Mazda Motor Corporation

Mazda Motor Corporat Ion

Masaki Fukuma

Satoshi Imamura

Atsushi Inoue

Kota Matsumoto

Yasushi Nakahara

Yuya Honda

Michiharu Kawano

Yoshiharu Ueki

Kento Onishi

Akira Asai

Masami Nishida

Masahiro Naito

Hiroaki Deguchi

Kouichi Shimizu

Futa Nishi

Naohiro Yamaguchi

Yoshitaka Wada

Shuji Takuma

Hiroaki Muranaka

Takashi Ikai

Masayuki Kidokoro

Shuma Aoki

Toru Kurisu

Kazuhiro Tomizawa

Hisashi Kajikawa

Ikuma Takahashi

Keisuke Yamamoto

Hiroaki Sugiura

Hiroshi Enomoto

Masunori Kanda

Eiichi Yanagida

Hiroshi Aino

Yasuyuki Imano

Toshinobu Yoneya

Ryoko Motohiro

Yuichi Someno

Takahiro Iwai

Hiroyuki Hamamoto

Takumi Uemura

An engine is provided, which includes a combustion chamber defined by a piston crown surface, an inner wall surface of a cylinder, and a pentroof ceiling surface formed in a cylinder head, and an ignition part of a spark plug disposed at the ceiling surface to achieve flame propagation combustion inside the combustion chamber. A cavity recessed in a spherical cap shape is formed in a central area of the crown surface. An opening of an intake port is formed in the ceiling surface (intake side) and an opening of an exhaust port is formed in the ceiling surface (exhaust side). When seen in a cross-sectional view taken along a cylinder axis, the ignition part is located above the cavity to be offset toward the exhaust side with respect to a cylinder axial line whereas a cavity center point is located to be offset toward the intake side.

Engine with combustion chamber

A structure of a combustion chamber for an engine includes a crown surface of a piston, a combustion chamber ceiling surface, an injector and an ignition plug provided on the combustion chamber ceiling surface, and an intake opening and an exhaust opening opened in the combustion chamber ceiling surface. A side where the intake opening is opened is defined as an intake port side, and a side where the exhaust opening is opened is defined as an exhaust port side. An ignition portion of the ignition plug is disposed on the intake port side. The ignition plug is ignited at a timing after the piston passes a compression top dead center. The injector is disposed on the center portion, and is configured to inject fuel toward the exhaust port side. A cavity is provided on the crown surface. A reverse squish flow generation portion is provided in the combustion chamber.

Combustion chamber structure for engines

A structure of a combustion chamber for an engine includes a crown surface of a piston, a combustion chamber ceiling surface formed on a cylinder head, an injector and an ignition plug provided on the combustion chamber ceiling surface, and an intake opening and an exhaust opening opened in the combustion chamber ceiling surface. A side where the intake opening is opened is defined as an intake port side, and a side where the exhaust opening is opened is defined as an exhaust port side, with respect to a position, as a reference, where an ignition portion of the ignition plug is disposed in a plan view from one side in a cylinder axis direction, the injector is configured to inject fuel toward the exhaust port side, and a reverse squish flow generation portion, which draws an air-fuel mixture toward the intake port side, is provided in the combustion chamber.

A structure of a combustion chamber for an engine includes a crown surface of a piston, a cylinder wall surface, a combustion chamber ceiling surface, and an ignition plug which includes an ignition portion. The crown surface of the piston includes: a cavity recessed in the cylinder axis direction; a parallel surface portion which is in parallel to a corresponding region on the combustion chamber ceiling surface at a position above the cylinder axis direction with a gap, when the piston is at a compression top dead center; and an inclined surface portion formed to continue to the parallel surface portion in such a way as to be directed to the ignition plug, when the piston is at a compression top dead center. The parallel surface portion and the corresponding region, in combination, constitute a squish flow generation portion generating a squish flow when the piston is lifted.

A structure of a combustion chamber for an engine includes: a crown surface of a piston; a combustion chamber ceiling surface formed on a cylinder head; and an ignition plug mounted on the combustion chamber ceiling surface, and including an ignition portion disposed in such a way as to face the combustion chamber. The crown surface of the piston includes a cavity which is recessed in a cylinder axis direction in a region including a position below the ignition portion of the ignition plug in a plan view from the cylinder axis direction. A rim portion of the cavity includes a guide portion, raised in the cylinder axis direction with respect to an inner region of the rim portion, interposing the ignition portion when the piston is at a compression top dead center, and configured to guide an air-fuel mixture within the combustion chamber to the ignition portion.

A combustion chamber structure for an engine includes a combustion chamber where SI combustion by spark ignition and CI combustion by self-ignition are conducted. A crown surface includes a cavity recessed to have a bowl-shape; a pair of first raised portions having a mound-shape along a pent roof shape; and a second raised portion provided to protrude at a position orthogonal to a ridge extending direction of the pair of first raised portions. With a height of the first raised portion relative to a height position of a deepest portion of the cavity being represented as H1 and a height of the second raised portion being represented as H2, H1/H2 as a ratio of the height H1 of the first raised portion to the height H2 of the second raised portion is set to be in a range of 1.92 or more and 2.75 or less.

