the direction along the axial line.

Abstract: The spark plug includes an insulator, a metal shell, and a buffering member. The buffering member is filled in a space that is enclosed by an inner peripheral surface of the metal shell and an outer peripheral surface of the insulator. 3 mm2?L×T is satisfied in a case where: a length in a direction of an axial line of a filled portion filled with the buffering member is defined as a filling length L; a thickness, of a screw portion of the metal shell, that is half a difference left after subtraction of the inner diameter of the metal shell from the pitch diameter of the screw portion is defined as an effective thickness; and a minimum value of the effective thickness of a portion, of the screw portion, present rearward of an inner diameter reduction portion of the metal shell is defined as a minimum thickness T.

Abstract: A tip is welded appropriately using an energy beam. The tip is welded to a base portion by irradiating the interface between the base portion and the tip with the energy beam. The welding the tip to the base portion includes: applying the energy beam continuously, while moving the irradiation position of the energy beam, in a first period of time; and applying the energy beam a plurality of times according to a pulsed output pattern, while moving the irradiation position of the energy beam, in a second period of time subsequent to the first period of time.

Abstract: The spark plug includes an insulator, a metal shell, and a buffering member. The buffering member is filled in a space that is enclosed by an inner peripheral surface of the metal shell and an outer peripheral surface of the insulator. 3 mm2?L×T is satisfied in a case where: a length in a direction of an axial line of a filled portion filled with the buffering member is defined as a filling length L; a thickness, of a screw portion of the metal shell, that is half a difference left after subtraction of the inner diameter of the metal shell from the pitch diameter of the screw portion is defined as an effective thickness; and a minimum value of the effective thickness of a portion, of the screw portion, present rearward of an inner diameter reduction portion of the metal shell is defined as a minimum thickness T.

Abstract: A tip is welded appropriately using an energy beam. The tip is welded to a base portion by irradiating the interface between the base portion and the tip with the energy beam. The welding the tip to the base portion includes: applying the energy beam continuously, while moving the irradiation position of the energy beam, in a first period of time; and applying the energy beam a plurality of times according to a pulsed output pattern, while moving the irradiation position of the energy beam, in a second period of time subsequent to the first period of time.

Abstract: A spark plug includes an insulator having an axial hole extending along an axial line, a center electrode disposed in the axial hole, a tubular metallic shell surrounding the insulator, a ground electrode whose proximal end is fixed to the metallic shell, and a cylindrical noble metal tip fixed to the ground electrode via an intermediate tip so as to form a gap between the noble metal tip and the center electrode. A weld portion is provided between the noble metal tip and the intermediate tip. The weld portion has a diameter larger than that of a portion of the intermediate tip which is adjacent to the weld portion. The noble metal tip is located inside a virtual tapered cylindrical surface which extends from a peripheral edge of a gap-side end of the center electrode so as to contact an outer circumferential edge of the weld portion.

Abstract: A spark plug includes an insulator having an axial hole extending along an axial line, a center electrode disposed in the axial hole, a tubular metallic shell surrounding the insulator, a ground electrode whose proximal end is fixed to the metallic shell, and a cylindrical noble metal tip fixed to the ground electrode via an intermediate tip so as to form a gap between the noble metal tip and the center electrode. A weld portion is provided between the noble metal tip and the intermediate tip. The weld portion has a diameter larger than that of a portion of the intermediate tip which is adjacent to the weld portion. The noble metal tip is located inside a virtual tapered cylindrical surface which extends from a peripheral edge of a gap-side end of the center electrode so as to contact an outer circumferential edge of the weld portion.

Abstract: A spark plug includes an insulator having an axial hole extending along an axial line, a center electrode disposed in the axial hole, a tubular metallic shell surrounding the insulator, a ground electrode whose proximal end is fixed to the metallic shell, and a cylindrical noble metal tip fixed to the ground electrode via an intermediate tip so as to form a gap between the noble metal tip and the center electrode. A weld portion is provided between the noble metal tip and the intermediate tip. The weld portion has a diameter larger than that of a portion of the intermediate tip which is adjacent to the weld portion. The noble metal tip is located inside a virtual tapered cylindrical surface which extends from a peripheral edge of a gap-side end of the center electrode so as to contact an outer circumferential edge of the weld portion.

