Abstract: An ultrasonic wave generation device including: an ultrasonic wave generation source; an ultrasonic wave condensation part; and a waveguide. The ultrasonic wave condensation part has a first reflection surface opposed to the ultrasonic wave generation source and a second reflection surface opposed to the first reflection surface. The first reflection surface reflects the ultrasonic wave, generated from the ultrasonic wave generation source, toward the second reflection surface. The second reflection surface reflects the ultrasonic wave, which has been reflected by the first reflection surface, toward the waveguide so as to introduce the ultrasonic wave into the waveguide. The waveguide protrudes from the first reflection surface to a side opposite the second reflection surface. A recessed portion is formed from the first reflection surface to the second reflection surface side along an outer circumferential surface of the waveguide.

Abstract: A ceramic heater 171,172 comprising: a ceramic base 17g extending in an axial-line-L direction; and a heat generation portion 17a, wherein a length Lh in the axial-line direction of the heat generation portion and a maximum outer diameter D of the ceramic heater satisfy a relationship of 8?Lh/D.

Abstract: A liquid heating device (200) including: a container (100) having an internal space (100i), inlet (103) and outlet (105); and a ceramic heater (171,172) of which base-end portion (17R) is retained by the container, the ceramic heater including ceramic sheet (17s) having a heat generation portion (17a) and being wrapped around an outer circumference of ceramic base (17g) such that, at a wrap-meeting part of the ceramic sheet, a slit (17v) extending in the axial-line L direction is formed as a non-heat generation portion, wherein the liquid is heated by the ceramic heater, the outlet is located apart from the inlet in the axial-line direction, and a first-axis n1 direction in a vicinity (105R) of an opening end (105e) facing the internal space, of the outlet, crosses the axial-line direction, and a front end of the heat generation portion is located on the base-end portion side relative to the outlet.

Abstract: A liquid heating device (200) including: a container surrounding an internal space (101i) and having an opening (107m1-107m3); a ceramic heater (171-173) extending in a front-rear direction L and penetrating through the opening, such that a distal-end portion (17T) of the ceramic heater is located in the internal space and a base-end portion (17R) thereof is located outside the internal space, the ceramic heater having a heat generation portion (17a) at the distal-end portion; and a fixation member (180) sealing a gap between the opening and the ceramic heater, and fixing the ceramic heater to the container, wherein a liquid W in the internal space is heated by the ceramic heater, and the liquid passes through a flow path (103i) penetrating from outside through inside of the fixation member, so as to be introduced into the internal space.

Abstract: A holding device including a plate-shaped member, a base member, a plurality of heater electrodes disposed in the plate-shaped member, a plurality of electricity supply terminals, a bonding portion, and insulating members. The holding device holds an object on the surface of the plate-shaped member. The plurality of electricity supply terminals disposed in the holding device include N individual electricity supply terminals (N is an integer of 2 or more) electrically connected to respective N heater electrodes of the plurality of heater electrodes, and a common electricity supply terminal electrically connected to all the N heater electrodes. The N individual electricity supply terminals are received in one terminal hole in which the common electricity supply terminal is not received and are insulated from one another by an insulating member. The common electricity supply terminal is received in another terminal hole in which the individual electricity supply terminals are not received.

Abstract: In one aspect of the present disclosure, there is provided an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al2O3 crystal grains and crystal grains represented by formula X3Al5O12:Ce. In the optical wavelength conversion member 9, atoms of element X are present also in an Al2O3 crystal grain adjacent to the interface between the Al2O3 crystal grain and an X3Al5O12:Ce crystal grain.

Abstract: A sensor element (10) having a laminate structure, and extending in an axial direction AX, the sensor element including a first and second ceramic layers (118B, 115) disposed apart from each other in a laminating direction; a third ceramic layer (118) intervening between the first and second ceramic layers in the laminating direction and having a hollow space (10G) formed therein; and an internal space which is the hollow space surrounded by the first ceramic layer, the second ceramic layer, and the third ceramic layer, wherein, at a periphery (10f) of the internal space, a fourth ceramic layer (181) containing as a main component a ceramic material different from that contained as a main component in the first and third ceramic layers intervenes between the first ceramic layer and the third ceramic layer which are exposed to the internal space. Also disclosed is a method for manufacturing the gas sensor element.

