Mazda Motor Corporation

Tomohisa Handa

Kouichi Miyamoto

Kenko Ujihara

Noriyuki Iwata

Ichiro Hirose

Hisashi Okazawa

Kenya Ishii

Masahiro Choshi

Kunihiro Nishi

Takayoshi Fujita

Kuniaki Wada

Tomonobu Mizuba

Provided is an engine oil deterioration diagnosis device () comprising annual traveling distance calculating part (), a used hour calculating part (), a severe condition determining part (), an oil traveling distance calculating part (), an oil traveling distance accumulating part (), and an engine oil deterioration diagnosis part () for diagnosing that engine oil is in a state of deterioration when an oil traveling distance accumulated by the oil traveling distance accumulating part reached a predetermined value, wherein the oil traveling distance calculating part () comprises an oil traveling distance addition correcting part () for calculating the oil traveling distance by adding a predetermined value to the traveling distance when the severe condition determining part determines the state as the severe condition.

Engine oil deterioration diagnosis device

An apparatus for diagnosing lubricant degradation includes a soot amount estimator configured to estimate an amount of soot formed in a predetermined period in a combustion chamber of an engine, and diagnoses the degradation of a lubricant based on a cumulative value of the amount of soot estimated. The soot amount estimator calculates the amount of soot based on a speed of the engine and a load parameter related to a load of the engine, and corrects, based on a temperature parameter correlated to the temperature of the combustion chamber, the amount of soot calculated into an increased value if the temperature parameter is lower than a predetermined first temperature.

Apparatus and method for diagnosing lubricant degradation in internal combustion engine

A valve driving mechanism for a double overhead camshaft engine includes a camshaft drive mechanism, including a camshaft sprocket for transmitting engine output from a crankshaft of the engine to one of intake and exhaust camshafts. A valve timing varying mechanism is driven so as to vary a valve timing of, for example, a set of intake valves relative to a valve timing of a set of exhaust valves. The valve timing varying mechanism includes a first helical gear, mounted on the exhaust camshaft for rotation, a second helical gear, in mesh with the first helical gear, which is rigidly secured to the intake camshaft, and a cylindrical sliding element, mounted on the exhaust camshaft for axial displacement. The cylindrical sliding element operationally couples the exhaust camshaft to the camshaft drive mechanism so as to cause a relative rotational displacement therebetween when the cylindrical sliding element undergoes axial displacement with respect to the exhaust camshaft.

Valve driving mechanism for double overhead camshaft engine

Growing community of inventors

Hatsukaichi, Japan

Tomohisa Handa