Ngk Spark Plug Company, Limited

Shunsuke Maeda

Yoshihiro Nakamura

Masayoshi Matsui

Takafumi Oshima

Takio Kojima

Yoshihiko Kohmura

Masanori Suda

Yasuhisa Kuzuya

Tadashi Watanabe

Masahiro Kawakatsu

Hiroyuki Suzuki

Yuichi Yamada

Tatsuya Gozawa

Tatsunori Yamada

Daiki Goto

Toshiyuki Matsuoka

Kenjiro Nishiyuki

Shinsuke Itoh

Tatsuki Hirabayashi

Akito Ishihara

Tadasi Watanabe

A spark plug includes a tubular metal shell; an insulator including a locking portion locked onto the metal shell; and a cap disposed at a front end side of the metal shell, the cap having a plurality of orifices. The plurality of orifices include orifices with different cross-sectional areas. A sum of the number of one or more largest orifices and the number of one or more large orifices that have a cross-sectional area of larger than or equal to 90% of the one or more largest orifices is smaller than the number of orifices that are other than the one or more largest orifices and the one or more large orifices. A length of the front end portion in an axial direction between a front end of the insulator and a front end of the locking portion is smaller than or equal to 12 mm.

Spark plug

A glow plug () includes: a housing () having a metal shell () and a cap unit (); and a heater unit (). A coupling member () is joined with the housing () and is also joined with the heater unit () at its edge portion (), so as to enable the heater unit () to move along an axis line O and couple the heater unit () with the housing (). When the edge portionof the coupling memberis irradiated with a laser, at least part of the edge portion () melted by laser welding fills a gap () between the coupling member () and the heater unit () to form a welded part (). As a result, even when there is a gap prior to welding, the weld strength between the coupling member () and the heater unit () can be maintained.

Glow plug with pressure sensor

A glow plug including a substantially cylindrical housing extending in an axial direction; a rod-shaped heater unit having a front end protruding from the front end of the housing and movable in the axial direction; a connecting member connecting the heater unit to the housing within the housing and allowing the heater unit to move in the axial direction; and a pressure sensor that detects pressure received by the heater unit. The heater unit has a large-diameter portion at the rear end thereof and a small-diameter portion frontward of the large-diameter portion and having a diameter smaller than the diameter of the large-diameter portion. The connecting member connects the small-diameter portion of the heater unit to the housing within the housing.

Glow plug with combustion pressure sensor

A glow plug wherein a combustion gas prevention wall () extends radially outward on the outer circumferential surface of heater () such that when the heater () is viewed rearward from its forward end () along the axial direction, the combustion gas prevention wall () closes an annular gap Kat a position forward of annular membrane portion () of seal member (). The combustion gas prevention wall () has an outer diameter Dgreater than the inner diameter Dof forward end () of the housing.

A combustion pressure sensor () includes a housing () having an axial hole (), a flexible member () fixed at one end to the housing () and being displaceable along the direction of axis (CL), a pressure transmission body () whose outer circumferential surface is fixed to the other end of the flexible member (), and a sensor element () fixed to the housing () and outputting a signal on the basis of a pressure applied thereto from the pressure transmission body (). The housing () includes a main body portion () having a screw portion (), and a cap member () having a press contact portion () which is pressed against the internal combustion engine when the screw portion () is screwed into the mounting hole of an internal combustion engine. The one end of the flexible member () is fixed to the main body portion ().

Combustion pressure sensor

A glow plug in which a convex portion () is formed in an outer peripheral surface () of a heater () in a part facing an inner peripheral surface () of a leading end part () of a housing () and interposed in a leading end side annular gap K, so as to maintain a gap with the inner peripheral surface (). A decline in detection accuracy can be prevented to the extent that combustion gas can be received by the leading end () of the convex portion () even if soot clogging should occur.

Glow plug fitted with combustion pressure detection sensor

A seal member () has a dual-tube structure consisting of an outer tubular seal member () and an inner tubular seal member (); the outer tubular seal member () is welded, at its rear end portion, to the inner circumferential surface of a forward-end housing (), thereby forming a housing-side joint W; the inner tubular seal member () is welded, at its forward end portion, to a forward end portion of the outer tubular seal member (), thereby forming an inter-tubular-seal-member joint W; and the inner tubular seal member () is welded, at its portion located rearward of the joint W, to the outer circumferential surface of the heater (), thereby forming a heater-side joint W. An action of pressing the heater forward is effected on the basis of an axial dimension Lbetween the joints Wand Wshorter than an axial dimension between the joints Wand Wand is, therefore, mitigated.

A glow plug including a pressure sensor () and a heater (). The glow plug includes a position-defining member which defines the positional relationship between the pressure sensor () and the heater () and has a coefficient of thermal expansion greater than that of the heater. The pressure sensor () is fixed at a predetermined sensor reference position relative to the position-defining member. The heater () is held by a heater-holding member () in such manner that an attachment position A of the heater-holding member to the heater can be displaced, with a change in external pressure, relative to a predetermined heater reference position defined by the position-defining member. A displacement transmission member () is arranged between the heater () and the pressure sensor () so as to transmit displacement of the heater () to the pressure sensor (). The coefficient of thermal expansion of the displacement transmission member () is rendered greater than that of the position-defining member.

