Denso Corporation

Nippondenso Co., Ltd.

Nippon Soken, Inc.

Denso Corpora Tion

Hiromi Hiramatsu

Tetsuya Miwa

Atsuya Mizutani

Masamichi Shibata

Takeo Maekawa

Noboru Yamamoto

Yasutoshi Horii

Hiroaki Okuchi

Atsushi Iwami

Hirofumi Suzuki

Kenji Yoneima

Masamichi Ishikawa

Tohru Yoshinaga

Hiroshi Yorita

Goichi Oda

Hideyuki Kato

Takehiro Watarai

Ryoichi Sugawara

Yuji Kajita

Fuminori Nakashima

Yoshiki Morita

Teiji Ishinada

Yasushi Noyori

Yukinobu Hiranaka

Tomoyuki Ichikawa

A glow plug is provided in a combustion chamber of a diesel engine. An ECU diagnoses existence or nonexistence of a disconnection abnormality of the glow plug through a controller. When there is an abnormality in the glow plug, processing for cutting fuel supply of an abnormal cylinder, processing for increasing fuel injection quantity of a normal cylinder, processing for delaying injection timing of the abnormal cylinder, or processing for delaying valve timing of an intake valve of the abnormal cylinder is performed. Thus, suitable startability of the engine can be ensured even when the abnormality occurs in the glow plug.

Controller of internal combustion engine

A glow plug degradation determination device energizes a glow plug immediately after an operation of an internal combustion engine is stopped. When a preset energization time elapses, the device senses a sensing value corresponding to resistance of the glow plug. The device determines degradation of the glow plug based on the sensing value. When the device determines that the glow plug is degraded, the device stores a result of the determination and reports the degradation of the glow plug before a next start. The device provisionally determines the degradation of the glow plug based on the sensing value during the operation of the internal combustion engine. After the device provisionally determines the degradation to be present, the device determines the degradation of the glow plug immediately after the operation of the internal combustion engine is stopped.

Glow plug degradation determination device

A control apparatus for controlling to supply of electric power to both a glow plug and a starter from a power source, the starter assisting start of the engine by using the glow plug, is provided. The control apparatus comprises a starter switch, starter, a detecting device detecting a state of the engine, a calculating circuit calculating a pre-glow time, an after-glow time, and a delay time. These times depend on both the detected state of the engine detected by the detecting device and a timing when the starter switch is turned on to a power-on position thereof. The control circuit controls the supply of the electric power to both the glow plug and the starter based on the delay time, the pre-glow time, and the after-glow time.

Energization control apparatus and method for glow plug during the period from preglow to afterglow steps

A combustion chamber pressure sensor for an internal combustion engine includes an elongated pressure transmitting member having one end exposed to the interior of an engine cylinder and the opposite end contacting a pressure sensing element which generates a pressure measurement signal, the pressure transmitting member and pressure sensing element being contained within an elongated housing. A damping body formed of a viscoelastic material is disposed on an outer or inner circumferential surface of the housing, for reducing an amount of engine vibration that is transmitted to the pressure sensing element and thereby reducing noise in the pressure measurement signal.

Combustion chamber pressure sensor equipped with damper body for attenuating transmitted engine vibration

A spark plug according to the invention includes a tubular metal shell, a cylindrical insulator, a plurality of center electrodes, and a plurality of ground electrodes. The meal shell has an end portion in which a plurality of thick-walled portions and a plurality of thin-walled portions are formed. The insulator is fixed in the metal shell. The center electrodes each are retained within one of a plurality of axial bores in the insulator. The ground electrodes each are joined to one of the thick-walled portions to ensure sufficient strength of the ground electrodes. The thin-walled portions each have an inner surface that is outwardly recessed in an angular range including the intersection of the inner surface with a reference line, thereby securing sufficient air pocket size of the spark plug. Accordingly, the spark plug has a high capability to ignite the air-fuel mixture and sufficient strength of the ground electrodes.

Spark plug having a plurality of center electrodes

A glow plug energization control apparatus is provided which includes a power supply working to supply electric power to a glow plug mounted in an internal combustion engine, an on-off switch working to produce a control trigger signal when turned on, and a controller including a microcomputer. The microcomputer is responsive to the control trigger signal to control supply of the electric power from the power supply to energize the glow plug. The microcomputer works to monitor an off-on interval from turning off to turning on of the on-off switch and control an amount of energization of the glow plug as a function of the off-on interval, thereby avoiding overheating of the glow plug.

Glow plug energization control to avoid overheating

An ignition device for an internal combustion engine has a spark plug, an ignition coil, a housing and a mounting portion. The spark plug is for discharging a current to ignite an air-fuel mixture in a combustion chamber of the internal combustion engine. The ignition coil is for supplying the current to the spark plug. The housing encloses the spark plug and the ignition coil therein. The housing has a mounting portion to be disposed in a mounting hole provided in a cylinder head of the internal combustion engine. The mounting portion includes a screw portion a non-screw portion. The screw portion is to be screw-fastened to the mounting hole. The non-screw portion is not to be screw-fastened to the mounting hole.

