Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Hirohisa Ishikawa

Hitoshi Abe

Naoyuki Kamiya

Akihisa Shinoda

Motohiro Fujita

Yoshikazu Yamada

Makoto Yonezawa

Haruo Tsusaka

Go Tanaka

Shigeru Shudo

Hideo Kurasawa

Yuichi Tokito

Yoji Fujinaga

Ryoji Saiki

In a cylinder head lubricating structure for an engine, in which a breather passage which guides, toward a cylinder head, gas including oil mist generated in a crank chamber by oil splashing means housed in the crank chamber so as to splash-oil in accordance with rotation of a crankshaft is formed in a crankcase, a cylinder block and the cylinder head to supply, toward the cylinder head, lubricating oil through the breather passage, a breather chamber with which an end portion, on the crank chamber side, of the breather passage communicates is formed in the crankcase, and a one-way valve preventing backflow of the oil toward the crank chamber is attached to the crankcase to be located between the crank chamber and the breather chamber. Accordingly, it is possible to supply a sufficient amount of oil to the cylinder head side even when the head difference between the crank chamber and the cylinder head is large.

Cylinder head lubricating structure for engine

In a diaphragm-type carburetor, a fuel vapor treating chamber is provided in a downstream fuel passage which interconnects a fuel pump operated in response to a pulsation pressure from a pulsation pressure generating source and an inlet bore in a constant-pressure fuel chamber. The fuel vapor treating chamber is located before the inlet bore, and a porous element for finely dividing fuel vapor is placed in the fuel vapor treating chamber. Thus, when a fuel vapor is generated in the fuel discharged from the fuel pump, a large amount of fuel vapor can be prevented from being ejected all at one time from a fuel nozzle by finely dividing the fuel vapor and introducing it along with the fuel into the constant-pressure fuel chamber, it is immediately passed toward the fuel nozzle, whereby the variation in air-fuel ratio of a fuel-air mixture can be suppressed to a very small level.

Diaphragm-type carburetor

A diaphragm-type carburetor includes a fuel well communicating with a lower end of a fuel nozzle, a constant-pressure fuel chamber communicating with the fuel well through an outlet bore, and a fuel pump incorporated in fuel passages defined between an inlet bore of the constant-pressure fuel chamber and a fuel tank. A fuel introduction control valve controls the introduction of fuel into the constant-pressure fuel chamber. The fuel introduction control valve includes a valve seat member which communicates at its lower end with the fuel well through a bypass passage extending above the constant-pressure fuel chamber. Thus, when fuel vapor is introduced into the constant-pressure fuel chamber, it immediately passes towards the fuel nozzle, whereby the extreme reduction in air-fuel ratio of a fuel-air mixture can be avoided.

A fuel supply passage leading to a fuel tank is connected to an intake side of a fuel pump of a diaphragm-type carburetor, and a fuel transfer chamber incorporated in an intermediate portion of the fuel supply passage is provided in an insulator interposed between the carburetor and an engine. The fuel pumped from the fuel tank is heated in the chamber moderately, thereby decreasing the difference in temperature between the carburetor and the fuel introduced into the carburetor. Thus, the generation of fuel vapor in the diaphragm-type carburetor can be restrained.

Device for supplying fuel to diaphragm-type carburetor

An OHC vertical crankshaft engine, comprising: a vertically disposed crankshaft having a first timing pulley at its lower end; a cooling fan attached to an upper end of the crankshaft; a camshaft extending in parallel with the crankshaft at a cylinder head end of the engine and having a second timing pulley at its lower end; and a timing belt passed around the timing pulleys. Thus, the need for lubrication for the transmission mechanism between the crankshaft and the camshaft is substantially eliminated, and the noise generation is reduced. Additionally, since the upper part of the cylinder head is directly exposed to the cooling air produced by a fan provided at an upper end of the crankshaft, a high engine cooling efficiency can be achieved. This effect is even more enhanced if the exhaust port of the engine is disposed above the intake port and extends horizontally and linearly away from the engine.

OHC vertical crankshaft engine

A cooling structure for cooling a liquid-cooled engine has engine cooling passages defined in portions of the engine for circulating a cooling medium therethrough. The cooling structure further includes a rotatable assembly having a rotatable element located outside of the engine, and a radiation passage system of a prescribed length disposed in the rotatable element for rotation therewith and connected to the engine cooling passages.

Growing community of inventors

Wako, Japan

Hirohisa Ishikawa