Glow plug

A glow plug includes a heater member; heater power lead wires which extend rearward along an axis and whose conductors electrically communicate with one and of a heater conductor for supply of power; a sensor, portion for detecting the combustion pressure of an internal combustion engine; a sensor connection line connected to the sensor portion and extending rearward along the axis; a housing; a sensor-portion-enclosing tube; and a grommet formed from an insulating rubber-like elastic material, having insertion holes through which the heater power lead wires and the sensor connection line are respectively inserted, the grommet liquid-tightly closing an end portion of the sensor-portion-enclosing tube and liquid-tightly holding the heater power lead wires and the sensor connection line.

Glow plug having built-in sensor

A split-flow-type flowmeter includes a detection element disposed to face a flow path thereof and a venturi structure formed within a flow path in the vicinity of the detection element and adapted to throttle a flow directed toward the detection element to thereby reduce disturbance of the flow. The venturi structure is disposed in opposition to the detection element within the flow path and includes a protrusion protruding toward the detection element within the flow path of the split-flow-type flowmeter.

Split-flow flowmeter with a profusion facing the detection element

A split-flow-type flowmeter in which an end portion of a flow splitter tube is inserted into a main-flow pipe having a diameter D. A flow splitter tube includes a U-shaped split-flow passage . A detection element is disposed at a bottom portion (not shown) of the U-shaped split-flow passage . The split-flow passage assumes a flow path structure symmetrical with respect to a plane passing through the detection element. A flow inlet and a flow outlet of the split-flow passage face in mutually opposite directions along the flow direction of the main-flow pipe and open symmetrically at the same position on the flow cross section of the main-flow pipe . In order to divert into the split-flow passage a portion of relatively high flow rate of flow from the main-flow pipe , the center of opening of the flow inlet /flow outlet is positioned between the center of the flow cross section of the main-flow pipe and an average-flow-velocity position at which flow in the main-flow pipe is of an average flow velocity, as observed on the flow cross section of the main-flow pipe

Split-flow-type flowmeter

A flow measurement device is disclosed, in which an accumulation of pollution substance onto a detection element is prevented, and which can measure a reverse flow similarly to a normal flow. On both ends of an outer wall outer peripheral portion of a divided flow pipe having a &OHgr;-shape pipe passage, there are oppositely formed an inlet port and an outlet port , which open in faces orthogonal to a flow direction of a main flow M that is a detection object. Within the divided flow pipe , by a curved partition , plural branch flow passages mutually branching and joining in the divided flow pipe are formed. Inside both end portions of the outer wall , undulation portions are formed so as to clog an inlet and an outlet of the outer peripheral side branch flow passage and, by this, throttles are formed respectively in a flow passage between the inlet port and the inlet of the branch flow passage and a flow passage between the outlet port and the outlet of the branch flow passage . In a bottom portion of the outer wall of the divided flow pipe , a detection element is attached so as to be exposed to a flow in the outer peripheral side branch flow passage and, against its detection face, a down flow DW further divided from a divided flow D obliquely impinges.

Flow rate and flow velocity measurement device

A flow rate and flow velocity measurement device. A part of a flow in a main flow pipe which is a detection object, is introduced into a passage of a divided flow pipe and becomes a flow The divided flow pipe has a curved portion or rather an inverted arc portion in which the flow is abruptly changed in direction or rather inverted by protuberances formed preferably in symmetry in upstream and downstream sides of the curved portion Outside the main flow pipe there is disposed on the bottom portion of the curved portion of the divided flow pipe a detection element fixed to a support body while protruding preferably 0.05-0.3 mm from flow passage faces in the vicinity thereof. An opposed face opposite to the detection element protrudes toward the detection face so as to throttle the passage and to accelerate a flow speed at the element. Thus, in the curved portion from the flow a down flow is constantly formed obliquely impinging against the detection face of the detection element improving flow measurement accuracy within a wide flow speed range.

Flow measurement device for measuring flow rate and flow velocity

A flow rate and flow velocity measurement device has a divided flow pipe ( ) which is attached so as to be orthogonal to an intake pipe ( ) of an engine, and into which a flow in the intake pipe ( ) is introduced, an inlet plate ( ) which extends in a direction orthogonal to a flow direction in the intake pipe ( ) and forms a U-shape form pipe passage in the divided flow pipe ( ) and a detection element ( ) which is disposed so as to be exposed to a flow in the divided flow pipe ( ) outside the intake pipe ( ) and detects a flow rate and a flow velocity, wherein one end of the inlet plate ( ) protrudes into the intake pipe ( ) while passing a top opening of the divided flow pipe ( ), and the divided flow pipe ( ) has a flow passage structure symmetrical with the detection element ( ) being made a center, so that an equivalent detection element ( ) output is obtained in regard to both cases in which a fluid flows through the intake pipe ( ) in a normal direction and a reverse direction.

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Toyota, Japan

Shunsuke Maeda