Honda Giken Kogyo Kabushiki Kaisha

Other

Yutaka Giken Co., Ltd.

Hiroyuki Murata

Hiroyuki Yoshida

Yoshiyuki Matsuda

Norimasa Takasaki

Hiroshi Kawamura

Morihiro Takemura

Tetsu Wada

Hideaki Takada

Hiroshi Mizuguchi

Masaki Tsunoda

Hiroki Tawa

Tomonori Ikuma

Kouji Koishikawa

Makoto Miyake

Nobuhiro Ishizaka

A process for forming an improved anodizing film on the surface of an aluminum alloy material. The film is impregnated with an amorphous substance which fills pores formed in the film during its growth. If the film has a flaw reaching the aluminum alloy material, the amorphous substance and aluminum form a layer of passivity which restrains the corrosion of the aluminum alloy material.

Process for improving an anodizing film, an anodizing film structure and an aluminum-alloy-made outboard engine

An outboard engine system includes a case member which is disposed below an engine body and integrally provided with an oil pan opening upwards, and a passage wall extending vertically to define an exhaust gas passage through which an exhaust gas flows. A portion of an outer wall of the case member is formed by the passage wall, and a recess is provided in the outer wall of the case member with a portion of the passage wall facing the recess. The recess is covered with a plate member fixed to the outer wall of the case member, and a cooling water passage, through which cooling water flows, is defined between the plate member and the recess. Thus, the passage wall integral with the oil pan is cooled effectively, while avoiding increases in size and weight.

Passage wall cooling structure in outboard engine system

An outboard motor includes a first case and a second case disposed below the first case. The first case houses therein an oil pan and an upper part of a drive shaft. Within the oil pan, engine oil is held. The second case has its upper edge portion coupled to a lower edge portion of the first case. The second case has a vertical wall disposed therewithin. The vertical wall separates a space within the second case into a cavity and part of an exhaust passage through which exhaust gas passes. The cavity is formed below the oil pan. This arrangement prevents the oil pan from being affected by heat of the exhaust gas. Thus, it becomes possible to prevent the engine oil held within the oil from increasing in temperature.

Outboard motor

A novel aluminum die-cast material having all good properties of high fluidity, good corrosion resistance and high mechanical strength is disclosed. As its Mg content, a factor to increase mechanical strength, is increased to fall between 0.4 and 0.6% by weight, the material has good mechanical properties. As its Cu content, a factor to cause corrosion, is reduced to at most 0.15% by weight, the material has good corrosion resistance to seawater. As its Si content, a factor to increase casting fluidity, is increased to fall between 10.0 and 11.5% by weight, the material has good fluidity.

Aluminum die-cast material for boats

The coating structure having a corrosion resistance of the invention contains a formation film formed on the surface of an aluminum alloy material. The formation film is subjected to a zirconium phosphate treatment. Because the zirconium phosphate reacts with an oxide film on the surface of the aluminum alloy to form a zirconium boehmite layer and to increase the adhesion of the coating material, a corrosion resisting structure is obtained without need of a sealing treatment while restraining the increase of the product cost. Also, a primer layer is formed on the outer surface of the formation film and the primer layer is composed of phosphomolybdic acid.

Coating structure having corrosion resistance

In an outboard engine, a support member for supporting a drive shaft and an exhaust pipe within an extension case can be cooled by outside water pumped by utilizing the exhaust pressure from the engine. The inside of the extension case is divided, by the support member for supporting the drive shaft and the exhaust pipe, into an upper chamber communicating with the open air, and a lower chamber into which outside water is introduced, so that the exhaust gas from the exhaust pipe is discharged into the lower chamber. Both the upper and lower chambers are in communication with each other through a communication pipe. Thus, during operation of the engine, the support member and the depending members are cooled by the outside water forced up from the lower chamber through the communication pipe into the upper chamber.

Cooling device in outboard engine system

An outboard motor includes an exhaust emission control system which is arranged rationally and neatly in the housing of an outboard motor body, irrespective of various limitations on the outside shape of the housing. An oil pan disposed below an engine of the outboard motor has an oil holding portion, and an exhaust pipe is disposed vertically along a vertical wall portion of the oil holding portion. A catalytic converter is disposed in an intermediate portion of the exhaust pipe in confronted relation to the vertical wall portion. The catalytic converter has a particular shape in horizontal section which is greater in size in a first direction than in a second direction perpendicular to the first direction. A fresh-air delivery passage is provided for introducing fresh air into an exhaust passage disposed upstream of the exhaust pipe. The fresh-air delivery passage is connected at one end to the top plate of an intake box and includes a check valve disposed at an intermediate portion of the fresh-air passage. The check valve is adapted to open only when the pressure in the exhaust passage is less than the atmospheric pressure. The exhaust system is perfectly protected against a possible entry of water and an engine combustion failure and corrosion of the exhaust system resulting therefrom.

Cooling water pumped by a cooling-water pump is passed via a cooling-water supply passage, a cooling-water dispensing chamber, two upper and lower through-holes and a water jacket, a thermo-valve and discharged via a cooling-water discharge passage. When the amount of cooling water supplied from the cooling-water pump is excessive, or when the thermo-valve has been closed, a relief valve mounted in a bypass passage which connects the cooling-water supply passage and the cooling-water discharge passage is opened, thereby permitting the cooling water to be diverted. The bypass passage diverges from the cooling-water supply passage upstream of the cooling-water dispensing chamber. Therefore, even if the relief valve is opened, the flow pattern of the cooling water flowing within the cooling-water dispensing chamber is not influenced, and the flow rates of the cooling water passed through the two through-holes cannot be unbalanced.

Engine for outboard engine system

An exhaust pipe for guiding an exhaust gas from an engine into an exhaust gas expansion chamber defined within an extension case is connected to a protrusion of an oil pan which is mounted on a lower surface of a mount case that supports the engine at its upper portion. A breathing bore is formed in an upper portion of the exhaust pipe, and an outer side of the breathing bore is covered with a shield plate. Therefore, water cannot enter the exhaust pipe through the breathing bore. A cooling-water supply pipe for introducing cooling water from a cooling-water pump into the engine is formed with a cooling-water ejection bore which is located at a position in which it is not opposed to the breathing bore. Therefore, even if cooling water is ejected through the cooling-water ejection bore to the exhaust pipe to cool the latter, the cooling water cannot enter the exhaust pipe.

Growing community of inventors

Wako, Japan

Hiroyuki Murata