Abstract: A ceramic member unit includes at least insertion members and a ceramic member having insertion sections into which the insertion members are inserted respectively. Each of the insertion sections has at least an insertion opening which opens on a deeper side of an introduction opening in the surface of the ceramic member while communicating with the introduction opening and into which the insertion member can be inserted. The insertion section further has taper hole portions becoming narrower toward the insertion opening in a communication region between the introduction opening and the insertion opening. The taper hole portions are connected to the insertion opening while increasing in a taper angle toward the insertion opening.

Abstract: The spark plug is provided with: an insulator; a main metal fitting in which a shelf portion for locking the insulator is provided; and a cap joined to the main metal fitting by way of a melted portion. The cap forms an auxiliary chamber, and includes an injection port penetrating from an inner surface to an outer surface. There is a gap extending from the auxiliary chamber to the melted portion, between a first surface connecting an inner peripheral surface of the main metal fitting and an outer peripheral surface of the main metal fitting on a tip end side of the shelf portion, and a second surface of the cap, connecting an inner surface and an outer surface thereof, and the gap includes an opening portion which opens into the auxiliary chamber in a radial direction.

Abstract: A piezoelectric element having a piezoelectric body and an electrode in contact with the piezoelectric body: the piezoelectric body being formed of a lead-free piezoelectric ceramic composition which includes a primary phase formed of an alkali niobate-based perovskite oxide represented by a compositional formula (A1aM1b)c(Nbd1Mnd2Tid3Zrd4Hfd5)O3+e (wherein element A1 represents at least one species among the alkali metals; element M1 represents at least one species among Ba, Ca, and Sr; the following conditions: 0<a<1, 0<b<1, a+b=1, 0.80<c<1.10, 0<d1<1, 0<d2<1, 0<d3<1, 0?d4<1, 0?d5<1, and d1+d2+d3+d4+d5=1, are satisfied; and e represents a value showing the degree of deficiency or excess of oxygen) and which satisfies the condition: b/(d3+d4+d5)?1, and the electrode containing a base metal as a main component.

Abstract: Provided is a spark plug with which pre-ignition of fuel gas that has flowed into an auxiliary chamber can be reduced. The spark plug is provided with: an insulator (11); a central electrode (14) disposed in the insulator; a main metal fitting (20) in which a shelf portion (23) for locking the insulator is provided; a grounding electrode (30) between the central electrode and which a spark gap (32) is provided; and a cap (40) joined to the main metal fitting by way of a melted portion (41). The cap forms an auxiliary chamber (42), and includes an injection port (45) penetrating from an inner surface (43) to an outer surface (44).

Abstract: A gas sensor (1) including: a sensor element (21) having an electrode pad (24); a metal terminal (75) electrically connected to the electrode pad via a contact portion C1; and a separator (91) retaining the metal terminal, wherein the metal terminal includes a stopper portion (75p) extending in a direction crossing the axial-line 0 direction, and where, in a pair of one of an electrode pad (241) and one of a metal terminal (751) connected thereto, as seen along a widthwise direction of the sensor element, an end of the one electrode pad that is closest to one inner surface 91si of the separator is defined as a pad end, a distance between the pad end and the contact portion is defined as DA, and a distance between the one inner surface of the separator and a distal end of the stopper portion is defined as DB, DA>DB is satisfied.

Abstract: An electrode-embedded member 1 includes a ceramic-made substrate 2, an electrode 3, a connection member 4 containing at least one of tungsten and molybdenum and embedded in the substrate 2 in a state in which a first principal surface 4a faces the electrode 3 and is electrically connected to the electrode 3, and a hole portion 5 extending from an outer surface of the substrate 2 to a second principal surface 4b of the connection member 4. A buffer member 10 embedded in the substrate 2 contains at least a ceramic material forming the substrate 2 and a conductive material containing at least one of tungsten and molybdenum as a constituent element. The buffer member 10 covers at least part of an edge of the connection member 4.

Abstract: A sensor element (10) including: a measurement chamber (150); a pump cell (110) including a solid electrolyte (111), an inner electrode (113) exposed to the measurement chamber, and an outer electrode (112), the pump cell being configured to adjust an oxygen concentration in the measurement chamber; a diffusion resistance portion (151); and a detection cell (120) configured to measure a concentration of a specific gas in the measurement target gas after the adjustment of the oxygen concentration. The outer electrode is covered by a porous layer (114) and is disposed in a hollow space (10G) surrounded by a gas non-permeable dense layer 115, 118. The hollow space is in communication with an air introduction hole (10h) that is open on a rear side relative to the diffusion resistance portion. The outer electrode is exposed via the porous layer to air introduced through the air introduction hole.