Ignition device for internal combustion engine

An ignition device for an internal combustion engine has a primary and secondary coils of an ignition coil, a center and ground electrodes of a spark plug, a cylinder shaped insulator and a cylinder shaped tube. The center electrode is disposed apart from the secondary coil in a longitudinal direction of the ignition device. The insulator is made of an insulating material and has a coil surrounding portion surrounding the secondary coil and a plug surrounding portion surrounding the center electrode. The primary coil is wound on an outer circumferential face of the coil surrounding portion. The ground electrode is disposed on an outer circumferential face of the plug surrounding portion. The tube is made of a magnetic material and has a coil covering portion covering the primary coil and a plug covering portion covering the plug surrounding portion and the ground electrode.

An internal combustion engine ignition device has a resin layer in a clearance between an insulator and a winding contained in the insulator. The ignition device has a cylindrical insulator and a resin layer. The insulator has an opening portion at one end and a bottom portion at the other end. The insulator contains one of a primary winding and a secondary winding. The resin layer is formed by charging a resin in the clearance between the insulator and one of the windings. The diameter of the inner periphery of the insulator gradually increases from the opening portion to the bottom portion. When the resin layer shrinks from the opening portion toward the bottom portion of the insulator, the resin layer can shrink without getting snagged on the inner periphery of the insulator.

The present invention relates to a multi-point spark plug capable of facilitating the attachment of a plug cap. The multi-point spark plug is made up of two center electrodes, an insulator for accommodating the center electrodes, a housing for holding the insulator and earth electrodes located at one end portion of the housing and each disposed in opposed relation each of the center electrodes in a state where a discharging gap is interposed therebetween. Moreover, first and second terminals to be electrically connected to the center electrodes are provided in a head portion of the insulator. In an outside configuration composed of the head portion and the first and second terminals, a contour between a location of the second terminal and a location of the first terminal is formed axis-symmetrically with respect to an axis of the head portion.

Multi-point spark plug

An insulator includes a plug side cylindrical portion having an inner space for accommodating a center electrode and a coil side cylindrical portion extending in a direction departing from a combustion chamber. The high-voltage portion of an ignition coil is entirely accommodated inside the coil side cylindrical portion. According to this arrangement, the coil side cylindrical portion can assure insulation between the high-voltage portion and the low-voltage portion. The portion to be insulated and fixed by an insulating resin is limited only to the secondary winding.

Ignition device for an internal combustion engine

A combustion pressure sensor for an internal combustion engine is provided. The sensor includes a sensing element such as a piezoelectric device sensitive to a physical load applied thereto to produce an electric signal indicative thereof and a bendable member. The bendable member is bent upon application of the combustion pressure in the engine to apply the physical load to the sensing element. Specifically, the physical load is applied to the sensing element which arises from the bend deformation of the bendable member, thus eliminating the need for a complete surface-to-surface contact between the sensing element and the bendable member. This results in a decreased unit-to-unit variation in sensitivity of combustion pressure sensors and ensures the stability of output characteristics of the combustion pressure sensor.

Combustion pressure sensor designed to ensure stability of output characteristic and sensitivity

An integrated ignition apparatus has a coil section and a plug section. The coil section has a spring as a connection member internally. The spring electrically connects other inside terminal members of the plug section. When the coil section and the plug section are integrated, the spring is pressed, and resiliently deforms in the axial direction. Spring-back force of the spring maintains electrical connection steadily, and prevents disconnection of the spring and the terminal members due to vibration. This structure prevents failure in electric conduction between the coil section and the plug section.

Ignition apparatus for engine

An earth electrode is formed on the brim surface of the plug insulator and on the outer surface of the middle portion of the plug insulator along the axial direction. The earth electrode connected with one side of the combustion pressure sensor is provided on a whole surface opposite to a combustion pressure signal electrode. The earth electrode works also a shield member for shielding the high frequency noise generated inside the insulator. A part of the outer side of the earth electrode is covered by an insulating layer for insulating the earth electrode from the combustion pressure signal electrode. The combustion pressure sensor held between the insulator brim and electrode brim is given a prescribed compression load by a metal cylindrical bolt which presses down the electrode brim of the toward the combustion pressure sensor.

Ignition apparatus for internal combustion engine

In an ignition device for an internal combustion engine which is mounted in a cylinder head in a state where a spark plug and an ignition coil are integrated with each other, the plug side tube section is made of ceramics and internally accommodates a center electrode and the coil side tube section is made of ceramics, with one of a primary winding and a secondary winding being wound around the coil side tube section. The plug side tube section and the coil side tube section are constructed as separate bodies and then combined with each other. This shortens the overall lengths of both the tube sections, thus preventing the occurrence of cracks or bends at calcining and improving the dimension accuracy after the calcining.

Growing community of inventors

Kariya, Japan

Hiromi Hiramatsu