Abstract: Provided is a novel lactic acid bacterium strain which is capable of suppressing production of volatile sulfur compounds by oral bacteria, has no cariogenicity and no causative role in infective endocarditis, and is safe in an oral cavity, and provided is an agent for preventing, improving and/or treating oral diseases and discomforts by use of the bacterial strain.

Abstract: A sparkplug includes a ground electrode forming a gap with a front end surface of the center electrode. A front end portion of the ground electrode includes an opposed surface facing the center electrode, and a pair of tapered surfaces sandwiching the opposed surface. A shortest distance between the center electrode and a boundary formed by the opposed surface and the tapered surface is equal to or less than 1.2 times a distance of the gap. At least a part of a cross section of the core portion is disposed in a region at a front side of the straight line that passes a rear end of a line segment corresponding to the tapered surface and is vertical to the line segment. A shortest distance between the line segment and the cross section of the core portion is 0.2 mm or more and 1.5 mm or less.

Abstract: A sparkplug includes a ground electrode forming a gap with a front end surface of the center electrode. A front end portion of the ground electrode includes an opposed surface facing the center electrode, and a pair of tapered surfaces sandwiching the opposed surface. A shortest distance between the center electrode and a boundary formed by the opposed surface and the tapered surface is equal to or less than 1.2 times a distance of the gap. At least a part of a cross section of the core portion is disposed in a region at a front side of the straight line that passes a rear end of a line segment corresponding to the tapered surface and is vertical to the line segment. A shortest distance between the line segment and the cross section of the core portion is 0.2 mm or more and 1.5 mm or less.

Abstract: Provided is a novel lactic acid bacterium strain which is capable of suppressing production of volatile sulfur compounds by oral bacteria, has no cariogenicity and no causative role in infective endocarditis, and is safe in an oral cavity, and provided is an agent for preventing, improving and/or treating oral diseases and discomforts by use of the bacterial strain.

Abstract: An object of the present invention is to provide a method for controlling the continuousness of deodorant effect after consumption of a chewing gum composition, and a chewing gum composition having excellent continuousness of the deodorant effect after consumption of the chewing gum composition. The method for controlling continuousness of the deodorant effect after consumption of the chewing gum composition, in which the chewing gum composition contains a biphenyl compounds-containing extract and a tannins-containing extract, includes the step of controlling the ratio of a blending amount of the tannins-containing extract to a blending amount of biphenyl compounds-containing extract. The chewing gum composition contains a biphenyl compounds-containing extract and a tannins-containing extract, in which the ratio by mass of the blending amount of the tannins-containing extract to the blending amount of the biphenyl compounds-containing extract is greater than 5.0.

Abstract: It is intended to provide an oral flora-improving agent capable of forming a favorable flora in the oral cavity and a food or a drink for improving the oral flora. An oral flora-improving agent containing as an active ingredient a ganglioside and a food, a drink, or a feed for improving the oral flora containing the ganglioside exhibit an antibacterial effect on harmful bacteria in the oral cavity, which are undesirable from the viewpoint of decay and diseases such as periodontal disease, and a growth-improving effect on useful bacteria to be preserved in the oral cavity. Further, the ganglioside is efficaciously used as an active ingredient in an antibacterial agent or an antibacterial drink, food, or feed, a growth promoter, or a food, a drink, or a feed for promoting growth.

Abstract: It is intended to provide an oral flora-improving agent capable of forming a favorable flora in the oral cavity and a food or a drink for improving the oral flora. An oral flora-improving agent containing as an active ingredient a ganglioside and a food, a drink, or a feed for improving the oral flora containing the ganglioside exhibit an antibacterial effect on harmful bacteria in the oral cavity, which are undesirable from the viewpoint of decay and diseases such as periodontal disease, and a growth-improving effect on useful bacteria to be preserved in the oral cavity. Further, the ganglioside is efficaciously used as an active ingredient in an antibacterial agent or an antibacterial drink, food, or feed, a growth promoter, or a food, a drink, or a feed for promoting growth.