Abstract: A gas sensor (1) including: a sensor element (5) having an electrode pad (31, 32, 34, 35); a metallic terminal member (41) electrically connected to the electrode pad; and a lead wire (37) electrically connected to the metallic terminal member. The metallic terminal member has a forward-end-side terminal portion (43) which comes into contact with the electrode pad and a rear-end-side terminal portion (45) which is connected to the lead wire. The forward-end-side terminal portion has a bent portion (43d), and an element contact portion (43e) which comes into contact with the electrode pad. The rear-end-side terminal portion has a crimp terminal portion (45a) which forms a tube or a part of a tube, surrounds a conductor (37a) of the lead wire, and fixedly holds the conductor when crimped. Further, the maximum thickness t1 of the bent portion is greater than a maximum thickness t2 of the crimp terminal portion.

Abstract: A gas sensor including: a sensor element extending in an axial direction; a metal shell surrounding and supporting the sensor element; an exterior tube that is tubular and is mounted to a rear end of the metal shell; a metal terminal including a first end connected to a lead wire and a second end electrically connected to the sensor element; a separator that is tubular and is disposed in the exterior tube and contains the metal terminal and the sensor element; and a holder being in contact with the separator in the axial direction. The holder includes ribs formed in a frontward face or a rearward face of the holder and arranged at predetermined intervals in a circumferential direction. Each of the ribs occupies a region having a length equal to or greater than a thickness of the holder, as viewed in the axial direction.

Abstract: A fluorescent plate includes a fluorescent phase which emits fluorescence by excitation light, a light-transmitting phase which allows passage of the excitation light, and a plurality of voids surrounded by the fluorescent phase and the light-transmitting phase, wherein, in a cross section of the fluorescent plate including cross sections of the voids, an average ratio of a portion of the circumference of a void, which portion is in contact with the fluorescent phase to the entire circumference of the void, is higher than an area ratio of the area of the fluorescent phase present in the fluorescent plate to the total area of the fluorescent phase and the light-transmitting phase present in the fluorescent plate.

Abstract: A sensor element (100) including: a detection element portion (300) provided with at least one cell (130, 140) having a solid electrolyte (105, 109) and a pair of electrodes (104, 106, 108, 110) disposed on the solid electrolyte; a measurement chamber (107c) faced by one of the electrodes; and a diffusion resistance portion (115) through which a gas to be measured is introduced from outside into the measurement chamber. The sensor element further includes a porous protection layer (21) that is in direct contact with the diffusion resistance portion and which at least covers the diffusion resistance portion. The porous protection layer contains ceramic particles which serve as a backbone, and has pores formed in gaps between the ceramic particles. Further, a diameter ratio R represented by (an average diameter D1 (nm) of the pores / a particle diameter D2 (nm) at which an accumulated number of the ceramic particles accounts for 50%) is not greater than 100.

Abstract: A holding device includes a ceramic member and a base member joined together via a joining portion. When a second direction is perpendicular to a first direction and a third direction is perpendicular to the first and second directions, the joining portion includes a first joining part which extends through the joining portion in the second direction, as viewed in the first direction, and whose thickness in the first direction is uniform in an arbitrary cross section perpendicular to the second direction and in an arbitrary cross section perpendicular to the third direction, and at least one second joining part which is located between the first joining part and one end of the joining portion in the third direction and whose thickness in the first direction increases from the first joining part side toward the end of the joining portion in an arbitrary cross section perpendicular to the second direction.

Abstract: A gas sensor includes a sensing element having an electrode pad a metal terminal, and a separator that has insertion holes in which the metal terminal is held. The metal terminal includes a main body and an elastic portion that is integrally connected to the main body and is elastically connected to the electrode pad at a predetermined contact point. The main body includes a front-end-side restricting portion and a rear-end-side restricting portion that restrict the movement of the main body by contacting wall surfaces of the insertion hole when the main body moves in a direction intersecting the direction of an axial line. The contact point is located between the front-end-side restricting portion and the rear-end-side restricting portion in the direction of the axial line. The front-end-side restricting portion and the rear-end-side restricting portion are connected to each other so that a flat board portion is interposed therebetween.