Combustion chamber structure for engine

A combustion chamber structure for an engine includes a combustion chamber where SI combustion by spark ignition and CI combustion by self-ignition are conducted. A crown surface includes a cavity recessed to have a bowl-shape, and a pair of raised portions. The cavity includes a bottom portion which is a lower region of the recessed part, the bottom portion having an outer circumferential edge which is circular in a top view. With a height of the raised portion relative to a height position of a deepest portion of the cavity being represented as H1 and a diameter of an outer circumferential edge of the bottom portion of the cavity being represented as D, H1/D as a ratio of the height H1 of the raised portion to the diameter D of the cavity is set to be in a range of 0.05 or more and 0.36 or less.

A counterweight forms a crankshaft of an engine, and includes: an arm connecting a crank journal and crank pin of the crankshaft; a neck extending from a first connection face of the arm in a direction opposite to the crank pin; and a substantially fan-shaped weight continuous with a portion of the neck opposite to the crank journal. The weight has left and right shoulders continuous with the neck, and each of the shoulders is tilted to be away from the neck at an angle with respect to a horizontal line orthogonal to a crankshaft center when viewed along the crankshaft center, the angle being 15&#xb0; or more and 22.5&#xb0; or less.

Counterweight, and crankshaft with the counterweight

A connecting rod includes a rod having the form of a bar, a smaller end part, and a larger end part. The rod is provided with a friction generation portion at which friction is generated due to deformation of the rod.

Connecting rod of engine

An oil ring to be attached to a ring groove of a piston for an engine is provided. The oil ring includes two annular ring bodies having a common axis and arranged in tandem, and an expander for biasing the ring bodies radially outward. A sliding surface is formed at an outer circumference of each ring body to bulge radially outward and slides on a cylinder inner circumferential surface. The sliding surface of one of the ring bodies has a tip portion and first and second curved surfaces. In cross sections of the first and second curved surfaces, the first and second curved surfaces are connected while tangent lines to the cross sections at the tip portion align with each other, and when positional change rates are compared between points on the first and second curved surfaces, a change rate of the first curved surface is lower.

Oil ring

In the variable valve timing system according to the present invention, portions of the intake-side advancing hydraulic line and a retarding hydraulic line respectively constitute annular groovesandfor advancing and retarding provided on the intake camshaftbearing surfaceof the cam capwhich supports the camshaftsand. In addition, portions of the advancing hydraulic line and the retarding hydraulic line for exhaust respectively constitute annular grooves for advancing and retardingandprovided on the exhaust camshaftbearing surfaceof the cam cap. Moreover, the annular groove for retardingon the intake camshaftbearing surfaceand the annular groove for advancingon the exhaust camshaftbearing surfaceare respectively provided in the center in the width direction of their respective bearing surfacesand

Engine variable valve timing system

A rotational angle sensor and a hydraulic pressure control valve are disposed such that a detecting end surface of the rotational angle sensor disposed close to a sensor rotor attached to an exhaust camshaft is located in a spray area of return oil discharged through a drain hole formed at a cam cap, which flows down through a lower drain port of the hydraulic pressure control valve attached on the cam cap from a variable valve timing mechanism. Further, the detecting end surface is located forward in the rotational direction, shown as the arrow a, of the exhaust camshaft so that the return oil can be positively carried toward the detecting end surface by the rotation of the sensor rotor. Accordingly, this can maintain properly detecting accuracy of the rotational sensor disposed close to the camshaft.

Valve driving device for engine

An internal combustion engine is equipped with a valve timing controller capable of minimizing the electric power consumption and frictional wear of elements. The valve timing controller can vary the valve timing of valves. A camshaft is moved axially forwardly or rearwardly by electrically energizing an outer solenoid clutch or a brake releasing solenoid, respectively. An axial movement of the camshaft results in a change in valve timing. With the exception of a transient period during which the valve timing is being varied, both the brake releasing solenoid and the outer clutch are electrically deenergized to thereby reduce the electric power consumption, and both of them are maintained out of contact with a displaceable disc 13 to thereby reduce frictional wear thereof.

Valve timing controller for use with internal combustion engine

A valve operating system of an engine opens and closes a valve by a swing cam being swung by rotation of an operating cam. The operating cam has a cam surface and is rotated by the engine, and the swing cam has a cam surface in sliding contact with the valve and a cam follower in sliding contact with the cam surface of the operating cam. The cam surface of the operating cam and the cam surface of the swing cam are formed so that an acceleration component of the swing cam is larger than that of the operating cam in a positive region of a valve lift acceleration defined as a sum of the acceleration component of the operating cam and the acceleration component of the swing cam.

Valve operating system of engine

An intake valve or an exhaust valve is lifted through a swingable cam by the rotation of a rotatable cam formed in the cam shaft. A surface at which the swingable cam abuts with the rotatable cam is tapered in the axial direction in which said cam shaft extends, and the valve shift timing is changed by transferring the cam shaft, that is, the rotatable cam in the axial direction in which said cam shaft extends. The power transmitting member such as a helical gear to be rotated with the output shaft of the engine is engaged with the cam shaft through a helical spline. The power transmitting member is so arranged as to be unmovable in the axial direction in which said cam shaft extends. The rotational phase of the rotatable cam relative to the output shaft of the engine is changed by displacement of the cam shaft relative to the power transmitting member in the axial direction in which said cam shaft extends.

Growing community of inventors

Hiroshima, Japan

Masaki Fukuma